Pressure sensor arrangement and method

Abstract

The present invention relates to a pressure sensor (100) including a biocompatible housing (110), a biocompatible flexible membrane (120) covering an opening in the housing (110), a pressure transmission medium, a mounting portion (130), an electrical connection (140), and a pressure-sensitive sensor (150).

Description

[Technical field]

[0001] In general, the present invention relates to pressure sensor placement suitable for intracardiac prostheses (total artificial hearts), cardiac assist pumps (Ventricular Assist Devices: VADs, LVADs, etc.), or as implants for measuring venous and arterial pressure in either the pulmonary or systemic circulation. [Background technology]

[0002] Blood pumping devices or artificial hearts are disclosed, for example, in US Pat. No. 5,399,633 or US Pat. No. 5,499,623 by the same applicant.

[0003] Other blood pumps are known, for example, through US Pat. No. 5,399,633 and US Pat. No. 5,499,623.

[0004] Despite steady progress in the development of permanent artificial hearts for long-term implantation in patients as a replacement for failing natural hearts, several challenges remain to be overcome. Among the challenges that need to be addressed in untethered artificial heart systems are control strategies that respond to various physiological demands and mechanisms for adapting to flow imbalances between the pulmonary and systemic circulations.

[0005] The difference in cardiac output between the left and right sides is well documented. Physiologically, the blood flow pumped by the left side of the heart is greater than the blood flow pumped by the right side of the heart. This difference is due in large part to a circulatory pathway known as the bronchial shunt. This flow originates in the left atrial system, passes through the bronchial tissue, and then returns directly to the left atrium. This difference usually appears to be a maximum of about 10% of the cardiac output, with the flow rate on the left side always being greater than that on the right side. An artificial heart system must take this inherent physiological circulatory imbalance into account. In addition, sources of flow imbalance can be created. For example, differences in the backflow through artificial valves on the left and right sides can cause flow imbalance. An artificial heart system must also take these types of circulatory imbalances into account. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2016 / 020219 [Patent Document 2] WO2017 / 137486 [Patent Document 3] US2003045772 [Patent Document 4] US20190351118 Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need for a pressure sensor that allows the measurement of pressure, particularly blood pressure, located on or in communication with cardiac assist pumps such as intracardiac prostheses, total artificial hearts (TAH), ventricular assist devices (VAD, LVAD) or as an implant for measuring venous and arterial pressure in both the pulmonary and systemic circulation. The invention also relates to a controller that can automatically control parameters such as the stroke rate and stroke volume of a blood pump based on pressure values ​​obtained from the pressure sensor. [Means for solving the problem]

[0008] For these reasons, a pressure sensor is provided that includes a biocompatible housing, a biocompatible flexible membrane covering an opening in the housing, a pressure transmission medium, an attachment portion, an electrical connection, and a pressure sensor. The sensor housing can be made of hard polyurethane, hard silicone, a biocompatible metal such as titanium or stainless steel, or any other biocompatible rigid material. The attachment portion can be made of a biocompatible material such as Dacron, ePTFE, polyester, or other material that can heal with natural tissue. The pressure sensor can include a MEMS (microelectromechanical system) sensor or a nanoelectromechanical system (NEMS). The flexible membrane can be made of polyurethane, titanium, silicone, or any other blood compatible material. The pressure transmission medium in the housing can be made of a biocompatible implantable oil such as medical grade silicone oil. The sensor is intended for use in or in communication with one or more of an intracardiac prosthesis, a total artificial heart, a cardiac assist pump, as an implant for measuring venous and arterial pressures in the pulmonary and systemic circulation, the thoracic, renal, bladder, or abdominal pressures.

[0009] The invention also relates to a controller unit for controlling an intracardiac prosthesis comprising: at least one pump portion; an inlet connected to said at least one pump portion; an outlet connected to said at least one pump portion; a pressure sensor configured to measure a pressure of a fluid flowing from the inlet to the outlet; and a pump actuator configured to induce a flow of a fluid flow, the controller unit further comprising a memory and a processing unit. The controller unit is configured to: obtain a pressure value from the pressure sensor, obtain a desired value of a pressure of a fluid flowing in the pump, calculate an error signal equal to the difference between the desired value of pressure and the measured pressure, and control an output of the pump such that the measured pressure is close to or equal to the desired pressure by controlling the pump stroke speed and / or the pump stroke volume.

[0010] The invention also relates to an intracardiac prosthesis including a pressure sensor as described.

[0011] Reference will now be made to the accompanying drawings, in which elements having the same reference numbers may represent similar elements throughout. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic perspective view of a pressure sensor according to an exemplary embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the pressure sensor of FIG. [Diagram 3] 1 is a first exemplary application embodiment of a pressure sensor according to the present invention; [Figure 4] 4 is a second exemplary application embodiment of the pressure sensor according to the present invention. [Diagram 5] 4 illustrates a third exemplary application embodiment of the pressure sensor according to the present invention. [Figure 6] 4 illustrates a third exemplary application embodiment of the pressure sensor according to the present invention. [Figure 7] 7a and 7b show a fourth exemplary application embodiment of the pressure sensor according to the present invention. [Figure 8] FIG. 2 is a schematic diagram of a controller according to one embodiment of the present invention. [Figure 9] FIG. 2 is a schematic diagram of a control unit according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The following detailed description refers to the accompanying drawings.

[0014] The term artificial heart, as used herein, can refer to a pumping device connectable to a subject.

[0015] 1 shows from below a pressure sensor 100 according to one exemplary embodiment of the invention. The pressure sensor includes a substantially dome-shaped housing 110, a pressure-sensitive elastic membrane 120, a mounting ring 130, and an electrical connection 140.

[0016] The pressure sensor 100 is detailed in the cross-sectional view of Figure 2. The pressure sensor 150 is disposed on a circuit board 160 which also carries connections to the electronics 162 and electrical connections 140.

[0017] The inner surface of the housing 110 includes an abutment 111 that includes a threaded hole for receiving a screw 112. The circuit board is attached to the inner surface of the housing 110 by the screw 112. Obviously, other attachment means, such as an adhesive, can also be used to attach the circuit board to the housing.

[0018] A directional pipe 163 may be disposed on one surface of the circuit board. The lumen of the directional pipe is in communication with the surface of the pressure sensor 150. However, in some exemplary embodiments, the directional pipe may be omitted.

[0019] The space 170 in the housing is completely filled with a pressure transmission medium.

[0020] The sensor housing 110 can be made from hard polyurethane, hard silicone, a biocompatible metal such as titanium or stainless steel, or any other biocompatible rigid material.

[0021] The attachment ring 130, which wholly or partially surrounds the lower portion of the housing, may be made from Dacron, ePTFE, polyester, or other materials capable of repairing with natural tissue.

[0022] The pressure sensor 150 may include a MEMS (Micro-Electro-Mechanical Systems) sensor, a Nano-Electro-Mechanical Systems (NEMS) sensor, or any other suitable pressure sensor architecture.

[0023] The flexible membrane 120 is leak-tight sealed to the housing 110, for example by means of an adhesive or a sealing washer, and can be made from polyurethane, silicone, titanium or any other blood-compatible material. As a result, the sensor body is hermetically sealed.

[0024] The pressure transmission medium or agent filled within the space 170 of the housing 110 can consist of a biocompatible implantable oil, such as medical grade silicone oil, or any other biocompatible medical grade fluid.

[0025] In operation, when the membrane 120 is influenced by, for example, blood pressure, the flexible membrane 120 will expand when the pressure on the membrane increases and will deflect outward when the pressure decreases. In this way, the pressure transmission medium inside the housing will be compressed or expanded due to the influence of the pressure on the flexible membrane 120. The pressure is transmitted from the membrane to the sensor 150 surface by the pressure transmission medium (if present) inside the pipe 163. Thus, the sensing surface of the MEMS sensor is influenced by the pressure changes in the pressure transmission medium, and the MEMS sensor converts the pressure to a digital value, and an electrical signal representative of the pressure is generated and can be provided to the controller.

[0026] The pressure sensor described and illustrated is given as an example. The sensor housing and configuration may vary in various ways depending on the requirements of the application. The sensor portion, electronics and connections may also vary depending on the application. Wireless transmission capabilities may also be included.

[0027] FIG. 3 shows a first example of the application of the pressure sensor described above. In this case, the subject's heart 300 is provided with a left ventricular assist device (LVAD). The LVAD includes a pump 310 and connecting conduits 311 and 312. The pump 310 pumps blood to the body and is a battery-powered mechanical device that is surgically implanted inside the subject's chest. The LVAD helps maintain the pumping capacity of a heart that is too weak to function on its own. The device supports the main pumping chamber, the left ventricle, by moving blood to the aorta and the rest of the body. The pump 310 is connected to the left ventricle through conduit 311 and to the aorta through conduit 312. The sensor 100 is placed on the conduits 311 and 312 at the inlet and outlet of the pump 310. The conduits include small windows that correspond to the shape of the flexible membrane 120 (FIG. 2) at the base of the pressure sensor 100. The base of the sensor is attached to the conduit and covers a window exposing the flexible membrane to the blood pressure within the conduit. The pressure sensor 100 is connected by connecting wires 140 to a controller unit 1000, either inside or outside the subject's body.

[0028] FIG. 4 illustrates a second exemplary application of the pressure sensor described above. A subject's heart 300 is provided with pressure sensors 100. In this example, the pressure sensors 100 are attached to the aorta, pulmonary artery, right atrium, left atrium, right ventricle and left ventricle (from the top of the figure). These locations are given as examples, and the pressure sensors can be positioned at any location where pressure values ​​are required. The pressure sensors can be attached to the cardiac tissue myocardium by Dacron, ePTFE, polyester, or can be attached to the epicardium. The pressure sensors in this example can be connected to an intracardiac prosthesis such as a TAH or VAD system to adjust the flow rate of the device according to the value of the blood pressure in the chamber of the heart 300.

[0029] A third application is shown in Figures 5 and 6. Figure 5 shows a portion of a thorax 500 and Figure 6 is a highly schematic illustration of a cross section taken along line AA in Figure 5, but including tissue.

[0030] Reference numeral 501 denotes ribs, 502 denotes skin, 503 denotes superficial fascia, 504 denotes intercostal muscles, 505 denotes parietal pleura, 506 denotes pleural cavity, 507 denotes visceral pleura, and 508 denotes lungs.

[0031] In this application, the pressure sensor 100 is placed between the rib 501 and the intercostal muscle 504. Not shown are electrical connections that may extend through tissue. The pressure sensor can also be placed near the costal cartilage.

[0032] In TAH or cardiac assist pump applications it may be crucial to measure the intrathoracic pressure. The intrathoracic pressure changes continuously during breathing. Since the intrathoracic pressure influences the intraatrial pressure, it is desirable to also measure the intrathoracic pressure (baseline pressure). In this way it is possible to compensate for intrathoracic pressure changes. The intrathoracic pressure can be measured by: 1. Using a pressure sensor that is integrated into the pump but is designed to measure pressure within the thoracic cavity; 2. Using a separate pressure sensor placed inside the thoracic cavity and connected to the pump by wires, or 3. Placing the pressure sensor outside the thoracic cavity, but inside the chest wall and in close contact with the parietal pleural layer 505, as in the example above.

[0033] For this reason, the pressure sensor 100 can be connected to the pleura (pleural) membrane, which acts as a natural flexible membrane between the thoracic cavity and the pressure sensor. To eliminate any influence of breathing, it is sufficient to use one pressure sensor to measure the pressure inside the thoracic cavity for both the right and left pumps, the pressure being measured outside the heart itself. The control unit can receive input signals from the pressure sensors and output signals to the pump driver system. The signals can be received and provided directly by wires.

[0034] The pressure sensor of the present invention may be implanted in or in communication with other body cavities or organs, such as the kidney, bladder, abdominal cavity, etc., where a pressure reading is desired.

[0035] 7a and 7b show a fourth exemplary application of the pressure sensor described above: Figure 7a shows a pump 700, one pump portion of a TAH, in a perspective view, and Figure 7b shows a cross-sectional view of pump 700.

[0036] This embodiment includes a first blood-receiving member 700 of the artificial heart and a driver / actuation system 750 that drives / actuates the artificial heart to generate the pumping mechanism. The artificial heart mainly consists of two pumps 700, namely a left pump and a right pump (not shown). Each pump includes one blood-receiving member and one driver / actuation system. The blood-receiving members are easily assembled to the driver system by screws, glue or a combination thereof. The blood-receiving members include an artificial atrium 709 and an artificial ventricle 712. Between the artificial atrium 709 and the artificial ventricle 712 there is a connecting cylinder 720 with valves corresponding to the mitral valve of the left side of the natural heart and the tricuspid valve of the right side of the natural heart. The connecting cylinder can be made of a flexible blood-compatible material such as polyurethane, silicone or any other blood-compatible material.

[0037] Each atrium 709 mainly consists of a wall covering the atrium, which consists mostly of two layers. The outer layer 7091 is rigid and made of hard polyurethane, hard silicone, biocompatible metal such as titanium or stainless steel, or any other biocompatible rigid metal. In addition, there is an inner flexible blood compatible membrane 7092 made of polyurethane, silicone or any other blood compatible material. The inner flexible membrane is an extension of the flexible atrial membrane, which is an extension of a flexible membrane 7093 that covers the inner surface of the connecting AV cylinder 720, which is an extension of the flexible ventricular membrane 7021. In addition, there is an atrial mounting ring 721, which is rigid and made of hard polyurethane, hard silicone, biocompatible metal such as titanium or stainless steel, or any other biocompatible hard material. The atrial mounting ring is assembled to the upper edge of the driver / actuation system by means of screws, glue or a combination thereof. The atrium has an inlet opening 710 for blood flow into the atrium. There is a pressure window 764 having a diameter of, for example, at least 5-30 mm, which may be circular, oval, or any other shape. The walls of the pressure window consist only of a flexible membrane with no rigid wall layer. This pressure window is part of the pressure sensor 100 structure, as explained above.

[0038] Each ventricle 712 mainly consists of a wall covering the ventricle, which consists mostly of two layers. The outer layer is rigid and made of rigid polyurethane, rigid silicone, biocompatible metal such as titanium or stainless steel, or any other biocompatible rigid material. In addition, there is an inner flexible blood-compatible membrane 7121 made of polyurethane, silicone, or any other blood-compatible material. The inner flexible membrane is an extension of the flexible ventricular membrane, which is an extension of the flexible membrane 7093 that covers the inner surface of the connecting AV cylinder 720. In addition, there is a ventricular mounting ring 722, which is rigid and made of rigid polyurethane, rigid silicone, biocompatible metal such as titanium or stainless steel, or any other biocompatible rigid material. The ventricular mounting ring is assembled to the lower edge of the driver / actuator system by screws, glue, or a combination thereof.

[0039] The driver / actuator system 750 consists of a housing 762, a gearbox 753 and an electric motor 751. The housing is made of a rigid plastic biocompatible material, such as PEEK and any other biocompatible plastic material, or a biocompatible metal. The housing encloses the gearbox and the electric motor. The gearbox consists of multiple gears and a metal shaft. The electric motor is a brushless motor type or any other type of electric motor with or without an encoder. The pressure sensor is described in detail later in this application. The motor 751 is located inside the pump housing between the outlet 713 and the pump. A spacer 760 can be located between the outlet 713 of the housing and the motor 751. The spacer 760 is made of a material with good heat transfer capacity so that when blood (or other liquid) flows through the outlet pipe (700), heat from the drive mechanism is transferred to the blood by the spacer 760 and the wall of the outlet 713, thereby transferring and reducing heat from the drive mechanism.

[0040] The center of the driver / actuation system has a cylindrical shape and surrounds the AV cylinder 720 made of a rigid plastic biocompatible material such as rigid polyurethane, rigid silicone, or a biocompatible metal such as titanium, stainless steel, or any other biocompatible rigid material. The AV cylinder is covered by a flexible membrane 7093. The flexible membrane 7093 is an extension of the flexible atrial membrane 7092 and the flexible ventricular membrane 7021. The AV cylinder surrounds the valve 714. There are two racks 725 and 726, one on each side of the AV cylinder 720. Each rack is articulated by a gear of a gearbox 753 that is actuated upwards and downwards.

[0041] There may be wiring (not shown) connected to the driver / actuation system to provide power and control signals to the electric motor, and there may also be a coating (not shown) that is a layer of a biocompatible plastic material such as polyurethane or silicone that surrounds the entire driver / actuation system and allows the wiring to the electric motor and the piping of the pressure sensor to pass through this coating.

[0042] The sensor 100 structure includes an opening 764 in the wall of the chamber 709 through which the flexible membrane 120 is exposed to pressure from the chamber 709. Thus, the pressure receiving portions of the pressure sensors are located in the left (or right) atrium 709 and the right pump atrium (or the top half of each pump) as described above. The flexible membrane 120 is located as part of the inner wall of the housing.

[0043] In operation, when the membrane 120 of the atrial wall 760 is affected by the pressure of blood inside the atrium 709 of each pump, the flexible membrane 120 will bulge inside the pressure sensor 100 when the pressure inside the atrium increases, or will flex inwardly into the atrial cavity when the pressure decreases. In this way, the pressure transmission medium inside the housing and the lumen of the pipe 163 will compress or expand due to the influence of the pressure inside the atrium 709. The pressure is transmitted from the membrane to the sensor 734 surface inside the pipe 163. Thus, the sensing surface of the MEMS sensor 150 is affected by the pressure changes in the pressure transmission medium, and the MEMS sensor converts the pressure into a digital value, and an electrical signal representative of the pressure is generated and provided to the controller unit.

[0044] While many of the above illustrated embodiments relate to pulsating or displacement pumps, the methods, sensors and control units of the present invention are equally applicable to systems having different types of pumps, such as centrifugal pumps, or other continuous flow pumps. Continuous flow pumps can include one or several of canned, radial, side channel, regenerative turbine, axial flow, mixed flow pump types. Displacement pumps can include one or several of dosing, axial screw, gear, multi-screw, piston diaphragm, plunger and piston, rotating lobe, vacuum and hose pump types.

[0045] Thus, the term "stroke volume" as used herein relates to a specific amount of fluid displaced in a specific time interval, and the term "heart rate" as used herein relates to the rate at which a pump displaces a certain amount of fluid.

[0046] The terms right atrium and left atrium as used herein refer to the compartments inside the pump housing where fluid is provided and discharged.

[0047] 8 shows a schematic diagram and functional blocks of an exemplary control unit 800 for a TAH application. The control unit 800, according to this embodiment, includes the following functional blocks: - a cardiac output control unit 801 for the right atrium; - a cardiac output control unit 802 for the left atrium; - a flow control block 803, and - processing block 804, may include.

[0048] The main function of the control unit 800 is to set the heart rate and stroke volume for one side of the blood pump 700 (ie, the left pump and the right pump) to values ​​appropriate for the subject's current physiological state.

[0049] The control problem can be solved by breaking it down into multiple subproblems, including: - Flow Control: This determines the correct flow limit and desired atrial pressure, which is entered and keeps the cardiac output within the proper range. The desired atrial pressure can be overridden by allowing the operator of the prosthesis to manually set the desired atrial pressure. - Determining the cardiac output of either pump to control the atrial pressure: this is done individually, without interdependence between the pumps. - Determine Heart Rate: The heart rate and cardiac output of either pump (calculated in the previous step) will now provide the stroke volume of either pump.

[0050] Inputs to the function block include: - (right) the right atrial pressure (RAP) measured by the pressure sensor 100 in the right atrium to the cardiac output control unit 801; and (Left) The left atrial pressure (LAP) measured by the pressure sensor 100 in the left atrium, to the cardiac output control unit 802.

[0051] Determination of cardiac output for either pump can be performed using only atrial pressure as an input.

[0052] As mentioned above, stroke volume can be calculated as stroke length multiplied by a constant and therefore may not match the actual pumped stroke volume, implying that the reported flow rate is also only an approximation.

[0053] The function block Flow Control 803 determines the flow limit and the desired atrial pressure. The flow limit is the limit of the cardiac output of the right pump.

[0054] The purpose of the flow control is to keep the flow rate of the right pump 802 low enough so that the left pump 803 never reaches its maximum flow rate. If this occurs, i.e. if the maximum flow rate is reached, the left pump will not be able to keep the LAP limited and there is a risk of pulmonary edema. By limiting the capacity of the right pump, the RAP may increase, which can be considered acceptable. A higher RAP also increases the central venous pressure (CVP), which helps to reduce venous return. The flow control block 803 receives the output from the left cardiac output control 802 and sets the desired RAP, the desired LAP and the limit of the right cardiac output.

[0055] The actual flow rate of either half of the pump, i.e. 700, even given the same heart rate and stroke length, may depend on various factors such as outflow and inflow pressures, etc. Due to this, the flow restriction of the right pump (700) cannot be constant but must vary dynamically.

[0056] The controller unit 800 can be an embedded or integrated microcomputer or electronic chip. The microcomputer can provide control signals to the pump actuation means to modify the pumping activity. If for some reason the microcomputer does not receive any input information, the pump actuation means can continue a certain level of activity. Figure 9 is a schematic block diagram of an alternative exemplary controller unit 900, for example for cardiac assist pump (VAD, LVAD, etc.) applications. The controller unit 900, according to this embodiment, comprises the following functional blocks: a cardiac output control unit 901; processing block 904; may include.

[0057] The main function of the control unit 900 may be to set the speed of the blood pump 310 to a value appropriate for the subject's current physiological state.

[0058] The controller unit 800 of the embodiment according to Fig. 8 may be suitable for a pulsatile pump, whereas the controller unit 900 of Fig. 9 may be suitable for a continuous flow pump. However, the controller unit 800 may also be configured to set the pulsation speed and thus the pump speed.

[0059] 10 is a diagram of an exemplary controller unit 1000 capable of implementing the methods described herein. The controller unit 1000 may include a bus 1010, a processor 1020, a memory 1030, a read-only memory (ROM) 1040, a storage device 1050, an input device 1060, an output device 1070, and a communication interface 1080. The bus 1010 enables communication between the components of the controller unit 1000. The controller unit 1000 may also include one or more power supplies (not shown). Those skilled in the art will appreciate that the controller unit 1000 may be configured in several other ways and may include other or different elements.

[0060] The processor 1020 may include any type of processor or microprocessor that interprets and executes instructions. The processor 1020 may also include logic that can decode media files and generate output, for example, to a speaker, display, etc. The memory 1030 may include a random access memory (RAM) or another dynamic storage device that stores information and instructions for execution by the processor 1020. The memory 1030 may also be used to store temporary variables or other intermediate information during execution of instructions by the processor 1020.

[0061] The ROM 1040 may include a conventional ROM device and / or another static storage device that stores static information and instructions for the processor 1020. The storage device 1050 may include a magnetic disk, solid state drive, or optical disk and its corresponding drive, and / or some other type of recording medium and its corresponding drive for storing information and instructions. The storage device 1050 may also include a flash memory (e.g., an electrically erasable programmable read only memory (EEPROM)) device for storing information and instructions.

[0062] The input device 1060 may include one or more conventional mechanisms that allow a user to input information to the controller unit 1000, such as a keyboard, a keypad, a directional pad, a mouse, a pen, voice recognition, a touch screen, and / or a biometric mechanism. The output device 1070 may include one or more conventional mechanisms that output information to a user, including a display, a printer, one or more speakers, and the like. The communication interface 1080 may include any transceiver-like mechanism that allows the controller unit 1000 to communicate with other devices and / or systems. For example, the communication interface 1080 may include a modem, or an Ethernet interface to a LAN. Alternatively, or in addition, the communication interface 1080 may include other mechanisms for communicating over a network, such as a wireless network. For example, the communication interface may include a radio frequency (RF) transmitter and receiver and one or more antennas for transmitting and receiving RF data.

[0063] A controller unit 1000 consistent with the present invention provides a platform as described above. According to an exemplary embodiment, the controller unit 1000 can perform various processes in response to the processor 1020 executing sequences of instructions contained in the memory 1030. Such instructions can be read into the memory 130 from another computer-readable medium, such as the storage device 1050, or from a separate device via the communication interface 1080. It should be understood that the computer-readable medium can include one or more memory devices or carrier waves. Execution of the sequences of instructions contained in the memory 1030 causes the processor 1020 to perform the operations described above. In alternative embodiments, hardwired circuitry can be used in place of or in combination with software instructions to implement aspects consistent with the present invention. Thus, the present invention is not limited to any specific combination of hardware circuitry and software.

[0064] It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed, and the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Furthermore, it should be noted that any reference signs do not limit the scope of the claims, and that the invention may be implemented at least in part by both hardware and by software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

[0065] The above described and illustrated embodiments are given as examples only and should not be limitations on the present invention. Other solutions, uses, objects and functions within the scope of the present invention, as claimed in the following claims, should be apparent to those skilled in the art.

[0066] Various embodiments of the invention described herein are described in the general context of method steps or processes, which in one embodiment may be implemented by a computer program product including computer-executable instructions, such as program code, embodied in a computer-readable medium and executed by a computer in a network environment. The computer-readable medium may include removable and non-removable storage devices, including, but not limited to, read-only memory (ROM), random access memory (RAM), compact discs (CDs), digital versatile discs (DVDs), solid-state drives, and the like. Generally, program modules may include routines, programs, objects, components, data structures, and the like that perform particular tasks or implement particular abstract data types. The computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0067] Software and web implementations of various embodiments of the present invention can be accomplished with standard programming techniques using rule-based and other logic to accomplish the various database search, correlation, comparison, and decision steps or processes. It should be noted that as used herein and in the claims that follow, the terms "component" and "module" are intended to encompass implementations using one or more lines of software code, and / or hardware implementations, and / or equipment for receiving manual input.

[0068] The above description of the embodiments of the present invention has been presented for purposes of illustration and description. The above description is not intended to be exhaustive or to limit the embodiments of the present invention to the precise form disclosed, as modifications and variations are possible in light of the above teachings or may be acquired from the practice of various embodiments of the present invention. The embodiments discussed herein have been selected and described in order to explain the principles and characteristics of various embodiments of the present invention, as well as their practical applications, and to enable those skilled in the art to utilize the present invention in various embodiments and with various modifications suited to the particular use contemplated. The features of the embodiments described herein can be combined in all possible combinations of methods, apparatus, modules, systems and computer program products.

Claims

1. A pressure sensor (100): A housing (110) having an opening; a flexible membrane (120) covering the opening of the housing (110); a space (170) formed by the housing and the flexible membrane; A space (170) completely filled with a pressure transmitting medium; Including, the housing further including a mounting ring (130) surrounding the opening in the housing and configured to mount the pressure sensor to a surface of an object for which pressure values ​​are to be measured; a pressure sensor (150) attached to the inner surface of the housing via a circuit board (160) and having one surface receiving pressure transmitted from the membrane by a pressure transmission medium; the housing and mounting portion are made from a biocompatible material, and the flexible membrane is made from a biocompatible flexible material; and an electrical connection wire (140) configured to connect said pressure sensor to a controller unit (1000); The pressure sensor.

2. The sensor of claim 1 , wherein the sensor housing (110) is made from one of hard polyurethane, hard silicone, a biocompatible metal including one of titanium or stainless steel, or any other biocompatible rigid material.

3. The sensor of claim 1 , wherein the mounting portion (130) is made from a biocompatible material including one of Dacron, ePTFE, polyester, or other materials capable of repairing with natural tissue.

4. The sensor of claim 1 , wherein the pressure sensitive sensor (150) comprises a MEMS (microelectromechanical system) sensor or a nanoelectromechanical system (NEMS) sensor.

5. The sensor of claim 1 , wherein the flexible membrane (120) is made from polyurethane, silicone, or any other blood compatible material.

6. 10. The sensor of claim 1, wherein the pressure transmitting medium within the housing comprises a biocompatible implantable oil, or a medical grade silicone oil, or other biocompatible medical grade fluid.

7. 13. The sensor of claim 1 for use as an implant in or in communication with one or more of an intracardiac prosthesis, a total artificial heart, a cardiac assist pump for measuring venous, atrial or arterial pressure in the pulmonary and systemic circulation, thoracic, renal, bladder or intestinal pressure.

8. A controller unit (800, 900, 1000) for controlling a heart pump (700, 310), the heart pump comprising: At least one pump portion (700, 310); an inlet (710) connected to said at least one pump portion; an outlet (713) connected to said at least one pump portion; A pressure sensor (100) as claimed in claim 1 configured to measure a pressure of a fluid flowing from an inlet to an outlet; a pump actuator (750) configured to induce flow of a fluid stream; Including, The controller unit further includes a memory (1030) and a processing unit (1020), the processing unit comprising: Receive a pressure value from the pressure sensor; receiving a desired value for the pressure of the fluid flowing within the pump; Calculating an error signal equal to the difference between the desired value of the pressure and the measured pressure; The controller unit is configured to control the output of the pump so that the measured pressure is close to or equal to the desired pressure by controlling pump control parameters, the pump control parameters including one or more of pump stroke rate and / or pump stroke volume and / or pump speed.

9. An intracardiac prosthesis (700) comprising the pressure sensor of claim 1.

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