Restriction device

Abstract

A system for treating a patient having a disorder related to a patient's intestine is provided. The system comprising: an artificial or artificially modified reservoir (140) adapted for receiving and temporarily collecting therein intestinal contents and further adapted to remain within the patient's body when emptying the reservoir, a flow control device (61, 62, 63) implantable in the patient's body and adapted to control flow of the intestinal contents from the reservoir and an implantable vibration device comprising a vibration generating unit (VGU) configured to cause the implantable vibration device to vibrate.

Description

[0001] RESTRICTION DEVICE Technical field The present invention relates to a system for treating a patient having a disorder related to the patient’s intestine. Such disorder may be caused by injury, birth defect, cancer or other diseases, such as constipation or incontinence. More specifically the invention relates to a system of regulating the flow through an intestinal reservoir. Background In an attempt to overcome such disorders, many different solutions have been proposed. These solutions often include surgery, in particular where a portion of the intestine has to be removed. The reason for such operation may be colorectal cancer, perforated diverticulitis or other kinds of diseases, such as ulceros colitis or Crohns disease. For instance, in the case of ileostoma, jejunostoma, colostoma and rectostoma operations the small intestine (jejunum or ileum) or the large intestine (colon or rectum) is cut and the open end of the healthy portion of the intestine is reattached either to a surgically created stoma in the patient’s abdominal wall or, where possible, to the patient’s rectum or anus or to tissue adjacent the patient’s anus. WO2009 / 046995 discloses a system comprising a reservoir in the patient’s body for receiving and temporarily collecting therein intestinal contents. The reservoir is surgically created and formed from a plurality of bent portions of the patient’s intestine. Laterally adjacent sections of the intestine are cut open along their mutual contact line and the resulting upper halves and lower halves thereof are interconnected so as to form the reservoir. The intestine exits the patient’s abdominal wall through a surgically created stoma. An exit valve is implanted within the intestine between the intestinal reservoir and the stoma. The exit valve is normally closed by resilient means. An external manually driven suction pump comprising a piston-cylinder-arrangement is used to be temporarily applied from outside the patient’s body for emptying the intestinal reservoir, wherein a conduit on the front end of the suction pump is inserted into the intestine, thereby mechanically urging the exit valve to open. An improved system is disclosed in WO 2011 / 128124 A1. The system comprises an artificial flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from said reservoir. The flow control device comprises at least one pump adapted to act on said intestinal wall so as to reduce the reservoir’s volume in order to empty the reservoir. The pump acts on the intestinal wall of the reservoir and is implanted within the patient’s body outside the reservoir. Due to the pump being implanted, an external collecting device need not be attached, removed and cleaned when emptying of the reservoir is desired. Three principles of such pump are disclosed therein, a mechanical type pump, a hydraulic type pump and an electrical stimulation type pump. The electrical stimulation type pump comprises an electrical stimulation device for electrically stimulating a muscle or neural tissue of said intestinal wall by applying electrical pulses to the muscle or neural tissue of the intestinal wall so as to cause at least partial contraction of the intestinal wall, in particular by a series of electrical pulses. For this purpose, the electrical stimulation apparatus comprises one or more electrodes adapted to generate the electrical pulses. This is a very gentle way of constricting the reservoir. By electrically stimulating different portions of said intestinal wall in a direction of natural intestinal contents flow over time, the intestinal contents are pumped along the intestinal reservoir and, thus, the intestinal reservoir is emptied. More specifically, the electrodes of the electrical stimulation type pump are mounted on one or more holding devices which are in the form of a cable or have any other longitudinal, stripe-like or rod-like or plate-like shape. A plurality of the electrodes may be arranged in one or more rows along the length of the holding devices. The longitudinal holding devices are arranged side by side, when implanted, so as to cover substantially the entire intestinal reservoir on one side or on opposing sides of the reservoir. The holding devices are either embedded in a flexible web which allows the holding devices to follow movements of the intestinal reservoir when sections thereof are constricted individually due to selective electrical stimulation. Or the longitudinal holding devices are implanted in surgically created folds of the intestinal wall of the reservoir. Alternatively, the electrodes are directly invaginated in the intestinal wall one by one or in groups without being carried on a common holding device. It is further suggested in WO 2011 / 128124 A1 that, instead of providing a plurality of longitudinal holding devices with electrodes, the electrical stimulation device may be formed as an integral unit on at least one side of the reservoir to make handling and manufacture easier. The electrical stimulation type pump may cooperate with the constriction type pump, i.e. with the mechanical or hydraulic type pump, and act on the same portions of the intestinal wall so as to pump the intestinal contents along the reservoir by, over time, electrically stimulating different portions of said intestinal wall and simultaneously constricting respective sections of the reservoir in the direction of natural intestinal contents flow. In particular, the constriction type pump in operation may constrict the intestinal reservoir only partly, in order not to damage the intestinal tissue, whereas complete constriction and, thus, emptying of the reservoir is obtained by additionally stimulating the intestinal wall portions electrically in a manner as described before. WO 2023 / 031066 A1 discloses a further development of the electrical stimulation type pump, according to which the electrical stimulation devices each comprise a wireless energy receiver configured to receive energy for stimulating the muscle or neural tissue wirelessly and one or a plurality of wireless energy transmitters configured to transfer energy to some or all of the electrical stimulation devices. This means that the electrical stimulation devices are not connected by wire, nor in any other way. Physically, the electrical stimulation devices are independent from each other. This way, they can be installed on or close to the intestine or even implanted in an intestinal wall and are able to follow any movement of the intestine, which may be caused by electrical stimulation via the respective electrical stimulation devices and / or by constriction via the aforementioned constriction type pump and / or by constriction via any other mechanical or hydraulic or other type of constriction device. Thus, the electrical stimulation devices are rather flexible and remain flexible over time since any danger that such flexibility may decrease due to fibrosis growing over and encapsulating the system and electrical stimulation devices is minimized. In one embodiment disclosed in WO 2023 / 031066 A1, the system is configured to electrically stimulate, by means of the electrodes of the electrical stimulation devices, the muscle or neural tissue in the area of the intestine, which is constricted by the mechanical or hydraulic constriction device, sufficiently for increasing blood flow through the tissue of the intestine. The purpose thereof is to exercise the tissue wall which is in contact with the constriction device. That is, the body tends to react to medical implants, partly because the implant is a foreign object, and partly because the implant interacts mechanically with tissue of the body. Exposing tissue to long-term engagement with, or pressure from, a mechanical or hydraulic or other type of constriction device may deprive the tissue cells of oxygen and nutrients, which may lead to deterioration of the tissue, atrophy and eventually necrosis. This may result in migration of the device, including migration through the tissue wall. By exercising the tissue cells, blood flow is stimulated and tolerance of the tissue for pressure from the implant is increased. WO 2023 / 031066 A1 further discloses a number of different sophisticated methods of safely communicating with the implanted parts of the system from outside the patient’s body. Summary Starting out from this prior art, the present invention seeks to improve the safety of those systems for treating a patient having a disorder related to a patient’s intestine, in particular in view of the health of the patient. Thus, in general, the present disclosure provides a system for treating a patient having a disorder related to a patient’s intestine, wherein the system comprises an artificial or artificially modified reservoir, such as the above-mentioned reservoir formed from the patient’s intestine, which is adapted for receiving and temporarily collecting therein intestinal contents and which is further adapted to remain within the patient’s body when emptying the reservoir, and wherein the system further comprises a flow control device implantable in the patient’s body so as to control flow of the intestinal contents from the reservoir. In this regard, the present disclosure substantially contains three specific aspects. According to a first aspect, the flow control device comprises at least one of: at least one piezoelectric motor and at least one piezoelectric pump. According to a second aspect, the system comprises an implantable vibration device. And according to a third aspect, the system comprises a variety of means for affecting an effector response in the patient or denervating an effector tissue. Before elaborating further on the first to third aspects of the present disclosure, it should be understood that, in the same way as the systems disclosed in WO 2011 / 128124 A1 and WO 2023 / 031066 A1, the system described herein may be configured and is particularly suitable for use on a reservoir section of the intestine which is formed from surgically modified intestine that has been cut along a mutual contact line of laterally adjacent sections of a bent portion of intestine and connected so that the upper and lower halves of the cut intestine form an intestinal wall of the reservoir section. More specifically, at least the electrodes of the electrical stimulation devices may be configured to be implanted in surgically created folds of the patient’s intestine. In addition to the one or more electrical stimulation devices or in the alternative thereto, the system may comprise at least one mechanical or hydraulic constriction device configured to be implanted outside the patient’s intestine in close proximity thereto for constricting the intestine from the outside thereof. The electrical stimulation devices and the mechanical or hydraulic constriction device may be configured to act on the same part of the patient’s intestine, as is generally known from WO 2011 / 128124 A1 and WO 2023 / 031066 A1. In this context, the mechanical or hydraulic constriction device may form part of a pump that is configured to advance intestinal contents through the patient’s intestine in a downstream direction. Alternatively, the mechanical or hydraulic constriction device may have the function of a valve configured to open and close the intestine by constriction to thereby control the flow of intestinal contents through the intestine, in particular into or out of the intestine. For instance, the valve may form an artificial sphincter close to the patient’s rectum or close to a stoma of the patient. The electrical stimulation devices may support the respective function of the mechanical or hydraulic constriction device. They may individually or together form an emptying device for emptying a respective section of the patient’s intestine. Furthermore, the system may be configured to electrically stimulate, by means of the electrodes of the electrical stimulation devices, the muscle or neural tissue in the area of the intestine constricted by a constriction device, such as by the mechanical or hydraulic constriction device, sufficiently for increasing a blood flow through the tissue of the intestine, in order to exercise the tissue wall which is in contact with the constriction device. FIRST ASPECT – PIEZOELECTRIC MOTOR AND / OR PUMP According to the first aspect of the present disclosure, the system for treating a patient having a disorder related to a patient’s intestine, comprises at least one piezoelectric motor and / or at least one piezoelectric pump. Accordingly, at least one of the motor or motors of any one of the components of the systems disclosed herein may be a piezoelectric motor and / or at least one of the pump or pumps of such systems may be a piezoelectric pump. For instance, a piezoelectric motor may be provided for the drive of a mechanical or hydraulic constriction device for emptying the reservoir, or for driving a pump thereof, whereas a piezoelectric pump may be provided, in particular, for the drive of a hydraulic constriction device. Piezoelectric motors and piezoelectric pumps are advantageous in that they can be manufactured without magnetic and / or metallic parts. Thus, piezoelectric motors and pumps can be made MRI-safe, meaning that the patient can undergo Magnetic Resonance Imaging (MRI) while having the piezo motor implanted. This reduces health risks and, thus, increases the safety of the system. The piezoelectric motor or pump is preferably substantially non-magnetic and / or non-metallic. In some embodiments, the piezoelectric motor or pump comprises a ceramic piezoelectric material. In some embodiments, the piezoelectric material is lead zirconate titanate (PZT). In some embodiments, the piezoelectric material is barium titanate. In some embodiments, the piezoelectric material is lead titanate. In some embodiments, the piezoelectric motor comprises a polymeric piezoelectric material. PIEZOELECTRIC MOTOR According to a first variant, the piezoelectric motor is a piezoelectric inchworm motor. According to a second variant, the piezoelectric motor is a piezoelectric inertial motor. According to a third variant, the piezoelectric motor is a piezoelectric walk-drive motor. According to a fourth variant, the piezoelectric motor is a piezoelectric ultrasonic motor. The piezoelectric motor may be a linear piezoelectric motor, which may operate with at least one of: a speed in the range of 1 mm / s – 10 mm / s, a stroke length in the range of 4 mm – 30 mm, and a force in the range of 2 N – 30 N, or the piezoelectric motor may be a rotary piezoelectric motor, which may operate with at least one of: a rotational speed in the range of 1 mrad / s – 100 mrad / s and a torque in the range of 100 Nmm – 900 Nmm. The piezoelectric ultrasonic motor may be a linear piezoelectric ultrasonic motor, which may operate with at least one of: a speed in the range of 4 mm / s – 100 mm / s, a stroke length in the range of 4 mm – 30 mm, and a force in the range of 0.006 N – 40 N, or it may be a rotary piezoelectric ultrasonic motor which may operate with at least one of: a rotational speed in the range of 10 mrad / s – 10,000 mrad / s, and a torque in the range of 20 Nmm – 450 Nmm. Although piezoelectric motors have a relatively complex structure and control system, they may feature a linear resolution as low as 0.21 μm. According to one sub-aspect, the piezoelectric motor comprises at least one bimorph piezoelectric actuator. In all of the variants, the piezoelectric motor may be a reversible piezoelectric motor. PIEZOELECTRIC PUMP According to one embodiment, a piezoelectric pump is provided comprising a first wall portion, a first diaphragm, a first chamber and a driving element. The first diaphragm and the first wall portion enclose the first chamber. The first wall portion comprises an inlet configured to connect the first chamber to a first inlet reservoir and an outlet configured to connect the first chamber to a first outlet reservoir. The first diaphragm is configured to bend in response to operation of the driving element, and the driving element comprises a piezoelectric actuator, or is configured to be operated by a piezoelectric motor. Piezoelectric pumps are advantageous in that they are miniaturized and energy-efficient implantable devices. Piezoelectric pumps may precisely deliver fluid with a flow rate in the range of 0.01 ml / min to 35 ml / min and a pressure in the range of 0.2 kPa to 36 kPa. According to one embodiment, a piezoelectric pump is provided wherein the inlet of the first wall portion comprises an inlet valve and the outlet of the first wall portion comprises an outlet valve. Any of the inlet valve of the first wall portion and outlet valve of the first wall portion may be a check valve or an active valve. The check valve may be a ball valve. The inlet valve and outlet valve are useful to stabilize the flow rate in the first chamber. According to one embodiment, the inlet of the first wall portion comprises an inlet static element and the outlet of the first wall portion comprises an outlet static element, wherein any of the inlet static element and outlet static element is configured to act as a nozzle or a diffuser. Nozzles and diffusers are advantageous in that they are more resistant to wear and fatigue failure as compared to check valves and active valves. According to one embodiment, the first diaphragm comprises a first movable wall portion. The first movable wall portion may comprise elevated and lowered portions, wherein the elevated and lowered portions enable at least one of compression and expansion for moving the first movable wall portion. The first movable wall portion may comprise a substantially stiff portion. The first movable wall portion may comprise a bellows. The bellows may comprise metal. The bellows may comprise at least one of an oval cross section, an elliptic cross-section and a circular cross-section. Metals are generally dense, which is advantageous as fluids do not diffuse through metals as easily. This reduces the risk that fluid diffuses from the first chamber or that fluids diffuse into the first chamber. According to one embodiment, a piezoelectric pump is provided which further comprises an auxiliary wall portion and an auxiliary chamber sealed from the first chamber. The auxiliary wall portion and the first diaphragm enclose the auxiliary chamber. The sealing of the auxiliary chamber from first chamber is advantageous in that a component unsuitable to be in contact with the fluid in the first chamber may be hosted by the auxiliary chamber. Such a component may be the driving element. According to one embodiment, a piezoelectric pump is provided which further comprises an auxiliary wall portion, an auxiliary chamber sealed from the first chamber, and an auxiliary diaphragm configured to bend in the same direction as the first diaphragm in response to operation of the driving element. The auxiliary wall portion and the auxiliary diaphragm enclose the auxiliary chamber. According to one embodiment, the auxiliary chamber is configured to be connected to a pressure adapter enabling variation of pressure in the auxiliary chamber. The pressure adapter may comprise an elastic portion having a surface area, and the elastic portion may be configured to maintain substantially the same surface area while enabling variation of pressure in the auxiliary chamber. This is advantageous in that a fibrotic tissue which at least partially covers the elastic portion may easily adapt to the elastic portion. According to one embodiment, a piezoelectric pump is provided which further comprises a second wall portion, a second diaphragm and a second chamber. The second diaphragm and the second wall portion enclose the second chamber. The second wall portion comprises an inlet, configured to connect the second chamber to a second inlet reservoir, and an outlet, configured to connect the second chamber to a second outlet reservoir. The second diaphragm is configured to bend in the same direction as the first diaphragm in response to operation of the driving element. The embodiment is advantageous in that the piezoelectric pump is configured to be operated in a double mode. According to one embodiment, the inlet of the second wall portion comprises an inlet valve and the outlet of the second wall portion comprises an outlet valve. Any of the inlet valve of the second wall portion and outlet valve of the second wall portion may be a check valve or an active valve. The check valve may be a ball valve. The inlet valve and outlet valve are useful to stabilize the flow rate in the second chamber. According to one embodiment, the inlet of the second wall portion comprises an inlet static element and the outlet of the second wall portion comprises an outlet static element, wherein any of the inlet static element and outlet static element is configured to act as a nozzle or a diffuser. Nozzles and diffusers are advantageous in that they are more resistant to wear and fatigue failure as compared to check valves and active valves. According to one embodiment, the piezoelectric pump comprises at least two portions connected in series, wherein each portion is a piezoelectric pump. The series connection allows for larger pressure compared to piezoelectric pumps in which fluid is transferred from an inlet to an outlet reservoir via a single chamber. According to one embodiment, the piezoelectric pump comprises at least two portions connected in series, wherein each portion is a piezoelectric pump configured to be operated in a double mode. The series connection allows for larger pressure as compared to piezoelectric pumps configured to be operated in a double mode in which a first fluid is transferred from a first inlet reservoir to a first outlet reservoir via a single first chamber and a second fluid is transferred from a second inlet reservoir to a second outlet reservoir via a single second chamber. According to one embodiment, the piezoelectric pump comprises at least two portions connected in parallel, wherein each portion is a piezoelectric pump. The parallel connection allows for a higher flow rate as compared to piezoelectric pumps in which the inlet reservoir is configured to be connected to a single inlet and the outlet reservoir is configured to be connected to a single outlet. According to one embodiment, the piezoelectric pump comprises at least two portions connected in parallel, wherein each portion is a piezoelectric pump configured to be operated in a double mode. The parallel connection allows for a higher flow rate as compared to piezoelectric pumps configured to be operated in a double mode in which the first inlet reservoir and second inlet reservoir are configured to be connected to a single first inlet and single second inlet, respectively, and the first outlet reservoir and second outlet reservoir are configured to be connected to a single first outlet and single second outlet, respectively. According to one embodiment, the medical device further comprises a controller configured to control the piezoelectric pump. According to one embodiment, the medical device further comprises a sensor configured to measure a parameter of the piezoelectric pump, and a feedback unit. The sensor is further configured to transmit the measured parameter to the feedback unit. The feedback unit is configured to transmit a conditioning signal to the controller based on the measured parameter received from the sensor and based on a set value of the parameter. The controller is configured to adjust the control of the piezoelectric pump based on the conditioning signal received from the feedback unit in order for the measured parameter to achieve the set value. SECOND ASPECT – IMPLANTABLE VIBRATION DEVICE According to the second aspect of the present disclosure, the system for treating a patient having a disorder related to a patient’s intestine comprises an implantable vibration device comprising a vibration generating unit (VGU) which is configured to cause the implantable vibration device to vibrate. The implantable vibration device may be provided in an area where the flow control device controlling flow of the intestinal contents contacts the intestinal wall, in order to cause vibration of the muscle or neural tissue of the intestinal wall in the respective area. This is particularly advantageous where the system comprises a mechanical or hydraulic constriction device. But it is likewise advantageous where the system is configured to electrically stimulate, by means of one or more electrodes, the muscle or neural tissue. The vibrational forces delivered to the tissue must be sufficiently high for activating at least some of the mechanoreceptors of the muscle tissue in the mechanically or hydraulically constricted and / or electrically stimulated area. The purpose is to exercise the tissue wall which is in contact with the constriction device, may it be a mechanical or hydraulic constriction device and / or an electrical stimulation device. That is, the body tends to react to medical implants, partly because the implant is a foreign object, and partly because the implant interacts mechanically with tissue of the body. Exposing tissue to long-term engagement with, or pressure from, a mechanical or hydraulic or other type of constriction device may deprive the tissue cells of oxygen and nutrients which may lead to deterioration of the tissue, atrophy and eventually necrosis. This may result in migration of the device, including migration through the tissue wall. Exercising the tissue cells stimulates the blood flow and, thereby, increases the tolerance of the tissue for pressure from the implant. As stated, it is preferable to configure the system such that vibrational stimulation of the muscle or neural tissue for increasing the blood flow through the tissue of the intestine is adjustable at a low level which is not enough to constrict the intestine. In some embodiments, the system comprises a casing enclosing at least the vibration generating unit. In some embodiments, the casing further encloses the wireless energy receiver. In some embodiments, the wireless energy receiver is provided outside the casing and coupled to the vibration generating unit through a lead. In some embodiments, the vibration generating unit is attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing. In some embodiments, the implantable vibration device further comprises a rechargeable energy storage unit, preferably provided within the casing, for storing at least part of the received wireless energy. In some embodiments, the implantable vibration device comprises an internal controller. In some embodiments, the internal controller is configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device. In some embodiments, the internal controller is configured to receive the vibration control data wirelessly via the wireless energy receiver. In some embodiments, the system does not comprise any metallic parts and does not comprise any magnetic parts. In some embodiments, the vibration generating unit is operated by a piezoelectric motor. In some embodiments, the piezoelectric motor is a piezoelectric inchworm motor. In some embodiments, the piezoelectric motor is a piezoelectric inertial motor. In some embodiments, the piezoelectric motor is a piezoelectric walk-drive motor. In some embodiments, the piezoelectric motor is a linear piezoelectric motor. In some embodiments, the piezoelectric motor is a rotational piezoelectric motor. In some embodiments, the vibration generating unit further comprises a weight configured to be eccentrically rotated by the rotational piezoelectric motor. In some embodiments, the piezoelectric motor is a reversable piezoelectric motor. In some embodiments, the vibration generating unit is configured to cause the implantable vibration device to vibrate at a frequency in a range of 1 – 150 Hz, such as in a range of 35 – 150 Hz. In some embodiments, the vibration generating unit is configured to cause the implantable vibration device to vibrate at an amplitude of at least 1 mm. In some embodiments, the implantable vibration device comprises an outer surface and a coating arranged on the outer surface. In some embodiments, the coating comprises at least one layer of a biomaterial. In some embodiments, the biomaterial comprises at least one drug or substance with one or more of the following characteristics: an antithrombotic, an antibacterial and an antiplatelet characteristic. In some embodiments, the biomaterial is fibrin-based. In some embodiments, further comprising a second coating arranged on the first coating. In some embodiments, the second coating is of a different biomaterial than said first coating. In some embodiments, the first coating comprises a layer of perfluorocarbon chemically attached to the surface, and wherein the second coating comprises a liquid perfluorocarbon layer. In some embodiments, the coating comprises a drug encapsulated in a porous material. In some embodiments, the outer surface of the implantable vibration device comprises a micro pattern. In some embodiments, the surface further comprises a layer of a biomaterial coated on the micro pattern. In some embodiments, the vibration generation unit comprises a wireless energy receiver configured to receive wireless energy to be used, directly or indirectly, by the vibration generating unit. THIRD ASPECT – EFFECTOR RESPONSE According to the third aspect of the present disclosure, the system for treating a patient having a disorder related to the patient’s intestine comprises means for affecting an effector response in the patient. First Sub-aspect – Parasympathetic / Sympathetic According to a first sub-aspect of this third aspect, the means for affecting the effector response in the patient may comprise a stimulation device configured to deliver, directly or indirectly, a first stimulation signal to a sympathetic nerve innervating a first effector tissue of the patient, and a second stimulation signal to a parasympathetic nerve innervating a second effector tissue. The system further comprises a control unit configured to control an operation of the stimulation device such that either the first stimulation signal stimulates an activity of the sympathetic nerve and the second stimulation signal inhibits an activity of the parasympathetic nerve or the first stimulation signal inhibits an activity of the sympathetic nerve and the second stimulation signal stimulates an activity of the parasympathetic nerve. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS) form part of the autonomous nervous system (ANS) of the body. The SNS and the PNS control involuntary bodily functions such as, for example, heart rate, blood pressure, digestion, breathing rate, pupil size, blood flow to the muscles, and sexual responses. The SNS is commonly described as the “fight or flight” system, preparing the body for stress or danger, whereas the PNS is commonly referred to as the “rest and digest” system, promoting relaxation, energy storage, and other non-emergency functions. Activation of the SNS may result in increased heart rate, dilated airways, inhibited digestion, dilated pupils, and redirection of blood to muscles. Activation of the PNS may result in decreased heart rate, stimulated digestion, contracted pupils, and relaxation of muscles. For the SNS, the preganglionic neurons generally originate in the thoracic and lumbar regions of the spinal cord, whereas for the PNS the preganglionic neurons generally originate in the brainstem and the sacral region of the spinal cord. The SNS and the PNS may have complementary functions on the same effector tissue, such as an organ or a muscle. For example, the SNS may accelerate the heart rate, while the PNS may slow it down. Both the SNS and the PNS are typically active to some extent all the time, but their relative activities may change depending on the situation. This dynamic balance between the SNS and the PNS is commonly referred to as the “autonomic tone”. The autonomic tone hence implies there is an ongoing, background level of activity in the SNS and PNS. The body may adjust this balance as needed, ramping up sympathetic or parasympathetic activity in response to specific situations. The tone may also capture the systems’ readiness to respond to stimuli. A certain “tone” or baseline activity level may ensure that the system can quickly ramp up or down its activity to adapt to different situations. Therefore, it may be of interest to adjust or affect this tone for therapeutic purposes, for example to affect the general level of stress in the body. Adjusting the level of activity in the SNS and / or the PNS may, for example, be employed to treat a variety of conditions. For example, increasing the PNS activity and / or decreasing the SNS activity can help treating conditions such as anxiety, hypertension, and irritable bowel syndrome (IBS). On the other hand, increasing SNS activity and / or decreasing PNS activity can help treating conditions such as depression, chronic fatigue syndrome, and postural orthostatic tachycardia syndrome (PoTS). In some instances, both systems work together to perform a function. For example, during sexual arousal and ejaculation, both systems are involved in different phases. During sexual arousal, the PNS may cause the arteries in the erectile tissue to dilate to increase the blood flow, whereas the SNS may cause the veins to contract to reduce the blood flow leaving the erectile tissue. The SNS and the PNS are also coopering during urination, wherein the PNS may cause the sphincters to relax and the SNS the bladder to contract. Adjusting or controlling the cooperation between the SNS and PNS may thus be employed to treat impotence and incontinence. The SNS and the PSNS may generally be considered to work together in a dynamic balance between arousal / activation / contraction and relaxation / inhibition / relaxation in the effector tissue innervated by the SNS and the PNS. Hence, the sympathetic activity and the parasympathetic activity may affect the response in the effector tissue, which typically may be a somatic effector tissue or an autonomic effector tissue. Examples of somatic effector tissue include muscular tissue, such as skeletal muscles, whereas examples of autonomic effector tissue include smooth muscle tissue, cardiac muscle tissue, and glandular or epithelial tissue (commonly involved in the production and secretion of various substances such as hormones, enzymes, and sweat). By stimulating a sympathetic nerve and / or a parasympathetic nerve innervating the effector tissue, the effector response may be controlled or affected accordingly. In case of muscular tissue, the effector response may be a contraction or relaxation of the tissue. In some examples, the stimulation of the sympathetic nerve and / or parasympathetic nerve may be employed to adjust the autonomic tone discussed above. Generally, ‘effector tissue’ refers to tissues in the body that produce a response or perform work (‘effector response’) when activated by nerve signals. Effectors may essentially be understood as the ‘end targets’ in the signalling pathways of the nervous system. They may be categorized based on their relationship with the nervous system. The somatic effectors are mostly skeletal muscles controlled by the somatic nervous system, responsible for voluntary actions, whereas the autonomic effectors typically are controlled by the autonomic nervous system and include smooth muscle tissue. These effectors are generally not under voluntary control. In an example of this first sub-aspect, the control unit may be configured to control the operation of the stimulation device such that at least one of the first stimulation signal and the second stimulation signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component. In another example, the first signal may be a low-frequency signal configured to stimulate the activity of the sympathetic nerve and the second signal is a high-frequency signal configured to inhibit the activity of the parasympathetic nerve. Alternatively, the first signal may be a high-frequency signal configured to inhibit the activity of the sympathetic nerve and the second signal is a low-frequency signal configured to stimulate the activity of the parasympathetic nerve. In an example, an amplitude of the low-frequency signal may vary with a frequency in the range of 0.1 - 100 Hz and an amplitude of the high-frequency signal vary with a frequency in the range of 1 - 10 kHz. In an example, at least one of the first and second stimulation signals may comprise a series of pulses having a negative voltage relative to ground. In an example, the control unit may be configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses. In an example, at least one of the first stimulation signal and second stimulation signal may be an electric signal. In an example, the control unit may be configured to operate the stimulation device to alternatingly apply the first stimulation signal to the sympathetic nerve and the second stimulation signal to the parasympathetic nerve. In an example, the control unit may be configured to operate the stimulation device to simultaneously apply the first stimulation signal to the sympathetic nerve and the second stimulation signal to the parasympathetic nerve. In an example, the control unit may be configured to control the operation of the stimulation device to generate an effector response being at least one of a muscular response. In an example, each of the first and second effector tissue may be a muscular tissue. Further, the control unit may be configured to control the operation of the stimulation device such that the first stimulation signal stimulates the activity of the sympathetic nerve and the second stimulation signal inhibits the activity of the parasympathetic nerve, thereby inducing contraction in the muscular tissue. In an example, each of the first and second effector tissue may be a muscular tissue. Furthermore, the control unit may be configured to control the operation of the stimulation device such that the first stimulation signal inhibits the activity of the sympathetic nerve and the second stimulation signal stimulates the activity of the parasympathetic nerve, thereby inducing relaxation in the muscular tissue. In an example, the first and second effector tissue may be smooth muscle tissue. In an example, the first and second effector tissue may form part of an intestine of the patient. In an example, the system may further comprise a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue and a control unit configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal. In an example, the sensor device may comprise a sensor electrode configured to measure an electric activity in the effector tissue. In an example, the sensor device may comprise a sensor electrode configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor device may comprise an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor electrode may be configured to be arranged at the effector tissue. The sensor may further comprise a reference electrode and be configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode. In an example, the reference electrode may be formed by a housing of the stimulation device or the sensor device. In an example, the sensor device may be configured to measure mechanical movement in the effector tissue. In an example, the sensor device may comprise a strain gauge configured to measure a contraction or relaxation of the effector tissue. In an example, the control unit may be configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response. In an example, the control unit may be configured to compare the response measure with a predetermined reference measure and control the stimulation device to, in response to the response measure being below the reference measure, increase an intensity of the first stimulation signal to stimulate the activity in the sympathetic nerve and / or increase an intensity of the second stimulation signal to inhibit the activity of the parasympathetic nerve. Further, the control unit may be configured to control the stimulation device to, in response to the response measure exceeding the reference measure, reduce the intensity of the first stimulation signal to inhibit the activity of the sympathetic nerve and / or stimulate the activity of the parasympathetic nerve. The predetermined reference measure may be based on a previous measurement of the effector response in the patient or previous measurement of effector responses in other patients. In an example, the control unit may be configured to monitor the response measure of the effector response over time, and to control the stimulation device based on a change rate in the effector response over time. In an example, the control unit may be configured to determine a calibration parameter of the stimulation device based on the response measure. In an example, the stimulation device may comprise a first electrode arrangement configured to be coupled to the sympathetic nerve to deliver the first stimulation signal and a second electrode arrangement configured to be coupled to the parasympathetic nerve to deliver the second stimulation signal. In an example, the first electrode arrangement may comprise a first stimulation electrode and a second stimulation electrode, wherein the first stimulation electrode and the second stimulation electrode may be configured to be spaced apart along the sympathetic nerve. In an example, the stimulation device may be configured to generate the first stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode. In an example, the system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the sympathetic nerve. In an example, the second electrode arrangement may comprise a third electrode and a fourth electrode, wherein the third electrode and the fourth electrode are configured to be arranged spaced apart along the parasympathetic nerve. The second electrode arrangement may further comprise a fifth electrode configured to be arranged spaced apart from the fourth electrode such that the fourth electrode is arranged between the third and fifth electrodes. In an example, the stimulation device may be configured to generate the second stimulation signal such that the fourth electrode serves as a cathode and the third and fifth electrodes serve as anodes. In an example, the system may further comprise a cuff configured to be at least partially arranged around the parasympathetic nerve and hold the second electrode arrangement in place against the parasympathetic nerve. Second Sub-aspect – Frequency In a second sub-aspect, the means for affecting an effector response in a patient may comprise a stimulation device configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, and a control unit configured to operate the stimulation device to apply at least one of a first stimulation signal and a second stimulation signal to the effector tissue. The first stimulation signal is a time-varying signal with an amplitude varying with a frequency lying in a first frequency interval and the second stimulation signal is a time-varying signal with an amplitude varying with a frequency lying in a second frequency interval. The first frequency interval is selected to inducing the effector response in the effector tissue and the second frequency interval is selected to inhibit the effector response in the effector tissue. In an example, the first frequency interval may be 0.1 - 100 Hz and the second frequency interval 1 - 10 kHz. In an example, at least one of the first and second stimulation signals may be an electric signal comprising a series of pulses having a negative voltage relative to ground. In an example, the control unit may be configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses. In an example, the control unit may be configured to operate the stimulation device to generate a first stimulation signal having a frequency of 0.5 - 3 Hz, and wherein the effector tissue is cardiac muscle tissue. In an example, the control unit may be configured to operate the stimulation device to generate a first stimulation signal having a frequency of 1 - 10 Hz, and wherein the effector tissue is skeletal muscle tissue. In an example, the control unit may be configured to operate the stimulation device to generate a first stimulation signal having a frequency of 0.1 - 100 Hz, and wherein the effector tissue is smooth muscle tissue. In an example, at least one of the first stimulation signal and second stimulation signal may be an electric signal or a vibrational signal. In an example, the control unit may be configured to operate the stimulation device to alternatingly apply the first stimulation signal and the second stimulation signal to the effector tissue. In an example, the system may further comprise a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, wherein the control unit may be configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal. In an example, the sensor device may comprise a sensor electrode configured to measure an electric activity in the effector tissue. In an example, the sensor device may comprise a sensor electrode configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor device may comprise an electromyographic sensor electrode configured to measure an electric activity in the effector tissue and an electric impedance sensor electrode configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor electrode may be configured to be arranged at the effector tissue. The sensor may further comprise a reference electrode and be configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode. In an example, the reference electrode may be formed by a housing of the stimulation device or the sensor device. In an example, the sensor device may be configured to measure mechanical movement in the effector tissue. In an example, the sensor device may comprise a strain gauge configured to measure a contraction or relaxation of the effector tissue. In an example, the control unit may be configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response. In an example, the control unit may be configured to compare the response measure with a predetermined reference measure and control the stimulation device to: in response to the response measure being below the reference measure, increase an intensity of the first stimulation signal to stimulate the activity in the effector tissue, and in response to the response measure exceeding the reference measure, increase the intensity of the second stimulation signal to inhibit the activity of the effector tissue. The predetermined reference measure may be based on a previous measurement of the effector response in the patient or previous measurement of effector responses in other patients. In an example, the control unit may be configured to monitor the response measure of effector response over time and control the stimulation device based on a change rate in the effector response over time. In an example, the control unit may be configured to determine a calibration parameter of the stimulation device based on the response measure. In an example, the stimulation device may comprise a first electrode arrangement configured to deliver the first stimulation signal and a second electrode arrangement configured to deliver the second stimulation signal. The first electrode arrangement may comprise a first stimulation electrode and a second stimulation electrode, wherein the first stimulation electrode and the second stimulation electrode are configured to be spaced apart along the nerve innervating the effector tissue. In an example, the stimulation device may be configured to generate the first stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode. In an example, the system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the nerve. In an example, the second electrode arrangement may comprise a third electrode and a fourth electrode, the third electrode and the fourth electrode being configured to be arranged spaced apart along the nerve. In an example, the stimulation device may be configured to generate the second stimulation signal such that the third electrode serves as a cathode and the fourth electrode serves as an anode. In an example, the system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the second electrode arrangement in place against the nerve. In an example, the system may further comprise a suppression electrode arrangement configured to be coupled to the nerve to apply a suppression signal suppressing action potentials propagating in the nerve in a direction towards the central nervous system. In an example, the control unit may be configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the first stimulation signal. In an example, the stimulation device may be configured to be coupled to the nerve at a position between the effector tissue and the suppression electrode arrangement, so as to induce action potentials travelling in the nerve in a direction towards the effector tissue. In an example, the control unit may be configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the stimulation device applying the first stimulation signal. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation device and the suppression electrode arrangement is actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the first stimulation signal. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement to apply the first stimulation signal and the suppression signal substantially at the same time. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement such that each of the first stimulation signal and the suppression signal is a time-varying signal, wherein the first stimulation signal is a low-frequency signal, and the suppression signal is a high-frequency signal. An amplitude of the first stimulation signal may vary with a frequency in the range of 0.1 - 100 Hz, while an amplitude of the suppression signal may vary with a frequency in the range of 1 - 10 kHz. Third Sub-aspect – Unidirectional In a third sub-aspect, the means for affecting an effector response in a patient may comprise a stimulation device comprising a first electrode arrangement and a second electrode arrangement Each of the first and a second electrode arrangements is configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient. A control unit is configured to drive the stimulation device to apply, by means of the first electrode arrangement, a stimulation signal inducing the effector response in the effector tissue and apply, by means of the second electrode arrangement, a suppression signal suppressing action potentials propagating in the nerve towards the central nervous system (CNS). The control unit is configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal. In an example, the first electrode arrangement may be configured to be coupled to the nerve at a position between the effector tissue and the second electrode so as to induce action potentials travelling in the nerve in a direction towards the effector tissue. In an example, the control unit may be configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the first electrode applying the stimulation signal. In an example, the control unit may be configured to drive the stimulation device such that each of the first and second electrode arrangements are actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the stimulation signal. In an example, the control unit may be configured to drive the stimulation device to apply the stimulation signal and the suppression signal substantially at the same time. In an example, the control unit may be configured to drive the stimulation device such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signal is a low-frequency signal and the suppression signal is a high- frequency signal. An amplitude of the stimulation signal may vary with a frequency in the range of 0.1 - 100 Hz, while an amplitude of the suppression signal may vary with a frequency in the range of 1 - 10 kHz. In an example, the first and second electrode arrangements may be configured to be spaced apart along nerve. In an example, the first electrode arrangement may comprise a first stimulation electrode and a second stimulation electrode configured to apply the stimulation signal to the effector tissue or nerve. In an example, the first stimulation electrode and the second stimulation electrode may be configured to be spaced apart along the nerve. In an example, the stimulation device may be configured to generate the stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode. In an example, the system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the nerve. In an example, the second electrode arrangement may comprise a first suppression electrode and a second suppression electrode configured to apply the suppression signal to the nerve. In an example, the first suppression electrode and the second suppression electrode may be configured to be spaced apart along the nerve. In an example, the second electrode arrangement may further comprise a third suppression electrode configured to be arranged spaced apart from the second suppression electrode such that the second suppression electrode is arranged between the first and third suppression electrodes. In an example, the stimulation device may be configured to generate the suppression signal such that the second suppression electrode serves as a cathode and the first and third suppression electrodes serve as anodes. In an example, the system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the second electrode arrangement in place against the nerve. In an example, the system may further comprise a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue. The control unit may be further configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal. In an example, the sensor device may comprise a sensor electrode configured to measure an electric activity in the effector tissue. In an example, the sensor device may comprise a sensor electrode configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor device may comprise an electromyographic sensor electrode configured to measure an electric activity in the effector tissue and an electric impedance sensor electrode configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor electrode may be configured to be arranged at the effector tissue. The sensor may further comprise a reference electrode and be configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode. In an example, the reference electrode may be formed by a housing of the stimulation device or the sensor device. In an example, the sensor device may be configured to measure mechanical movement in the effector tissue. The sensor device may comprise a strain gauge configured to measure a contraction or relaxation of the effector tissue. In an example, the control unit may be configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response. The control unit may be configured to compare the response measure with a predetermined reference measure and control the stimulation device to: in response to the response measure being below the reference measure, increase an intensity of the stimulation signal to stimulate the activity in the effector tissue, and in response to the response measure exceeding the reference measure, reduce the intensity of the stimulation signal to inhibit the activity of the effector tissue. The predetermined reference measure may be based on a previous measurement of the effector response in the patient or previous measurement of effector responses in other patients. In an example, the control unit may be configured to monitor the response measure of the effector response over time and control the stimulation device based on a change rate in the effector response over time. In an example, the control unit may be configured to determine a calibration parameter of the stimulation device based on the response measure. Fourth Sub-aspect – Feedback In a fourth sub-aspect, the means for affecting the effector response in the patient may comprise a stimulation device which is configured to deliver, directly or indirectly, a stimulation signal to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, and a control unit. The control unit is configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal. In an example, the sensor device may comprise a sensor electrode configured to measure an electric activity in the effector tissue in response to the stimulation signal. In an example, the sensor device may comprise a sensor electrode configured to measure a change in electrical impedance in the effector tissue in response to the stimulation signal. In an example, the sensor device may comprise an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue. In an example, the sensor electrode may be configured to be arranged at the effector tissue. The sensor electrode may comprise a reference electrode and the sensor device may be configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode. The reference electrode may be formed by a housing of the stimulation device or the sensor device. In an example, the sensor device may be configured to measure mechanical movement in the effector tissue in response to the stimulation signal. The sensor device may comprise a strain gauge configured to measure a contraction or relaxation of the effector tissue in response to the stimulation signal. In some examples, the sensor device may be configured to measure a heart rate of the patient, a blood pressure of the patient, or a rate of respiration of the patient. In an example, the control unit may be configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response. In an example, the control unit may be configured to compare the response measure with a predetermined reference measure and control the stimulation device to: increase an intensity of the stimulation signal in response to the response measure being below the reference measure, and reduce the intensity of the stimulation signal in response to the response measure exceeding the reference measure. In an example, the control unit may be configured to increase the intensity of the stimulation signal by increasing at least one of a frequency, current amplitude and voltage amplitude of the stimulation signal and reduce the intensity of the stimulation signal by reducing at least one of the frequency, current amplitude and voltage amplitude of the stimulation signal. The predetermined reference measure may be based on a previous measurement of the effector response in the patient or previous measurement of effector responses in other patients. In an example, the control unit may be configured to monitor the level of effector response over time and control the stimulation device based on a change rate in the effector response over time. In an example, the control unit may be configured to determine a calibration parameter of the stimulation device based on the response measure. In an example, the control unit may be configured to control the operation of the stimulation device to generate an effector response being at least one of a muscular response. The effector tissue may be smooth muscle tissue forming part of an intestine of the patient. In an example, the control unit may be configured to control the operation of the stimulation device such that the stimulation signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component. The stimulation signal may be one of a low-frequency signal with an amplitude varying in the range of 0.1 - 100 Hz and a high-frequency signal with an amplitude varying in the range of 1 - 10 kHz. The stimulation signal may comprise series of pulses having a negative voltage relative to ground. In an example, the control unit may be configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses. The stimulation signal may be an electric signal. In an example, the stimulation device may comprise a first stimulation electrode and a second stimulation electrode, the first stimulation electrode and the second stimulation electrode being configured to be spaced apart along the nerve innervating the effector tissue. The stimulation device may be configured to generate the stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode. The system may further comprise a cuff configured to be at least partially arranged around the nerve and hold the first and second stimulation electrodes in place against the nerve. In an example, the system may further comprise a suppression electrode arrangement configured to be coupled to the nerve to apply a suppression signal suppressing action potentials propagating in the nerve in a direction towards the central nervous system. The control unit may be configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal. Furthermore, the stimulation device may be configured to be coupled to the nerve at a position between the effector tissue and the suppression electrode arrangement, so as to induce action potentials travelling in the nerve in a direction towards the effector tissue. In an example, the control unit may be configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the stimulation device applying the stimulation signal. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation device and suppression electrode arrangement is actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the stimulation signal in the nerve. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement to apply the first stimulation signal and the suppression signal substantially at the same time. In an example, the control unit may be configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signal is a low- frequency signal and the suppression signal is a high-frequency signal. An amplitude of the stimulation signal may vary with a frequency in the range of 0.1 - 100 Hz, whereas an amplitude of the suppression signal may vary with a frequency in the range of 1 - 10 kHz. Fifth Sub-aspect – Printed Circuit Board (PCB) In a fifth aspect, the means for affecting the effector response in the patient may comprise a stimulation device configured to deliver a stimulation signal to at least one of the effector tissue and a nerve innervating the effector tissue of the patient, a source of energy configured to energize the stimulation device, a control unit operably connected to the stimulation device and configured to control an operation of the stimulation device such that the stimulation signal causes at least one of an effector response and inhibition of the effector response in the effector tissue, and a printed circuit board (PCB), supporting at least one of the stimulation device, the source of energy and the control unit. The PCB is at least one of a multi-layer PCB, a flexible PCB, a stretchable PCB. It will be appreciated that the PCB may be implemented in any of the systems of the above-discussed aspects and examples. In an example, the PCB may comprise a first multi-layer portion and a second multi-layer portion interconnected by a stretchable portion. In an example, the PCB may comprise a first multi-layer portion and a second multi-layer portion interconnected by a flexible portion. Sixth Sub-aspect – Stimulation / DC-blocking Capacitor In a sixth aspect, the means for stimulating the effector tissue of the patient may comprise a stimulation device configured to deliver a stimulation signal to at least one of the effector tissue and a nerve innervating the effector tissue of the patient, a source of energy configured to energize the stimulation device, a control unit operably connected to the stimulation device and configured to control an operation of the stimulation device such that the stimulation signal causes at least one of an effector response and inhibition of the effector response in the effector tissue, and a capacitor configured to reduce a current leakage of the system to 1 μA or less, such as 0.1 μA or less. It will be appreciated that such capacitor may be implemented in any of the systems of the above-discussed aspects and examples. In an example, the capacitor may be configured to be connected in series with the body of the patient and at least one of the stimulation devices, the source of energy, and the control unit. In an example, the stimulation device may comprise an electrode arrangement configured to be coupled to the effector tissue or the nerve. The capacitor may be configured to be connected in series with the body of the patient and the electrode arrangement. In an example, the electrode arrangement may comprise a first stimulation electrode and a second stimulation electrode for applying the stimulation signal. The capacitor may be configured to be connected in series with the first stimulation electrode and the second stimulation electrode. In an example, the capacitor may be integrated in a circuitry for controlling the operation of the stimulation device. In an example, the system may further comprise a printed circuit board, PCB, supporting the capacitor and at least one of the stimulation devices, the source of energy, and the control unit. The PCB may be at least one of a multi-layer PCB, a flexible PCB, and a stretchable PCB. Seventh Sub-aspect – Electrical Inhibition / Denervation According to a seventh sub-aspect, the means for at least partly denervating the effector tissue of the patient may comprise an inhibition device configured to temporarily inhibit a nerve innervating the effector tissue, a sensor configured to generate a sensor signal indicative of an effector response in the effector tissue, the effector response being at least partly induced by the inhibiting of the nerve, and a processing unit configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response, compare the response measure with a predetermined reference measure, and determine, based on the comparison, whether a desired effector response has been achieved. The system further comprises a denervation device configured to at least partly denervate the effector tissue. In an example, the inhibition device may be an electric stimulation device configured to deliver an inhibition signal to the nerve to cause a temporary inhibition of the nerve. In some examples, the inhibition signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component. An amplitude of the signal may vary in the range of 1 - 10 kHz. In an example, the inhibition signal may be an electric signal comprising a series of pulses having a negative voltage relative to ground. A positive voltage pulse may follow one or more negative voltage pulses. In an example, the inhibition signal may be generated such that a first inhibition electrode serves as a cathode and a second inhibition electrode serves as an anode, the first and second inhibition electrodes being arranged spaced apart along the nerve. In an example, a suppression signal may be delivered to the nerve to suppress action potentials propagating in the nerve in a direction towards the central nervous system. In an example, the suppression signal may be regulated to suppress the action potentials induced in the nerve in response to the inhibition signal. In an example, the inhibition signal may be delivered at a position between the effector tissue and the position in which the suppression signal is applied to the nerve. In an example, the suppression of the action potentials is delivered to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the electric inhibition signal. In an example, the electric inhibition signal and the suppression signal may be delivered in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the electric inhibition signal in the nerve. In an example, a sensor signal, indicative of the effector response, may be received at the control unit which may determine the response measure based on the received sensor signal. In an example, the sensor signal may be indicative of an electric activity in the effector tissue. In an example, the sensor signal may be indicative of a change in electrical impedance in the effector tissue. In some examples, the effector tissue may form part of a gastrointestinal tract of the patient and the sensor signal may be indicative of a level of motility of the gastrointestinal tract. In an example, the effector tissue may be muscle tissue and the sensor signal may be indicative of mechanical movement of the muscle tissue. The sensor signal may be generated by a strain gauge measuring a contraction or relaxation of the muscle tissue. In some examples, the sensor signal may be indicative of a heart rate of the patient, a blood pressure of the patient, or a rate of respiration of the patient. Eighth Sub-aspect – Electrical Inhibition / Denervation Method

[0001] According to an eighth sub-aspect, there is provided a method for at least partly denervating an effector tissue of a patient, which is muscle tissue forming part of the gastrointestinal tract of the patient. The method comprises temporarily inhibiting a nerve innervating the effector tissue, determining a response measure indicative of an effector response in the effector tissue, wherein the effector response is at least partly induced by the inhibiting of the nerve, comparing the response measure with a predetermined reference measure, and at least partly denervating the effector tissue based at least in part on the comparison. Ninth Sub-aspect – Surgical methods According to a ninth sub-aspect, there is provided laparoscopic surgical methods and surgical methods of treating a patient, which may be used to implant any of the systems described with reference to any of sub-aspects one through eight. According to a first ninth sub-aspect, there is provided a laparoscopic surgical method of treating a patient. The laparoscopic surgical method of treating a patient, comprises the steps of: introducing at least one of; a needle, a trocar, a tube, a tubular instrument and a surgical instrument, through the fascia of at least one of any muscles or any fibrotic intersections comprising; the rectus abdominalis, transversus abdominalis, the External Oblique, the Internal Oblique, any Serratus or any pyramidalis, the linea alba, a tendnous intersection, and the umbilicus, blowing in pressurized gas through the needle or trocar or surgical instrument or any device inflating the abdominal cavity, introducing working instruments comprising the steps of: inserting at least one first trocar into the abdominal cavity, introducing at least one camera through the trocar, inserting at least a second trocar into the abdominal cavity, inserting at least one instrument preferably through the second trocar, inserting at least a third trocar into the abdominal cavity, and inserting at least one second instrument preferably through the third trocar; the method further comprising: dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing a control device in the body for controlling the flow control device, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, camera and trocar, and, in relation thereto suturing, if necessary, the abdominal wall and permanently closing the skin. According to an embodiment, the laparoscopic surgical further comprises placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. According to an embodiment, the laparoscopic surgical further comprises, fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. According to an embodiment, the laparoscopic surgical further comprises placing at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical further comprises placing a holding device configured to hold at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical further comprises transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. According to an embodiment, the laparoscopic surgical further comprises stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. According to an embodiment, the laparoscopic surgical further comprises stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. According to an embodiment, the laparoscopic surgical further comprises stimulating the electrodes on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical further comprises training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. According to an embodiment, the laparoscopic surgical further comprises training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. According to a second ninth sub-aspect, there is provided a surgical method of treating a patient. The surgical method comprising the steps of: cutting the patient's skin and abdominal wall, dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a control device in the body, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, and in relation thereto, suturing, the abdominal wall and closing the skin According to an embodiment, the surgical method further comprises placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions: close to anus or close to a stoma opening. According to an embodiment, the surgical method further comprises fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. According to an embodiment, the surgical method further comprises placing at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the surgical method further comprises placing a holding device configured to hold at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the surgical method further comprises transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. According to an embodiment, the surgical method further comprises stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. According to an embodiment, the surgical method further comprises stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. According to an embodiment, the surgical method further comprises stimulating the electrodes on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir. According to an embodiment, the surgical method further comprises training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. According to an embodiment, the surgical method further comprises training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. According to a third ninth sub-aspect, there is provided a a laparoscopic surgical method of treating a patient. The laparoscopic surgical method comprising the steps of: introducing at least one of; a needle, a trocar, a tube, a tubular instrument and a surgical instrument, through the fascia of at least one of any muscles or any fibrotic intersections comprising; the rectus abdominalis, transversus abdominalis, the External Oblique, the Internal Oblique, any Serratus or any pyramidalis, the linea alba, a tendnous intersection, and the umbilicus, blowing in pressurized gas through the needle or trocar or surgical instrument or any device inflating the abdominal cavity, introducing working instruments comprising the steps of: inserting at least one first trocar into the abdominal cavity, introducing at least one camera through the trocar, inserting at least a second trocar into the abdominal cavity, inserting at least one instrument preferably through the second trocar, inserting at least a third trocar into the abdominal cavity, and inserting at least one second instrument preferably through the third trocar; dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing a control device in the body for controlling the flow control device, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, camera and trocar, and in relation thereto suturing, if necessary, the abdominal wall and permanently closing the skin According to an embodiment, the laparoscopic surgical method comprises of placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. According to an embodiment, the laparoscopic surgical method comprises of fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. According to an embodiment, the laparoscopic surgical method comprises placing at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical method comprises placing a holding device configured to hold at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical method comprises transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. According to an embodiment, the laparoscopic surgical method comprises stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. According to an embodiment, the laparoscopic surgical method comprises stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. According to an embodiment, the laparoscopic surgical method comprises stimulating the electrodes on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrode to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the laparoscopic surgical method comprises training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. According to an embodiment, the laparoscopic surgical method comprises training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. According to a fourth ninth sub-aspect, there is provided a surgical method of treating a patient, comprising the steps of: cutting the patient's skin and abdominal wall, dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a control device in the body, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, and in relation thereto, suturing, the abdominal wall and closing the skin. According to an embodiment, the surgical method further comprises placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. According to an embodiment, the surgical method further comprises fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. According to an embodiment, the surgical method further comprises placing at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the surgical method further comprises placing a holding device configured to hold at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the surgical method further comprises transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. According to an embodiment, the surgical method further comprises stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. According to an embodiment, the surgical method further comprises stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. According to an embodiment, the surgical method further comprises stimulating the electrodes on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrode to be able to execute a direct massive blow type of emptying of the reservoir. According to an embodiment, the surgical method further comprises training the intestinal wall at a different time point at the position of the valve by, stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. According to an embodiment, the surgical method further comprises training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. According to a fifth ninth sub-aspect, there is provided an apparatus for treating a patient. The apparatus may be combined with any of the systems and devices described with reference to sub-aspects one through eight. The apparatus comprising: a flow control device adapted to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from a reservoir made by patients intestine to empty to outside the patient's body, the flow control device comprising: an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command, the reservoir created by: a selected suitable portion from the jejunum or ileum, that has been bent to create a 180° bend where an instrument has made two small holes in the bent area, wherein a stapler instrument with two separate two halves has been introduced through the two small holes in the intestine to clamp the intestines between the two halves of the stapler instrument to be stapled with at least one staple line on each side of the instrument and the two intestinal halves has been cut in between the staple lines to create a larger reservoir, wherein the two small holes in the intestine has been closed with sutures or staplers, and wherein optionally a second intestinal area has been bent to thereby repeat the process at least once as disclosed in this section to increase the size of the reservoir, a control unit, wherein the control unit is configured to execute at least one of a peristaltic type of emptying of the reservoir, at least one valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, the control unit is configured to: stimulate the at least first and second electrode when placed on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir, the flow control device further comprising: at least two electrodes, at least first and second electrode, adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side at least 2 cm distance away from each other in one or more grows of the reservoir and adapted to be covered by suturing or stapling together intestine from both halves of the intestine, wherein the control unit is configured to execute a stimulation pattern creating a peristaltic type of emptying of the reservoir, wherein the control unit is configured to open the valve when the flow control device is emptying the reservoir. According to an embodiment, the control device is configured to empty the reservoir with electrical stimulation simultaneously as the valve is not stimulated and opened. According to an embodiment, the valve at least one of a stimulation, hydraulic, pneumatic, mechanical valve or any combination thereof. According to an embodiment, the apparatus comprises a holding device adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side holding the electrodes with at least 2 cm distance away from each other to allow the peristaltic type of stimulation pattern and emptying of the reservoir. According to an embodiment, the control unit is configured to train the intestinal wall when the reservoir is not emptied. According to an embodiment, the control unit is configured to stimulate the muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by the at least two electrodes. According to an embodiment, the control unit is configured to train the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. According to an embodiment, the apparatus comprises at least one sensor, configured to sense at least one of a physical parameter of the patient's body and a functional parameter of the apparatus. According to an embodiment, the at least one sensor is configured to sense the physical parameter in the patient's body, comprising sensing at least one of the following physical parameters of the patient: a pressure measured on the outside of the reservoir, a pressure within the patient's intestine, an expansion of the reservoir, and a distension of an intestinal wall of the patient's intestine; and the at least one sensor is configured to sense the functional parameter of the apparatus when implanted, comprising sensing at least one of the following parameters: a pressure against a part of the system such as the valve, an electrical parameter such as voltage, current or energy balance, a position or movement of a movable part of the system, and any stimulation parameter in relation to the system. According to an embodiment, the apparatus is configured to provide a signal when a value for the physical or functional parameter sensed is beyond a predetermined threshold value. According to an embodiment, the apparatus comprises a vibration generation unit for stimulating at least one of the intestinal portions forming the reservoir and the intestine closed by the valve. According to an embodiment, the vibration generating unit is attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing. According to an embodiment, the implantable vibration device (110) comprises an internal controller (CI). According to an embodiment, wherein an internal controller (CI) is configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device. According to an embodiment, the apparatus does not comprise any metallic parts and does not comprise any magnetic parts. According to an embodiment, the vibration generating unit is operated by a piezoelectric motor. According to an embodiment, at least one piezoelectric motor is arranged for driving a pump for pumping fluid to at least one of the valve or for supporting the emptying of the reservoir. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric inchworm motor. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric inertial motor. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric walk-drive motor. According to an embodiment, the piezoelectric motor is a linear piezoelectric motor. According to an embodiment, the linear piezoelectric motor operates with at least one of: a speed in a range of 1 mm / s to 10 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 2 N – 30 N. According to an embodiment, the piezoelectric motor is a rotary piezoelectric motor. According to an embodiment, the rotary piezoelectric motor which operates with at least one of: a rotational speed in a range of 1 mrad / s – 100 mrad / s, and a torque in a range of 100 Nmm – 900 Nmm. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric ultrasonic motor. According to an embodiment, the piezoelectric ultrasonic motor is a traveling wave ultrasonic motor or a standing wave ultrasonic motor. According to an embodiment, the piezoelectric ultrasonic motor is a rotary piezoelectric ultrasonic motor which operates with at least one of: a rotational speed in a range of 10 mrad / s – 10,000 mrad / s, and a torque in a range of 20 Nmm – 450 Nmm. According to an embodiment, the piezoelectric ultrasonic motor is a linear piezoelectric ultrasonic motor which operates with at least one of: a speed in a range of 4 mm / s – 100 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 0.5 N – 30 N. According to an embodiment, the at least one piezoelectric motor comprises at least one bimorph piezoelectric actuator. According to an embodiment, the at least one piezoelectric motor is a reversible piezoelectric motor. According to an embodiment, the valve is adapted to be placed close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. According to an embodiment, the apparatus is configured to: advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. According to an embodiment, the apparatus is configured to: stimulating the intestine in the reservoir thereby advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. According to a sixth ninth-sub aspect, there is provided an apparatus for treating a patient. The apparatus may be combined with any of the systems and devices described with reference to sub-aspects one through eight. The apparatus comprises: a flow control device adapted to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from a reservoir made by patient’s intestine to empty to outside the patient's body, the flow control device comprising: an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command, the reservoir created by: a selected suitable portion from the jejunum or ileum, that has been bent to create a 180° bend where an instrument has made two small holes in the bent area, wherein a stapler instrument with two separate two halves has been introduced through the two small holes in the intestine to clamp the intestines between the two halves of the stapler instrument to be stapled with at least one staple line on each side of the instrument and the two intestinal halves has been cut in between the staple lines to create a larger reservoir, wherein the two small holes in the intestine has been closed with sutures or staplers, and wherein optionally a second intestinal area has been bent to thereby repeat the process at least once as disclosed in this section to increase the size of the reservoir, a control unit, wherein the control unit is configured to execute at least one of a peristaltic type of emptying of the reservoir and to execute a direct massive blow type of emptying of the reservoir, at least one valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, the control unit is configured to at least one of: stimulate the at least first and second electrode when placed on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrodes to be able to execute a stimulation pattern creating a direct massive blow type of emptying of the reservoir, the flow control device further comprising at least one of: at least two electrodes, at least first and second electrode, adapted to be placed with on the reservoir folds of two stapled halves of intestine laying side by side maximum 2 cm distance from each other in one or more grows of the reservoir and adapted to be covered by suturing or stapling together intestine from both halves of the intestine, wherein the control unit is configured to execute a stimulation pattern creating a direct massive blow type of emptying of the reservoir, wherein the control unit is configured to open the valve when the flow control device is emptying the reservoir. According to an embodiment, the control device is configured to empty the reservoir with electrical stimulation simultaneously as the valve is not stimulated and opened. According to an embodiment, the valve at least one of a stimulation, hydraulic, pneumatic, mechanical valve or any combination thereof According to an embodiment, the apparatus comprises a holding device adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side holding the electrodes with maximum 2 cm distance away from each other to allow the massive blow type of stimulation pattern and emptying of the reservoir. According to an embodiment, the control unit is configured to train the intestinal wall when the reservoir is not emptied. According to an embodiment, the control unit is configured to stimulate the muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by the at least two electrodes. According to an embodiment, the control unit is configured to train the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. According to an embodiment, the apparatus comprises at least one sensor configured to sense at least one of a physical parameter of the patient's body and a functional parameter of the apparatus. According to an embodiment, the at least one sensor is configured to sense the physical parameter in the patient's body, comprising sensing at least one of the following physical parameters of the patient: a pressure measured on the outside of the reservoir, a pressure within the patient's intestine, an expansion of the reservoir, and a distension of an intestinal wall of the patient's intestine; and the at least one sensor is configured to sense the functional parameter of the apparatus when implanted, comprising sensing at least one of the following parameters: a pressure against a part of the system such as the valve, an electrical parameter such as voltage, current or energy balance, a position or movement of a movable part of the system, and any stimulation parameter in relation to the system. According to an embodiment, the apparatus is configured to provide a signal when a value for the physical or functional parameter sensed is beyond a predetermined threshold value. According to an embodiment, the apparatus comprises a vibration generation unit for stimulating at least one of the intestine forming the reservoir and the intestine closed by the valve. According to an embodiment, the vibration generating unit is attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing. According to an embodiment, the implantable vibration device (110) comprises an internal controller (CI). According to an embodiment, a internal controller (CI) is configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device. According to an embodiment, the apparatus does not comprise any metallic parts and does not comprise any magnetic parts. According to an embodiment, the vibration generating unit is operated by a piezoelectric motor. According to an embodiment, at least one piezoelectric motor is arranged for driving a pump for pumping fluid to at least one of the valve or for supporting the emptying of the reservoir. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric inchworm motor. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric inertial motor. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric walk-drive motor. According to an embodiment, the piezoelectric motor is a linear piezoelectric motor. According to an embodiment, the linear piezoelectric motor operates with at least one of: a speed in a range of 1 mm / s to 10 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 2 N – 30 N. According to an embodiment, the piezoelectric motor is a rotary piezoelectric motor. According to an embodiment, the rotary piezoelectric motor which operates with at least one of: a rotational speed in a range of 1 mrad / s – 100 mrad / s, and a torque in a range of 100 Nmm – 900 Nmm. According to an embodiment, the at least one piezoelectric motor comprises a piezoelectric ultrasonic motor. According to an embodiment, the piezoelectric ultrasonic motor is a traveling wave ultrasonic motor or a standing wave ultrasonic motor. According to an embodiment, the piezoelectric ultrasonic motor is a rotary piezoelectric ultrasonic motor which operates with at least one of: a rotational speed in a range of 10 mrad / s – 10,000 mrad / s, and a torque in a range of 20 Nmm – 450 Nmm. According to an embodiment, the piezoelectric ultrasonic motor is a linear piezoelectric ultrasonic motor which operates with at least one of: a speed in a range of 4 mm / s – 100 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 0.5 N – 30 N. According to an embodiment, the at least one piezoelectric motor comprises at least one bimorph piezoelectric actuator. According to an embodiment, the at least one piezoelectric motor is a reversible piezoelectric motor. According to an embodiment, the valve is adapted to be placed close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. According to an embodiment, the apparatus is configured to advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. According to an embodiment, the apparatus is configured stimulating the intestine in the reservoir thereby advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. The invention will now be described in more detail in context with some preferred embodiments of the invention as shown in the accompanying drawings. Brief description of the drawings In the following, the invention will be described, by way of example, with reference to the accompanying drawings, in which: Fig.1A and Fig.1B show a surgically modified section of a human intestine forming an intestinal reservoir, Fig.2A and Fig.2B show a plan view and a side view, respectively, of an electrical type pump for emptying the intestinal reservoir shown in Figs.1A and 1B with an electrical stimulation apparatus, Fig.3A and Fig.3B show a side view and a different, cross-sectional side view, respectively, of a variant of the electrical type pump of Figs.2B and 2B, Fig.4A and Fig.4B show a plan view and a side view, respectively, of a mechanical type pump for emptying the intestinal reservoir shown in Figs.1A and 1B, Figs.5A and 5B show a plan view and a side view, respectively, of a hydraulic type pump for emptying the intestinal reservoir of Fig.1B, Fig.6A to Fig.6C show different views of an embodiment of a system for electrically stimulating tissue of a patient’s intestine, Fig.7A and Fig.7B show different views of a further embodiment of a system for electrically stimulating tissue of a patient’s intestine, Fig.8 shows a top view of an even further embodiment of a system for electrically stimulating tissue of a patient’s intestine, Fig.9A to Fig.9D show various examples of electrode arrangements for electrically stimulating muscle tissue of the patient, Fig.10 and Fig.11 illustrate a pulsed signal for electrically stimulating muscle tissue, Fig.12 to Fig.14 are schematic illustrations of systems for treating reflux disease, PIEZOELECTRIC MOTORS AND PUMPS Fig.15 shows, schematically, an embodiment of an inchworm motor, Fig.16 illustrates, schematically, an operation cycle of a piezoelectric inchworm motor, Fig.17 shows, schematically, an embodiment of a piezoelectric inertial motor, Fig.18 shows, schematically, an embodiment of a piezoelectric walk-drive motor, Fig.19 illustrates, schematically, an operation cycle of a piezoelectric walk-drive motor, Fig.20 shows, schematically, a Traveling Wave Ultrasonic Motor (TWUSM), Fig.21 shows, schematically, an embodiment of a Standing Wave Ultrasonic Motor (SWUSM), Fig.22 shows, schematically, an embodiment of a linear ultrasonic motor, Fig.23A to Fig.23C show, schematically, an embodiment of a piezoelectric pump, Fig.24 shows, schematically, an embodiment of a piezoelectric pump in which a diaphragm comprises bellows, Fig.25 shows, schematically, an embodiment of a piezoelectric pump in which a chamber is configured to be connected to a pressure adapter, Fig.26A and Fig.26B show, schematically, an embodiment of a ball valve, Fig.27A and Fig.27B show, schematically, an embodiment of a piezoelectric pump wherein the inlet and outlet comprise static elements acting as nozzles or diffusers, Fig.28 shows, schematically, an embodiment of a piezoelectric pump configured to be operated in a double mode, Fig.29 shows, schematically, an embodiment of a piezoelectric pump comprising at least two portions connected in series, Fig.30 shows, schematically, an embodiment of a piezoelectric pump comprising at least two portions connected in parallel, Fig.31 shows, schematically, an embodiment of a piezoelectric pumping system, IMPLANTABLE VIBRATION DEVICE Fig.32A and Fig.32B schematically shows implantable vibration devices according to the present invention, Fig.33A and Fig.33B illustrate, schematically, implantable vibration devices comprising an eccentric mechanism operated by a motor, Fig.34 shows, schematically, an embodiment of an implantable vibration device comprising a piezoelectric vibration generating unit, EFFECTOR RESPONSE Fig.35A shows an example of a system for affecting an effector response in a patient, Fig.35B to Fig.35E show various examples of electrodes and electrode arrangement, Fig.36A shows an example of a system for affecting an effector response in effector tissue of a patient, Fig.36B to Fig.36F show various examples of electrodes and electrode arrangements, Fig.37A shows an example of a system comprising a sensor device for generating feedback indicative of an effector response, Fig.37B to Fig.37D show various examples of sensor devices, Fig.37E shows an example of a multi-layer PCB, Fig.37F shows an example of a stretchable PCB, and Fig.38 shows an example of a system comprising an inhibition device and a denervation device. E-HEALTH Figs.39A – 39FH show an embodiment and describes various functions of an implantable controller for controlling the implantable medical device. Fig.39G shows an elevated perspective view from the left of a housing unit. Fig.39H shows a plain view from the left of a housing unit. Fig.39I shows an elevated perspective view from the left of a housing unit. Fig.39J shows a plain view from the left of a housing unit. Fig.39K shows a system overview of an external device comprising a housing unit and a display device in wireless communication with an implanted medical device. Fig.39L shows a system having a first and a second remote control. Fig 39LL shows the second remote control comprised in a housing unit. Fig.39M schematically shows a medical implant when implanted in a patient. Fig.39N shows a flow chart for a method for training a medical implant to recognize a voice command, according to some embodiments. Fig.39O shows a flow chart for a method for using voice commands to control a medical implant, according to some embodiments. Fig.39P-T illustrates implantable medical devices and external devices for transferring wireless energy to the implantable medical devices. Fig.39U illustrates an implantable medical device and an external device configured to transmit data using near field magnetic induction. Fig.39V shows a schematic illustration of a system including an implantable medical device having a backup function. Detailed description In the following, a detailed description of embodiments of the invention will be given with reference to the accompanying drawings. The drawings are for illustrational purpose only and are not in any way restricting the scope of the invention. It should be noted that the features having the same reference numerals have the same function. A feature in one embodiment may thus be exchanged for a feature from another embodiment having the same reference numeral unless clearly contradictory. The descriptions of the features having the same reference numerals are thus to be seen as complementing each other in describing the fundamental idea of the feature and thereby showing the feature’s versatility. Restriction of the intestine is to be understood as any operation decreasing a cross-sectional area of the intestine. The restriction may decrease the flow of matter in the intestine or may completely close the intestine such that no matter can pass. Constriction is to be understood as a special way of restricting the intestine, namely a restriction by constriction, e.g. by means of a mechanical or hydraulic constriction device acting on the intestine from its outside and thereby constricting it. A controller is to be understood as any unit capable of controlling at least a part of the system. A controller may include a motor and / or pump or any another operational device for operating at least part of the system. It may be separate from the electrical stimulation device and / or mechanical or hydraulic constriction device and may be adapted to control only the operation thereof. Preferably, a controller includes a CPU which enables the controller to process data. A control signal is to be understood as any signal capable of carrying information and / or electric power such that the electrical stimulation device and / or mechanical or hydraulic constriction device or any other part of the system can be controlled directly or indirectly. Fig.1A shows a reservoir 140 formed from human intestine 70. A plurality of bent portions of the human’s intestine 70 is cut open along the mutual contact lines of laterally adjacent sections thereof. The resulting upper halves and lower halves are interconnected so as to form the walls of the intestinal reservoir 140. At the exit of the intestinal reservoir 140, an exit valve comprising a plurality of valve sections 61, 62, 63 is provided and encloses a non-modified terminate section 80 of the patient’s intestine. The non-modified terminate section 80 is passed through the patient’s abdominal wall and forms a surgically created stoma 170. The non-modified terminate section 80 may likewise lead to the patient’s rectum or anus. The valve sections 61, 62, 63 each comprise an electrical stimulation device adapted to electrically stimulate muscle or neutral tissue of the intestine’s terminate section 80 so as to cause contraction of the terminate section 80 so that flow through the terminate section 80 is prevented. The electrical stimulation in each valve section 61, 62, 63 always occurs for a short time period only so that the respective other, non-stimulated sections have time to recover from a previous constriction so that sufficient blood flow within the intestinal wall is ensured. Since the electric stimulation may cause an undesired effector response somewhere in the patient, it is advantageous to provide means for affecting such effector response, according to the third aspect of the present disclosure, which will be described in more detail below in relation to Fig.35 to Fig.38. The electrical stimulation devices 61, 62, 63 may be combined with a further constriction device, such as of the hydraulic type, e.g. in the form of pressure cuffs, or of the mechanical type. The constriction may correspond to the entry valve 194 provided at the entry of the reservoir 140. The entry valve 194 here has the form of a hydraulic cuff. While the valve sections 61, 62, 63 of the exit valve are provided to normally close the exit of the intestinal reservoir 140 in order to keep intestinal contents inside the reservoir 140, the entry valve 194 is normally open to allow intestinal contents to flow into the reservoir 140. Since the hydraulic constriction device in the form of the entry valve 194194 as well as the electrical stimulation devices 61, 62, 63 each contact the intestinal wall, implantable vibration devices, according to the second aspect of the present disclosure, may advantageously be provided in the respective areas in order to cause vibration of the muscle or neural tissue of the intestinal wall. This will be described in more detail below in relation to Fig.32 to Fig.34. The vibrational forces delivered to the tissue must be sufficiently high for activating at least some of the mechanoreceptors of the muscle tissue in the mechanically or hydraulically constricted and / or electrically stimulated areas. The purpose is to exercise the tissue wall which is in contact with the constriction device so as to stimulate the blood flow and, thereby, increase the tolerance of the tissue for pressure from the implant. The vibrational stimulation of the muscle or neural tissue is adjusted at a low level which is not enough to constrict the intestine. The cuff of the entry valve 194 can be filled with a hydraulic fluid from an artificial hydraulic reservoir 195 so as to completely constrict the intestine 70 in front of the reservoir 140. This way, backflow of intestinal contents into the intestine 70 may effectively be prevented, when emptying of the reservoir is desired. At the same time, the valve sections 61, 62, 63 of the exit valve are opened to allow emptying of the intestinal reservoir 140. This is shown in Fig.1B. A pump for filling the entry valve with the hydraulic fluid from an artificial hydraulic reservoir 195, as well as for withdrawing the hydraulic fluid therefrom, is advantageously a piezoelectric pump, according to the first aspect of the present disclosure, as will be described in more detail below in relation to Fig.23 to Fig.31. In the following, different embodiments of a system for emptying the intestinal reservoir 140 are described. As shown in Fig.2A, the reservoir 140 may be emptied by means of an electrical stimulation type pump comprising an electrical stimulation apparatus with electrode-carrying holding devices 160 which are adapted to electrically stimulate muscle or neural tissue of the intestinal reservoir 140 so as to cause at least partial contraction of the reservoir 140. A second set of electrode-carrying holding devices 161 is arranged on the opposite side of the reservoir 140, as can be seen in Fig.2B. The holding devices 160, 161 have a longitudinal shape so as to span over the reservoir 140. The holding devices 160, 161 may each comprise a row of electrodes arranged along the length thereof and adapted to apply electric pulses to the intestinal wall of the reservoir 140. Alternatively, each holding device may substantially consist of only one longitudinal electrode. Emptying of the reservoir 140 can be activated by the patient by pressing a manually operable actuator which is subcutaneously implanted, e.g., in the patient’s abdominal wall in the form of a switch 14. The switch 14 is connected to a combined energy storage means and controller device 145. Under the control of the device 145, different portions of the intestinal wall of the reservoir 140 are stimulated at different times in a predetermined stimulation pattern by means of the electrodes of the holding devices 160, 161 and, thus, different sections of the intestinal reservoir 140 are constricted by such stimulation. In another embodiment shown in Fig.3A and Fig.3B, the electrode-carrying holding devices 160, 161 are specifically provided for being embedded in folds or invaginations 141 surgically created in the intestinal wall of the reservoir 140. By providing the invaginations 141 in the reservoir 140, the holding devices 160, 161 are substantially surrounded by tissue of the reservoir 140 and, thus, contact area is increased. Stimulation of the reservoir 140 can thus be improved, and fixation of the holding devices 160, 161 is also improved. Again, since the electric stimulation may cause an undesired effector response somewhere in the patient, it is advantageous to provide means for affecting such effector response, according to the third aspect of the present disclosure, as will be described in more detail below in relation to Fig.35 to Fig.38. Likewise, since the holding devices are in contact with the intestinal wall, implantable vibration devices, according to the second aspect of the present disclosure, as will be described in more detail below in relation to Fig.32 to Fig.34, may advantageously be provided in the respective areas. Fig.4A and Fig.4B show an embodiment of a mechanical type pump comprising mechanically acting members in the form of rollers 180, 181 for emptying the reservoir 140. The rollers 180, 181 are arranged on opposite sides of the reservoir 140 and have a length spanning the entire width of the reservoir 140. The rollers are each guided by two tracks 182a, 183a and 182b, 183b, respectively, and are driven by one or two motors. As can be seen from Fig.4B, the tracks have bent end portions 184a, 184b so that the rollers 180, 181 can assume an inactive position in which they do not constrict the reservoir 140. When emptying of the reservoir 140 is desired, the rollers 180, 181 are driven along the tracks in the direction of the arrows, thereby approaching each other and constricting the reservoir 140 and squeeze intestinal contents in the direction towards and out of the exit of the reservoir 140. Again, since the rollers 180, 181 are in contact with the intestinal wall, implantable vibration devices, according to the second aspect of the present disclosure, as will be described in more detail below in relation to Fig.32 to Fig.34, may advantageously be provided, e.g, at lateral sides of the reservoir 140. Preferably, the motor or motors for driving the rollers 180, 181 are piezoelectric motors according to the first aspect of the present disclosure, as will be described in more detail below in relation to Fig.15 to Fig.22. Fig.5A and Fig.5B show an embodiment of a hydraulic type pump comprising a hydraulically acting member 190 adapted to act on the intestinal wall of the reservoir 140 from the outside thereof. The hydraulically acting member 190 is connected to an artificial reservoir 193 supplying the hydraulically acting member 190 with hydraulic fluid. The hydraulically acting member 190 may be tube-like or bag-like so as to accommodate therein the intestinal reservoir 140, as shown in Fig.5B. The hydraulically acting member 190 is divided into a plurality of chambers, wherein a first chamber 191 and a last chamber 194 are connected to the artificial reservoir 193 by hydraulic conduits. The chambers are interconnected via connections 192 which may be simple holes acting as a throttle or may include one or more valves that are preferably automatically controlled. Upon activation of the system by the patient using the subcutaneous actuator 14, emptying of the intestinal reservoir 140 is started by supplying hydraulic fluid from the artificial reservoir 193 to the first chamber 191. The next following chambers are supplied with the hydraulic fluid through the connections 192, thereby causing the hydraulically acting member 190 to be filled slowly from the first chamber 191 to the last chamber 194. The filling of the chambers occurs sequentially, with the next following chamber starting to fill before the foregoing chamber is filled completely. In this manner, intestinal contents are hydraulically squeezed out in the direction towards the exit of the reservoir 140. When the hydraulically acting member 190 is completely filled with hydraulic fluid, the reservoir 140 is completely constricted. The hydraulic fluid is then withdrawn from the chambers of the hydraulically acting member 190 back into the artificial reservoir 193 using negative pressure. The intestinal reservoir 140 may then start to fill up with intestinal contents again. In another embodiment, each chamber of the hydraulically acting member 190 may have separate fluid connection to the artificial reservoir 193 in order to be able to be filled individually. The intestinal reservoir 140 may be emptied by consecutively filling two adjacent chambers of the hydraulically acting member 190, i.e. first filling the first and second chamber, then emptying the first chamber while filling the third chamber, then emptying the second chamber while filling the fourth chamber, and so forth. In this manner intestinal contents are squeezed towards and out of the exit of the intestinal reservoir 140. Connected to or integrally formed with the artificial reservoir 193 is an electrically driven pump (not shown) for pumping the hydraulic fluid into and withdrawing the hydraulic fluid from the hydraulically acting member. The electrically driven pump is supplied with energy from the combined energy storage means and control device 145. Preferably, the pump comprises a piezoelectric pump or, alternatively, a motor for driving the pump comprises a piezoelectric motor, according to the first aspect of the present disclosure, as will be described in more detail below in relation to Fig.15 to Fig.31. Fig.6A shows a top view of another embodiment of a system for treating a patient having a disorder related to a patient’s intestine 100. Again, a reservoir section of the intestine 100 is formed from surgically modified intestine that has been cut along a mutual contact line of laterally adjacent sections of a bent portion of intestine and connected so that the upper and lower halves of the cut intestine form an intestinal wall of the reservoir section. The connection lines are sewn together by sutures 101. The system involves electrical stimulation by a plurality of wirelessly activated electrical stimulation devices 10 which, in the embodiment shown, each comprise seven electrodes 11. The electrodes 11 are interconnected by an electrical wire 12, which means that those electrodes 11 are energized simultaneously when a voltage is applied to the wire 12. Each one of the electrical stimulation devices 10 further comprises a wireless energy receiver R configured to receive energy for wirelessly stimulating the muscle or neural tissue of the intestine 100. Thus, the electrical stimulation devices 100 are not physically interconnected but are independent from each other. As can be seen from the side view shown in Fig.6B, the electrical stimulation device 10 includes two branches 10A, 10B which share a common wireless energy receiver R. As can be seen in a different view shown in Fig.6C, the electrodes 11 may be arranged in surgically created folds 102, either with or without the electrical wire 12. Alternatively, the electrodes 11 and / or the electrical wire 12 may be attached to an outside wall 103 of the intestine 100, as shown in Fig.6B, or may be implanted in the wall 103 (not shown). In the embodiment shown in Figs.7A to 7C, a wireless energy transmitter T is provided for each one of the respective wireless energy receivers R. Thus, energy is transmitted wirelessly to the electrical stimulation devices 10, which makes the electrical stimulation devices 10 relatively independent not only from each other but also from the remaining part of the overall system. This way, the electrical stimulation devices 10 remain rather flexible over time since the danger of decreased flexibility due to fibrosis growing over and encapsulating the system is minimized. This applies not only to an intestinal reservoir as modified and shown in e.g. Fig.6A to Fig.6C, but also to regular intestines to which the systems as disclosed herein are likewise applicable. Energy transfer between the wireless energy transmitters T and the wireless energy receivers R is preferably carried out via cooperating antennas, such as a primary coil on each of the transmitters T and a secondary coil on each of the receivers R, wherein the primary coils are configured to induce a voltage in the associated secondary coil, for which reason the wireless energy transmitters and receivers should be arranged close to each other, when implanted. The primary and secondary coils of the wireless transmitters T and receivers R allow for using RFID technology to transfer the energy from the energy transmitter to the energy receiver. This technology is well established. In particular, the wireless energy receivers R may be configured to receive the energy via RFID pulses. In turn, the wireless energy transmitters T do not necessarily need to maintain flexibility over time and, therefore, they are each connected to a controller via electric wiring 13. The controller referenced with CE represents an “external” controller, as compared to an internal controller which may make part of the electrical stimulation devices 10, as will be described herein after. More specifically, the external controller CE is an implanted external controller. Here, implantation is under the skin such that it can be actuated manually by means of a switch 14, which may have the form of a press button. In particular, the switch 14 may be implanted under the skin, as shown in Fig.6A, or may be provided on the patient’s skin outside the patient’s body. Furthermore, an energy storage unit E, which is rechargeable, is connected to the external controller CEso as to provide energy to the wireless energy transmitters T when controlled accordingly by the external controller CE. The energy storage unit is rechargeable wirelessly through the patient’s skin 200, as indicated in Fig.6A by an arrow. Accordingly, when the system is implanted and used by a patient or by a care person, one may actuate the switch 14 implanted underneath the skin 200 by pressing thereon, which initiates the controller CE so as to run a program installed in a CPU of the external controller CE. According to such program, the external controller CEwill release energy from the energy storage unit E sequentially to the electrical stimulation devices 10. Consequently, different parts of the intestine 100 are electrically stimulated at different times so that they contract and, thereby, restrict the volume inside the intestine 100. This way, intestinal contents contained inside the intestine 100 may be urged further and further through the intestine 100 towards an end of the intestine 100. At the end of the program, energy transfer between the wireless energy transmitters T and receivers R is terminated so that the neural and muscle tissue of the intestine 100 may relax. Of course, the running of the program in the external controller CEcan be interrupted at any time by actuating the switch 14 once again, if desired. The system may hence be operable to deliver a stimulation signal to a plurality of stimulation sites along the gastrointestinal tract, such as the small intestine, the large intestine, and to various sites on any reservoir 140. The stimulation sites may be separated from each other, i.e., spaced apart, in a flow direction of the intestinal content. In different words, the stimulation sites may be distributed along a part or, or an entire length of, the gastrointestinal tract. The spacing may be selected based on a wavelength of a wave pattern caused by a movement of the smooth muscles, or by a multiple of such a wavelength. Beneficially, this may allow for the stimulation to be applied in a way that amplifies the natural movement of the walls of the intestines, or counteracts the same, depending on the timing or phase of the applied signals. A typical wavelength of the peristalsis, i.e., the distance between two consecutive peaks of the wave-like muscle contractions that move food along the gastrointestinal tract, varies with the location and function of the organ involved. For example, in the esophagus of a typical, healthy individual, the wavelength is typically about 15 cm and the wave speed about 3 cm / s. In the small intestine, the wavelength is about 10 cm and the wave speed about 0.5 cm / s. In the large intestine, the wavelength is typically about 20 cm and the wave speed is about 0.2 cm / s. Exemplary spacings of the applications points for the stimulation signal may hence be about 10 cm for the small intestine, such as 2-18 cm, such as 6-14 cm, such as 8-12 cm, or multiples thereof. For the large intestine, exemplary spacings between the points in which the stimulation signal is applied may include about 20 cm, such as 10-30 cm, such as 14-26 cm, such as 18-22 cm, or multiples thereof. In some examples, the stimulation signals are applied in pulses, or pulse trains, wherein a frequency of such pulses or pulse trains is determined based on a frequency of the wave pattern of the movement of the smooth muscles The stimulation signal may hence be delivered in a pulsed manner, in which the system is switched between an OFF state and an ON state. In the OFF state, no stimulation signal (or a stimulation signal with a very low, negligible intensity) is delivered to the tissue. This may be referred to as a ‘silent’ period. In the ON state, the stimulation signal is delivered to induce a response in the tissue. The signal delivered in the ON state may comprise a series of pulses with a frequency selected to induce a response in the smooth muscle tissue. The frequency may, for example, be less than 1 Hz, such as 0.01-0.1 Hz, or a few Hz. The pacing of the ON and OFF states, as well as the separation between consecutive ON and OFF states (i.e., the silent period), may thus be determined based on a frequency of the wave pattern in the smooth muscle tissue. This wave pattern may be the result of a natural movement of the smooth muscle tissue, or a movement induced or controlled by the applied stimulation. The stimulation may be applied to induce contraction of a smooth muscle when the muscle is about to contract according to the wave pattern, and / or induce relaxation in the smooth muscle when the muscle is about to relax according to the wave pattern. In different words, the length of the silent periods may be selected to match a time between consecutive peaks of the wave movement of the smooth muscle tissue. With the wavelength and wave speed examples above, the stimulation signal may be pulsed with silent periods of about 20 s for the small intestine, such as 10-30 s, such as 14-26 s, such as 18-22 s. For the large intestine, the stimulation signal may be pulsed with silent periods of about 100 s, such as 40-160 s, such as 60-140 s, such as 80-120 s. The pulse length, or pulse duration, may be varied based on the strength or intensity of the stimulation signal. Typically, the pulse duration may be in the order of milliseconds, such as the range of 0.01-100 milliseconds, or 100-1000 ms, or in the order of seconds, such as a few seconds. Fig.7A and Fig.7B show a further embodiment of a system for electrically stimulating tissue of a patient’s intestine by means of wirelessly activated electrical stimulation devices 10, in a top view and a side view, respectively. This embodiment differs from the embodiment shown in Fig.6A to Fig.6C in that a single wireless energy transmitter T is provided to transmit energy to all of the electrical stimulation devices 10. Since it is not desired to energize all electrical stimulation devices 10 at the same time, there is further provided an internal controller CIin each electrical stimulation device 10. The internal controller CIcontrols a switch 17 which interrupts and closes, respectively, an electrical connection between the associated wireless energy receiver R and the electrode or electrodes 11 of the respective electrical stimulation device 10. Thus, the wireless energy transmitter T is adapted to not only transmit energy but also data to the wireless energy receiver R, which is likewise adapted not only to receive energy wirelessly but also data. For this purpose, an RFID technology is particularly suitable, because an RFID signal may be used to transport both energy and information, as is well known in the art. The transfer of energy, on the one hand, and data, on the other hand, between the wireless energy transmitters T and receivers R is indicated by respectively different arrows in Fig.6A and Fig.6B. More specifically, the internal controller CI of each of the plurality of electrical stimulation devices 10 may be addressed individually by the external controller CI(or by a remote controller as will be described hereinafter) using an individual code which is specific to the respective internal controller CI. In the situation where the electrical stimulation devices are to be actuated sequentially in order to stimulate the intestine in a wave-like manner, the respective electrical stimulation device may be addressed individually using the individual code of the corresponding internal controller CI. Accordingly, the wireless energy transmitter T may comprise a single primary coil extending over the entirety of the secondary coils in the wireless energy receivers R of all of the electrical stimulation devices 10. Even further embodiments of a system for electrically stimulating tissue of a patient’s intestine by means of wirelessly activated electrical stimulation devices 10 are described in WO 2023 / 031066 A1. Again, since the electric stimulation may cause an undesired effector response somewhere in the patient, it is advantageous to provide means for affecting such effector response, according to the third aspect of the present disclosure, as will be described in more detail below in relation to Fig.35 to Fig.38. Likewise, since the electrodes 10 are in contact with the intestinal wall, implantable vibration devices, according to the second aspect of the present disclosure, as will be described in more detail below in relation to Fig.32 to Fig.34, may advantageously be provided in the respective areas. The systems for electrically stimulating tissue of a patient’s intestine by means of wirelessly activated electrical stimulation devices 10, as described above, may be combined with a mechanical or hydraulic constriction device shown in Fig.4A to Fig.5B. Particularly suitable is the hydraulic constriction device as shown in Fig.5A and Fig 5B or any other hydraulic constriction device because hydraulic forces can be easily controlled in a patient. Likewise, they may be implemented in valves for temporarily restricting or even closing an intestinal passageway with or without an additional constriction device, such as a hydraulic constriction device. In other words, a system as described above including a wirelessly controllable electrical stimulation device may be used in a valve, such as an artificial sphincter. Such valve or artificial sphincter may be used as an exit valve and / or as an entry valve of an intestinal reservoir, such as the reservoir made from the patient’s intestine as described above or an artificial reservoir. This is further described in relation to the embodiment as shown in Fig.8. This embodiment differs from the third embodiment shown in Fig.7A in that an exit valve 40 about the patient’s colon or rectum or next to a stoma and an entry valve 30 upstream thereof are provided. While both the exit valve 40 and the entry valve 30 are shown in an open configuration in Fig.8, usually one of the two valves is closed while the other one is open. The respectively closed state can be achieved by electrically stimulating the neural or muscle tissue of the intestine 100 adjacent the electrode 11 of the corresponding electrical stimulation device 10. The electrical stimulation device 10 of the exit valve 40 comprises a wireless energy transmitter TEXoverlying the wireless energy receiver R of that electrical stimulation device 10, whereas the electrical stimulation device 10 of the entry valve 30 comprises a wireless energy transmitter TENoverlying the associated wireless energy receiver R. Both the wireless energy transmitters TEX and TEN are controlled by the external controller CE in the same way as described before. Thus, stimulation of the respective sections of the intestine 100 may be achieved by transmitting energy from the energy storage unit E to the wireless energy receiver R via the wireless energy transmitters TEX and TEN, respectively, using the external controller CE. In addition to the electrical stimulation device 10, both the exit valve 40 and entry valve 30 comprise a hydraulic constriction device, which may likewise be controlled by the external controller CE so as to coordinate electrical stimulation with hydraulic constriction. The hydraulic constriction device comprises a hollow hydraulic member 41 and 31, respectively, a hydraulic pump P and an energy storage unit E, which may be the same energy storage unit which supplies energy to the electrical stimulation devices 10. In particular, a single energy storage device E may be provided for the entire system. The hydraulic pump P is configured to pump a hydraulic fluid into and withdraw the hydraulic fluid from the interior of the hollow hydraulic members 41 and 31, respectively. Of course, instead of a hydraulic constriction device, the exit valve 40 and / or entry valve 30 may comprise a mechanical constriction device serving the same purpose. In those embodiments of the present disclosure where the system comprises a mechanical or hydraulic constriction device and where the system is configured to electrically stimulate, by means of one or more electrodes, the muscle or neural tissue in an area of the intestine constricted by the mechanical or hydraulic constriction device, such electrical stimulation may be limited to merely increase the blood flow through the tissue of the intestine without causing the intestine to contract or, if at all, contract only partly without completely restricting flow through the respective intestinal section. The purpose thereof is to exercise the tissue wall which is in contact with the constriction device, may it be mechanical or hydraulic to stimulate blood flow and, thereby, increase the tolerance of the tissue for pressure from the implant. SURGICAL METHODS OF FORMING THE RESERVOIR In the following, various examples of how to surgically form the reservoir as outlined above in connection with figures 1-8 will be discussed. Hence, according to an embodiment, there is provided laparoscopic surgical methods and surgical methods of treating a patient. The laparoscopic surgical method of treating a patient, comprises the steps of: introducing at least one of; a needle, a trocar, a tube, a tubular instrument and a surgical instrument, through the fascia of at least one of any muscles or any fibrotic intersections comprising; the rectus abdominalis, transversus abdominalis, the External Oblique, the Internal Oblique, any Serratus or any pyramidalis, the linea alba, a tendnous intersection, and the umbilicus, blowing in pressurized gas through the needle or trocar or surgical instrument or any device inflating the abdominal cavity, introducing working instruments comprising the steps of: inserting at least one first trocar into the abdominal cavity, introducing at least one camera through the trocar, inserting at least a second trocar into the abdominal cavity, inserting at least one instrument preferably through the second trocar, inserting at least a third trocar into the abdominal cavity, and inserting at least one second instrument preferably through the third trocar; the method further comprising: dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing a control device in the body for controlling the flow control device, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, camera and trocar, and, in relation thereto suturing, if necessary, the abdominal wall and permanently closing the skin. The laparoscopic surgical may further comprise placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. The laparoscopic surgical method may further comprise, fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. The laparoscopic surgical method may further comprise placing at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. The laparoscopic surgical method may further comprise placing a holding device configured to hold at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. The laparoscopic surgical method may further comprise transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. The laparoscopic surgical method may further comprise stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. The laparoscopic surgical method may further comprise stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. The laparoscopic surgical method further comprises stimulating the electrodes on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir. The laparoscopic surgical method may further comprise training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. The laparoscopic surgical method may further comprise training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. There is also provided a surgical method of treating a patient, which may be used to surgically form the reservoir as outlined above in connection with figures 1-8. The surgical method comprises the steps of: cutting the patient's skin and abdominal wall, dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a control device in the body, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, and in relation thereto, suturing, the abdominal wall and closing the skin The surgical method may further comprises placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions: close to anus or close to a stoma opening. The surgical method may further comprise fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. According to an embodiment, the surgical method further comprises placing at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. The surgical method may further comprise placing a holding device configured to hold at least two electrodes on the reservoir folds with at least 2 cm distance from each other to be able to execute a peristaltic type of emptying of the reservoir. The surgical method may further comprise transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. The surgical method may further comprise stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. The surgical method may further comprise stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. The surgical method may further comprise stimulating the electrodes on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir. The surgical method may further comprise training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. The surgical method may further comprise training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. There is further provided a laparoscopic surgical method of treating a patient, which may be used to surgically form the reservoir as outlined above in connection with figures 1-8. The laparoscopic surgical method comprising the steps of: introducing at least one of; a needle, a trocar, a tube, a tubular instrument and a surgical instrument, through the fascia of at least one of any muscles or any fibrotic intersections comprising; the rectus abdominalis, transversus abdominalis, the External Oblique, the Internal Oblique, any Serratus or any pyramidalis, the linea alba, a tendnous intersection, and the umbilicus, blowing in pressurized gas through the needle or trocar or surgical instrument or any device inflating the abdominal cavity, introducing working instruments comprising the steps of: inserting at least one first trocar into the abdominal cavity, introducing at least one camera through the trocar, inserting at least a second trocar into the abdominal cavity, inserting at least one instrument preferably through the second trocar, inserting at least a third trocar into the abdominal cavity, and inserting at least one second instrument preferably through the third trocar; dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing a control device in the body for controlling the flow control device, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, camera and trocar, and in relation thereto suturing, if necessary, the abdominal wall and permanently closing the skin The laparoscopic surgical method may further comprise placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. The laparoscopic surgical method may further comprise fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. The laparoscopic surgical method may further comprise placing at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. The laparoscopic surgical method may further comprise placing a holding device configured to hold at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. The laparoscopic surgical method may further comprise transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. The laparoscopic surgical method may further comprise stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. The laparoscopic surgical method may further comprise stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. The laparoscopic surgical method may further comprise stimulating the electrodes on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrode to be able to execute a direct massive blow type of emptying of the reservoir. The laparoscopic surgical method may further comprise training the intestinal wall at a different time point at the position of the valve by stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. The laparoscopic surgical method may further comprise training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training. There is further provided a surgical method of treating a patient, which may be used to surgically form the reservoir as outlined above in connection with figures 1-8. The surgical method comprises the steps of: cutting the patient's skin and abdominal wall, dissecting an area of the jejunum or ileum, identifying a suitable portion for creating a reservoir from the jejunum or ileum, bending the portion of the jejunum or ileum creating a 180° bend, using one of the first and second instrument making two small holes in the bent area, introducing a stapler instrument into the abdomen, separating the two halves of the stapler instrument, introducing the two halves of the stapler instrument through the two small holes in the intestine, clamping the intestine between the two halves of the stapler instrument, stapling the two intestinal halves together with at least one staple line on each side of the instrument, cutting the two intestinal halves in between the staple lines, closing the two small holes in the intestine with sutures or staplers, optionally bending a second intestinal area and repeating the process at least once as disclosed in the previous 8 points to increase the size of the reservoir, implanting a flow control device so as to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from the reservoir to outside the patient's body, placing as part of the flow control device at least one electrode in one or more grows of two stapled halves of intestine laying side by side, covering the electrode by suturing or stapling together intestine from both halves of intestine, placing a control device in the body, placing a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir, placing at least one of a stimulation, hydraulic, pneumatic or mechanical valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, extracting the instruments, and in relation thereto, suturing, the abdominal wall and closing the skin. According to an embodiment, the surgical method further comprises placing the valve close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. The surgical method may further comprise fixating the device or intestine close to the device to pelvic bone, pelvic ligaments, muscle, fascia, bone, abdominal or pelvic wall, anal soft tissue. The surgical method may further comprise placing at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. The surgical method may further comprise placing a holding device configured to hold at least two electrodes on the reservoir folds with maximum 2 cm distance from each other to be able to execute a direct massive blow type of emptying of the reservoir. The surgical method may further comprise transporting the power to the electrodes wirelessly or by wire from the control unit to the electrodes. The surgical method may further comprise stimulating by one or more electrical devices of the flow control device that form an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. The surgical method may further comprise stimulating by the control device by the control device electrical stimulation to empty the reservoir via the at least one electrode simultaneously as the valve is opened. The surgical method may further comprise stimulating the electrodes on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrode to be able to execute a direct massive blow type of emptying of the reservoir. The surgical method may further comprise training the intestinal wall at a different time point at the position of the valve by, stimulating muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by at least two electrodes. The surgical method may further comprise training the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. Further, there is provided an apparatus for treating a patient, the apparatus may be comprise any of the flow control devices described herein. The apparatus comprising: a flow control device adapted to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from a reservoir made by patients intestine to empty to outside the patient's body, the flow control device comprising: an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command, the reservoir created by: a selected suitable portion from the jejunum or ileum, that has been bent to create a 180° bend where an instrument has made two small holes in the bent area, wherein a stapler instrument with two separate two halves has been introduced through the two small holes in the intestine to clamp the intestines between the two halves of the stapler instrument to be stapled with at least one staple line on each side of the instrument and the two intestinal halves has been cut in between the staple lines to create a larger reservoir, wherein the two small holes in the intestine has been closed with sutures or staplers, and wherein optionally a second intestinal area has been bent to thereby repeat the process at least once as disclosed in this section to increase the size of the reservoir, a control unit, wherein the control unit is configured to execute at least one of a peristaltic type of emptying of the reservoir, at least one valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body, the control unit is configured to: stimulate the at least first and second electrode when placed on the reservoir folds with at least 1 second time in between the stimulation of the at least first and second electrode to be able to execute a peristaltic type of emptying of the reservoir, the flow control device further comprising: at least two electrodes, at least first and second electrode, adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side at least 2 cm distance away from each other in one or more grows of the reservoir and adapted to be covered by suturing or stapling together intestine from both halves of the intestine, wherein the control unit is configured to execute a stimulation pattern creating a peristaltic type of emptying of the reservoir, wherein the control unit is configured to open the valve when the flow control device is emptying the reservoir. The control device may be configured to empty the reservoir with electrical stimulation simultaneously as the valve is not stimulated and opened. The valve may comprise at least one of a stimulation, hydraulic, pneumatic, mechanical valve or any combination thereof. The apparatus may comprise a holding device adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side holding the electrodes with at least 2 cm distance away from each other to allow the peristaltic type of stimulation pattern and emptying of the reservoir. The control unit may be configured to train the intestinal wall when the reservoir is not emptied. The control unit may be configured to stimulate the muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by the at least two electrodes. In some examples, the control unit is configured to train the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. The apparatus may further comprise at least one sensor, configured to sense at least one of a physical parameter of the patient's body and a functional parameter of the apparatus. The at least one sensor may be configured to sense the physical parameter in the patient's body, comprising sensing at least one of the following physical parameters of the patient: a pressure measured on the outside of the reservoir, a pressure within the patient's intestine, an expansion of the reservoir, and a distension of an intestinal wall of the patient's intestine; and the at least one sensor is configured to sense the functional parameter of the apparatus when implanted, comprising sensing at least one of the following parameters: a pressure against a part of the system such as the valve, an electrical parameter such as voltage, current or energy balance, a position or movement of a movable part of the system, and any stimulation parameter in relation to the system. The apparatus may be configured to provide a signal when a value for the physical or functional parameter sensed is beyond a predetermined threshold value. The apparatus may comprise a vibration generation unit for stimulating at least one of the intestinal portions forming the reservoir and the intestine closed by the valve. The vibration generating unit may be attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing. In some examples, the implantable vibration device (110) comprises an internal controller (CI). The internal controller (CI) may be configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device. The vibration generating unit may be operated by a piezoelectric motor. The apparatus does, in some examples, not comprise any metallic parts and does not comprise any magnetic parts. In some examples, at least one piezoelectric motor is arranged for driving a pump for pumping fluid to at least one of the valve or for supporting the emptying of the reservoir. The at least one piezoelectric motor may comprise a piezoelectric inchworm motor. The at least one piezoelectric motor may comprise a piezoelectric inertial motor. The at least one piezoelectric motor may comprise a piezoelectric walk-drive motor. The piezoelectric motor may be a linear piezoelectric motor. The linear piezoelectric motor may, for example, operate with at least one of: a speed in a range of 1 mm / s to 10 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 2 N – 30 N. The piezoelectric motor may be a rotary piezoelectric motor. The rotary piezoelectric motor may operates with at least one of: a rotational speed in a range of 1 mrad / s – 100 mrad / s, and a torque in a range of 100 Nmm – 900 Nmm. The at least one piezoelectric motor may comprise a piezoelectric ultrasonic motor. The piezoelectric ultrasonic motor may be a traveling wave ultrasonic motor or a standing wave ultrasonic motor. The piezoelectric ultrasonic motor may be a rotary piezoelectric ultrasonic motor which operates with at least one of: a rotational speed in a range of 10 mrad / s – 10,000 mrad / s, and a torque in a range of 20 Nmm – 450 Nmm. The piezoelectric ultrasonic motor may be a linear piezoelectric ultrasonic motor which operates with at least one of: a speed in a range of 4 mm / s – 100 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 0.5 N – 30 N. The at least one piezoelectric motor may comprise at least one bimorph piezoelectric actuator. The at least one piezoelectric motor may be a reversible piezoelectric motor. The valve may be adapted to be placed close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. The apparatus may be configured to: advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. The apparatus may be configured to: stimulating the intestine in the reservoir thereby advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. Further, there is provided an apparatus for treating a patient, the apparatus may comprise any of the flow control devices described herein. The apparatus may be combined with any of the systems and devices described with reference to sub-aspects one through eight. The apparatus may comprise a flow control device adapted to permanently reside inside the patient's body and be adapted to control flow of intestinal contents from a reservoir made by patient’s intestine to empty to outside the patient's body. The flow control device may comprise an electrical stimulation type pump advancing intestinal contents through the patient’s intestine in a downstream direction on patient command. The reservoir may be created by a selected suitable portion from the jejunum or ileum, that has been bent to create a 180° bend where an instrument has made two small holes in the bent area, wherein a stapler instrument with two separate two halves has been introduced through the two small holes in the intestine to clamp the intestines between the two halves of the stapler instrument to be stapled with at least one staple line on each side of the instrument and the two intestinal halves has been cut in between the staple lines to create a larger reservoir, wherein the two small holes in the intestine has been closed with sutures or staplers, and wherein optionally a second intestinal area has been bent to thereby repeat the process at least once as disclosed in this section to increase the size of the reservoir. The apparatus may further comprise a control unit, wherein the control unit is configured to execute at least one of a peristaltic type of emptying of the reservoir and to execute a direct massive blow type of emptying of the reservoir, and at least one valve for opening and closing the intestine to control flow of intestinal contents from the reservoir through the intestine out from the body. The control unit may be configured to at least one of: stimulate the at least first and second electrode when placed on the reservoir folds with maximum 1 second time in between the stimulation of the at least first and second electrodes to be able to execute a stimulation pattern creating a direct massive blow type of emptying of the reservoir. The flow control device may further comprise at least one of: at least two electrodes, at least first and second electrode, adapted to be placed with on the reservoir folds of two stapled halves of intestine laying side by side maximum 2 cm distance from each other in one or more grows of the reservoir and adapted to be covered by suturing or stapling together intestine from both halves of the intestine, wherein the control unit is configured to execute a stimulation pattern creating a direct massive blow type of emptying of the reservoir, wherein the control unit is configured to open the valve when the flow control device is emptying the reservoir. The control device may be configured to empty the reservoir with electrical stimulation simultaneously as the valve is not stimulated and opened. The valve may comprise at least one of a stimulation, hydraulic, pneumatic, mechanical valve or any combination thereof The apparatus may comprise a holding device adapted to be placed on the reservoir folds of two stapled halves of intestine laying side by side holding the electrodes with maximum 2 cm distance away from each other to allow the massive blow type of stimulation pattern and emptying of the reservoir. The control unit may be configured to train the intestinal wall when the reservoir is not emptied. The control unit may be configured to stimulate the muscle or neural tissue of the intestine in a peristaltic way in the opposite direction of intestinal flow by the at least two electrodes. In some examples, the control unit is configured to train the intestinal muscle wall to an extent, that together with the valve that may be slightly released, constricting the intestine to hinder intestinal contents flowing through the patient’s intestine in a downstream direction during the training execution. The apparatus may further comprise at least one sensor configured to sense at least one of a physical parameter of the patient's body and a functional parameter of the apparatus. The at least one sensor may be configured to sense the physical parameter in the patient's body, comprising sensing at least one of the following physical parameters of the patient: a pressure measured on the outside of the reservoir, a pressure within the patient's intestine, an expansion of the reservoir, and a distension of an intestinal wall of the patient's intestine; and the at least one sensor is configured to sense the functional parameter of the apparatus when implanted, comprising sensing at least one of the following parameters: a pressure against a part of the system such as the valve, an electrical parameter such as voltage, current or energy balance, a position or movement of a movable part of the system, and any stimulation parameter in relation to the system. The apparatus may be configured to provide a signal when a value for the physical or functional parameter sensed is beyond a predetermined threshold value. The apparatus may comprise a vibration generation unit for stimulating at least one of the intestine forming the reservoir and the intestine closed by the valve. The vibration generating unit may be attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing. The implantable vibration device (110) comprises an internal controller (CI). The internal controller (CI) may be configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device. The apparatus, in some examples, does not comprise any metallic parts and does not comprise any magnetic parts. The vibration generating unit may be operated by a piezoelectric motor. In some examples, at least one piezoelectric motor is arranged for driving a pump for pumping fluid to at least one of the valve or for supporting the emptying of the reservoir. The at least one piezoelectric motor may comprise a piezoelectric inchworm motor. The at least one piezoelectric motor may comprise a piezoelectric inertial motor. The at least one piezoelectric motor may comprise a piezoelectric walk-drive motor. The piezoelectric motor may a linear piezoelectric motor. The linear piezoelectric motor may operate with at least one of: a speed in a range of 1 mm / s to 10 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 2 N – 30 N. The piezoelectric motor may be a rotary piezoelectric motor. The rotary piezoelectric motor may operate with at least one of: a rotational speed in a range of 1 mrad / s – 100 mrad / s, and a torque in a range of 100 Nmm – 900 Nmm. The at least one piezoelectric motor may comprise a piezoelectric ultrasonic motor. The piezoelectric ultrasonic motor may be a traveling wave ultrasonic motor or a standing wave ultrasonic motor. The piezoelectric ultrasonic motor may be a rotary piezoelectric ultrasonic motor which operates with at least one of: a rotational speed in a range of 10 mrad / s – 10,000 mrad / s, and a torque in a range of 20 Nmm – 450 Nmm. The piezoelectric ultrasonic motor may be a linear piezoelectric ultrasonic motor which operates with at least one of: a speed in a range of 4 mm / s – 100 mm / s, a stroke length in a range of 4 mm – 30 mm, and a force in a range of 0.5 N – 30 N. The at least one piezoelectric motor may comprise at least one bimorph piezoelectric actuator. The at least one piezoelectric motor may comprise a reversible piezoelectric motor. The valve may be adapted to be placed close to the outlet of the intestine distal of the reservoir out from the body in one of the following positions; close to anus or close to a stoma opening. The apparatus may be configured to advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. The apparatus may be configured stimulating the intestine in the reservoir thereby advancing intestinal contents from the reservoir through the patient’s intestine in a downstream direction on patient command to defecate, and opening the valve placed close to anus or stoma before executing the emptying. ELECTRICAL STIMULATION / ELECTRODES The arrangement of the electrodes as described hereinafter may be implemented in any of the embodiments of the present disclosure, in particular also for the purpose of exercising a tissue wall of the intestine which is in contact with a constriction device, such as a mechanical or hydraulic constriction device. Muscle tissue is generally formed of muscle cells that are joined together in tissue that can either be striated or smooth, depending on the presence or absence, respectively, of organized, regularly repeated arrangements of myofibrillar contractile proteins called myofilaments. Striated muscle tissue is further classified as either skeletal or cardiac muscle tissue. Skeletal muscle tissue is typically subject to conscious control and anchored by tendons to bone. Cardiac muscle tissue is typically found in the heart and not subject to voluntary control. A third type of muscle tissue is the so-called smooth muscle tissue, which is typically neither striated in structure nor under voluntary control. Smooth muscle tissue makes up the muscular part of the walls of the digestive tract and ducts, including the intestinal tract. The contraction of the muscle tissue may be activated both through the interaction of the nervous system as well as by hormones. The different muscle tissue types may vary in their response to neurotransmitters and endocrine substances depending on muscle type and the exact location of the muscle. A nerve is an enclosed bundle of nerve fibers called axons, which are extensions of individual nerve cells or neurons. The axons are electrically excitable, due to maintenance of voltage gradients across their membranes, and provide a common pathway for the electrochemical nerve impulses called action potentials. An action potential is an all-or-nothing electrochemical pulse generated by the axon if the voltage across the membrane changes by a large enough amount over a short interval. The action potentials travel from one neuron to another by crossing a synapse, where the message is converted from electrical to chemical and then back to electrical. The distal terminations of an axon are called axon terminals and comprise synaptic vesicles storing neurotransmitters. The axonal terminals are specialized to release the neurotransmitters into an interface or junction between the axon and the muscle cell. The released neurotransmitter binds to a receptor on the cell membrane of the muscle cell for a short period of time before it is dissociated and hydrolyzed by an enzyme located in the synapse. This enzyme quickly reduces the stimulus to the muscle, which allows the degree and timing of muscular contraction to be regulated carefully. The action potential in a normal skeletal muscle cell is similar to the action potential in neurons and is typically about -90 mV. Upon activation, the intrinsic sodium / potassium channel of the cell membrane is opened, causing sodium to rush in and potassium to trickle out. As a result, the cell membrane reverses polarity and its voltage quickly jumps from the resting membrane potential of -90 mV to as high as +75 mV as sodium enters. The muscle action potential lasts roughly 2 to 4 ms, the absolute refractory period is roughly 1 to 3 ms, and the conduction velocity along the muscle is roughly 5 m / s. This change in polarity causes in turn the muscle cell to contract. The contractile activity of smooth muscle cells is typically influenced by multiple inputs such as spontaneous electrical activity, neural and hormonal inputs, local changes in chemical composition, and stretch. This in contrast to the contractile activity of skeletal and cardiac muscle cells, which may rely on a single neural input. Some types of smooth muscle cells are able to generate their own action potentials spontaneously, which usually occurs following a pacemaker potential or a slow wave potential. However, the rate and strength of the contractions can be modulated by external input from the autonomic nervous system. Autonomic neurons may comprise a series of axon-like swellings, called varicosities, forming motor units through the smooth muscle tissue. The varicosities comprise vesicles with neurotransmitters for transmitting the signal to the muscle cell. The muscle cells are known to react to external stimuli, such as electrical stimuli applied by electrodes. A distinction can be made between stimulation transmitted by a nerve and direct electrical stimulation of the muscle tissue. In case of stimulation via a nerve, an electrical signal may be provided to the nerve at a location distant from the actual muscle tissue, or at the muscle tissue, depending on the accessibility and extension of the nerve in the body. In case of direct stimulation of the muscle tissue, the electrical signal may be provided to the muscle cells by an electrode arranged in direct or close contact with the cells. However, other tissue such as fibrous tissue and nerves may of course be present at the interface between the electrode and the muscle tissue, which may result in the other tissue being subject to the electrical stimulation as well. In the context of the present application, the electrical stimulation discussed in connection with the various aspects and embodiments may be provided to the tissue in direct or indirect contact with the implantable constriction device. Preferably, the electrical stimulation is provided by one or several electrode elements arranged on or in the tissue or at the interface or contact surface between an implantable constriction device and the tissue. Thus, the electrical stimulation may, in terms of the present disclosure, be considered as a direct stimulation of the tissue. Particularly when contrasted to stimulation transmitted over a distance by a nerve, which may be referred to as an indirect stimulation or nerve stimulation. Hence, an electrode arrangement comprising one or several electrode elements may be arranged in, partly in, on, or in close vicinity of the tissue that is to be exercised by means of an electrical signal. Preferably, the electrode may be arranged to transmit the electrical signal to the portions of the tissue that is to be stimulated so as to cause it to constrict or so as to cause it to exercise with no or little constriction, namely in situations where the tissue is affected, or risks to be affected, by mechanical forces exerted by a medical implant. Thus, the electrode element may be considered to be arranged between the medical implant, such as a constriction device, and the tissue against which the implant is arranged to rest, when implanted. During operation of the electrical stimulation device, the electrical signal may cause the muscle cells to contract and relax repeatedly. If such activity is little, this action of the cells may be referred to as exercise and may have a positive impact in terms of preventing deterioration and damage of the tissue. Further, the exercise may help to increase tolerance of the tissue for pressure and mechanical forces generated by the medical implant. The interaction between the electrode or electrodes of the electrical stimulation device and the tissue of the patient’s intestine is to a large extent determined by the properties at the junction between the tissue and the electrode element. The active electrically conducting surface of the electrode element (in the following referred to as “metal”, even though other materials are equally conceivable) can either be uncoated resulting in a metal-tissue interface or insulated with some type of dielectric material. The uncoated metal surface of the electrode may also be referred to as a bare electrode. The interface between the electrode and the tissue may influence the behavior of the electrode since the electrical interaction with the tissue is transmitted via this interface. In the biological medium surrounding the electrode, such as the actual tissue and any electrolyte that may be present in the junction, the current is carried by charged ions, while in the material of the electrode the current is carried by electrons. Thus, in order for a continuous current to flow, there needs to be some type of mechanism to transfer charge between these two carriers. In some examples, the electrode may be a bare electrode wherein the metal may be exposed to the surrounding biological medium when implanted in, or at, the muscle or neural tissue that is to be stimulated. In this case there may be a charge transfer at a metal–electrolyte interface between the electrode and the tissue. Due to the natural strive for thermodynamic equilibrium between the metal and the electrolyte, a voltage may be established across the interface which in turn may cause an attraction and ordering of ions from the electrolyte. This layer of charged ions at the metal surface may be referred to as a “double layer” and may physically account for some of the electrode capacitance. Hence, both capacitive faradaic processes may take place at the electrode. In a faradaic process, a transfer of charged particles across the metal-electrolyte interface may be considered as the predominant current transfer mechanism. Thus, in a faradaic process, after applying a constant current, the electrode charge, voltage and composition tend to go to constant values. Instead, in a capacitive (non-faradaic) process, charge is progressively stored at the metal surface and the current transfer is generally limited to the amount which can be passed by charging the interface. In some examples, the electrode may comprise a bare electrode portion, i.e. an electrode having an uncoated surface portion facing the tissue such that a conductor–tissue interface is provided between the electrode and the tissue when the electrode element is implanted. This allows for the electrical signal to be transmitted to the tissue by means of a predominantly faradaic charge transfer process. A bare electrode may be advantageous from a power consumption perspective since a faradaic process tends to be more efficient than a capacitive-charge transfer process. Hence, a bare electrode may be used to increase the current transferred to the tissue for a given power consumption. In some examples, the electrode may comprise a portion that is at least partly covered by a dielectric material so as to form a dielectric-tissue interface with the muscle tissue when the electrode is implanted. This type of electrode allows for a predominantly capacitive, or non-faradaic, transfer of the electrical signal to the muscle tissue. This may be advantageous over the predominantly faradaic process associated with bare electrodes since faradaic charge transfer may be associated with several problems. Examples of problems associated with faradaic charge transfer include undesirable chemical reactions such as metal oxidation, electrolysis of water, oxidation of saline, and oxidation of organics. Electrolysis of water may be damaging since it produces gases. Oxidation of saline can produce many different compounds, some of which are toxic. Oxidation of the metal may release metal ions and salts into the tissue which may be dangerous. Finally, oxidation of organics in a situation with an electrode element directly stimulating tissue may generate chemical products that are toxic. These problems may be alleviated if the charge transfer by faradaic mechanisms is reduced, which may be achieved by using an electrode at least partly covered by a dielectric material. Preferably, the dielectric material is chosen to have as high capacitance as possible, restricting the currents flowing through the interface to a predominantly capacitive nature. Several types of electrode elements can be combined with the present disclosure. The electrode element can for example be a plate electrode, comprising a plate-shaped active part forming the interface with the tissue. In other examples, the electrode may be a wire electrode, formed of a conducting wire that can be brought in electrical contact with the tissue. Further examples may include needle- or pin-shaped electrodes, having a point at the end which can be attached to or inserted in the muscle tissue. The electrodes may for example be encased in epoxy for electrical isolation and protection, and comprise gold wires or contact pads for contacting the muscle tissue. It will be appreciated that both faradaic and capacitive mechanisms may be present at the same time, irrespective of the type of electrode used. Thus, capacitive charge transfer may be present also for a bare electrode forming a metal-tissue interface, and faradaic charge transfer may be present also for a coated electrode forming a dielectric-tissue interface. It has been found that the faradaic portion of the current delivered to the muscle tissue can be reduced or even eliminated by reducing the duration of the pulses of the electrical signal. Reducing the pulse duration has turned out to be an efficient way of increasing the portion of the signal which can be passed through the interface as a capacitive current, rather than by a faradaic current. As a result, shorter pulses may produce less electrode and tissue damage. The capacitive portion of the current may further be increased, relative to the faradaic portion, by reducing the amplitude of the current pulses of the electrical signal. Reducing the amplitude may reduce or suppress the chemical reactions at the interface between the electrode and the tissue, thereby reducing potential damage that may be caused by compounds and ions generated by such reactions. In one example, the electrical stimulation may be controlled in such a manner that a positive pulse of the electrical signal is followed by a negative pulse (or, put differently, a pulse of a first polarity being followed by a pulse of a second, reversed polarity), preferably of the same amplitude and / or duration. Advantageously, the subsequent negative (or reversed) pulse may be used to reverse or at least moderate chemical reactions or changes taking place in the interface in response to the first, positive pulse. By generating a reversed pulse, the risk of deterioration of the electrode and / or the tissue at the interface between the electrode and the muscle tissue may be reduced. Although Fig.8 shows an embodiment where the entry and exit valves 30, 40 each comprise a single electrode 11, there may be provided more than one electrode 11 for electrically stimulating the tissue of the intestinal section for exercising the muscle tissue in order to improve the conditions for long-term implantation of the entry and exit valves 30, 40. In the embodiment of Fig.8, the electrode 11 is arranged underneath the hollow hydraulic members 31, 41 and, thus, placed in abutment and in electrical connection with the tissue of the intestine. Alternatively, a first and possibly even a second electrode 11 may be placed on a first side of the luminary organ, and a third and possibly even a fourth electrode 11 may be placed on a second, opposing side of the intestine. Each of the two or four electrodes 11 are connected to the external controller CE (alternatively a wireless remote controller CR) for controlling the electrical stimulation of the tissue of the intestine such that the tissue of the intestine is stimulated by a series of electrical pulses. The pulses may comprise a pulse of a first polarity followed by a pulse of a second, reversed polarity, and the pulsed electrical stimulation signal generated may comprise a pulse frequency of 0.01 - 150 Hz. The electrical stimulation signal may comprise a pulse duration of 0.01 - 100 ms and a pulse amplitude of 1 - 15 mA. More specifically, the electrical stimulation signal may comprise a pulse frequency of 0.15 - 0.25 Hz, a pulse duration of 20 - 30 ms and a pulse amplitude of 3 - 10 mA. Further, the electrical stimulation signal may comprise a build-up period of 0.01 - 2 s in which the amplitude gradually increases, a stimulation period of 1 - 60 s, and a stimulation pause of 0.01 - 60 s, wherein the electrical signal may comprise a pulse frequency of 1 - 50 Hz and a pulse duration of 0.1 - 10 ms. Fig.9A is an example of a bipolar electrode arrangement 150, comprising a first and a second electrode element 152, 154 which may be similarly configured as the electrode elements discussed with reference to any of the previous embodiments. In the following figures, the first and second electrode elements will be distinguished by reference numerals E1 and E2, respectively. The first and second electrode elements E1, E2 may be connected to different electrical potentials. Thus, the first electrode element E1 can be operated as an anode and the second electrode element E2 can be operated as a cathode. In alternative embodiments, however, both electrode elements E1, E2 may be operated as cathodes, while using the tissue of the body as anode. The electrode elements E1, E2 may be attached directly to an outer surface of the implantable device, such as disclosed with reference to Fig.8. In some examples the electrode elements E1, E2 may be arranged on a support, such as a flexible patch, which may be configured to be attached to the implantable constriction device 30. The electrode arrangement 150 can be arranged between the implantable constriction device 30 and the tissue (such as disclosed with reference to Fig.8) and may in some examples be provided as a separate, physically distinct item and in other examples be integrated in the apparatus 100. The electrode arrangement 150 may comprise one or several contact pads for increasing the contact surface between the electrode and the tissue when implanted. During operation, the electrical signal may be delivered to the muscle tissue by means of the first and second electrode elements E1, E2 so as to stimulate contraction of the muscle cells. Fig.9B is another example of an electrode arrangement 150, which in the present example may be a unipolar electrode element 152, 154. The electrode element E1 may for example be operated as a cathode when implanted. The electrode element 152 may be formed of a flat, coiled wire for increasing the contact surface between the electrode element 152 and the tissue. Further, the coiled configuration allows for a certain mechanical flexibility of the electrode element 152 such that it can follow the muscle tissue during contraction and relaxation. Fig.9C illustrates the end portion of a needle- or pin-shaped electrode arrangement 150, wherein the active portion of the electrode element 152 is provided as a bare electrode surface 155 at the end of the electrode element 152, protruding from an insulation 156 covering the rest of the electrode element 152. Thus, when implanted at or in the muscle tissue, the active, bare electrode surface 155 of the electrode element 152 may form a metal-tissue interface with the muscle tissue, wherein the interface may surround the end portion of the electrode element 152 so as to provide a relatively large contact surface. The present example is advantageous in that it can be inserted into the tissue, thereby allowing for a selective stimulation at a certain depth of the tissue. Fig.9D shows a similar electrode element 152 as the one in Fig.9C, with the difference that the present electrode element 152 comprises an active portion that is covered by a dielectric material 157 so as to protect the electrode material from deterioration and to facilitate capacitive current transfer. The dielectric material 157 may for example be electrochemically deposited tantalum oxide, which allows the electrical charge to pass through the interface but reduces the risk for electrode corrosion, gas formation and metabolite reactions. It will be appreciated that both faradaic and capacitive mechanisms may be present at the same time, irrespectively of the type of electrode used. Thus, capacitive charge transfer may be present also for a bare electrode forming a metal–tissue interface, and faradaic charge transfer may be present also for a coated electrode forming a dielectric–tissue interface. It has been found that the faradaic portion of the current delivered to the muscle tissue can be reduced or even eliminated by reducing the duration of the pulses of the electric signal. Reducing the pulse duration has turned out to be an efficient way of increasing the portion of the signal which can be passed through the interface as a capacitive current, rather than by a faradaic current. As a result, shorter pulses may produce less electrode and tissue damage. The capacitive portion of the current may further be increased, relative to the faradaic portion, by reducing the amplitude of the current pulses of the electrical signal. Reducing the amplitude may reduce or suppress the chemical reactions at the interface between the electrode and the tissue, thereby reducing potential damage that may be caused by compounds and ions generated by such reactions. In one example, the electrical stimulation may be controlled in such a manner that a positive pulse of the electrical signal is followed by a negative pulse (or, put differently, a pulse of a first polarity being followed by a pulse of a second, reversed polarity), preferably of the same amplitude and / or duration. Advantageously, the subsequent negative (or reversed) pulse may be used to reverse or at least moderate chemical reactions or changes taking place in the interface in response to the first, positive pulse. By generating a reversed pulse, the risk of deterioration of the electrode and / or the tissue at the interface between the electrode and the muscle tissue may be reduced. Fig.10 shows an example of a pulsed electrical signal to be applied to an electrode for electrically stimulating muscle tissue via an electrode-tissue interface as discussed above. The electrical signal may be generated by a stimulation controller arranged outside the body or implanted in the body (as described with reference to Fig.8). The stimulation controller 170 may be operatively connected to the electrode element 152, 154 by means of a lead 172, and the electrical signal shown in the present figure may either reflect the signal as generated at the stimulation controller 170, or the signal as delivered to the electrode element 152, 154 at the electrode–tissue interface. The characteristics of the electrical signal may be selected and varied determined on the electrical and properties at the electrode–tissue interface and on the actual response of the tissue. The electrical stimulation delivered to the muscle cells may depend on several factors, such as the configuration and placement of the electrode element 152, 154 at the tissue, the presence of fibrous material at the interface, the composition of the electrolyte in the interface, accumulation of non-conducting material on the electrode surfaces, etcetera. It is therefore suggested that the characteristics of the electric signal, as shown in the present figure, be selected, and varied based on an observed or estimated response from the stimulated tissue. In the present example, the electrical signal is a pulsed signal comprising square waves PL1, PL2, PL3, PL4. However, other shapes of the pulses may be employed as well. The pulse signal may be periodic, as shown, or may be intermittent (i.e., multiple series of pulses separated by periods of no pulses). The pulses may have an amplitude A, which may be measured in volts, ampere, or the like. Each of the pulses of the signal may have a pulse width D. Likewise, if the signal is periodic, the pulse signal may have a period F that corresponds to a frequency of the signal. Further, the pulses may be either positive or negative in relation to a reference. The pulse frequency may for example lie within the range of 0.01 - 150 Hz. More specifically, the pulse frequency may lie within at least one of the ranges of 0.1 - 1 Hz, 1 - 10 Hz, 10 - 50 Hz and 50 - 150 Hz. It has been observed that relatively low pulse frequencies may be employed to imitate or enhance the slow wave potential associated with pacemaker cells of the smooth muscle tissue. Thus, it may be advantageous to use relatively low pulse frequencies, such as 0.01 - 0.1 Hz or frequencies below 1 Hz or a few Hz for such applications. The pulse duration may for example lie within the range of 0.01 - 100 milliseconds (ms), such as 0.1 - 20 milliseconds, and preferably such as 1 - 5 ms. The natural muscle action potential has in some studies been observed to last about 2 - 4 ms, so it may be advantageous to use a pulse duration imitating that range. The amplitude may for example lie within the range of 1 - 15 milliamperes (mA), such as 0.5 - 5 mA in which range a particularly good muscle contraction response has been observed in some studies. In a preferred, specific example the electrical stimulation may hence be performed using a pulsed signal having a pulse frequency of 10 Hz, a pulse duration of 3 ms and an amplitude of 3 mA. Fig.11 shows an example of a pulsed signal, comprising build-up period X1, in which the amplitude is gradually increasing, a stimulation period X2 during which the muscle tissue is exposed to a contracting stimulation 30 signal, a ramp down period X3 in which the amplitude is gradually decreasing, and a stimulation pause X4 before a new build-up period is initiated. The build-up period may for example be 0.01 - 2 seconds, the stimulation period 1 - 85 seconds, the ramp-down period 0.01 - 2 seconds, and the stimulation pause 0.01 - 60 seconds. The pulse frequency may for example be 1 - 50 Hz, the pulse duration 0.1 - 10 milliseconds and the amplitude during the stimulation period be 1 - 15 mA. The stimulation of skeletal muscle tissue may for example be performed using a frequency of 50 Hz and pulses having a duration of 100 μs. The current amplitude may be 1, 2.5, 7.5 or 10 mA. In particular, a desired muscle contraction response has been experimentally observed within a range of 0.5 to 5.0 mA. In the present example, a coiled electrode may be used as a cathode. Another example design is a multi-stranded wire arranged in a helical design. They can be imbricated in the muscular wall of the fundus (or esophagus) and can be stimulated in any desired pattern. The stimulus parameters may for example be biphasic pulses, 10 to 40 Hz, lasting 0.1 to 5 ms, with a current density of 3 to 5 mA / cm2. Fig.12 is a schematic outline of a system for electrically stimulating or exercising muscle cells to increase tolerance of the tissue for pressure from the apparatus 100. The system may be used in combination with the implantable apparatus 100 and may in some examples be comprised in such an apparatus 100. The system may comprise an electrode arrangement 150 which may be similarly configured as the electrodes arrangements / electrode elements discussed above in connection with the previous examples, an energy source 160 for providing the electrical energy required for generating the electrical signal, and a stimulation controller 170 controlling the generation of the electrical signal. The electrode arrangement 150, which may comprise one or several electrode elements 152, 154, such as a bare electrode or an electrode at least partly covered by a dielectric material 157 shown in Fig.9D, may be configured to be implanted in the muscle tissue to be stimulated, or to engage the muscle, so as to form an electrode–tissue interface through which the stimulating signal may be transferred. Alternatively, or additionally, the electrode element 152, 154 may be arranged in close vicinity to the muscle tissue such that an electrical coupling between the electrode element and the muscle tissue may be established. This may for example be the case when other tissue, such as connective tissue, is present between the implanted device and the muscle tissue. The electrode may be electrically connected to the energy source 160, for example by means of a wiring or a lead, such that the electrical signal may be transferred to the electrode–tissue interface. In some examples, the electrode 152, 154 may be integrated with or attached to the apparatus so that the electrode 152, 154 when implanted in the patient is arranged at the interface between the apparatus 100 and the muscle tissue. The electrode 152, 154 can thereby be used for exercising the muscle tissue that is mechanically affected by the implant. The energy source 160 may for example be of a non-rechargeable type, such as a primary cell, or of a rechargeable type, such as a secondary cell. The energy source 160 may be rechargeable by energy transmitted from outside the body, from an external energy source, or be replaced by surgery. Further, the electrode arrangement 150 may be operably connected to a stimulation controller 170, which may comprise an electrical pulse generator, for generating the electrical pulse. The stimulation controller 170 may be integrated with the energy source 160 or provided as a separate, physically distinct unit which may be configured to be implanted in the body or operate from the outside of the body. In case of the latter, is may be advantageous to allow the external control unit to communicate wirelessly with the stimulation controller 150. The system may according to some examples comprise a sensor S1 that is configured to sense a physical parameter of the body and / or the apparatus 100. The sensor S1 may for example be employed to sense or detect a bodily response to the electrical stimulation, such as for example a contraction of the stimulated muscle tissue. In an example, the sensor S1 may be configured to sense action potentials that are being sent to the muscle tissue. The action potentials may for example be generated by pacemaker cells of the muscle tissue, which may be registered by the sensor S1 and transmitted to the stimulation controller 170. The stimulation controller 170 may use the received signal when controlling the energy source 160, such that the generated electrical signal amplifies the sensed action potentials. The energy source 160 may preferably be an implantable energy source 160 configured to be placed on the inside of the patient’s body. Preferably, the implantable energy source 160 may comprise a secondary cell, which can be charged from the outside of the body so as to reduce the need for surgical battery replacement procedures. As indicated in the present figure, the implantable energy source 160 may be configured to be supplied with electrical energy from an external energy source 165 arranged outside the body. In such an example, the system may further comprise an implantable charger 190 configured to be electrically connected to the implantable energy source 160 and to enable charging of the implantable energy source 160 by the external energy source 165. The implantable charger 190 may for example be configured to be electrically connected to the implantable energy source 160 by means of a wiring or a lead, such that the electrical energy may be transferred from the implantable charger 190 to the implantable energy source 160. The implantable charger 190 may further be coupled to the external energy source 165 by a wireless coupling or by a wired coupling, using a wiring or lead which may be similar to the one between the charger 190 and the implantable energy source 160. In case of the latter, the wiring or lead may terminate in a terminal which may be access via the skin of the patient, either as a contact port surfacing the skin or being arranged under the skin. Electrical energy may then be transmitted to the charger 190 by connecting the external energy source 165 to the port, for example by incising the skin to expose the port and making it possible for the external energy source 165 to be plugged in. Alternatively, the implantable charger 190 may be configured to receive energy from the external energy source 165 wirelessly, such as for example inductively. In this case, the charger 190 may comprise an electromagnetic coil configured to receive the electrical power wirelessly from the external energy source 165. The charger 190 may for example be arranged subcutaneously so as to facilitate inductive transfer of the energy via the skin of the patient. The charging of the implantable energy source 160 may be controlled according to several different schemes. In an example, the charging of the implantable energy source 160 may be controlled by controlling the receipt of electrical power, from the external energy source, at the implantable charger 190. Put differently, the charger 190 may be configured to vary or control its capability of receiving electrical energy from the external energy source 165. Hence, the amount of electrical power delivered to the implantable energy source 160 may be regulated at the implantable charger 190 rather than at the external energy source 165, which hence may be allowed to transmit a substantially constant power. By varying the receipt at the charger 190, rather than the transmission at the external power source 165, the charging of the implantable energy source 160 may be performed without sending control signals to the external energy source 165. Instead, the intelligence required for regulating and controlling the charging of the implanted energy source 160 may be accommodated within the body of the patient, without the need of communication with the outside of the body. In an alternative embodiment, the charging of the implantable energy source 160 may be controlled by controlling the transmission of electrical power at the external energy source 165. Thus, the charger 190 (or any other component of the apparatus / system arranged in the body) may send transmission instructions, for example via a control signal, to the external energy source 165 which may regulate its transmitting power accordingly. The charging of the implantable energy source 160 may be controlled by the controller 170, which hence may be configured to issue control instructions to the implantable charger 190 and / or the external energy source 165, as discussed above. In some examples, the controller 170 may be configured to indicate a functional status of the implantable energy source 160, such as for example charge level, charging capacity, voltage and / or temperature of the implantable energy source 160. The functional status may for example be used for controlling the charging of the implantable energy source 160 as described above, and for indicating the status of the implantable energy source 160 to the patient or another, external entity such as medical staff. The functional status may for example be transmitted to the outside of the body, where it can be interpreted and used for diagnosis of the status / condition of the implanted apparatus. Further, the functional status may be transmitted to the outside of the body to provide a warning signal, for example indicating low battery or overheating. The transmission of a signal to / from the controller 170 is described in further detail in connection with the following Fig.12 to Fig.14. The functional status may for example be based on a signal from a sensor, such as a temperature sensor configured to sense a temperature of the implanted energy source 160, or a current or voltage meter configured to measure an electrical condition of the implanted energy source 160. The sensor output may be transmitted to the controller 170, for example by means of a wiring or electrical conductor, where it can be processed and acted upon in the form of an issued signal comprising control instructions for the charger 190 / external energy source 165 and / or functional status information. The functional status may in some examples be transmitted via a carrier signal to the outside of the body by means of a transmitter, which for example may be arranged subcutaneously. In some examples, the transmitter may be integrated in the charger 190. Fig.13 shows a similar embodiment as the system described above with reference to Fig.12. However, as indicated in the present figure, the system may further comprise an external signal transmitter 175, such as a wireless remote 175, which may be configured to be operably connected to the controller 170. The external signal transmitter 175 may be arranged to allow for the patient or another external entity, such as a service technician or medical staff, to interact with the controller 170. The external signal transmitter 175 may for example be used to control, or adjust, the operation of the implanted controller 170 in order to affect or adjust the electrical stimulation signal delivered to the tissue by the electrode arrangement 150. The external control of the controller 170 may for example serve the purpose of increasing or reducing an amplitude or frequency of the electrical stimulation signal, or for activating / deactivating the electrical stimulation. In an example, the external signal transmitter 175 may be used for increasing the electrical stimulation of the cardiac sphincter in response to experienced reflux symptoms. In this way, the patient may be allowed to increase the contraction of the cardiac sphincter so as to further hinder stomach contents from rising in the esophagus. The signal, by which the external signal transmitter 175 is communicating with the implanted controller 170, may be selected from the group consisting of: a sound signal, an ultrasound signal, an electromagnetic signal, and infrared signal, a visible light signal, an ultra violet light signal, a laser signal, a microwave signal, a radio wave signal, an X-ray radiation signal and a gamma radiation signal. While illustrated as separate components / entities in the figure, it is appreciated that the implanted, or internal, controller 170 may be integrated in the implantable charger 190 and / or in the implantable energy source 160. Further, the external signal transmitter 175 may be integrated in the wireless remote. Fig.14 is a schematic diagram of a system, or an apparatus, which may be similarly configured as the system described with reference to Fig.12 and Fig.13. Hence, a system is disclosed, comprising an electrode arrangement 150 for exercising muscle tissue affected by an implanted apparatus according to any of the embodiments discussed above in connection with Figs.1 to 8, and a controller 170 configured to be operably connected to the electrode arrangement 150 for controlling the electrical stimulation of the muscle tissue. The controller 170 may be coupled to an implantable energy source 160 for providing the electrode arrangement with electrical power according to a stimulation signal or pattern generated by the controller 170. Fig.15 further illustrates an implantable communicator 171, which may be configured to transmitting a signal between the controller 170 and the outside of the patient’s body, similar to what is described above in connection with Fig.13. The communicator 171 may be comprised in the control unit 170 or provided as a separate unit. The communicator 171 may hence be used for transmitting the signal comprising the functional status of the implantable energy source 160, and for communicating with an external controller 176 used for controlling or adjusting the operation of the implantable controller 170. The external controller 176 may for example be comprised in a remote controller 175 as shown in Fig.13. The implantable controller 170, which also may be referred to as an internal controller or a stimulation controller 170, may be understood as any implantable unit capable of controlling the electrical stimulation of the tissue. A controller may include an electrical signal generator, a modulator or other electrical circuitry capable of delivering the electrical stimulation signal to the electrode arrangement. Further, the controller may be capable of processing control signals and generate the electrical stimulation signal in response thereto, and further to generate control signals for the control of other components of the system or apparatus, such as for example the implanted energy source 160 and / or the implantable charger 190. A control signal may thus be understood as any signal capable of carrying information and / or electric power such that a component of the system / apparatus can be directly or indirectly controlled. FIRST ASPECT – PIEZOELECTRIC MOTORS AND PUMPS As mentioned above, according to an first aspect of the present disclosure, the system may comprise one or more piezoelectric motors and / or one or more piezoelectric pumps. More specifically, the system may comprise an artificial or artificially modified reservoir adapted for receiving and temporarily collecting therein intestinal contents and further adapted to remain within the patient’s body when emptying the reservoir, an at least partly artificial flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir and at least one piezoelectric motor and / or at least one piezoelectric pump. Thus, any one of the motor or motors and pump or pumps for driving certain parts of the system of any one of the embodiments of the present disclosure are preferably piezoelectric. This will be further explained in relation to Fig.15 to Fig.31. The piezoelectric effect is a property of certain solid materials to generate an electrical voltage in response to an applied mechanical stress (so-called direct piezoelectric effect) and to deform elastically in response to an applied electrical voltage (so-called inverse piezoelectric effect). The piezoelectric effect is a reversible process, meaning that materials exhibiting the direct piezoelectric effect also exhibit the inverse piezoelectric effect. Materials exhibiting the piezoelectric effect are denoted as piezoelectric materials. Examples of piezoelectric materials comprise: crystalline materials, such as lithium niobate, lithium tantalate and quartz; ceramics, such as lead zirconate titanate, potassium niobate and barium titanate; polymers, such as polyvinylidene fluoride. Piezoelectric coefficients are a fundamental property of piezoelectric materials. A given piezoelectric material is characterized by a set of piezoelectric coefficients, wherein a piezoelectric coefficient is a measure of the relationship between the applied mechanical stress along a first direction and the generated electric charge along a second direction. Piezoelectric coefficients are usually expressed in units of picocoulombs per newton (pC / N). The value of piezoelectric coefficients may strongly vary depending on the piezoelectric material and piezoelectric coefficient being considered. For example, the ^^ଷଷpiezoelectric coefficient is commonly reported for piezoelectric materials and quantifies the electric charge generated along a given direction in response to the mechanical stress applied along the same direction. A piezoelectric motor or piezo motor is a type of electric motor that uses the inverse piezoelectric effect to generate mechanical motion, typically linear or rotatory motion. Piezo motors are often used in applications where precise positioning and fine control of movement are required. Piezo motors have the advantage of providing high motion accuracy, being possible to miniaturize and being relatively immune to interference, such as electromagnetic interference. Piezoelectric motors can also be manufactured without magnetic and / or metallic parts, and instead be manufactured from ceramics or certain composites. This feature is particularly advantageous in medical and biotechnology applications with strong magnetic fields. Piezoelectric motors can thus be made MRI-safe, meaning that the patient can undergo Magnetic Resonance Imaging (MRI) while having the piezo motor implanted. MRI is a medical imaging technique used to form pictures of the anatomy and the physiological processes of the body using strong magnetic fields. Conventional implantable electromagnetic motors prevent the use of MRI as the strong magnetic field risks damaging both the patient and the implant. As discussed in more detail below, inchworm motors, inertial motors, walk-drive motors and ultrasonic motors are four suitable types of piezoelectric motors. Fig.15 shows an embodiment of an inchworm motor MO configured to generate linear motion. The inchworm motor MO comprises a first lateral piezoelectric actuator 801a and second lateral piezoelectric actuator 801b. The first lateral piezoelectric actuator 801a is laterally connected to a first clutching actuator 802a’ and a second clutching actuator 802a’’. The second lateral piezoelectric actuator 801b is laterally connected to a third clutching actuator 802b’ and a fourth clutching actuator 802b’’. The inchworm motor MO is configured to impart a linear motion to a movable member 805. The movable member 805 is configured to be attached to the load or mechanism to be moved, for instance to a signal emitter (1) or a relevant part thereof. Fig.16 illustrates an operation cycle of the piezoelectric inchworm motor MO wherein the movable member 805 is linearly moved in a direction to the right in the illustration by sequentially controlling the first and second piezoelectric actuators 801a, 801b and the clutching actuators 802a’, 802a’’, 802b’, 802b’’. In an initial relaxation state, the movable member 805 is detached from all the clutching actuators 802a’, 802a’’, 802b’, 802b’’. The inchworm motor MO is subsequently brought into an initialization state by electrically activating the second and fourth clutching actuators 802a’’, 802b’’. As a result, the clutching actuators 802a’’, 802b’’ extend and clutch the movable member 805. In step 1, the first and second lateral actuators 801a, 801b extend in response to an applied electrical voltage. As a result, the movable member 805 undergoes a first linear displacement with a distance equal to half the distance of the extension of the lateral actuators 801a, 801b. In step 2, the first and third clutching actuators 802a’, 802b’ are electrically activated. As a result, the first and third clutching actuators 802a’, 802b’ extend and clutch the movable member 805. In step 3, the electrical voltage applied to the third and fourth clutching actuators 802a’’, 802b’’ is decreased as compared to the initialization state. As a result, the third and fourth clutching actuators 802a’’, 802b’’ detach from the movable member 805. In step 4, the electrical voltage applied to the first and second lateral actuators 801a, 801b is decreased as compared to step 1. As a result, the first and second lateral actuators 801a, 801b contract and the movable member 805 undergoes a second linear displacement with a distance equal to half the distance of the contraction of the lateral actuators 801a, 801b. In step 5, the second and fourth clutching actuators 802a’’, 802b’’ are electrically activated such that they extend and clutch the movable member 805. In step 6, the electrical voltage applied to the first and second clutching actuators 802a’, 802b’ is decreased as compared to step 2. As a result, the first and second clutching actuators 802a’, 802b’ contract and detach from the movable member 805. The steps from 1 to 6 may be repeated a number of times in the sequence illustrated above in order to move the movable member 805 by a desired distance. This configuration of an inchworm piezoelectric motor MO creating a linear motion can be used to generate the linear motion of the infusion needle 11. Where the infusion needle 11 is moved in two lateral directions, such as sideways and upward / downward, two piezoelectric motors may be provided. In the embodiment shown in Fig.16, the inchworm motor is configured to generate a linear motion at a speed in the range of 1 mm / s to 10 mm / s, a stroke length of up to 5 mm and a force in the range of 2 N – 30 N. In another embodiment, the movable member 805 may be replaced with a rotary module (not shown) such that the inchworm motor can be used to generate rotary motion of the infusion needle 11 in those embodiments where the needle 11 is rotatable. An inchworm motor configured to generate rotary motion may have a rotational speed in the range of 0.5 mrad / s to about 70 mrad / s and a torque ranging from about 100 Nmm to about 900 Nmm. Fig.17 illustrates an embodiment of a piezoelectric inertial motor MO configured to generate linear motion. The motor MO comprises a movable member 805, a piezoelectric actuator 801, a recoiling member 804 and a base 806. The movable member 805 is attached to the piezoelectric actuator 801. The piezoelectric actuator 801 is attached to the recoiling member 804. The movable member 805 is in contact with the base 806. The movable member 805 is configured to be attached to the load or mechanism to be moved, for instance to a signal emitter (1) or a relevant part thereof. An operation mode of the piezoelectric inertial motor MO described in Fig.17 comprises two steps. In step 1, the piezoelectric actuator 801 slowly elongates in response to an applied voltage. Due to the static friction between the movable member 805 and the base 806, the movable member 805 does not move. In step 2, the piezoelectric actuator 801 rapidly contracts in response to a change in the applied voltage. As a result of the recoil produced by the recoiling member 804, the movable member 805 moves by a distance ∆x to the left in the illustration of Fig.17. By reversing the operation cycle, the piezoelectric inertial motor MO generates motion in the opposite direction. In the embodiment shown in Fig.17, the piezoelectric inertial motor MO is configured to generate linear motion and may feature a speed in the range of 1 mm / s – 10 mm / s, a stroke length of up to 5 mm and a force in the range of 2 N – 30 N. This configuration of a piezoelectric inertial motor MO creating a linear motion can be used to generate the linear motion of the infusion needle 11. Where the infusion needle 11 is moved in two lateral directions, such as sideways and upward / downward, two piezoelectric motors may be provided. In alternative embodiments of piezoelectric inertial motors (not shown), the movable member 805 may be replaced with a rotary module such that the piezoelectric inertial motor is configured to generate rotary motion. Such a piezoelectric inertial motor creating a rotary movement can be used to generate rotary motion of the infusion needle 11 in those embodiments where the needle 11 is rotatable. Piezoelectric inertial motors configured to generate rotary motion may have a rotational speed in the range of 1 mrad / s – 100 mrad / s and a torque in the range of 100 Nmm – 900 Nmm. Yet another design of a piezoelectric motor suitable for use in the implantable medical device described herein is the walk- drive motor. Walk-drive motors take their name from the fact that their working principle essentially resembles a walk. Linear motion is achieved through the coordinated and sequential action of a number of piezoelectric actuators acting as legs. Fig.18 shows an embodiment of a piezoelectric walk-drive motor MO. The piezoelectric walk-drive motor MO comprises a number of piezoelectric actuators 801a – 801d attached to a supporting member 800. The piezoelectric actuators 801a – 801d may be divided into a first set 801a, 801c and a second set 801b, 801d. The first and second set 801a, 801c and 801b, 801d of piezoelectric actuators may be controlled independently. The piezoelectric walk-drive motor MO is configured to impart a linear motion to a movable member 805 by sequentially controlling the piezoelectric actuators 801a – 801d. The movable member 805 is configured to be attached to the load or mechanism to be moved, for instance to a signal emitter (1) or a relevant part thereof. A piezoelectric walk-drive motor 805 may be operated in various operation modes, each offering specific advantages in terms of performance. Fig.19 illustrates an operation cycle of a piezoelectric walk-drive motor MO according to one embodiment. In this embodiment, the first set of piezoelectric actuators 801a, 801c is controlled by a first electrical voltage ^^^. The second set of piezoelectric actuators 801b, 801d is controlled by a second electrical voltage ^^ଶ. The cycle comprises a number of steps. In step 1, in response to a change in ^^^, the first set of piezoelectric actuators 801a, 801c stretch and make contact with the movable member 805. When in contact, the first set of piezoelectric actuators 801a, 801c are bended sideways in a direction opposite to the motion direction D. Conversely, the second set of piezoelectric actuators 801b, 801d detach from the movable member 805 in response to a change in ^^ଶ. In step 2, the first set of piezoelectric actuators 801a, 801c maintain contact with the movable member 805 and bend in the motion direction D in response to a change in ^^^. The second set of piezoelectric actuators 801b, 801d remain detached from the movable member 805. As a result of the friction between the first set of piezoelectric actuators 801a, 801c and the movable member 805, the movable member 805 is moved in the motion direction D. In step 3, in response to a change in ^^ଶ, the second set of piezoelectric actuators 801b, 801d stretch and make contact with the movable member 805. When in contact, the second set of piezoelectric actuators 801b, 801d are bended in a direction opposite to the motion direction D. Conversely, the first set of piezoelectric actuators 801a, 801c detach from the movable member 805 in response to a change in ^^^. In step 4, the second set of piezoelectric actuators 801b, 801d maintain contact with the movable member 805 and bend in the motion direction D in response to a change in ^^ଶ. The first set of piezoelectric actuators 801a, 801c remain detached from the movable member 805. As a result of the friction between the second set of piezoelectric actuators 801b, 801d and the movable member 805, the movable member 805 is moved in the motion direction D. The piezoelectric actuators 801a – 801d in Fig.16 and Fig.17 may be bimorph piezoelectric actuators. A bimorph actuator comprises at least two piezoelectric layers bonded together and oppositely responding to a given applied voltage. E.g., one layer extends and the other contracts. As a result, the bimorph actuator may stretch and bend. Alternatively, any of the piezoelectric actuators 801a – 801d in Fig.16 and Fig.17 may comprise a top part (illustrated as 801a’ in Fig.16), configured to be attached to the supporting member 800, and a bottom part (exemplified by illustration as 801a’’ in Fig.16). The top part 801a’ is configured to deform perpendicularly to the motion direction D in response to the voltage applied to the piezoelectric actuator 801a. The bottom part 801a’’ is configured to deform parallelly to the motion direction D in response to the voltage. As a result, the piezoelectric actuator 801a may stretch and bend. By reversing the operation cycle, the piezoelectric walk-drive motor MO generates motion in the opposite direction. In the embodiment shown in Fig.16 and Fig.17, the piezoelectric walk-drive motor MO is configured to generate linear motion at a speed in the range of 1 mm / s to 10 mm / s and a force in the range of 2 N – 30 N. As the maximum stroke is limited by the length of the movable member 805 (also called a runner), there is no set limit for the maximum stroke. This configuration of a piezoelectric walk-drive motor MO creating a linear motion can be used to generate the linear motion of the infusion needle 11. Where the infusion needle 11 is moved in two lateral directions, such as sideways and upward / downward, two piezoelectric motors may be provided. In alternative embodiments of the piezoelectric walk-drive motor (not shown), the movable member 805 may be replaced with a rotary module such that the piezoelectric walk-drive motor is configured to generate rotary motion. Such a piezoelectric walk-drive motor configured to generate rotary motion can be used to generate rotary motion of the infusion needle 11 in those embodiments where the needle 11 is rotatable. Piezoelectric walk-drive motors configured to generate rotary motion may have a rotational speed in the range of 0.5 mrad / s to about 70 mrad / s and a torque ranging from about 100 Nmm to about 900 Nmm. An ultrasonic motor is another type of piezoelectric motor. In ultrasonic motors, a first component of the motor, the stator, supports mechanical vibrations in the ultrasonic frequency range – from tens to hundreds of kHz. The stator comprises a number of piezoelectric actuators. Ultrasonic mechanical vibrations are excited in the stator in response to an electrical voltage applied to the piezoelectric actuators. The stator is configured to transfer the ultrasonic vibrations to a second component of the motor, such as a rotor or slider depending on the scheme of operation. Depending on the scheme of operation, various types of motion, such as linear or rotary, may be imparted to the second component. A rotary ultrasonic motor is a piezoelectric ultrasonic motor configured to generate rotary motion. Rotary ultrasonic motors comprise traveling wave ultrasonic motors (TWUSM) and standing wave ultrasonic motor (SWUSM). In TWUSMs the stator vibrates according to a travelling wave pattern. In SWUSMs the stator vibrates according to a standing wave pattern. Fig.20 shows an embodiment of a TWUSM MO. The TWUSM MO comprises a ring-shaped stator 810 with a top and a bottom surface. The stator 810 is configured to engage with a ring-shaped rotor 811. The stator 810 comprises a ring-shaped member 810’, a first number of piezoelectric actuators 801a and a second number of piezoelectric actuators 801b. The piezoelectric actuators 801a, 801b areattached to the ring-shaped member 810’. An alternating electrical voltage VA may be applied from a first voltage generator 812a (typically acontroller connected to an energy source) to the piezoelectric actuators 801a. An alternating electrical voltage VB, phase-shifted with respect to VA, may be applied from a second voltage generator 812b to the second number of piezoelectric actuators 801b. The ring-shaped member 810’ may comprise a number of teeth 813. The rotor 811 is configured to be attached to the load or mechanism to be moved. The first number of piezoelectric actuators 801a deform in response to the voltage VAsuch that they induce a first vibration pattern in the stator 810. The second number of piezoelectric actuators 801b deform in response to the voltage VB such that they induce a second vibration pattern in the stator 810. The interference of the first and second vibration pattern excites a travelling wave 814 in the stator 810. The travelling wave 814 has a given propagation direction D1, either clock-wise or counter-clockwise. The regions of maximum displacement – so-called antinodes – and regions of no displacement – so-called nodes – of the travelling wave pattern oscillate transversely with respect to the top and bottom surface of the stator 810, but they also travel circumferentially along the stator 810 perimeter. The propagation of the travelling wave 814 makes the stator vibrate accordingly. As a result, the stator 810 imparts a rotatory motion to the rotor 811 in a rotation direction D2, opposite to the travelling wave 814 propagation direction D1. The teeth 813 facilitate the motion transmission from the stator 810 to the rotor 811 by enhancing the friction between the rotor 811 and the stator 810. The frequency and amplitude of the applied electrical voltages may be controlled and adjusted to tune the performance of the TWUSM MO, including speed, direction and accuracy of motion. In contrast to TWUSMs, a standing wave ultrasonic motor (SWUSM) requires only a single alternating electrical voltage to operate. In response to this applied voltage, the piezoelectric actuators 801a, 801b of the stator 810 make the stator 810 vibrate according to a standing wave pattern. A standing wave is characterized by antinodes and nodes that do not travel in space. As a result, a standing wave does not have a propagation direction. The stator 810 vibrates in a way that antinodes and nodes oscillate transversely with respect to the top and bottom surface of the stator. However, antinodes and nodes do not travel circumferentially along the stator. Fig.21 shows an embodiment of a SWUSM. The SWUSM MO comprises a ring-shaped stator 810 with a top and a bottom surface. The stator 810 is configured to engage with a ring-shaped rotor 811. The stator 810 comprises a first set of piezoelectric actuators 801a and a second set of piezoelectric actuators 801b. An alternating electrical voltage may be selectively and exclusively applied to either set of piezoelectric actuators 801a, 801b while the other set is left floating. In such a case, the set to which the voltage is applied is referred to as active, while the other set is referred to as free. The stator 810 comprises a number of protrusions 815. The stator 810 is configured to engage with the rotor 811 via the protrusions 815. The rotor 811 is configured to be attached to the load or mechanism to be moved. A standing wave vibration pattern may be excited in the stator 810 in response to the applied voltage. As a result, the protrusions 815 oscillate at a first angle with respect to the top surface of the stator 810 when the piezoelectric actuators 801a are active. The protrusions 815 oscillate at a second angle with respect to the top surface of the stator 810 when the piezoelectric actuators 801b are active, with the second angle different from the first angle. The first angle is such that the stator 810 imparts a clockwise rotary motion to the rotor 811. The second angle is such that the stator 810 imparts a counter-clockwise rotary motion to the rotor 811. In the embodiment shown in Fig.21, the rotary ultrasonic motor MO has a rotational speed in the range of 10 mrad / s – 10,000 mrad / s. and produces a torque in the range of 20 Nmm – 450 Nmm. Rotary ultrasonic motors, such as the SWUSM or TWUSM, configured to generate rotary motion, can be used as the rotational electrical motor. Such a rotary ultrasonic motor configured to generate rotary motion can be used to generate rotary motion of the infusion needle 11 in those embodiments where the needle 11 is rotatable. Fig.22 shows an embodiment of a linear ultrasonic motor MO. The linear ultrasonic motor MO comprises a piezoelectric actuator 801, a pushing member 816, and a movable member 805 (or slider). The piezoelectric actuator 801 vibrates at its resonance frequency in response to an applied alternating voltage. The piezoelectric actuator 801 is attached to the pushing member 816. As a result of the vibrations in the piezoelectric actuator 801, the pushing member 816 alternatively contacts the movable member 805 and makes it move linearly by frictional coupling. In the embodiment shown in Fig.22, the linear ultrasonic piezo motor MO is configured to generate linear motion with a speed in the range of 4 mm / s to 100 mm / s and a force in the range of 0.5 N – 30 N. As the maximum stroke is limited by the length of the movable member 805 (also called a slider), there is no set limit for the maximum stroke. This configuration of a linear ultrasonic piezo motor creating a linear motion can be used to generate the linear motion of the infusion needle 11. Fig.23A illustrates an embodiment of a piezoelectric pump P configured to be implanted in the body of a patient. The piezoelectric pump P comprises a chamber 831a, a diaphragm 832a and a wall. The wall comprises a wall portion 833a. The diaphragm 832a is connected to the wall portion 833a, such that the wall portion 833a and the diaphragm 832a enclose the chamber 831a. The wall portion 833a comprises an inlet 834a and an outlet 835a. The inlet 834a and the outlet 835a are configured to connect the chamber 831a with an inlet reservoir (not shown) and an outlet reservoir (not shown), respectively. The diaphragm 832a is configured to bend such that the volume of the chamber varies The piezoelectric pump P is configured to be operated in a supply mode and a pump mode, as shown in Fig.23B and Fig.23C, respectively. In the supply mode, the diaphragm 832a bends downwards such that the volume of the chamber 831a increases, thereby decreasing the pressure in the chamber 831a compared to the inlet reservoir. Thus, an amount of fluid is supplied by the inlet reservoir to the chamber 831a via the inlet 834a. In the pump mode, the diaphragm 832a bends upwards such that the volume of the chamber 831a decreases, thereby increasing the pressure in the chamber 831a compared to the outlet reservoir. Thus, an amount of fluid is pumped from the chamber 831a to the outlet reservoir via the outlet 835a. The piezoelectric pump P comprises a driving element 836. The driving element 836 is coupled to the diaphragm 832a. A controller (cf. Fig.31) is configured to control the action of the driving element 836. In some embodiments, the driving element 836 is a piezoelectric actuator, e.g. a bimorph piezoelectric actuator or any of the piezoelectric actuators herein disclosed. The driving element 836 is configured to be connected to a voltage generator. In response to an applied voltage, the driving element 836 deforms elastically, thereby imparting stress to the diaphragm 832a. As a result, the diaphragm 832a bends downwards or upwards depending on the applied voltage. In other embodiments, the driving element 836 is driven by a piezoelectric motor. In these embodiments, the diaphragm 832a bends downwards or upwards in response to a mechanical displacement of the driving element 836 induced by the piezoelectric motor. Any one of the motors MO in Fig.15 to Fig.22 may be a piezoelectric motor. In any of the embodiments herein disclosed, the diaphragm 2a may comprise bellows 852, as shown in Fig.24. The bellows 852 enable the contraction and expansion of the diaphragm 2a by means of the elasticity of the bellows 852. In particular, in the embodiment shown in Fig.24, the bellows 852 is a metal bellows 852, in particular a titanium bellows 852. As the chamber 831a comprises the titanium bellows 852, at least a portion of the wall portion 833a being in contact with the fluid in the chamber 831a comprises metal, namely titanium. Metals are generally dense, which is advantageous as fluids do not diffuse through metals as easily. This reduces the risk that fluid diffuses from the chamber 831a or that fluids diffuse into the chamber 831a. In the embodiment shown in Fig.24, the entire wall enclosing the chamber 831a is made from metal, in particular titanium. In embodiments in which the wall enclosing the chamber is made from a composite of metallic or non-metallic materials, the non-metallic materials could be provided as a layer or a coating applied or sprayed onto the metal. In some embodiments, at least 50% of the area of the wall enclosing the chamber 831a comprises metal, and in alternative embodiments at least 80% of the area of the wall enclosing the chamber 831a comprises metal, and in yet alternative embodiments at least 90% of the area of the wall enclosing the chamber 831a comprises metal. Referring again to Fig.23A to Fig.23C, the wall may further comprise a wall portion 833b and the piezoelectric pump P a chamber 831b. In this case, the diaphragm 832a is connected to the wall portion 833b such that the wall portion 833b and the diaphragm 832a enclose the chamber 831b. The chamber 831a and chamber 831b are separated by the diaphragm 832a. The chamber 831a and chamber 831b are configured to contain a first fluid and a second fluid, respectively, the two fluids being possibly different. The chamber 831a is sealed from the chamber 831b, thereby preventing mixing of fluids between the two chambers. The fluid in the chamber 831b may be a gas, e.g. air. The sealing of the chamber 831a from chamber 831b is advantageous. In fact, a component unsuitable to be in contact with the fluid in the chamber 831a may be hosted by the chamber 831b. Such a component may be the driving element 836. In some embodiments, the piezoelectric pump P may further comprise a diaphragm 832b connected to the wall portion 833b. In these embodiments, the wall portion 833b and the diaphragm 832b enclose the chamber 831b. Both the diaphragm 832a and diaphragm 832b are coupled to the driving element 836. In response to the action of the driving element 836, the diaphragm 832a and diaphragm 832b bend towards the same direction, i.e. upwards or downwards. The driving element 836 may be interposed between the diaphragm 832a and diaphragm 832b to prevent contact of the driving element 836 with the fluid in any of the chambers 831a and 831b. Alternatively, the wall portion 833b may be open, such that no chamber 831b is formed. Then the driving element 836 is interposed between the diaphragm 832a and diaphragm 832b to prevent contact of the driving element 836 with, for instance, the fluid in the chamber 831a or the body of the patient. In some embodiments, the diaphragm 832b may comprise bellows 852. Then, the same considerations made on the diaphragm 832a, wall portion 833a and chamber 831a in connection with Fig.24 apply, mutatis mutandis, to the diaphragm 832b, wall portion 833b and chamber 831b. In any of the embodiments herein disclosed in which the wall portion 833b encloses the chamber 831b, the chamber 831b may be configured to be connected to a pressure adapter 861, as shown in Fig.25. In particular, in the embodiment in Fig.25 the pressure adapter 861 comprises a substantially stiff portion 862, an elastic portion 863 and a conduit 864. The elastic portion 863 is attached to the rigid portion 862, and connected to the conduit 864. The conduit 864 is configured to be connected to the chamber 831b via an opening 865 to enable variation of pressure in the chamber 831b. The volume enclosed by the elastic portion 863 increases when the pressure in the chamber 831b increases. Vice versa, the volume enclosed by the elastic portion 863 decreases when the pressure in the chamber 831b decreases. In some embodiments, the elastic portion 863 is configured to maintain the same surface area when the volume enclosed by the elastic portion 863 varies. This is advantageous in that a fibrotic tissue, as disclosed herein, which at least partially covers the elastic portion 863 may easily adapt to the elastic portion 863. The inlet 834a and the outlet 835a comprise an inlet valve 837a’ and an outlet valve 838a’, respectively. The inlet valve 837a’ and the outlet valve 838a’ are check valves, e.g. ball valves, bridge-type valves and cantilever-type valves. Check valves are configured to enable fluid flow in one direction while preventing backflow in the opposite direction. The inlet valve 837a’ is configured to enable fluid flow from the inlet reservoir to the chamber 831a, while preventing backflow in the opposite direction. Likewise, the outlet valve 838a’ is configured to enable fluid flow from the chamber 831a to the outlet reservoir, while preventing backflow in the opposite direction. In other embodiments, the inlet valve 837a’ and the outlet valve 838a’ are active valves, i.e. valves controlled by a driving element. The driving element may be an actuator, e.g. a piezoelectric actuator, or a motor, e.g. a piezoelectric motor. A controller (cf. Fig. 31) is configured to synchronize the opening and closing of the active valves so as to enable fluid transfer from the inlet 834a to the outlet 835a. Fig.26A and Fig.26B illustrate an embodiment of a ball valve 841 when enabling or inhibiting fluid flow, respectively. The ball valve comprises a flow control element 842, e.g. a ball, and a conduit 843. The conduit 843 comprises a portion 843a and a portion 843c. The conduit 843 further comprises a portion 843b connecting the conduit portion 843a and conduit portion 843c. The flow control element 842 is configured to move along the conduit portion 843c. The size of the flow control element 842 is such that the flow control element 842 cannot pass from the conduit portion 843c to the conduit portion 843a. For instance, if the flow control element 842 is a ball, the diameter of the ball is larger than a cross-section of a conduit portion 843b. When the pressure in the conduit portion 843a is larger than the pressure in the conduit portion 843c, the flow control element is pushed away from the conduit portion 843b and fluid flow is enabled from the conduit portion 843a to the conduit portion 843c. On the contrary, when the pressure in the conduit portion 843c is larger than the pressure in the conduit portion 843a, the flow control element 842 seals the conduit portion 843b such that fluid flow is inhibited from the conduit portion 843c to the conduit portion 843a. Fig.27A and Fig.27B illustrate an embodiment of a piezoelectric pump P operating in the supply mode and pump mode, respectively. The piezoelectric pump P is configured to be implanted in the body of a patient. In this embodiment, the inlet valve 837a’ and outlet valve 838a’ (cf. Fig.23A to Fig.23C) are replaced by a static element 837a’’ and a static element 838a’’, respectively. The static element 837a’’ and static element 838a’’ are configured to control the fluid flow throughout the chamber 831a while maintaining a static geometry. The static element 837a’’ comprises a passage 839a’’ with an increasing cross-sectional area when entering the chamber 831a. On the contrary, the static element 838a’’ comprises a passage 840a’’ with a decreasing cross-sectional area when entering the chamber 831a. The static element 837a’’ and static element 838a’’ are advantageous in that they are more resistant to wear and fatigue failure as compared to check valves and active valves. In fact, maintenance or replacement of an implantable device, such as the piezoelectric pumps disclosed herein or any of their components, pose risks for the patient. In the supply mode (cf. Fig.27A), the static element 837a’’ acts as a diffuser and the static element 838a’’ acts as a nozzle. An amount of fluid may enter the chamber 831a from the outlet 835a. However, the passage 839a’’ opposes a lower flow restriction than the passage 840a’’. As a result, the amount of fluid flowing into the chamber 831a via the inlet 834a is larger than the amount of fluid flowing into the chamber 831a via the outlet 835a. In the pump mode (cf. Fig.27B), the static element 837a’’ acts as a nozzle and the static element 838a’’ acts as a diffuser. An amount of fluid may exit the chamber 831a from the inlet 834a. However, the passage 840a’’ opposes a lower flow restriction than the passage 839a’’. As a result, the amount of fluid flowing out of the chamber 831a via the outlet 835a is larger than the amount of fluid flowing out of the chamber 831a via the inlet 834a. An embodiment of a piezoelectric pump P is illustrated in Fig.28. The piezoelectric pump P is configured to be implanted in the body of a patient. The piezoelectric pump P is configured to be operated in a double mode, as illustrated in the following. The piezoelectric pump P comprises an upper portion Pa and a lower portion Pc. The upper portion Pa comprises a chamber 831a, a diaphragm 832a and a wall portion 833a. The diaphragm 832a is connected to the wall portion 833a such that the wall portion 833a and the diaphragm 832a enclose the chamber 831a. The wall portion 833a comprises an inlet 834a and an outlet 835a. The inlet 834a and the outlet 835a are configured to connect the chamber 831a with a first inlet reservoir (not shown) and first outlet reservoir (not shown), respectively. The inlet 834a comprises an inlet valve 837a’ or a static element 837a’’. The outlet 835a comprises an outlet valve 838a’ or a static element 838a’’. The lower portion Pc comprises a chamber 831c, a diaphragm 832c and a wall portion 833c. The diaphragm 832c is connected to the wall portion 833c such that the wall portion 833c and the diaphragm 832c enclose the chamber 831c. The wall portion 833c comprises an inlet 834c and an outlet 835c. The inlet 834c and the outlet 835c are configured to connect the chamber 831c with a second inlet reservoir (not shown) and a second outlet reservoir (not shown), respectively. The inlet 834c comprises an inlet valve 837c’ or a static element 837c’’. The outlet 835c comprises an outlet valve 838c’ or a static element 838c’’. The chamber 831a and chamber 831c are configured to contain a first fluid and a second fluid, respectively, the two fluids being possibly different. The chamber 831a is sealed from the chamber 831c, thereby preventing mixing of fluids between the two chambers. The diaphragm 832a and diaphragm 832c are coupled and configured to bend towards the same direction, i.e. upwards or downwards. A driving element 836, e.g. a piezoelectric actuator or any other driving element herein disclosed, is coupled to the diaphragm 832a and diaphragm 832c. In response to the action of the driving element 836, the diaphragm 832a and diaphragm 832c bend towards the same direction, i.e. upwards or downwards. The driving element 836 may be interposed between the diaphragm 832a and diaphragm 832b to prevent contact of the driving element 836 with the fluid in any of the chambers 831a and 831c. In some embodiments, the diaphragm 832c may comprise bellows 852. Then, the same considerations made on the diaphragm 832a, wall portion 833a and chamber 831a in connection with Fig.24 apply, mutatis mutandis, to the diaphragm 832c, wall portion 833c and chamber 831c. The variation of the volume of the chamber 831a, due to a bending of the diaphragm 832a, is mirrored by an equal opposite variation of the volume of the chamber 831c, due to a bending of the diaphragm 832c. As a result, when the upper portion Pa operates in a supply mode, the lower portion Pc operates in the complementary mode, i.e. the pump mode. Vice versa, when the upper portion Pa operates in a pump mode, the lower portion Pc operates in the complementary mode, i.e. the supply mode. The double mode configuration illustrated in Fig.28 is advantageous in that a single driving element 836 simultaneously drives two chambers. Therefore, a piezoelectric pump P configured to be operated in a double mode may be cheaper, more space-efficient and more energy-efficient as compared to two independent piezoelectric pumps, each having its own driving element. It may also eliminate the need for an enclosed gas in the implant. Fig.29 shows an embodiment of a piezoelectric pump P comprising at least a first portion PL and a last portion PR connected in series. The series may comprise additional portions. Each of the portions may be any of the embodiments disclosed with reference to Fig. 23A to Fig.23C and Fig.27A and 27B. The piezoelectric pump P is configured to be implanted in the body of a patient. The outlet of the first portion PL is configured to be connected to the inlet of the next portion of the series. The inlet of the last portion PR is configured to be connected to the outlet of the previous portion of the series. The inlet of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the outlet of the previous portion of the series. The outlet of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the inlet of the next portion of the series. The piezoelectric pump P is configured to transfer an amount of fluid from an inlet reservoir, configured to be connected to the inlet 834a of the first portion PL, to an outlet reservoir, configured to be connected to the outlet 835a of the last portion PR. This amount of fluid passes, sequentially, through the chamber 831a of the first portion PL, the chambers 831a of the next portions, if any, and the chamber 831a of the last portion PR. A controller (cf. Fig.31) is configured to synchronize the action of the driving elements of the portions of the series. Thus, the bending of the diaphragms of the portions of the series is synchronized so as to create the pressure required for the fluid transfer. If any of the inlet and outlets comprises an active valve, the opening and closing of any of the active valves is controlled by the controller so as to enable the fluid transfer. The series connection allows for larger pressure compared to piezoelectric pumps in which fluid is transferred from an inlet to an outlet reservoir via a single chamber. In another embodiment (not shown), a piezoelectric pump P is provided comprising at least a first portion PL and a last portion PR connected in series. The series may comprise additional portions. The piezoelectric pump P is configured to be operated in a double mode. Each of the portions of the series may correspond to the embodiment disclosed with reference to Fig.28. Thus, each of the portions of the series may be configured to be operated in a double mode. Then, the outlet 835a of the first portion PL is configured to be connected to the inlet 834a of the next portion of the series, and the outlet 835c of the first portion PL is configured to be connected to the inlet 834c of the next portion of the series. The inlet 834a of the last portion PR is configured to be connected to the outlet 835a of the previous portion of the series, and the inlet 834c of the last portion PR is configured to be connected to the outlet 835c of the previous portion of the series. The inlet 834a of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the outlet 835a of the previous portion of the series. The inlet 834c of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the outlet 835c of the previous portion of the series. The outlet 835a of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the inlet 834a of the next portion of the series. The outlet 835c of each of the portions other than the first portion PL and last portion PR, if any, is configured to be connected to the inlet 834c of the next portion of the series. The piezoelectric pump P is configured to transfer an amount of a first fluid from a first inlet reservoir, configured to be connected to the inlet 834a of the first portion PL, to a first outlet reservoir, configured to be connected to the outlet 835a of the last portion PR. This amount of fluid passes, sequentially, through the chamber 831a of the first portion PL, the chambers 831a of the next portions, if any, and the chamber 831a of the last portion PR. The piezoelectric pump P is further configured to transfer an amount of a second fluid from a second inlet reservoir, configured to be connected to the inlet 834c of the first portion PL, to a second outlet reservoir, configured to be connected to the outlet 835c of the last portion PR. This amount of fluid passes, sequentially, through the chamber 831c of the first portion PL, the chambers 831c of the next portions, if any, and the chamber 831c of the last portion PR. A controller (cf. Fig.31) is configured to synchronize the action of the driving elements of the portions of the series. Thus, the bending of the diaphragms of the portions of the series is synchronized so as to create the pressure required for the fluid transfer. If any of the inlet and outlets comprises an active valve, the opening and closing of any of the active valves is controlled by the controller so as to enable the fluid transfer. The series connection allows for larger pressure as compared to piezoelectric pumps configured to be operated in a double mode in which a first fluid is transferred from a first inlet reservoir to a first outlet reservoir via a single first chamber and a second fluid is transferred from a second inlet reservoir to a second outlet reservoir via a single second chamber. Fig.30 shows an embodiment of a piezoelectric pump P comprising at least a first portion PU and a last portion PD connected in parallel. The parallel connection may comprise additional portions. Each of the portions may be any of the embodiments disclosed with reference to Fig.23A to 23C and Figs.27A and 27B. The piezoelectric pump P is configured to be implanted in the body of a patient. The inlet of each portion is configured to be connected to an inlet reservoir. The outlet of each portion is configured to be connected to an outlet reservoir. The piezoelectric pump P is configured to transfer an amount of fluid from the inlet reservoir to the outlet reservoir. A controller (cf. Fig.31) is configured to synchronize the action of the driving elements of the portions of the parallel connection in order to ensure synergetic operation, wherein, at a given operation stage, each portion operates in the same mode, i.e. either in the supply mode or pump mode. If any of the inlet and outlets comprises an active valve, the opening and closing of any of the active valves is controlled accordingly by the controller. The parallel connection allows for a higher flow rate as compared to piezoelectric pumps in which the inlet reservoir is configured to be connected to a single inlet and the outlet reservoir is configured to be connected to a single outlet. In another embodiment (not shown), a piezoelectric pump P is provided comprising at least a first portion PU and a last portion PD connected in parallel. The parallel connection may comprise additional portions. Each of the portions may correspond to the embodiment disclosed with reference to Fig.28. Thus, each of the portions of the parallel connection is configured to be operated in a double mode. Then the inlet 834a and inlet 834c of each portion are configured to be connected to a first inlet reservoir and second inlet reservoir, respectively. The outlet 835a and outlet 835c of each portion are configured to be connected to a first outlet reservoir and second outlet reservoir, respectively. The piezoelectric pump P is configured to transfer an amount of a first fluid from the first inlet reservoir to the first outlet reservoir. The piezoelectric pump P is further configured to transfer an amount of a second fluid from the second inlet reservoir to the second outlet reservoir. A controller (cf. Fig.31) is configured to synchronize the action of the driving elements of the portions of the parallel connection in order to ensure synergetic operation. Thus, at a given operation stage, the chamber 831a of each portion operates in the same mode, i.e. either in the supply mode or pump mode, and the chamber 831b of each portion operates in the complementary mode. If any of the inlet and outlets comprises an active valve, the opening and closing of any of the active valves is controlled accordingly by the controller. The parallel connection allows for a higher flow rate as compared to piezoelectric pumps configured to be operated in a double mode in which the first inlet reservoir and second inlet reservoir are configured to be connected to a single first inlet and single second inlet, respectively, and the first outlet reservoir and second outlet reservoir are configured to be connected to a single first outlet and single second outlet, respectively. The piezoelectric pumps herein disclosed are configured to be operated with a flow rate in the range of 0.01 ml / min to 35 ml / min and a pressure in the range of 0.2 kPa to 36 kPa. Fig.31 shows an embodiment of a piezoelectric pumping system configured to be implanted in the body of a patient. The system comprises a piezoelectric pump, an inlet reservoir, an outlet reservoir and a controller. The piezoelectric pump may be any of the piezoelectric pumps herein disclosed. The controller is configured to control the piezoelectric pump. The piezoelectric pumping system may comprise a sensor and a feedback unit. The sensor is configured to measure a parameter of the piezoelectric pump, such as flow rate and pressure. Based on the sensor measurement and a set value of the measured parameter, the feedback unit sends a conditioning signal to the controller. Thus, the controller adjusts the control of the piezoelectric pump in order for the measured parameter to achieve the set value. SECOND ASPECT – IMPLANTABLE VIBRATION DEVICE The present disclosure also relates to implantable vibration devices configured to deliver vibration stimulation to human tissue at an implanted position in the human body. In particular, the implantable vibration device may comprise a vibrating generating unit as described in greater detail in the following. In those embodiments of the present disclosure where the system comprises flow control device controlling flow of the intestinal contents which contacts the intestinal wall, such as a mechanical or hydraulic constriction device and / or an electrical stimulation device, the implantable vibration device may be provided in order to cause vibration of the muscle or neural tissue in the respective area in order to activate at least some of the mechanoreceptors of the muscle tissue in that area. The purpose is to exercise the tissue wall which is in contact with the device. Fig.32A schematically illustrates an implantable vibration device 110 which is suitable for operation in the human body according to any one of the embodiments described herein. It preferably comprises a casing 120. Contained in the casing 120, there is provided a piezoelectric vibration generating unit (VGU). The VGU is capable of causing the implantable vibration device 110 to vibrate in a suitable manner. In Fig.32A, the implantable vibration device 110 is also provided with a wireless energy receiver R for receiving wireless energy for the operation of the vibration generating unit, and an internal controller CI configured to control the operation of the vibration generating unit. By providing a wireless energy receiver R and an internal controller CI within the casing 120, a physically independent vibration generating device is obtained which can be implanted in the human body. Thus, leads and cables for controlling and / or providing energy to the vibration generating device can be omitted. In alternative embodiments, the wireless energy receiver R and the internal controller CImay be provided in a different casing, separate from the casing 120, and connected to the vibration generating unit via a lead or cable. Preferably, such lead or cable is flexible and short, typically having a length of less than 10 cm, such as less than 5 cm. This may be advantageous as it allows for the casing 120 to be implanted via invagination in the tissue of the patient, whereas a smaller casing containing the wireless energy receiver and / or internal control CI can be implanted in a different manner. The casing is shown in Fig.32A to have a substantially cylindrical outer shapes, but other shapes, in particular flat or such as a sphere, can also be contemplated, which is shown in Fig.32B. The casing 120 may be made of any suitable biocompatible material known to the person skilled in the art. In order to mitigate fibrin creation caused by contact between the implantable vibration device 110 and the tissue or flowing blood of the patient, the casing 120 may comprise a specific coating arranged on the outer surface of the casing 120. The coating may comprise at least one layer of a biomaterial. The biomaterial is preferably fibrin-based. The coating may comprise at least one drug or substance with antithrombotic and / or antibacterial and / or antiplatelet characteristics. The drug or substance may be encapsulated in a porous material. There may be provided a second coating arranged on the first coating. The second coating may be a different biomaterial than said first coating. In particular, the first coating may comprise a layer of perfluorocarbon chemically attached to the outer surface and the second coating may comprise a liquid perfluorocarbon layer. Finally, the surface may comprise a micro pattern, wherein the micro pattern may be etched into the outer surface prior to insertion into the patient’s body. The layer of a biomaterial may be coated on the micro pattern. According to an embodiment, the implantable vibration device 110 may be configured to be invaginated when placed on the outside of the intestinal wall. In another embodiment, the implantable vibration device 110 may be configured to be invaginated when placed on the inside of the intestinal wall. In some embodiments, the implantable vibration device 110 is configured to be at least partially invaginated by the tissue of the intestinal wall using intestine-to-intestine sutures or staplers. In some embodiments, the system comprises the intestine-to-intestine sutures or staplers. Thus, the implantable vibration device 110 can be kept in a partly invaginated position, preferably on the outside of the intestinal wall. Consequently, the vibration device can be kept in a position where it abuts the tissue of the intestinal wall. The vibration device may be adapted to be placed in the abdomen. In some embodiments the implantable vibration device is configured to abut the tissue of the intestinal wall on the outside thereof, preferably by being invaginated by the tissue of the intestinal wall. In some embodiments, the implantable vibration device has a volume of from 0.3 cm3– 6.6 cm3, or in a range 0.5 cm3– 7.3cm3, or in a range 3 cm3– 8 cm3, or in a range 2.5 cm3– 6.6 cm3, or in a range 4 cm3– 7.3 cm3. The wireless energy receiver R is configured to receive wireless energy for the operation of the vibration generating unit. In some embodiments, the wireless energy receiver R of the implantable vibration device 110 includes a secondary coil, configured to receive wireless energy from a wireless energy transmitter, preferably comprising a primary coil configured to induce a voltage in the secondary coil of the vibration device. This way, energy can be transmitted wirelessly from the energy transmitter to the energy receiver via the primary and secondary coils. A suitable transmitter is typically implanted at a second, distant position in the body of the patient. In some embodiments, RFID technology is used to transfer the energy wirelessly from an energy transmitter to the energy receiver R. RFID technology is widely known, and transfer of energy via the afore-mentioned primary and secondary coils is a well-known way of transferring energy by RFID technology. More specifically, the wireless energy receiver R may be configured to receive the energy via RFID pulses. In some embodiments, the internal controller CI further comprises a feedback unit configured to provide feedback pertaining to an amount of energy received by the wireless energy receiver (R) via the RFID pulses. Based on this feedback an amount of transmitted and / or received energy can be controlled based on the feedback. More specifically, the amount of RFID pulse energy that is being received may be adjusted based on the feedback such that the pulse frequency is successively raised until a satisfying level is reached. In some embodiments, the implantable vibration device 110 comprises a rechargeable energy storage unit for temporarily storing at least part of the wirelessly received energy. The rechargeable energy storage unit may be a rechargeable battery or a capacitor. The rechargeable energy storage unit may be charged over time so that an energy amount required by the implantable vibration device or devices is available when needed. The internal controller CImay serve various functions, the main function consisting in controlling the timing and amount of energy applied to the implantable vibration device 110 for controlling the vibrations. Another important function consists in controlling and possibly storing away the amount of energy that is received via the wireless energy receiver. In some embodiments, the rechargable energy storage unit discussed above forms part of the internal controller CI. The internal controller may further serve to communicate with an external controller and / or with a remote controller. For instance, such communication may relate, inter alia, to the energy transfer via the energy receiver and / or to the timing and / or amount of energy to be applied to the implantable vibration device 110. The internal controller CImay further be adapted to control whether the received energy should be utilized to charge the rechargeable energy storage device or to operate the vibration generating unit. In some embodiments, the internal controller CI is configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device 110. In some embodiments, the internal controller is configured to receive the vibration control data wirelessly via the wireless energy receiver R. The control data may be used to for controlling the vibration of the implantable vibration device 110, such that the relevant response in the patient can be activated. Thus, not only the energy transfer but also data transfer is carried out wirelessly in order for the implantable vibration device 110 to be physically independent from other parts of the system. Such data may be received either from an implanted external controller or from a remote controller outside the patient’s body. Preferably, the internal controller receives the vibration control data wirelessly via the wireless energy receiver R. In other words, the same port may be used to receive both energy and data. In particular, the energy transferred to and received by the implantable vibration device 110 via the wireless energy receiver R may be appropriately modulated, the modulation defining and, thus, carrying a signal which may be decoded by the internal controller CI and interpreted as data. This is a well-known technique, which is particularly known and used within the RFID technology. That is, an RFID signal may be used to transport both energy and information. In some embodiments, the internal controller CI includes an individual code by which it is individually addressable by an external controller or remote controller. If more than one implantable vibration device 110 is provided in the patient, each implantable vibration device 110 may be addressable individually by an external controller or remote controller using an individual code, i.e. a code which is specific to the respective internal controller. This is particularly useful where one external controller or remote controller is used to control more than one implantable vibration device 110 and / or where one wireless transmitter is used to transmit energy wirelessly to the wireless energy receivers CI of more than one implantable vibration device 110. For instance, when the implantable vibration devices 110 are to be activated sequentially, e.g. for stimulating the intestine in a wave-like manner, the respective implantable vibration device may be addressed individually using the individual code of the corresponding internal controller. Typically, such individual code is placed at the beginning of the data transmitted to the internal controller CI. This way, only one or more desired implantable vibration device 110 may be instructed at a given time to vibrate and / or only one or more implantable desired vibration devices 110 will receive and possibly store energy received through the wireless energy receiver CI. The vibration generating unit VGU is configured to cause the implantable vibration device 110 to vibrate, so that it is capable of temporarily agitating tissue of the patient when the implantable vibration device 110 is in its implanted position in the body. The vibrations provided by the implantable vibration device 110 can generally be defined by their frequency, their period and by their amplitude. The frequency denotes the number of complete cycles of vibration occurring per period of time. The vibration generating unit VGU can be configured to cause the implantable vibration device 110 to vibrate with a frequency in a range of from 0.01 Hz to 10,000 Hz. It has been found that a vibration frequency in a range of 1 – 200 Hz, such as in a range of 1 – 150 Hz, such as in a range of 30 – 150 Hz, preferably in a range of 35 – 150 Hz, such as in a range of 35 – 100 Hz, such as in a range of 60 – 100 Hz has proven advantageous for activating at least some of the mechanoreceptors responsible for constricting the intestine of the patient. In some embodiments, the implantable vibration device 110 is configured to vibrate with a period of 0.01 – 1 second, such as of 0.05 –1 second. The period of the vibration is defined as the time it takes for the vibration to complete its cycle. In some embodiments, the vibration generating unit VGU is configured to cause the implantable vibration device 110 to vibrate at an amplitude of at least mm. In some embodiments the vibration generating unit VGU is configured to cause the implantable vibration device 110 to vibrate at an amplitude of from 0.01 mm – 30 mm. The amplitude is defined as the maximum displacement of the mass center of the implantable vibration device 110 from its resting position. Preferably, the implantable vibration device 110 is provided at its invaginated position such that it can displace tissue of the intestinal wall for a distance approximately corresponding to the amplitude of the vibrations. A displacement of tissue of at least 1 mm has been found sufficient to activate the relevant mechanoreceptors in the intestine. Preferably, the implantable vibration device 110 is configured to vibrate at an amplitude of at least1 mm, such as of at least 2 mm, such as of at least 3 mm, such as at of at least 4 mm, such as at least 5 mm, such as at least 6 mm. In some embodiments, the vibration generating unit VGU is configured to cause the implantable vibration device 110 to vibrate at an amplitude in the range of 1 – 10 mm, such in the range of 1 - 5 mm, preferably 2 - 4 mm. This means that tissue which abuts the implantable vibration device 110 in the implanted position can be displaced a corresponding length by each vibration cycle. In some embodiments, the implantable vibration device 110 has a mass of at least 10 g. A sufficient mass is preferred such that a sufficient force can be delivered to the tissue for activating at least some of the mechanoreceptors. The vibration generating unit VGU is preferably operated by a piezoelectric motor. As described above in relation the first aspect of the present disclosure, piezoelectric motors can be made MRI-safe. Depending on the piezoelectric motor type, the vibrations may be caused by various mechanisms, such as by inchworm motors as described in relation to Fig.15 and Fig.16, inertial motors as described in relation to Fig.17, walk-drive motors as described in relation to Fig.18 and Fig.19, linear ultrasonic piezo motor shown in greater detail in Fig.22 and rotary ultrasonic motors, such as a traveling wave ultrasonic motor (TWUSM) shown in greater detail in Fig.20 or a standing wave ultrasonic motor (SWUSM) shown in greater detail in Fig.21. As also already explained above in relation to Fig.15 to Fig.19, the movable member of a piezoelectric inchworm, a piezoelectric inertial and a piezoelectric walk-drive motor may be replaced with a rotary module such that the piezoelectric inchworm / inertial / walk-drive motor is configured to generate rotary motion. A rotary piezoelectric inchworm / inertial / walk-drive motor can be used to rotate an eccentric mechanism to thereby cause a rotation in the implantable vibrator. Such a configuration is described in greater detail in relation to Fig.33A and Fig.33B. Fig.33A and Fig.33B schematically show two further embodiments of an implantable vibration device 110. These embodiments differ in the shape of their casing 120. Fig.33A shows a substantially cylindrical casing. Fig.33B shows a substantially spherical casing. Of course, other casing shapes suitable for implantation in the human body are also contemplated. The implantable vibration device 110 comprises a casing 120 which contains the vibration generating unit VGU. Herein, the vibration generating unit VGU is based on an eccentric mechanism for causing the implantable vibration device 110 to vibrate. The vibration generating unit VGU comprises a motor 604, a first motor axis 606, an eccentric element 608 eccentrically mounted to the first motor axis 606, a second axis 610 which is suitably supported by a bearing mounted to the casing 120. The vibration generating unit VGU may comprise a gear box 611 that transforms the speed of rotation of the motor 604 to a suitable speed. Upon operation of the motor 201, the eccentric element 608 will rotate eccentrically about the first axis 606, to thereby cause the implantable vibration device to vibrate. The operation of the motor is preferably operated by the internal control unit CI.The motor is preferably powered by energy received wirelessly by the energy transmitter. Another option for causing vibrations in the implantable vibration device 110 is to mount a weight on the motor 604 via an axis 606, wherein said axis is attached to the weight at a position offset from the center of the weight. Upon rotation of the weight, the implantable vibration device will be made to vibrate. All parts of the vibration generating unit VGU, including the motor 201, are preferably made of materials compatible with MRI scanning. Consequently, the VGU does not comprise any metallic and / or magnetic parts, and can instead be manufactured solely from polymeric and / or ceramic materials. Fig.34 illustrates an alternative mechanism suitable for a vibration generating unit, which is also based on a piezoelectric motor. In Fig.34 is a schematic side view of a vibration generating unit VGU, suitable to be placed in an implantable vibration device 110 according to the present invention. Fig.34 shows a simple design of a vibration generating mechanism VGU which comprises a piezoelectric material 101 sandwiched between electrode layers 102a, 102b. Each electrode layer comprises a tab which extends outside the footprint of the piezoelectric material and allows for further electrical connections in the form of leads connected to the wireless energy receiver R and / or controller CI. The energy transfer from the energy receiver R to the vibration generating unit is typically controlled by an internal controller CI. The piezoelectric material 101 is configured to extend in response to an applied electrical voltage controllable by the internal controller CI, or by an external controller. Once the voltage is removed or reversed, the piezoelectric material 101 contracts to its relaxed state. Consequently, by alternatingly applying and removing (or reversing) a voltage over the piezoelectric material, the material can be made to expand and contract at a frequency which corresponds to the frequency of the alternating voltage. If this is performed at a certain frequency, the alternating expansion and contraction can cause an implantable vibration device to vibrate at a corresponding frequency. The vibration generating unit is attached to the casing 120 of the implantable vibration device 110 via attachment means 104 such that the expansion and contraction movement of the piezoelectric material in the vibration generating unit can be transferred to the casing and cause the implantable vibration device 110 to vibrate. The “electrode – piezoelectric material – electrode” configuration is sandwiched between a pair of insulators 103a and 103b. THIRD ASPECT – EFFECTOR RESPONSE An exemplary system for affecting an effector response in a patient will now be discussed with reference to Fig.35A to Fig. 35E. Fig.35A is a schematic illustration of a particular example of the system and its interaction with the body of the patient P, and more particularly with an effector tissue 230 innervated by a sympathetic nerve 231 and a parasympathetic nerve 232. As indicated, the sympathetic nerve 231 and the parasympathetic nerve 232 may extend between the effector tissue 230 and the central nervous system (CNS) 233. The sympathetic nerve 231 may, for example, originate from the thoracic or lumbar regions of the spinal cord, whereas the parasympathetic nerve may originate in the brainstem or the sacral region of the spinal cord. In the present example, the origin of the illustrated nerves 231, 232 is represented by item 233. It will be appreciated that the effector tissue 230 and the CNS 233 are merely schematically indicated and that the technology described in the following may be applied to various types of nerves and effector tissues, located in various positions and parts of the body P. In some examples, the sympathetic nerve 231 and the parasympathetic nerve 232 may innervate the same effector tissue 230, which thus may be considered to have a dual autonomous nervous system (ANS) innervation. This means that the effector tissue 230 may receive competing inputs from the sympathetic and the parasympathetic divisions of the ANS. In other examples, the sympathetic nerve 231 may innervate a first effector tissue and the parasympathetic nerve 232 may innervate a second effector tissue, the second effector tissue being different from the first effector tissue 230. In other words, the sympathetic nerve 231 and the parasympathetic nerve 232 may innervate different organs, muscles, or part of a muscle. Both these examples, i.e., in which the sympathetic and parasympathetic nerves 231, 232 innervate the same or different tissue, are represented by item 230. As illustrated, the system comprises a stimulation device configured to deliver, directly or indirectly, a first simulation signal to the sympathetic nerve 231 innervating the first effector tissue 230 and a second stimulation signal to the parasympathetic nerve 232 innervating the second effector tissue 230. The effector tissue 230 may hence be the same effector tissue, forming part of the same muscle or organ, or different effector tissues 230, forming part of different muscles or organs. The system further comprises a control unit or controller 240, configured to control an operation of the stimulation device such that the first stimulation signal stimulates an activity of the sympathetic nerve 231 and the second stimulation signal inhibits an activity of the parasympathetic nerve 232 or such that the first stimulation signal inhibits an activity of the sympathetic nerve 231 and the second stimulation signal stimulates an activity of the parasympathetic nerve 232. Hence, each of the first and second stimulation signals may result either in an activation or an inhibition, depending on the characteristics of the stimulation signal. A signal that results in an activation of the nerve (and / or the effector tissue) may be referred to as an activation signal, whereas a signal that results in an inhibition of the nerve (and / or the effector tissue) may be referred to as an inhibition signal. “Activation of a nerve” is generally to be understood as the generation of a nerve signal, i.e., action potentials travelling in the nerve, whereas “inhibition of a nerve” is generally to be understood as blocking or hindering any nerve signals from propagating through the nerve. Inhibition may also be referred to as a suppression or blocking of the nerve and / or its signals. It should be noted that the blocking may not always be complete; on the contrary, there may still be some activity in the nerve. However, it is preferable to suppress the nerve signal to a degree that results in no or a negligible response in the effector tissue 230. The nervous response, or effector response, may typically be determined by, inter alia, a frequency content of the signal. The signal may be a periodic signal, including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component. Generally, a low-frequency stimulation may be more likely to result in inhibition, whereas high-frequency stimulation tends to excite neural pathways and effector tissue. Further, higher voltages and currents may more often lead to activation as compared to lower voltages and currents. The response to a stimulation signal may however vary based on other factors, such...

Claims

CLAIMS 1. A system for treating a patient having a disorder related to a patient’s intestine, comprising: - an artificial or artificially modified reservoir adapted for receiving and temporarily collecting therein intestinal contents and further adapted to remain within the patient’s body when emptying the reservoir, - a flow control device implantable in the patient’s body and adapted to control flow of the intestinal contents from the reservoir and - an implantable vibration device comprising a vibration generating unit (VGU) configured to cause the implantable vibration device to vibrate.

2. The system of claim 1, comprising a casing enclosing at least the vibration generating unit.

3. The system of claim 2, wherein the vibration generation unit comprises a wireless energy receiver (R) configured to receive wireless energy to be used, directly or indirectly, by the vibration generating unit, wherein the casing further encloses the wireless energy receiver (R).

4. The system of claim 2, wherein the vibration generation unit comprises a wireless energy receiver (R) configured to receive wireless energy to be used, directly or indirectly, by the vibration generating unit, wherein a wireless energy receiver is provided outside the casing and coupled to the vibration generating unit through a lead.

5. The system of any one of claims 2 to 4, wherein the vibration generating unit is attached to the casing, so that vibrations generated by the vibration generating unit can travel to the casing.

6. The system of any one of claims 2 to 5, further comprising a rechargeable energy storage unit for storing at least part of the received wireless energy.

7. The system of any one of claims 2 to 6, wherein the implantable vibration device (110) comprises an internal controller (CI).

8. The system of claim 7, wherein the internal controller (CI) is configured to wirelessly receive vibration control data for controlling the vibration of the implantable vibration device.

9. The system of claim 8, wherein the internal controller (CI) is configured to receive the vibration control data wirelessly via the wireless energy receiver (R).

10. The system of any one of claims 2 to 9, wherein the system does not comprise any metallic parts and does not comprise any magnetic parts.

11. The system of any one of claims 2 to 10, wherein the vibration generating unit is operated by a piezoelectric motor.

12. The system of claim 11, wherein the piezoelectric motor is a rotational piezoelectric motor.

13. The system of claim 12, wherein the vibration generating unit further comprises a weight configured to be eccentrically rotated by the rotational piezoelectric motor.

14. The system of any one of claims 2 to 13, wherein the implantable vibration device comprises an outer surface and a coating arranged on the outer surface.

15. The system of claim 14, wherein the coating comprises at least one layer of a biomaterial.

16. The system of claim 15, wherein the biomaterial comprises at least one drug or substance with one or more of the following characteristics: an antithrombotic, an antibacterial and an antiplatelet characteristic.

17. The system of claim 15 or 16 wherein the biomaterial is fibrin-based.

18. The system of any one of claims 15 to 17, further comprising a second coating arranged on the first coating.

19. The system of claim 18, wherein the second coating is of a different biomaterial than said first coating.

20. The system of claim 19, wherein the first coating comprises a layer of perfluorocarbon chemically attached to the surface, and wherein the second coating comprises a liquid perfluorocarbon layer.

21. The system of any one of claims 15 to 20, wherein the coating comprises a drug encapsulated in a porous material.

22. The system of any one of claims 15 to 21, wherein the outer surface of the implantable vibration device comprises a micro pattern.

23. The system of claim 22, further comprising a layer of a biomaterial coated on the micro pattern.

24. The system of any one of claims 1 to 23, wherein the system is configured to be applied to a reservoir section of the intestine (100) which is formed from surgically modified intestine (100) that has been cut along a mutual contact line of laterally adjacent sections of a bent portion of intestine (100) and connected so that the upper and lower halves of the cut intestine (100) form an intestinal wall of the reservoir section.

25. The system of any one of claims 1 to 24, comprising at least one mechanical or hydraulic constriction device configured to be implanted outside the patient’s intestine (100) in close proximity thereto for constricting the intestine (100) from the outside thereof.

26. The system of claim 25, wherein the mechanical or hydraulic constriction device forms part of a pump that is configured to advance intestinal contents through the patient’s intestine (100) in a downstream direction.

27. The system of claim 26, wherein the mechanical or hydraulic constriction device is a valve configured to open and close the intestine (100) by constriction to thereby control flow of intestinal contents through the intestine (100).

28. The system of any one of claims 1 to 27, comprising one or more electrical stimulation devices (10), wherein each of the one or more electrical stimulation devices (10) comprises one or more electrodes (11) for electrically stimulating muscle or neural tissue of the intestine (100) and a wireless energy receiver (R) configured to receive energy for stimulating the muscle or neural tissue wirelessly.

29. The system of claim 28, configured to electrically stimulate, by means of the electrodes (11) of the one or more electrical stimulation devices (10), the muscle or neural tissue sufficiently for a muscle of the intestine (100) to contract to an extent such that the intestine (100) constricts.

30. The system of claim 28 or 29, wherein the one or more electrical stimulation devices (10) form part of an electrical stimulation type pump that is configured to advance intestinal contents through the patient’s intestine (100) in a downstream direction.

31. The system of any one of claims 28 to 30, wherein at least the electrodes (11) of the one or more electrical stimulation devices (10) are configured to be implanted in surgically created folds (102) of the patient’s intestine (100).

32. The system of any one of claims 28 to 31, configured to electrically stimulate, by means of the electrodes (11) of the one or more electrical stimulation devices (10), the muscle or neural tissue in an area of the intestine (100) constricted by the at least one mechanical or hydraulic constriction device sufficiently for increasing blood flow through the tissue of the intestine (100).

33. The system of claim 32, wherein the electrical stimulation of the muscle or neural tissue for increasing blood flow through a tissue of the intestine (100) is adjustable at a level which is not enough to constrict the intestine (100).

34. The system of any one of claims 1 to 33, wherein the flow control device comprises at least one of: at least one piezoelectric motor and at least one piezoelectric pump.

35. The system of claim 34, wherein the at least one piezoelectric motor or pump is substantially non-magnetic.

36. The system of claim 34 or 35, wherein the at least one piezoelectric motor or pump is substantially non-metallic.

37. The system of any one of claims 34 to 36, wherein the piezoelectric motor or pump comprises a ceramic piezoelectric material.

38. The system of claim 37, wherein the piezoelectric material is lead zirconate titanate (PZT).

39. The system of claim 37, wherein the piezoelectric material is barium titanate.

40. The system of claim 37, wherein the piezoelectric material is lead titanate.

41. The system of any one of claims 36 to 40, wherein the piezoelectric motor comprises a polymeric piezoelectric material.

42. The system of claim 41, wherein the polymeric piezoelectric material is polyvinylidene fluoride (PVDF).

43. The system of any one of claims 36 to 42, wherein the at least one piezoelectric motor is arranged for driving a pump for pumping fluid between the first and second fluid chambers.

44. The system of any one of claims 36 to 43, wherein the at least one piezoelectric motor comprises a piezoelectric inchworm motor.

45. The system of any one of claims 36 to 43, wherein the at least one piezoelectric motor comprises a piezoelectric inertial motor.

46. The system of any one of claims 36 to 43, wherein the at least one piezoelectric motor comprises a piezoelectric walk-drive motor.

47. The system of any one of claims 36 to 46, wherein the piezoelectric motor is a linear piezoelectric motor.

48. The system of claim 47, wherein the linear piezoelectric motor operates with at least one of: - a speed in a range of 1 mm / s to 10 mm / s, - a stroke length in a range of 4 mm – 30 mm, and - a force in a range of 2 N – 30 N.

49. The system of any one of claims 36 to 47, wherein the piezoelectric motor is a rotary piezoelectric motor.

50. The system of claim 49, wherein the rotary piezoelectric motor which operates with at least one of: - a rotational speed in a range of 1 mrad / s – 100 mrad / s, and - a torque in a range of 100 Nmm – 900 Nmm.

51. The system of any one of claims 36 to 43, wherein the at least one piezoelectric motor comprises a piezoelectric ultrasonic motor.

52. The system of claim 51, wherein the piezoelectric ultrasonic motor is a traveling wave ultrasonic motor.

53. The system of claim 51, wherein the piezoelectric ultrasonic motor is a standing wave ultrasonic motor.

54. The system of any one of claims 51 to 53, wherein the piezoelectric ultrasonic motor is a rotary piezoelectric ultrasonic motor which operates with at least one of: - a rotational speed in a range of 10 mrad / s – 10,000 mrad / s, and - a torque in a range of 20 Nmm – 450 Nmm.

55. The system of any one of claims 51 to 53, wherein the piezoelectric ultrasonic motor is a linear piezoelectric ultrasonic motor which operates with at least one of: - a speed in a range of 4 mm / s – 100 mm / s, - a stroke length in a range of 4 mm – 30 mm, and - a force in a range of 0.5 N – 30 N.

56. The system of any one of claims 36 to 55, wherein the at least one piezoelectric motor comprises at least one bimorph piezoelectric actuator.

57. The system of any one of claims 34 to 56, wherein the at least one piezoelectric motor is a reversible piezoelectric motor.

58. The system of any one of claims 34 to 57, wherein the at least one piezoelectric motor forms part of the drive unit.

59. The system of any one of claims 34 to 58, wherein the at least one piezoelectric pump is configured for pumping fluid between the first and second fluid chambers.

60. The system of claim 59, wherein the piezoelectric pump comprises a first wall portion, a first diaphragm, a first chamber and a driving element, wherein - the first diaphragm and the first wall portion enclose the first chamber, - the first wall portion comprises an inlet, configured to connect the first chamber to a first inlet reservoir, and an outlet, configured to connect the first chamber to a first outlet reservoir, - the first diaphragm is configured to bend in response to operation of the driving element and - the driving element comprises a piezoelectric actuator or is configured to be operated by a piezoelectric motor.

61. The system of claim 60, wherein the inlet of the first wall portion comprises an inlet valve and the outlet of the first wall portion comprises an outlet valve.

62. The system of claim 61, wherein any of the inlet valve of the first wall portion and outlet valve of the first wall portion is a check valve or an active valve.

63. The system of claim 62, wherein the check valve is a ball valve.

64. The system of claim 60, wherein the inlet of the first wall portion comprises an inlet static element and the outlet of the first wall portion comprises an outlet static element, wherein any of the inlet static element and outlet static element is configured to act as a nozzle or a diffuser.

65. The system of any one of claims 60 to 64, wherein the first diaphragm comprises a first movable wall portion.

66. The system of claim 65, wherein the first movable wall portion comprises elevated and lowered portions, wherein the elevated and lowered portions enable at least one of compression and expansion for moving the first movable wall portion.

67. The system of claim 66, wherein the first movable wall portion comprises a substantially stiff portion.

68. The system of any one of claims 65 to 67, wherein the first movable wall portion comprises a bellows.

69. The system of claim 68, wherein the bellows comprises metal.

70. The system of claim 69, wherein the bellows comprises at least one of: an oval cross-section, an elliptic cross-section and a circular cross-section.

71. The system of any one of claims 60 to 70, wherein the piezoelectric pump further comprises: - an auxiliary wall portion and - an auxiliary chamber sealed from the first chamber, wherein the auxiliary wall portion and the first diaphragm enclose the auxiliary chamber.

72. The system of any one of claims 60 to 70, wherein the piezoelectric pump further comprises:- an auxiliary wall portion, - an auxiliary chamber sealed from the first chamber and - an auxiliary diaphragm configured to bend in the same direction as the first diaphragm in response to operation of the driving element, wherein the auxiliary wall portion and the auxiliary diaphragm enclose the auxiliary chamber.

73. The system of claim 71 or 72, wherein the auxiliary chamber is configured to be connected to a pressure adapter enabling variation of pressure in the auxiliary chamber.

74. The system of claim 73, wherein the pressure adapter comprises an elastic portion having a surface area and wherein the elastic portion is configured to maintain substantially the same surface area while enabling variation of pressure in the auxiliary chamber.

75. The system of any one of claims 60 to 70, wherein the piezoelectric pump further comprises a second wall portion, a second diaphragm and a second chamber, wherein - the second diaphragm and the second wall portion enclose the second chamber, - the second wall portion comprises an inlet, configured to connect the second chamber to a second inlet reservoir, and an outlet, configured to connect the second chamber to a second outlet reservoir, and - the second diaphragm is configured to bend in the same direction as the first diaphragm in response to operation of the driving element.

76. The system of claim 75, wherein the inlet of the second wall portion comprises an inlet valve and the outlet of the second wall portion comprises an outlet valve.

77. The system of claim 76, wherein any of the inlet valve of the second wall portion and outlet valve of the second wall portion is a check valve or an active valve.

78. The system of claim 77, wherein the check valve is a ball valve.

79. The system of claim 75, wherein the inlet of the second wall portion comprises an inlet static element and the outlet of the second wall portion comprises an outlet static element, wherein any of the inlet static element and outlet static element is configured to act as a nozzle or a diffuser.

80. The system of any one of claims 60 to 74, wherein the piezoelectric pump comprises at least two portions connected in series, wherein each portion is a piezoelectric pump of any one of claims 60 to 74.

81. The system of any one of claims 75 to 79, wherein the piezoelectric pump comprises at least two portions connected in series, wherein each portion is a piezoelectric pump of any one of claims 75 to 79.

82. The system of any one of claims 60 to 74, wherein the piezoelectric pump comprises at least two portions connected in parallel, wherein each portion is a piezoelectric pump of any one of claims 60 to 74.

83. The system of any one of claims 75 to 79, wherein the piezoelectric pump comprises at least two portions connected in parallel, wherein each portion is a piezoelectric pump of any one of claims 75 to 79.

84. The system of any one of the claims 60 to 83, wherein the system further comprises a controller configured to control the piezoelectric pump.

85. The system of claim 84, comprising a sensor configured to measure a parameter of the piezoelectric pump, and a feedback unit, wherein: - the sensor is further configured to transmit the measured parameter to the feedback unit, - the feedback unit is configured to transmit a conditioning signal to the controller based on the measured parameter received from the sensor and based on a set value of the parameter, and - the controller is configured to adjust the control of the piezoelectric pump based on the conditioning signal received from the feedback unit in order for the measured parameter to achieve the set value.

86. The system of claim 85, wherein the parameter of the piezoelectric pump measured by the sensor comprises at least a flow rate or a pressure.

87. The system of any one of claims 1 to 86, comprising means for affecting an effector response in the patient, said means comprising: - a stimulation device configured to deliver, directly or indirectly, a first stimulation signal to a sympathetic nerve innervating a first effector tissue of the patient and a second stimulation signal to a parasympathetic nerve innervating a second effector tissue; and - a control unit configured to control an operation of the stimulation device such that: - the first stimulation signal stimulates an activity of the sympathetic nerve and the second stimulation signal inhibits an activity of the parasympathetic nerve or - the first stimulation signal inhibits an activity of the sympathetic nerve and the second stimulation signal stimulates an activity of the parasympathetic nerve.

88. The system of claim 87, wherein the control unit is configured to control the operation of the stimulation device such that at least one of the first stimulation signal and second stimulation signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component.

89. The system of claim 87 or 88, wherein: - the first signal is a low-frequency signal configured to stimulate the activity of the sympathetic nerve and the second signal is a high-frequency signal configured to inhibit the activity of the parasympathetic nerve; or- the first signal is a high-frequency signal configured to inhibit the activity of the sympathetic nerve and the second signal is a low-frequency signal configured to stimulate the activity of the parasympathetic nerve.

90. The system of claim 89, wherein an amplitude of the low-frequency signal varies with a frequency in a range of 0.1 - 100 Hz and wherein an amplitude of the high-frequency signal varies with a frequency in a range of 1 - 10 kHz.

91. The system of any one of claims 87 to 90, wherein at least one of the first and second stimulation signals comprises a series of pulses having a negative voltage relative to ground.

92. The system of claim 91, wherein the control unit is configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses.

93. The system of any one of claims 87 to 92, wherein at least one of the first stimulation signal and the second stimulation signal is an electric signal or a vibrational signal.

94. The system of any one of claims 87 to 93, wherein the control unit is configured to operate the stimulation device so as to alternatingly apply the first stimulation signal to the sympathetic nerve and the second stimulation signal to the parasympathetic nerve.

95. The system of any one of claims 87 to 94, wherein the control unit is configured to operate the stimulation device so as to simultaneously apply the first stimulation signal to the sympathetic nerve and the second stimulation signal to the parasympathetic nerve.

96. The system of any one of claims 87 to 95, wherein the control unit is configured to control the operation of the stimulation device to generate an effector response as a muscular response.

97. The system of claim 96, wherein: each of the first and second effector tissue is a muscular tissue; and the control unit is configured to control the operation of the stimulation device such that the first stimulation signal stimulates the activity of the sympathetic nerve and the second stimulation signal inhibits the activity of the parasympathetic nerve, thereby inducing contraction in the muscular tissue.

98. The system of claim 96, wherein: each of the first and second effector tissue is a muscular tissue; and the control unit is configured to control the operation of the stimulation device such that the first stimulation signal inhibits the activity of the sympathetic nerve and the second stimulation signal stimulates the activity of the parasympathetic nerve, thereby inducing relaxation in the muscular tissue.

99. The system of claim 97 or 98, wherein the first and second effector tissue is smooth muscle tissue.

100. The system of claim 99, wherein the first and second effector tissue form part of an intestine of the patient.

101. The system of any one of claims 87 to 100, further comprising: a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue and a control unit configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal.

102. The system of claim 101, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue.

103. The system of claim 101, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue.

104. The system of claim 101, wherein the sensor device comprises an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue.

105. The system of claim 102 or 103, wherein: the sensor electrode is configured to be arranged at the effector tissue, the sensor device further comprises a reference electrode and the sensor device is configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode.

106. The system of claim 105, wherein the reference electrode is formed by a housing of the stimulation device or the sensor device.

107. The system of any one of claims 101 to 106, wherein the sensor device is configured to measure mechanical movement in the effector tissue.

108. The system of claim 107, wherein the sensor device comprises a strain gauge configured to measure a contraction or relaxation of the effector tissue.

109. The system of any one of claims 101 to 108, wherein the control unit is configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response.

110. The system of claim 109, wherein the control unit is configured to compare the response measure with a predetermined reference measure and control the stimulation device to:in response to the response measure being below the reference measure, one or both: (a) increase an intensity of the first stimulation signal to stimulate the activity in the sympathetic nerve and (b) increase an intensity of the second stimulation signal to inhibit the activity of the parasympathetic nerve, and in response to the response measure exceeding the reference measure, one or both: (a) reduce the intensity of the first stimulation signal to inhibit the activity of the sympathetic nerve and (b) stimulate the activity of the parasympathetic nerve.

111. The system of claim 110, wherein the predetermined reference measure is based on a previous measurement of the effector response in the patient.

112. The system of claim 110 or 111, wherein the predetermined reference measure is based on previous measurement of effector responses in other patients.

113. The system of any one of claims 109 to 112, wherein the control unit is configured to monitor the response measure of effector response over time and control the stimulation device based on a change rate in the effector response over time.

114. The system of any one of claims 109 to 112, wherein the control unit is configured to determine a calibration parameter of the stimulation device based on the response measure.

115. The system of any one of claims 87 to 114, wherein the stimulation device comprises a first electrode arrangement configured to be coupled to the sympathetic nerve to deliver the first stimulation signal and a second electrode arrangement configured to be coupled to the parasympathetic nerve to deliver the second stimulation signal.

116. The system of claim 115, wherein the first electrode arrangement comprises a first stimulation electrode and a second stimulation electrode, wherein the first stimulation electrode and the second stimulation electrode are configured to be spaced apart along the sympathetic nerve.

117. The system of claim 115 or 116, wherein the stimulation device is configured to generate the first stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode.

118. The system of any one of claims 115 to 117, further comprising a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the sympathetic nerve.

119. The system of any one of claims 115 to 118, wherein the second electrode arrangement comprises a third electrode and a fourth electrode, the third electrode and the fourth electrode being configured to be arranged spaced apart along the parasympathetic nerve.

120. The system of claim 119, wherein the second electrode arrangement further comprises a fifth electrode configured to be arranged spaced apart from the fourth electrode such that the fourth electrode is arranged between the third and fifth electrodes.

121. The system of claim 120, wherein the stimulation device is configured to generate the second stimulation signal such that the fourth electrode serves as a cathode and the third and fifth electrodes serve as anodes.

122. The system of any one of claims 116 to 121, further comprising a cuff configured to be at least partially arranged around the parasympathetic nerve and hold the second electrode arrangement in place against the parasympathetic nerve.

123. The system of any one of claims 1 to 86, comprising means for affecting an effector response in the patient, comprising: - a stimulation device configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, and - a control unit configured to operate the stimulation device to apply at least one of a first stimulation signal and a second stimulation signal to the effector tissue, wherein the first stimulation signal is a time-varying signal with an amplitude varying with a frequency lying in a first frequency interval, wherein the second stimulation signal is a time-varying signal with an amplitude varying with a frequency lying in a second frequency interval, wherein the first frequency interval is selected to induce the effector response in the effector tissue, and wherein the second frequency interval is selected to inhibit the effector response in the effector tissue.

124. The system of claim 123, wherein the first frequency interval is in a range of 0.1 - 100 Hz and the second frequency interval is in a range of 1 - 10 kHz.

125. The system of claim 123 or 124, wherein at least one of the first and second stimulation signals is an electric signal comprising a series of pulses having a negative voltage relative to ground.

126. The system of claim 125, wherein the control unit is configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses.

127. The system of claim 125 or 126, wherein the control unit is configured to operate the stimulation device to generate a first stimulation signal having a frequency in a range of 0.1 - 100 Hz, and wherein the effector tissue is smooth muscle tissue.

128. The system of any one of claims 123 to 127, wherein at least one of the first stimulation signal and the second stimulation signal is an electric signal.

129. The system of any one of claims 123 to 128, wherein the control unit is configured to operate the stimulation device to alternatingly apply the first stimulation signal and the second stimulation signal to the effector tissue.

130. The system of any one of claims 123 to 129, further comprising a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, wherein the control unit is further configured to: receive the sensor signal andcontrol an operation of the stimulation device based at least in part on the sensor signal.

131. The system of claim 130, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue.

132. The system of claim 130, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue.

133. The system of claim 130, wherein sensor device comprises an electromyographic sensor electrode configured to measure an electric activity in the effector tissue and an electric impedance sensor electrode configured to measure a change in electrical impedance in the effector tissue.

134. The system of claim 131 or 132, wherein: the sensor electrode is configured to be arranged at the effector tissue, the sensor device further comprises a reference electrode, and the sensor device is configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode.

135. The system of claim 134, wherein the reference electrode is formed by a housing of the stimulation device or the sensor device.

136. The system of any one of claims 130 to 135, wherein the sensor device is configured to measure mechanical movement in the effector tissue.

137. The system of claim 136, wherein the sensor device comprises a strain gauge configured to measure a contraction or relaxation of the effector tissue.

138. The system of any one of claims 130 to 137, wherein the control unit is configured to determine a response measure based on the sensor signal, the response measure being indicative of the effector response.

139. The system of claim 138, wherein the control unit is configured to compare the response measure with a predetermined reference measure and control the stimulation device to: in response to the response measure being below the reference measure, increase an intensity of the first stimulation signal to stimulate the activity in the in the effector tissue, and in response to the response measure exceeding the reference measure, increase the intensity of the second stimulation signal to inhibit the activity of the effector tissue.

140. The system of claim 139, wherein the predetermined reference measure is based on a previous measurement of the effector response in the patient.

141. The system of claim 139 or 140, wherein the predetermined reference measure is based on a previous measurement of effector responses in other patients.

142. The system of any one of claims 138 to 141, wherein the control unit is configured to monitor the response measure of effector response over time and control the stimulation device based on a change rate in the effector response over time.

143. The system of any one of claims 138 to 142, wherein the control unit is configured to determine a calibration parameter of the stimulation device based on the response measure.

144. The system of any one of claims 123 to 143, wherein the stimulation device comprises a first electrode arrangement configured to deliver the first stimulation signal and a second electrode arrangement configured to deliver the second stimulation signal.

145. The system of claim 144, wherein the first electrode arrangement comprises a first stimulation electrode and a second stimulation electrode, wherein the first stimulation electrode and the second stimulation electrode are configured to be spaced apart along the nerve innervating the effector tissue.

146. The system of claim 144 or 145, wherein the stimulation device is configured to generate the first stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode.

147. The system of any one of claims 144 to 146, further comprising a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the nerve.

148. The system of any one of claims 144 to 147, wherein the second electrode arrangement comprises a third electrode and a fourth electrode, wherein the third electrode and the fourth electrode is configured to be arranged spaced apart along the nerve.

149. The system of claim 148, wherein the stimulation device is configured to generate the second stimulation signal such that the third electrode serves as a cathode and the fourth electrode serves as an anode.

150. The system of any one of claims 144 to 149, further comprising a cuff configured to be at least partially arranged around the nerve and hold the second electrode arrangement in place against the nerve.

151. The system of any one of claims 123 to 150, further comprising a suppression electrode arrangement configured to be coupled to the nerve in order to apply a suppression signal which is configured to suppress action potentials propagating in the nerve in a direction towards the central nervous system.

152. The system of claim 151, wherein the control unit is configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the first stimulation signal.

153. The system of claim 151 or 152, wherein stimulation device is configured to be coupled to the nerve at a position between the effector tissue and the suppression electrode arrangement so as to induce action potentials travelling in the nerve in a direction towards the effector tissue.

154. The system of any one of claims 151 to 153, wherein the control unit is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, wherein the undesired response is generated responsive to the stimulation device applying the first stimulation signal.

155. The system of any one of claims 151 to 154, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation device and the suppression electrode arrangement is actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the first stimulation signal.

156. The system of any one of claims 151 to 154, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement so as to apply the first stimulation signal and the suppression signal substantially at the same time.

157. The system of any one of claims 151 to 156, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement such that each of the first stimulation signal and the suppression signal is a time-varying signal, wherein the first stimulation signals is a low-frequency signal and the suppression signal is a high-frequency signal.

158. The system of any one of claims 151 to 157, wherein an amplitude of the first stimulation signal varies with a frequency in a range of 0.1 - 100 Hz and wherein an amplitude of the suppression signal varies with a frequency in a range of 1 - 10 kHz.

159. The system of any one of claims 1 to 86, comprising means for affecting an effector response in the patient, comprising: - a stimulation device comprising a first electrode arrangement and a second electrode arrangement, each configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, and - a control unit configured to drive the stimulation device to apply, by means of the first electrode arrangement, a stimulation signal inducing the effector response in the effector tissue, and, by means of the second electrode arrangement, a suppression signal suppressing action potentials propagating in the nerve towards the central nervous system (CNS), wherein the control unit is configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal.

160. The system of claim 159, wherein the first electrode arrangement is configured to be coupled to the nerve at a position between the effector tissue and the second electrode so as to induce action potentials travelling in the nerve in a direction towards the effector tissue.

161. The system of claim 160, wherein the control unit is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, wherein the undesired response is generated responsive to the first electrode applying the stimulation signal.

162. The system of claim 160 or 161, wherein the control unit is configured to drive the stimulation device such that each of the first and second electrode arrangements are actuated in sequence, with a delay of the suppression signal timed to match a conduction velocity of the stimulation signal.

163. The system of any of claims 159 to 161, wherein the control unit is configured to drive the stimulation device to apply the stimulation signal and the suppression signal substantially at the same time.

164. The system of any one of claims 159 to 163, wherein the control unit is configured to drive the stimulation device such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signal is a low-frequency signal and the suppression signal is a high-frequency signal.

165. The system of claim 164, wherein an amplitude of the stimulation signal varies with a frequency in a range of 0.1 - 100 Hz and wherein an amplitude of the suppression signal varies with a frequency in a range of 1 - 10 kHz.

166. The system of any one of claims 159 to 165, wherein the first and second electrode arrangements are configured to be spaced apart along the nerve.

167. The system of any one of claims 159 to 166, wherein the first electrode arrangement comprises a first stimulation electrode and a second stimulation electrode configured to apply the stimulation signal to the effector tissue or the nerve.

168. The system of claim 167, wherein the first stimulation electrode and the second stimulation electrode are configured to be spaced apart along the nerve.

169. The system of claim 167 or 168, wherein the stimulation device is configured to generate the stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode.

170. The system of any one of claims 159 to 169, further comprising a cuff configured to be at least partially arranged around the nerve and hold the first electrode arrangement in place against the nerve.

171. The system of any one of claims 159 to 170, wherein the second electrode arrangement comprises a first suppression electrode and a second suppression electrode configured to apply the suppression signal to the nerve.

172. The system of claim 171, wherein the first suppression electrode and the second suppression electrode are configured to be spaced apart along the nerve.

173. The system of claim 171 or 172, wherein the second electrode arrangement further comprises a third suppression electrode configured to be arranged spaced apart from the second suppression electrode such that the second suppression electrode is arranged between the first and third suppression electrodes.

174. The system of claim 173, wherein the stimulation device is configured to generate the suppression signal such that the second suppression electrode serves as a cathode and the first and third suppression electrodes serve as anodes.

175. The system of any one of claims 171 to 174, further comprising a cuff configured to be at least partially arranged around the nerve and hold the second electrode arrangement in place against the nerve.

176. The system of any one of claims 159 to 175, further comprising a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, wherein the control unit is further configured to: receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal.

177. The system of claim 176, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue.

178. The system of claim 176, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue.

179. The system of claim 176, wherein sensor device comprises an electromyographic sensor electrode configured to measure an electric activity in the effector tissue and an electric impedance sensor electrode configured to measure a change in electrical impedance in the effector tissue.

180. The system of claim 177 or 178, wherein: the sensor electrode is configured to be arranged at the effector tissue; the sensor device further comprises a reference electrode, and the sensor device is configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode.

181. The system of claim 180, wherein the reference electrode is formed by a housing of the stimulation device or the sensor device.

182. The system of any one of claims 176 to 181, wherein the sensor device is configured to measure mechanical movement in the effector tissue.

183. The system of claim 182, wherein the sensor device comprises a strain gauge configured to measure a contraction or relaxation of the effector tissue.

184. The system of any one of claims 176 to 181, wherein the control unit is configured to determine a response measure based on the sensor signal, wherein the response measure is indicative of the effector response.

185. The system of claim 184, wherein the control unit is configured to compare the response measure with a predetermined reference measure and control the stimulation device to:in response to the response measure being below the reference measure, increase an intensity of the stimulation signal to stimulate the activity in the in the effector tissue, and in response to the response measure exceeding the reference measure, reduce the intensity of the stimulation signal to inhibit the activity of the effector tissue.

186. The system of claim 185, wherein the predetermined reference measure is based on a previous measurement of the effector response in the patient.

187. The system of claim 184 or 185, wherein the predetermined reference measure is based on a previous measurement of effector responses in other patients.

188. The system of any one of claims 184 to 187, wherein the control unit is configured to monitor the response measure of effector response over time, and to control the stimulation device based on a change rate in the effector response over time.

189. The system of any one of claims 184 to 187, wherein the control unit is configured to determine a calibration parameter of the stimulation device based on the response measure.

190. The system of any one of claims 1 to 86, comprising means for affecting an effector response in the patient, comprising: - a stimulation device configured to deliver, directly or indirectly, a stimulation signal to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, - a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, and - a control unit configured to receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal.

191. The system of claim 190, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue in response to the stimulation signal.

192. The system of claim 190, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue in response to the stimulation signal.

193. The system of claim 190, wherein sensor device comprises an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue.

194. The system of claim 191 or 192, wherein: the sensor electrode is configured to be arranged at the effector tissue, the sensor device further comprises a reference electrode, andthe sensor device is configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode.

195. The system of claim 194, wherein the reference electrode is formed by a housing of the stimulation device or the sensor device.

196. The system of any one of claims 190 to 195, wherein the sensor device is configured to measure mechanical movement in the effector tissue in response to the stimulation signal.

197. The system of claim 196, wherein the sensor device comprises a strain gauge configured to measure a contraction or relaxation of the effector tissue in response to the stimulation signal.

198. The system of claim 190, wherein the sensor device is configured to measure a heart rate of the patient.

199. The system of claim 190, wherein the sensor device is configured to measure a blood pressure of the patient.

200. The system of claim 190, wherein the sensor device is configured to measure a rate of respiration of the patient.

201. The system of any one of claims 190 to 200, wherein the control unit is configured to determine a response measure based on the sensor signal, wherein the response measure is indicative of the effector response.

202. The system of claim 201, wherein the control unit is configured to compare the response measure with a predetermined reference measure and control the stimulation device to: increase an intensity of the stimulation signal in response to the response measure being below the reference measure and reduce the intensity of the stimulation signal in response to the response measure exceeding the reference measure.

203. The system of claim 202, wherein the control unit is configured to: increase the intensity of the stimulation signal by increasing at least one of a frequency, current amplitude, and voltage amplitude of the stimulation signal; and reduce the intensity of the stimulation signal by reducing at least one of the frequency, current amplitude, and voltage amplitude of the stimulation signal.

204. The system of claim 202 or 203, wherein the predetermined reference measure is based on a previous measurement of the effector response in the patient.

205. The system of claim 202 or 203, wherein the predetermined reference measure is based on previous measurements of effector responses in other patients.

206. The system of claim 201, wherein the control unit is configured to monitor the level of effector response over time and control the stimulation device based on a change rate in the effector response over time.

207. The system of claim 201, wherein the control unit is configured to determine a calibration parameter of the stimulation device based on the response measure.

208. The system of any one of claims 190 to 207, wherein the control unit is configured to control the operation of the stimulation device to generate an effector response being a muscular response.

209. The system of claim 208, wherein the effector tissue is smooth muscle tissue.

210. The system of claim 209, wherein the effector tissue forms part of an intestine of the patient.

211. The system of any one of claims 190 to 210, wherein the control unit is configured to control the operation of the stimulation device such that the stimulation signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component.

212. The system of claim 211, wherein the stimulation signal is one of a low-frequency signal with an amplitude varying in a range of 0.1 - 100 Hz and a high-frequency signal with an amplitude varying in a range of 1 - 10 kHz.

213. The system of any one of claims 190 to 212, wherein the stimulation signal comprises series of pulses having a negative voltage relative to ground.

214. The system of claim 213, wherein the control unit is configured to operate the stimulation device to generate a positive voltage pulse following one or more negative voltage pulses.

215. The system of any one of claims 190 to 214, wherein the stimulation signal is an electric signal or a vibrational signal.

216. The system of any one of claims 190 to 215, wherein the stimulation device comprises a first stimulation electrode and a second stimulation electrode, wherein the first stimulation electrode and the second stimulation electrode are configured to be spaced apart along the nerve innervating the effector tissue.

217. The system of claim 216, wherein the stimulation device is configured to generate the stimulation signal such that the first stimulation electrode serves as a cathode and the second stimulation electrode serves as an anode.

218. The system of claim 216 or 217, further comprising a cuff configured to be at least partially arranged around the nerve and hold the first and second stimulation electrodes in place against the nerve.

219. The system of any one of claims 190 to 218, further comprising a suppression electrode arrangement configured to be coupled to the nerve so as to apply a suppression signal which is configured to suppress action potentials propagating in the nerve in a direction towards the central nervous system.

220. The system of claim 219, wherein the control unit is configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal.

221. The system of claim 219 or 220, wherein stimulation device is configured to be coupled to the nerve at a position between the effector tissue and the suppression electrode arrangement so as to induce action potentials travelling in the nerve in a direction towards the effector tissue.

222. The system of any one of claims 219 to 221, wherein the control unit is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, wherein the undesired response is generated responsive to the stimulation device applying the stimulation signal.

223. The system of any one of claims 219 to 222, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation device and the suppression electrode arrangement is actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the stimulation signal in the nerve.

224. The system of any one of claims 219 to 222, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement so as to apply the first stimulation signal and the suppression signal substantially at the same time.

225. The system of any one of claims 219 to 224, wherein the control unit is configured to drive the stimulation device and the suppression electrode arrangement such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signals is a low-frequency signal and the suppression signal is a high-frequency signal.

226. The system of any one of claims 219 to 225, wherein an amplitude of the stimulation signal varies with a frequency in a range of 0.1 - 100 Hz and wherein an amplitude of the suppression signal varies with a frequency in a range of 1 - 10 kHz.

227. The system of any one of claims 1 to 86, comprising means for stimulating an effector response in a patient, comprising: - a stimulation device configured to deliver a stimulation signal to at least one of the effector tissue and a nerve innervating the effector tissue of the patient, - a source of energy configured to energize the stimulation device, - a control unit operably connected to the stimulation device and configured to control an operation of the stimulation device such that the stimulation signal causes at least one of stimulating an effector response in the effector tissue and inhibiting an effector response in the effector tissue, and - a printed circuit board (PCB) supporting at least one of the stimulation device, the source of energy, and the control unit, wherein the PCB is at least one of a multi-layer PCB, a flexible PCB, a stretchable PCB.

228. The system of claim 227, wherein the PCB comprises first multi-layer portion and a second multi-layer portion interconnected by a stretchable portion.

229. The system of claim 227, wherein the PCB comprises a first multi-layer portion and a second multi-layer portion interconnected by a flexible portion.

230. The system of any one of claims 227 to 229, further comprising a capacitor configured to reduce a current leakage of the system to 1 μA or less.

231. The system of claim 230, wherein the capacitor is connected in series with a part of the system and the body of the patient.

232. The system of claim 230, wherein the capacitor is connected in series with a first and a second stimulation electrode of the stimulation device.

233. The system of claim 230 or 231, wherein the capacitor is arranged on the PCB.

234. The system of any one of claims 227 to 233, wherein: the stimulation device is configured to deliver a first stimulation signal to a sympathetic nerve innervating a first effector tissue of the patient and a second stimulation signal to a parasympathetic nerve innervating a second effector tissue and the control unit is configured to control the operation of the stimulation device such that: - the first stimulation signal stimulates an activity of the sympathetic nerve and the second stimulation signal inhibits an activity of the parasympathetic nerve or - the first stimulation signal inhibits an activity of the sympathetic nerve and the second stimulation signal stimulates an activity of the parasympathetic nerve.

235. The system of claim 234, wherein: the first signal is a low-frequency signal configured to stimulate the activity of the sympathetic nerve and the second signal is a high- frequency signal configured to inhibit the activity of the parasympathetic nerve, or the first signal is a high-frequency signal configured to inhibit the activity of the sympathetic nerve and the second signal is a low- frequency signal configured to stimulate the activity of the parasympathetic nerve.

236. The system of claim 235, wherein an amplitude of the low-frequency signal varies with a frequency in a range of 0.1 - 100 Hz and wherein an amplitude of the high-frequency signal varies with a frequency in a range of 1 - 10 kHz.

237. The system of any one of claims 227 to 236, wherein: the stimulation device comprises a first electrode arrangement and a second electrode arrangement, each configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, the control unit is configured to drive the stimulation device to apply, by means of the first electrode arrangement, a stimulation signal inducing the effector response in the effector tissue, and, by means of the second electrode arrangement, a suppression signal suppressing action potentials propagating in the nerve towards the central nervous system (CNS), andthe control unit is further configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal.

238. The system of claim 237, wherein the first electrode arrangement is configured to be coupled to the nerve at a position between the effector tissue and the second electrode so as to induce action potentials travelling in the nerve in a direction towards the effector tissue.

239. The system of claim 238, wherein the control unit is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the first electrode applying the stimulation signal.

240. The system of claim 238 or 239, wherein the control unit is configured to drive the stimulation device such that each of the first and second electrode arrangements are actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the stimulation signal.

241. The system of any one of claims 237 to 239, wherein the control unit is configured to drive the stimulation device to apply the stimulation signal and the suppression signal substantially at the same time.

242. The system of any one of claims 237 to 241, wherein the control unit is configured to drive the stimulation device such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signal is a low-frequency signal and the suppression signal is a high-frequency signal.

243. The system of claim 242, wherein an amplitude of the stimulation signal varies with a frequency in a range of 0.1 - 100 Hz, and wherein an amplitude of the suppression signal varies with a frequency in a range of 1 - 10 kHz.

244. The system of any one of claims 227 to 243, further comprising a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, wherein the control unit is configured to: receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal.

245. The system of claim 244, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue in response to the stimulation signal.

246. The system of claim 244, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue in response to the stimulation signal.

247. The system of claim 244, wherein sensor device comprises an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue.

248. The system of any one of claims 1 to 86, comprising means for stimulating an effector response in a patient, comprising:- a stimulation device configured to deliver a stimulation signal to at least one of the effector tissue and a nerve innervating the effector tissue of the patient, - a source of energy configured to energize the stimulation device, - a control unit operably connected to the stimulation device and configured to control an operation of the stimulation device such that the stimulation signal causes at least one of: stimulating an effector response in the effector tissue and inhibiting an effector response in the effector tissue, and - a capacitor configured to reduce a current leakage of the system to 1 μA or less.

249. The system of claim 248, wherein the capacitor is configured to be connected in series with the body of the patient and at least one of the stimulation device, the source of energy, and the control unit.

250. The system of claim 248, wherein the stimulation device comprises an electrode arrangement configured to be coupled to the effector tissue or nerve, and wherein the capacitor is configured to be connected in series with the body of the patient and the electrode arrangement.

251. The system of claim 248, wherein the electrode arrangement comprises a first stimulation electrode and a second stimulation electrode for applying the stimulation signal, and wherein the capacitor is configured to be connected in series with the first stimulation electrode and second stimulation electrode.

252. The system according any one of claims 248 to 251, wherein the capacitor is integrated in a circuitry for controlling the operation of the stimulation device.

253. The system of any one of claims 248 to 252, further comprising a printed circuit board (PCB) supporting the capacitor and at least one of the stimulation device, the source of energy, and the control unit.

254. The system of claim 253, wherein the PCB is at least one of a multi-layer PCB, a flexible PCB, and a stretchable PCB.

255. The system of any of claims 248 to 254, wherein: the stimulation device is configured to deliver a first stimulation signal to a sympathetic nerve innervating a first effector tissue of the patient and a second stimulation signal to a parasympathetic nerve innervating a second effector tissue and the control unit is configured to control the operation of the stimulation device such that: - the first stimulation signal stimulates an activity of the sympathetic nerve and the second stimulation signal inhibits an activity of the parasympathetic nerve, or - the first stimulation signal inhibits an activity of the sympathetic nerve and the second stimulation signal stimulates an activity of the parasympathetic nerve.

256. The system of claim 255, wherein: the first signal is a low-frequency signal configured to stimulate the activity of the sympathetic nerve and the second signal is a high- frequency signal configured to inhibit the activity of the parasympathetic nerve, or the first signal is a high-frequency signal configured to inhibit the activity of the sympathetic nerve and the second signal is a low- frequency signal configured to stimulate the activity of the parasympathetic nerve.

257. The system of claim 256, wherein an amplitude of the low-frequency signal varies with a frequency in a range of 0.1 - 100 Hz and an amplitude of the high-frequency signal varies with a frequency in a range of 1 - 10 kHz.

258. The system of claim 248, wherein: the stimulation device comprises a first electrode arrangement and a second electrode arrangement, each configured to be coupled to at least one of an effector tissue and a nerve innervating the effector tissue of the patient, the control unit is configured to drive the stimulation device to apply, by means of the first electrode arrangement, a stimulation signal inducing the effector response in the effector tissue, and, by means of the second electrode arrangement, a suppression signal suppressing action potentials propagating in the nerve towards the central nervous system (CNS), and the control unit is further configured to regulate the suppression signal so as to suppress the action potentials induced in response to the stimulation device applying the stimulation signal.

259. The system of claim 258, wherein the first electrode arrangement is configured to be coupled to the nerve at a position between the effector tissue and the second electrode so as to induce action potentials travelling in the nerve in a direction towards the effector tissue.

260. The system of claim 259, wherein the control unit is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of a nervous system of the patient, the undesired response being generated responsive to the first electrode applying the stimulation signal.

261. The system of claim 259 or 260, wherein the control unit is configured to drive the stimulation device such that each of the first and second electrode arrangements are actuated in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the stimulation signal.

262. The system of any one of claims 258 to 260, wherein the control unit is configured to drive the stimulation device to apply the stimulation signal and the suppression signal substantially at the same time.

263. The system of any one of claims 258 to 262, wherein the control unit is configured to drive the stimulation device such that each of the stimulation signal and the suppression signal is a time-varying signal, wherein the stimulation signal is a low-frequency signal and the suppression signal is a high-frequency signal.

264. The system of claim 263, wherein an amplitude of the stimulation signal varies with a frequency in a range of 0.1 - 100 Hz, and wherein an amplitude of the suppression signal varies with a frequency in a range of 1 - 10 kHz.

265. The system of any one of claims 248 to 263, further comprising a sensor device configured to generate a sensor signal indicating an effector response in the effector tissue, wherein the control unit is configured to: receive the sensor signal and control an operation of the stimulation device based at least in part on the sensor signal.

266. The system of claim 265, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue in response to the stimulation signal.

267. The system of claim 265, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue in response to the stimulation signal.

268. The system of claim 265, wherein sensor device comprises an electromyographic sensor configured to measure an electric activity in the effector tissue and an electric impedance sensor configured to measure a change in electrical impedance in the effector tissue.

269. The system of any one of claims 1 to 86, comprising means for at least partly denervating an effector tissue of the patient, said means comprising: - an inhibition device configured to temporarily inhibit a nerve innervating the effector tissue, - a sensor configured to generate a sensor signal indicative of an effector response in the effector tissue, wherein the effector response is at least partly induced by the inhibiting of the nerve, and - a processing unit configured to: - determine a response measure based on the sensor signal, wherein the response measure is indicative of the effector response; - compare the response measure with a predetermined reference measure, and - determine, based on the comparison, whether a desired effector response has been achieved, wherein the system further comprises a denervation device configured to at least partly denervate the effector tissue.

270. The system of claim 269, wherein the inhibition device is an electric stimulation device configured to deliver an inhibition signal to the nerve to cause a temporary inhibition of the nerve.

271. The system of claim 270, wherein the inhibition signal is a periodic signal including at least one of: a variable frequency component, a variable duty cycle component, a variable amplitude component, and a variable pause component.

272. The system of 270 or 271, wherein the inhibition signal comprises an amplitude varying in a range of 1 - 10 kHz.

273. The system of any one of claims 270 to 272, wherein the inhibition signal is an electric signal comprising a series of pulses having a negative voltage relative to ground.

274. The system of claim 273, wherein the electric stimulation device is configured to generate a positive voltage pulse following one or more negative voltage pulses.

275. The system of any one of claims 270 to 274, wherein the inhibition device comprises a first inhibition electrode and a second inhibition electrode, wherein the first inhibition electrode and the second inhibition electrode are configured to be arranged spaced apart along the nerve innervating the effector tissue.

276. The system of claim 275, wherein the inhibition device is configured to generate the inhibition signal such that the first inhibition electrode serves as a cathode and the second inhibition electrode serves as an anode.

277. The system of any one of claims 270 to 276, wherein the inhibition device further comprises a suppression electrode arrangement configured to be coupled to the nerve to apply a suppression signal which is configured to suppress action potentials propagating in the nerve in a direction towards the central nervous system.

278. The system of claim 277, wherein the inhibition device is configured to regulate the suppression signal so as to suppress the action potentials induced in response to the electric inhibition signal.

279. The system of claim 277 or 278, wherein the inhibition device is configured to apply the electric inhibition signal to the nerve at a position between the effector tissue and a position in which the suppression signal is applied to the nerve.

280. The system of any one of claims 277 to 279, wherein the inhibition device is configured to regulate the suppression of the action potentials so as to inhibit an undesired response of the nervous system of the patient, the undesired response being generated responsive to the electric inhibition signal.

281. The system of any one of claims 277 to 280, wherein the inhibition device is configured to apply the electric inhibition signal and the suppression signal in sequence, with a delay of the suppression signal timed to generally match a conduction velocity of the electric inhibition signal in the nerve.

282. The system of any one of claims 269 to 281, wherein the sensor device comprises a sensor electrode configured to measure an electric activity in the effector tissue.

283. The system of any one of claims 269 to 282, wherein the sensor device comprises a sensor electrode configured to measure a change in electrical impedance in the effector tissue.

284. The system of claim 282 or 283, wherein: the sensor electrode is configured to be arranged at the effector tissue;the sensor device further comprises a reference electrode, and the sensor device is configured to generate the sensor signal based on an electrical interaction between the sensor electrode and the reference electrode.

285. The system of any one of claims 269 to 284, wherein the inhibition device is configured to temporarily inhibit a nerve innervating effector tissue forming part of a gastrointestinal tract of the patient, and wherein the sensor is configured to generate a sensor signal indicative of a level of motility of the gastrointestinal tract.

286. The system of any one of claims 269 to 284, wherein the inhibition device is configured to temporarily inhibit a nerve innervating effector tissue being muscle tissue, and wherein the sensor is configured to generate a sensor signal indicative of mechanical movement of the muscle tissue.

287. The system of claim 286, wherein the sensor device comprises a strain gauge configured to measure a contraction or relaxation of the muscle tissue.

288. The system of any one of claims 269 to 284, wherein the sensor device is configured to measure a heart rate of the patient.

289. The system of any one of claims 269 to 284, wherein the sensor device is configured to measure a blood pressure of the patient.

290. The system of any one of claims 269 to 284, wherein the sensor device is configured to measure a rate of respiration of the patient.

291. The system of any one of claims 269 to 290, wherein the denervation device is an ablation device.

292. The system of claim 291, wherein the ablation device is configured to at least partly denervate the effector tissue by means of at least one of: radiofrequency ablation, cryoablation, heat ablation, electrocautery, and chemical ablation. - - -

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