Inflation of the balloon in the bowel irrigation system

Abstract

A system for inflating an inflatable balloon of a catheter of a bowel irrigation system, comprising a container for holding a liquid, a catheter, a conduit connecting the container and the catheter, a pump, a control unit, and a pressure sensor. The catheter is for insertion into the rectum of a user and comprises an inflatable balloon. The pump is for pumping liquid from the container through the conduit to the balloon. The control unit comprises a processor. The pressure sensor is in fluid communication with the interior of the inflatable balloon. The method comprises the steps of providing liquid in the container and initiating an inflation process comprising a feedback loop, the feedback loop comprising the steps of: (i) inflating the balloon with a predetermined amount of liquid; (ii) assessing the static pressure inside the balloon; and (iii) selecting an output based on the static pressure assessed according to step (ii), the output being selected from restarting the feedback loop according to step (i), skipping step (i) and continuing to assess the static pressure according to step (ii), and terminating the feedback loop.

Description

Technical Field

[0001] The present disclosure relates to a method for inflating an inflatable balloon of a catheter for a bowel irrigation system. Background Art

[0002] Intestinal irrigation is one of the many treatments used to help people with intestinal problems. People with intestinal problems are often paralyzed due to spinal cord injuries and are confined to wheelchairs or hospitalized. Under these conditions, peristaltic function, i.e., the reflexes and muscles of the intestines, cannot usually be properly stimulated. This leads to constipation or the random discharge of intestinal contents. By using intestinal irrigation, stimulation of peristaltic movement of the colon can be provided. In order to perform such intestinal irrigation, a device including a catheter (also known as an anal catheter, anal probe, rectal catheter or speculum) is provided. The catheter is inserted into the rectum through the anus. The catheter is typically held in the rectum by a retaining device (most commonly a balloon), which is inflated and rests against the rectal wall. Liquid (also known as irrigation liquid, such as water or saline solution) is then introduced into the rectum / intestinal tract through the catheter. Depending on the individual, the amount of liquid is usually up to 1.5 liters. The introduced liquid stimulates the peristaltic movement of the intestine. After a specified period of time (such as 15 minutes), the catheter is removed and the liquid is released through the anus together with the output from the intestine. Summary of the invention

[0003] According to one aspect of the present disclosure, there is provided a system for inflating an inflatable balloon of a catheter for a bowel irrigation system, the system comprising:

[0004] - a container adapted to contain a liquid;

[0005] - a catheter adapted for insertion into the rectum of a user, the catheter comprising an inflatable balloon;

[0006] - a pipe connecting the container and the conduit;

[0007] - a pump adapted to pump liquid from the container through the conduit to the balloon;

[0008] - a control unit comprising a processor; and

[0009] - a pressure sensor in fluid communication with the interior of the inflatable balloon;

[0010] Wherein, the system further comprises:

[0011] - a quantity of liquid contained in the container for inflating the balloon, and

[0012] - means for initiating a stepwise inflation process comprising a feedback loop comprising the steps of:

[0013] (i) inflating the balloon with a predetermined amount of liquid by means of the pump,

[0014] (ii) evaluating the static pressure inside the balloon by means of the pressure sensor, and

[0015] (iii) selecting, with the aid of the processor, an output based on the static pressure evaluated according to step (ii), the output being selected from:

[0016] - restarting the feedback loop according to step (i),

[0017] - skipping step (i) and continuing with step (ii) to evaluate said static pressure, and

[0018] - terminate said feedback loop,

[0019] wherein the processor is adapted to select, in step (iii) of a first cycle of the feedback loop, an output of the feedback loop to be restarted, thereby establishing two consecutively assessed static pressures,

[0020] wherein the processor is adapted to calculate a difference between two consecutively assessed static pressures, and

[0021] Therein, the processor is adapted to select an output based on the assessed static pressure of a current cycle and a difference between two consecutive assessed static pressures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and are a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the embodiments. Other embodiments and many of the expected advantages of the embodiments will be readily appreciated as they will become better understood by reference to the following detailed description. The elements of the accompanying drawings are not necessarily to scale with respect to each other. The same reference numerals indicate corresponding similar parts.

[0023] Figure 1 shows the pressure inside the balloon as a function of time during the inflation process according to one embodiment of the present invention,

[0024] Figure 2 shows the pressure inside the balloon as a function of time during the inflation process according to one embodiment of the present invention,

[0025] Figure 3shows the pressure inside the balloon as a function of time during the inflation process according to one embodiment of the present invention,

[0026] Figure 4A A flow chart showing an inflation process according to an embodiment of the present invention is shown.

[0027] Figure 4B A flow chart showing an inflation process according to an embodiment of the present invention is shown.

[0028] Figure 5A shows a volume scale for visualizing the inflation process according to one embodiment of the present invention,

[0029] Figure 5B shows a volume scale for visualizing the inflation process according to one embodiment of the present invention,

[0030] Figure 6 A cross-sectional view of one embodiment of a catheter of a rectal and intestinal irrigation system is shown,

[0031] Figure 7 An embodiment of a bowel irrigation system is shown, and

[0032] Figure 8 A cross-sectional view of one embodiment of a catheter of a bowel irrigation system is shown. DETAILED DESCRIPTION

[0033] Hereinafter, when relevant, a number of different exemplary embodiments and details are described with reference to the accompanying drawings. It should be noted that the drawings may or may not be drawn to scale, and throughout all drawings, the same reference numerals are used to represent elements with similar structures or functions. It should also be noted that the drawings are intended only to facilitate the description of the embodiments. They are not intended to serve as an exhaustive description of the invention or to limit the scope of the invention. In addition, the embodiments shown do not necessarily have all the aspects or advantages shown. The aspects or advantages described in conjunction with a specific embodiment are not necessarily limited to that embodiment, and may be practiced in any other embodiment even if not so shown or so explicitly described.

[0034] Hereinafter, whenever the proximal end of an element of the present invention is mentioned, it is meant the end adapted for insertion. Whenever the distal end of an element is mentioned, it is meant the end opposite to the insertion end. In other words, the proximal end is the end closest to the user when the catheter is to be inserted, and the distal end is the opposite end (the end farthest from the user when the catheter is to be inserted). The longitudinal direction is the direction from the distal side to the proximal end. The transverse direction is the direction perpendicular to the longitudinal direction, which corresponds to the direction across the axis of the catheter.

[0035] Hereinafter, whenever a bowel irrigation system or bowel irrigation is mentioned, it refers to a system or method that can use a catheter to irrigate the user's intestines. Typically, the catheter is inserted through the anus. Bowel irrigation (system) is also known in the art as anal irrigation (system) and rectal irrigation (system), and these terms can be used interchangeably in embodiments where the bowel irrigation system is adapted for use through the anus.

[0036] Hereinafter, whenever reference is made to the intestinal tract of a user, reference is made to the intestine of the user. Reference may be made specifically to the lower intestine, e.g., the rectum and / or the colon / large intestine. Hereinafter, whenever reference is made to the rectum, reference is made to the terminal segment / tube of the intestine ending at the anus. Hereinafter, whenever reference is made to the anus, reference is made to the opening at the lower end of the alimentary canal through which digested waste is typically discharged. Hereinafter, whenever reference is made to the anus, reference is made to a feature, device, method or system related to (e.g., related to or through the engagement of) the anus. Hereinafter, whenever reference is made to the rectal wall, reference is made to the intestinal wall surrounding and defining the rectal tube.

[0037] Hereinafter, whenever a quantity (such as pressure) is referred to as complying with a threshold, it is meant that the quantity is within a range in which such quantity reaches a desired value. Where the threshold defines an upper limit of acceptable values ​​for the quantity, compliance is met whenever the value is equal to or below the threshold. Likewise, where the threshold defines a lower limit of acceptable values ​​for the quantity, compliance is met whenever the value is equal to or above the threshold. Thus, non-compliance is used to describe a value of a quantity that is not in compliance (i.e., falls outside a compliance range).

[0038] In the following, pressure is given in psi (pounds per square inch), where 1 psi = 7 × 10 1 mbar = 7 kPa, and 1.0 psi = 69 mbar = 6.9 kPa, and 1.00 psi = 68.9 mbar = 68.9 kPa, and 1.000 psi = 68.95 mbar = 6.895 kPa.

[0039] The present disclosure provides a method for inflating an inflatable balloon of a catheter for a bowel irrigation system.

[0040] In a first aspect of the present invention, a method for inflating an inflatable balloon of a catheter for a bowel irrigation system is disclosed. The bowel irrigation system comprises a container for holding a liquid, a catheter, a conduit connecting the container to the catheter, a pump, a control unit, and a pressure sensor. The catheter is adapted for insertion into a rectum of a user and comprises an inflatable balloon. The pump is adapted for pumping liquid from the container through the conduit to the balloon. The control unit comprises a processor. The pressure sensor is in fluid communication with the interior of the inflatable balloon. The method comprises the steps of providing liquid in the container and initiating an inflation process comprising a feedback loop, the feedback loop comprising the steps of: (i) inflating the balloon with a predetermined amount of liquid; (ii) assessing a static pressure inside the balloon; and (iii) selecting an output based on the static pressure assessed according to step (ii), the output being selected from restarting the feedback loop according to step (i), skipping step (i) and continuing to assess the static pressure according to step (ii), and terminating the feedback loop.

[0041] In the following, whenever "inflation" or "deflation" is mentioned, these terms refer to the inflation / deflation fluid, respectively. In the following, inflation refers to the procedure of pumping fluid into the balloon, while deflation refers to the procedure of withdrawing fluid from the balloon. Therefore, deflation can be considered as the opposite / opposite of inflation, and vice versa.

[0042] The disclosed method provides for the progressive inflation of an inflatable balloon through an inflation process comprising a feedback loop, thereby facilitating controlled inflation that can respond to physiological changes during inflation (such as peristaltic motion) or resistance encountered, for example, due to scar tissue or feces. The output will be considered as an instruction on how to continue the feedback loop. In an embodiment, the output is selected / generated by a processor included in the control unit and is based on certain inputs (such as, at least, the static pressure as assessed in the previous step). In an embodiment, a comparison device of the processor determines compliance of the input(s) with a predetermined threshold value, and the processor selects the output based on the compliance. In an embodiment, in addition to the static pressure as assessed in step (ii), the output is also based on volume, intestinal pressure and / or time.

[0043] The disclosed method for inflating a balloon provides a more controllable size of the balloon, since the method uses a liquid for inflation. The liquid is an incompressible fluid, and thus the volume of the balloon is proportional to the volume of the liquid provided. Furthermore, overpressure inside the balloon due to compression is avoided, thus minimizing the risk of balloon rupture.

[0044] Intestinal irrigation systems are typically operated by the user themselves without the need for medical training or the assistance of a medical professional. Irrigation is typically performed in the user's own home and does not require a medical environment (such as a hospital). Irrigation can also be performed as a paid service in a commercial environment, which also does not require medical personnel or a specific medical environment. Compared to surgical or other procedures performed by medical professionals, the irrigation procedure is a relatively minor intervention and does not carry substantial health risks when performed by the user themselves with the required care and skills. Indeed, and as discussed herein, inflating the balloon with liquid is a significant safety improvement compared to inflating with air.

[0045] In an embodiment, the container can be any container suitable for holding a liquid. In an embodiment, the container can be considered a reservoir. In an embodiment, the container is capable of storing at least the amount of liquid required for the irrigation procedure, or at least the amount of liquid required for the irrigation procedure and the amount of liquid required to inflate the balloon of the catheter. In an embodiment, the liquid is water (such as tap water) or a saline solution. In an embodiment, the liquid is an irrigation liquid for irrigating the intestine. In an embodiment, the irrigation liquid is also used to inflate the balloon. Thus, depending on the condition or use, the liquid can be referred to as both an irrigation liquid and an inflation liquid. In the following, irrigation liquid or inflation liquid is used to highlight the specific use of the liquid, but it should be understood that the irrigation liquid and the inflation liquid can be the same substance / material. In an embodiment, the container can include separate compartments: one for the required amount of irrigation liquid and one for the required amount of inflation liquid.

[0046] In an embodiment, the liquid may be provided by a simple procedure of assessing the container, for example, by removing a lid of the container and pouring the liquid into the container. In an embodiment, the step of detecting the presence of the liquid in the container is equivalent to providing the liquid in the container. In an embodiment, the detection of the presence of the liquid is achieved by means of a sensor included in the container. In an embodiment, providing the liquid in the container comprises providing sufficient liquid so that at least the balloon can be inflated by the liquid in the container.

[0047] In an embodiment, the catheter is adapted for insertion into the rectum of a user. A useful exemplary catheter includes a main tubular portion (typically referred to as a shaft) extending from a distal end to a proximal end. The tip is positioned in the proximal end of the catheter and is provided as a rounded closed end of the shaft. In an embodiment, the catheter includes a connector in the distal end and may include a flared end of the catheter in an embodiment so that the diameter of the connector increases relative to the tubular portion. In particular, the proximal end of the catheter is configured for insertion into the rectum of the user. Typically, the outer diameter of a catheter for intestinal lavage is typically 8-16 mm, for example, 10 mm. The length may be 70-200 mm, for example, 150 mm. In an embodiment, the catheter has a size that reflects the needs or requirements of the user. In this way, a range of different catheter sizes may be provided. In particular, throughout this disclosure, catheter sizes marked as small and conventional are used. The small catheter has a smaller diameter than a conventional catheter. For example, a small catheter may be suitable for children, while a conventional catheter may be suitable for adults.

[0048] In an embodiment, the catheter is provided with holes in the proximal end, which are in communication with the irrigation channel inside the catheter, so that the irrigation liquid pumped into the distal end of the catheter can leave the catheter through these holes in the proximal end. Experiments have shown that a diameter of the irrigation channel of about 3-7 mm (e.g., 4.3 mm) allows sufficient flow. The catheter is provided with an inflatable balloon, which is used to retain the catheter inside the rectum during the irrigation procedure. Therefore, the inflatable balloon can be considered as a retaining device. In an embodiment, the balloon is suitable for sealing the anus so that the irrigation liquid cannot escape the rectum. In an embodiment, the balloon extends radially around the catheter. In an embodiment, the balloon is similar to a ring surrounding the catheter when inflated. The balloon can be considered to be expandable. In an embodiment, the balloon is arranged near the proximal end of the catheter. By extending radially around the catheter, the inflated balloon hinders the irrigation liquid from escaping the rectum through the anus (during the irrigation procedure). For the purpose of inflating the balloon, the catheter is provided with an inflation channel extending from the distal end of the catheter and terminating below the balloon (i.e., in the interior of the balloon). A sufficient diameter of the balloon channel is about 1-4 mm (such as, 2 mm). In an embodiment, the balloon is inflated with a volume of liquid, in particular with a liquid held in a container. Once the catheter is inserted into the rectum, and before the irrigation liquid is introduced into the rectum, the balloon is inflated. The balloon is made of an elastic / flexible material. In an embodiment, the balloon is made of a thermoplastic elastomer. Thereby, the balloon can expand and adapt to the internal shape of the rectum, and thereby temporarily fix the catheter in the rectum during the irrigation procedure.

[0049] In an embodiment, the catheter is adapted for insertion by means of having an appropriate size, shape and by appropriate material selection. In an embodiment, the method includes the step of inserting the catheter into the rectum of the user. In an embodiment, the insertion of the catheter into the rectum is performed manually by the user or by a healthcare professional. In an embodiment, the insertion is assisted by providing a lubricant. In an embodiment, the insertion is assisted by a certain surface treatment of the catheter to reduce its friction. In an embodiment, the catheter is inserted a distance such that at least the entire balloon passes through the anal sphincter of the user, such as the internal anal sphincter.

[0050] In an embodiment, the balloon may be inflated to a nominal volume, depending on the size of the catheter used (e.g., small and regular). Nominal means that the amount (here, volume) is set by the system, and the pump and / or other mechanism of the system is adapted to meet such a nominal value. Therefore, the nominal value is the value expected by the system. The volume of liquid in the balloon is related to its diameter, and thus reflects the needs and physical requirements of the user. In an embodiment, for a regular size catheter, the balloon may be inflated to a nominal volume of 20 ml, 40 ml, 60 ml, 100 ml, or 160 ml. In an embodiment, for a small size catheter, the balloon may be inflated to a nominal volume of 12 ml, 26 ml, 40 ml, 60 ml, or 80 ml. A healthcare professional may help the user determine the optimal nominal volume, and thus determine the resulting size of the balloon. In an embodiment, the nominal volume is predetermined and stored in a memory of the control unit. By specifying a predetermined volume, the user's selection of an appropriate volume is simplified, such as being reduced to selecting from a range of 0 (zero), XS, S, M, L, and XL, as explained below.

[0051] Table 1 summarizes exemplary sizes of inflatable balloons (0-XL as selectable by the user) and the corresponding nominal volumes and diameters for conventional and small-sized catheters. The indicated diameters were obtained in an experimental procedure of measuring the diameters after inflating the balloons to the indicated nominal volumes. Therefore, uncertainty is attached to the diameters. Therefore, the diameters should not be considered as limiting the present invention. The diameters (10 mm) for small and conventional catheters of balloon size 0 (zero) reflect the base diameter of the selected catheter when the balloon is not inflated.

[0052] Table 1

[0053]

[0054] In embodiments, providing a conduit connecting the container with the catheter allows for selective transfer of liquid from the container to the balloon and rectum (i.e., to an eyelet in the proximal end of the catheter and from there into the rectum once inserted). In embodiments, the conduit comprises a first lumen connecting the interior of the balloon with the container and a second lumen connecting the tip of the catheter with the container. In embodiments, the conduit is flexible. In embodiments, the conduit is transparent for providing visual assessment of the flow of fluid (i.e., both liquid and air, such as air generated by a flushing procedure where air is intentionally drawn into the conduit to avoid stagnant water).

[0055] In an embodiment, a pump such as an electric pump allows the fluid in the tube (e.g., liquid intended for inflation / deflation of the balloon and intestinal irrigation and air generated by the flushing procedure) to flow. In an embodiment, the pump is adapted to inflate the balloon with a liquid amount, that is, the pump is adapted to pump (inflate) the liquid from the container to the balloon. In an embodiment, the pump is adapted to inflate and discharge the balloon. The amount of liquid may be as specified in Table 1 above. In an embodiment, the pump is adapted to pump (irrigation) liquid from the container through the catheter to the rectum to irrigate the intestine. The irrigation system may include a system or capability for switching the pumping between pumping (irrigation) liquid into the rectum and inflating the retaining device / balloon. In an embodiment, two pumps are provided: one for pumping irrigation liquid into the rectum and one for inflating the balloon of the catheter. The pump may be battery-powered, so that the irrigation system is transportable and independent of the supply of the power grid. The pump may be a gear pump or a centrifugal pump. In an embodiment, the pump is a reversible electric pump. In an embodiment, the pump is capable of pumping air through the system in order to clear the tubing of liquid.

[0056] In an embodiment, the control unit allows control of the flow of fluid generated by the pump. In an embodiment, the control unit is adapted to control the flow of fluid in the system. For example, the control unit is arranged at an appropriate position along the pipeline. In an embodiment, the control unit includes a processor for generating / selecting an output based on a calculation performed by a received input (e.g., an input received from a pressure sensor, a number of pump revolutions, and a pressure sensor related to the pump pressure (i.e., an alternative pressure sensor capable of evaluating the pressure generated by the pump)). In an embodiment, the control unit is provided with a memory. In an embodiment, the control unit communicates with the interior of the pipeline so that the control unit can evaluate the fluid flowing in the lumen of the pipeline. In an embodiment, an electric wire is arranged in and / or along the pipeline to allow an electrical connection between the pump and the control unit so that the control unit can be used to control the performance of the pump and / or other parts of the irrigation system. In an embodiment, the electric wire is arranged between the catheter and the control unit, thereby providing electrical communication therebetween. In an embodiment, the control unit and the pump communicate via a wireless protocol. In an embodiment, the control unit includes a user interface for receiving input from a user and a graphical user interface for presenting information to the user. In an embodiment, the control unit includes a device for alerting the user, for example, by tactile feedback, sound or light. In an embodiment, the control unit is capable of receiving one or more inputs, analyzing the one or more inputs, and selecting one or more outputs based on the analysis. In an embodiment, selecting an output is equivalent to generating an output. Thus, according to an embodiment, selecting an output comprises a computational task of the system, wherein the inputs are analyzed (such as compared to one or more thresholds) in order to select an appropriate output.

[0057] In an embodiment, a pressure sensor is adapted to assess the pressure inside the balloon. In an embodiment, assessing the pressure involves reading the pressure sensor and obtaining a value. In an embodiment, the pressure sensor is assessed / read by means of a processor. In an embodiment, the assessed pressure indicates the pressure inside the balloon. In an embodiment, the assessed pressure is referred to as the balloon pressure. In an embodiment, the pressure sensor is in fluid communication with the inside of the balloon. In an embodiment, the pressure sensor is arranged in the balloon, for example by being an integral part of the catheter. In an embodiment, the pressure sensor is arranged in a control unit. In an embodiment, the pressure sensor is in fluid communication with the inside of the balloon through a first lumen. Thus, the pressure can be assessed inside the first lumen connecting the inside of the balloon with the container. Since the first lumen is in fluid communication with the inside of the balloon, the pressure assessed by the control unit indicates the pressure inside the balloon. Providing a pressure sensor in / by the control unit allows for easier manufacture of the catheter and / or a simpler catheter construction. In an embodiment, the control unit is adapted to assess / read the pressure sensor so that the control unit can store and / or analyze measurements / readings from the pressure sensor. Alternatively or additionally, the / a pressure sensor can be arranged where the pipeline is connected to the pump. In an embodiment, the secondary pressure sensor is in fluid communication with the irrigation channel of the catheter, such that the secondary pressure sensor is adapted to assess a pressure in the irrigation channel indicative of intestinal pressure. In an embodiment, the intestinal pressure is continuously assessed by the secondary pressure sensor in fluid communication with the irrigation channel of the catheter. In an embodiment, a mathematical model is used to eliminate the contribution from the balloon material in order to estimate the actual intestinal pressure. In an embodiment, simultaneously assessing the intestinal pressure and the balloon pressure allows monitoring the condition of the balloon of the catheter once the balloon has been inflated. Therefore, by providing a secondary pressure sensor in fluid communication with the irrigation channel of the catheter together with a pressure sensor adapted to assess the pressure inside the balloon, a method for monitoring the condition of an inflated balloon of a catheter of an intestinal irrigation system during an irrigation procedure of the intestine of a user can be established. In an embodiment, such a method of monitoring the condition of an inflated balloon comprises the steps of: assessing a balloon pressure related to the interior of the balloon; assessing an intestinal pressure related to the interior of the intestine; and calculating a pressure difference between the balloon pressure and the intestinal pressure. In a typical case of an inflated balloon during an irrigation pressure, the balloon pressure is greater than the intestinal pressure, for example due to tension introduced by the balloon material. Thus, a certain pressure differential exists during the lavage procedure. In the unlikely event that the balloon bursts during the lavage procedure (such as due to a sudden increase in pressure exerted on the balloon), the pressure differential drops to zero (i.e. becomes negligible) because the pressure sensor that was initially in fluid communication with the interior of the balloon is now in fluid communication with the intestine. Thus, in an embodiment, the bowel lavage system is adapted to issue a notification, e.g. in a user interface of the control unit, in the event that the pressure differential drops to zero.In an embodiment, the irrigation procedure is terminated if a balloon burst is detected.

[0058] According to a first aspect of the invention, the method comprises the steps of providing a liquid in a container and initiating an inflation process comprising a feedback loop, the feedback loop comprising the steps of: (i) inflating a balloon with a predetermined amount of liquid; (ii) evaluating a static pressure inside the balloon; and (iii) selecting an output based on the static pressure evaluated according to step (ii). The output is selected from: restarting the feedback loop according to step (i); skipping step (i) and continuing to evaluate the static pressure according to step (ii); and terminating the feedback loop. In an embodiment, terminating the feedback loop is equivalent to not restarting the feedback loop, and thus can be considered as the opposite of the optional output of restarting the feedback loop. Thus, in an embodiment, the output is selected from: restarting the feedback loop according to step (i); and skipping step (i) and continuing to evaluate the static pressure according to step (ii). Thus, the inflation process can be terminated by not selecting an output that affects future cycles of the feedback loop. In an embodiment, when an output has been selected, the associated step of routing the selected output to the feedback loop is implicitly included in step (iii). In an embodiment, the final step of the feedback loop includes routing the output to the associated step of the feedback loop. In an embodiment, skipping step (i) and continuing to assess the static pressure according to step (ii) includes reassessing the static pressure and selecting the output based on the reassessed static pressure according to step (iii). Thus, the static pressure is assessed twice without being interrupted by the step of inflating the balloon with a predetermined amount of fluid.

[0059] By initiating an inflation process including a feedback loop is meant that the system (such as a control unit) includes pre-programmed instructions that will function as described, such as after providing liquid in a container and inserting a catheter into the rectum of a user.

[0060] Due to this inflation process including a feedback loop, the inflation of the balloon with a predetermined amount of liquid and the assessment of the static pressure inside the balloon are separated in time. Thus, the pressure is assessed in the static phase of the liquid, where the volume in the balloon is stable / constant (static system), and as such the pressure is referred to as static pressure. Thus, the pressure assessment is less sensitive to liquid flow (i.e., dynamic system), and the assessment may therefore be more reliable for certain uses. In embodiments, the assessment of pressure may be considered a measurement of pressure or a reading of pressure.

[0061] The first step of the feedback loop comprises inflating the balloon with a predetermined amount of liquid. In other words, during the first step, a predetermined amount of liquid is introduced / pumped into the balloon by means of a pump. In an embodiment, the predetermined amount of liquid is less than 40 ml, such as between 10 ml and 40 ml, or between 15 ml and 30 ml, such as 20 ml. In an embodiment, before starting the inflation process, a maximum volume to be pumped into the balloon is specified in a step of the method. In such a case, the predetermined amount of liquid is less than such maximum volume. Thus, the balloon cannot be fully inflated (reaching the maximum volume) during a single inflation step. Alternatively, multiple cycles of the feedback loop may be applied in order to reach the maximum volume. Once the balloon has been inflated with the predetermined amount of liquid, the feedback loop proceeds to the second step. In an embodiment, when step (i) is met in each cycle of the feedback loop, the pump is turned off.

[0062] During the second step of the feedback loop, the static pressure inside the balloon is assessed by means of a pressure sensor. In an embodiment, the static pressure inside the balloon is measured by means of a pressure sensor. In an embodiment, the assessed static pressure is indicative of the static pressure inside the balloon. The pressure inside the balloon depends on a number of factors. Such factors include tension in the material of the balloon, intestinal pressure, hydrostatic pressure, and the general pressure generated by inflating the balloon in a confined space, such as in the rectum of a user. By assessing the pressure inside the balloon after inflation, the system receives an indication of the effect of introducing a predetermined amount of liquid during the first step of the cycle.

[0063] In an embodiment, immediately after inflation with a predetermined amount of liquid, the liquid may be turbulent (dynamic pressure), which may interfere with the pressure assessment. In an embodiment, by separating the inflation from the assessment of the pressure inside the balloon by a predetermined period of time, the pressure may be considered static. In an embodiment, the predetermined period of time is at least 1 second (such as 1 second), or at least 2 seconds (such as 2 seconds), or at least 3 seconds (such as 3 seconds).

[0064] The third step of the loop comprises selecting an output. In an embodiment, the output is selected by means of a processor of the control unit. In an embodiment, the output is based on the static pressure evaluated according to the second step of the loop. In an embodiment, the output is based on a compliance check of one or more thresholds set for the static pressure, such as a first threshold specifying the maximum static pressure allowed in the balloon and a second threshold specifying the maximum allowed change in static pressure allowed from two consecutive evaluations of the static pressure. In an embodiment, the static pressure is considered as an input and the selected output specifies the future operating state of the feedback loop. In an embodiment, the output is routed to the relevant steps of the feedback loop to form a closed loop. In an embodiment, the evaluation of the static pressure inside the balloon (step (ii)) is used to predict the effect of a second inflation of a predetermined amount of liquid by means of the processor. In an embodiment, the processor may find, based on the pressure evaluation, that (in a subsequent cycle) additional inflation may cause the balloon to exert an alarming backpressure on the rectal wall or cause the intestinal pressure to exceed a pressure that is considered safe. Thus, by means of the processor, an output specifying how the feedback loop should proceed may be selected. Thus, by providing a method for gradual inflation of a balloon, such inflation may be monitored and the inflation process aborted / terminated before health-related risks arise due to the high pressure inside the balloon or before a risk of balloon rupture arises.

[0065] In an embodiment, the output is based on static pressure. In an embodiment, the output is based on one or more inputs including static pressure, relative change in static pressure, time, temperature, volume and / or intestinal pressure.

[0066] In an embodiment, the output prompts to restart the cycle. For example, such an output may be selected when the processor finds that further inflation can be considered safe based on compliance with predetermined thresholds and further inflation is necessary to reach the target volume. In an embodiment, outputting to restart the cycle is the default. Thus, the cycle is automatically restarted unless otherwise prompted (e.g., by means of an output prompting to terminate or skip step (i) and continue with pressure assessment).

[0067] In an embodiment, an output prompts to pause the feedback loop for a predetermined amount of time. For example, such an output may be selected when the processor finds that further inflation may constitute a risk to the user and / or a risk of balloon rupture based on non-compliance with a predetermined threshold. In an embodiment, a pause is a specified time period in which no further output is selected. For example, a pause allows peristaltic motion to die down and / or the rectum to adapt to the balloon. In an embodiment, the pause lasts at least three seconds.

[0068] In an embodiment, the output prompts to skip step (i) of the feedback loop and proceed to assess static pressure. In an embodiment, the static pressure is reassessed to establish whether the reason for selecting to skip step (i) and reassess the output of pressure (e.g., due to the presence of feces or scar tissue) is reasonable or whether the cycle can be restarted. The presence of peristaltic motion can cause the pressure inside the balloon to increase. However, such peristaltic motion can disappear over time. Therefore, by skipping step (i) and continuing to assess pressure, it can be found that further inflation according to step (i) can be considered safe because the reason for non-compliance (the presence of peristaltic motion) has disappeared in the meantime.

[0069] In an embodiment, the output prompts to terminate the feedback loop and thus terminate the entire inflation process. Thus, terminating the feedback loop is equivalent to not restarting the feedback loop. For example, such an output may be selected due to non-compliance with a predetermined threshold (i.e., the pressure and / or pressure change exceeds the relevant threshold). In an embodiment, the output to terminate the feedback loop is selected when the target volume has been reached. In an embodiment, the output to terminate the feedback loop is selected when the pressure inside the balloon exceeds certain thresholds. In an embodiment, the output to terminate the feedback loop is after skipping step (i) and evaluating the output of the static pressure (if such evaluation finds that it is still not complied with).

[0070] In an embodiment, if the intestinal pressure exceeds a fourth threshold, an output is selected that prompts termination of the feedback loop. In an embodiment, the intestinal pressure is continuously monitored, for example, at a sampling rate above 1 Hz or above 10 Hz. Therefore, in case of an assessment that the intestinal pressure exceeds the fourth threshold, the feedback loop can be terminated, and the inflation process is therefore terminated. In an embodiment, compliance of the intestinal pressure with the fourth threshold is checked continuously and in parallel with the inflation process by means of a processor. In an embodiment, the fourth threshold is 2 psi (1×10 2 mbar), or 2.0 psi (1.4 × 10 2 mbar), or 2.00 psi (138 mbar). In an embodiment, the fourth threshold is selected to prevent the intestinal pressure from exceeding 2 psi (1 × 10 2 mbar), or 2.0 psi (1.4 × 10 2 mbar), or 2.00 psi (138 mbar). Depending on how the secondary pressure sensor that assesses the intestinal pressure is arranged in the system, the fourth threshold can be 2 psi (1 × 10 2 mbar), or 2.0 psi (1.4× 10 2mbar), or an acceptable maximum value of 2.00 psi (138 mbar). In an embodiment, contributions unrelated to the actual intestinal pressure are eliminated by means of the application of a mathematical model that takes into account different contributions to the intestinal pressure (including the hydrostatic pressure). Therefore, in an embodiment, the fourth threshold is selected so that the actual intestinal pressure does not exceed 2 psi (1 × 10 2 mbar), or 2.0 psi (1.4 × 10 2 mbar), or 2.00 psi (138 mbar).

[0071] In an embodiment, the output that terminates the feedback loop is the default. Thus, it is ensured that inflation only occurs when the system is specifically prompted to do so (e.g., by selecting an output that restarts the feedback loop).

[0072] Due to surgery and / or radiotherapy, the rectal wall or underlying tissue may include scar tissue or rectal ulcers. In addition, the rectal wall may be sensitive after such treatment or due to the use of drugs. Thus, it is necessary to provide a careful inflation process of the balloon of the intestinal irrigation system so that the balloon does not apply excessive pressure to the rectal wall or cause intestinal pressure that exceeds the regulatory limit at any time. The pressure inside the balloon indicates the pressure applied by the balloon on the rectal wall and / or the intestinal pressure induced. Thus, by monitoring the pressure inside the balloon during inflation, the pressure applied to the rectal wall or the intestinal pressure induced can be estimated, and a device for mitigating the risks associated therewith is introduced. In an embodiment, the intestinal pressure is evaluated by means of a secondary pressure sensor. In an embodiment, the intestinal pressure forms the basis for the selectable output in the third step of the feedback loop.

[0073] In an embodiment, during each step (ii) of the cycle, a series of static pressure assessments are made at a certain sampling rate. Thus, during the second step of the cycle, multiple assessments of static pressure may be made. Such multiple assessments of static pressure may be averaged to form a basis for selecting an output.

[0074] In an embodiment, the method comprises an initial step of specifying a maximum volume and determining in step (ii) a current volume in addition to evaluating the static pressure inside the balloon.

[0075] The initial step refers to the step before the step of initiating the inflation process, and thus the specification of the maximum volume can be performed before or after providing the liquid in the container. The maximum volume can be considered as a target volume, thereby implying the intention to reach such a volume. The maximum volume refers to the expected / desired final volume of the balloon, assuming that the inflation process is not terminated in advance. In an embodiment, the maximum volume is the nominal volume of the balloon reflecting the needs and physical requirements of the user. Therefore, the maximum volume reflects the desired final size of the balloon as selected by a healthcare professional and / or a user. The maximum volume can be specified by a user interface of the control unit.

[0076] According to an embodiment, in addition to evaluating the static pressure inside the balloon, the current volume in the balloon is determined in step (ii) of the feedback loop. For example, the current volume can be determined from the product of the number of times the balloon has been inflated according to step (i) of the feedback loop and the amount of liquid contained in the predetermined amount of liquid.

[0077] In an embodiment, the current volume in the balloon is an input to the processor, and an output can be selected based on the current volume. For example, the output based on the volume can be an output that prompts the termination of the feedback loop, and thus terminates the inflation process, because the volume in the balloon has reached a specified maximum volume.

[0078] In an embodiment, if the current volume in the balloon has reached the maximum volume, an output is selected to terminate the feedback loop.

[0079] In an embodiment, if no conflicting output is selected, the feedback loop is restarted (i.e., the loop starts over from the beginning) until the maximum volume has been reached. Thus, if the maximum volume is 100 ml and the predetermined amount of liquid is 20 ml, the feedback loop is restarted five times in order to reach the maximum volume. Thus, five inflations and five static pressure assessments are performed.

[0080] In an embodiment, the output of the feedback loop is selected to terminate only when the static pressure and / or the pressure change exceeds the associated threshold, thereby allowing the balloon to reach any volume as long as the associated input complies with its associated threshold. Thus, the only limiting factor on the ultimate size of the balloon is noncompliance with the thresholds set for the static pressure and / or the static pressure change.

[0081] In an embodiment, selecting an output in step (iii) of the first cycle of the feedback loop restarts the feedback loop, thereby establishing two consecutively evaluated static pressures. Thus, before selecting any other output, the balloon is inflated with a predetermined amount of liquid at least twice and the static pressure inside the balloon is evaluated at least twice. Evaluating the static pressure at least twice allows establishing a trend of the static pressure over time and calculating a relative change / difference between two consecutively evaluated static pressures. In an embodiment, the trend of the static pressure over time and / or the relative change between two consecutively evaluated static pressures forms the basis for selecting an output according to step (iii) of the feedback loop.

[0082] In an embodiment, the difference between two consecutively evaluated static pressures is calculated. Successive evaluation refers to calculating the difference between the static pressure evaluated in the current cycle and the static pressure evaluated in the previous cycle. For example, the calculation is performed in step (iii) of a cycle, where the static pressure evaluated in the current cycle refers to the static pressure as evaluated in step (ii) of the cycle. The previous cycle refers to the cycle immediately before the current cycle. In an embodiment, the difference is the absolute value of the calculated difference, that is, the difference is non-negative.

[0083] In an embodiment, the calculated difference is the relative change in static pressure from the static pressure of the previous cycle and the static pressure of the current cycle. In an embodiment, a large relative change / difference indicates a sudden presence of resistance (e.g., feces or scar tissue), which needs to be considered when selecting an output. A sudden presence may also indicate peristaltic motion, and it may be beneficial to select an output that prompts skipping step (i) and continuing with (re)assessing pressure, so as to allow such peristaltic motion to dissipate in the meantime.

[0084] In an embodiment, the calculated difference value forms the basis for selecting an output. In an embodiment, the calculated difference value is stored in a memory of the control unit.

[0085] In an embodiment, the selected output is based on the assessed static pressure of the current cycle and the difference between two consecutive assessed static pressures. As previously described, the selection of the output is provided in step (iii) of the feedback loop. Thus, according to this embodiment, the processor uses the assessed static pressure of the current cycle and the difference between two consecutive assessed static pressures to select the output. Thus, the relative change in static pressure forms the basis for selecting the output in conjunction with the assessed static pressure according to step (ii).

[0086] In an embodiment, the output is selected to restart the feedback loop if the assessed static pressure of the current cycle is lower than or equal to the first threshold and / or the difference between two consecutive assessed static pressures is lower than or equal to the second threshold. Thus, the output prompting the feedback loop to restart is conditioned on two conditions, both of which are subject to relevant thresholds. According to an embodiment, the processor is used to establish whether the assessed static pressure of the current cycle (i.e., according to step (ii) of the cycle) is lower than or equal to the first threshold, and whether the calculated difference as defined above is lower than or equal to the second threshold. The output is routed to step (i) of the feedback loop so that the balloon is inflated by a predetermined amount of liquid. The output to restart the feedback loop is selected based on a comparison of the assessed static pressure of the current cycle and the calculated difference with a predetermined threshold. In an embodiment, the predetermined threshold is stored in a memory in communication with the processor. In an embodiment, once the balloon has been inflated at least twice according to step (i) of the feedback loop, the output to restart the feedback loop is selectable if the assessed static pressure of the current cycle is lower than or equal to the first threshold and the difference is lower than or equal to the second threshold.

[0087] In embodiments, the threshold is selected such that compliance with the threshold reflects that further inflation is deemed safe, whereas non-compliance reflects encountering too high a resistance (e.g., due to increased restriction of the balloon due to the presence of feces, scar tissue, etc.). In the event of non-compliance, one may choose to skip step (i) and (re)evaluate the static pressure or terminate the output of the feedback loop. In embodiments, a large difference between the static pressure evaluated in the current cycle and the static pressure evaluated in the previous cycle may indicate that the most recent inflation step (i.e., step (i) of the current cycle) encountered resistance (e.g., feces or scar tissue).

[0088] In an embodiment, if the assessed static pressure of the current cycle is above a first threshold and / or the difference between two consecutive assessed static pressures is above a second threshold, an output is selected to terminate the feedback loop. In an embodiment, the first (second) threshold is selected such that an assessed static pressure (change in static pressure) equal to or below it is considered safe for further inflation, while an assessed pressure (change in static pressure) above it indicates that further inflation may cause harm. A change in static pressure / difference between two consecutive assessed static pressures above the second threshold may indicate that the inflatable balloon has encountered resistance in the rectum, and further inflation may cause displacement of the source of resistance and / or potentially cause an increase in intestinal pressure and / or exert alarming pressure on the rectal wall. Therefore, a safety mechanism is provided by introducing an output to terminate the feedback loop if the assessed static pressure of the current cycle is above the first threshold and / or the difference between two consecutive assessed static pressures is above the second threshold, thereby avoiding the consequences of achieving further inflation listed above.

[0089] In an embodiment, if the difference between two consecutive evaluated static pressures is above a second threshold, then the choice is made to skip step (i) and to proceed with the output of the evaluated static pressure according to step (ii). In an embodiment, skipping (i) and proceeding with the output of the evaluated static pressure according to step (ii) is considered a re-evaluation of the static pressure, since no inflation according to step (i) has occurred between the two evaluations of the static pressure. In other words, the static pressure is re-evaluated if the difference between the static pressure evaluated in the current cycle and the static pressure evaluated in the previous cycle is above the second threshold. In an embodiment, the re-evaluation of the static pressure is separated from the previous evaluation by a specified time period, which period thus constitutes a pause. In an embodiment, the specified time period is between 1 second and 5 seconds, such as 3 seconds.

[0090] Instead of completely terminating the feedback loop and the inflation process as such, if the evaluated static pressure or the change in static pressure (the difference between two consecutive evaluated static pressures) does not comply with a predetermined threshold, the static pressure is (re)evaluated before selecting an output to terminate the feedback loop. Thus, the risk of false signals causing an undesirable termination of the inflation process is reduced. In an embodiment, false signals may occur due to a system malfunction or due to a temporary peristaltic movement. Thus, a single evaluation of a static pressure exceeding a threshold may be due to the presence of a temporary peristaltic movement, and it is therefore desirable to provide a system that enables an inflatable balloon to be inflated in the rectum despite the presence of a vanished peristaltic movement, which may not pose a risk to the user. However, if a re-evaluation of the static pressure establishes that non-compliance is justified, an output to terminate the feedback loop may be selected, whereby the balloon is not further inflated.

[0091] In an embodiment, non-compliance with the first threshold value may also result in an output that selects to skip the first step and proceed with evaluating the static pressure. In an embodiment, if the evaluated static pressure of the current cycle is above the first threshold value, an output prompts to re-evaluate the static pressure. Thus, the absolute value of the static pressure forms the basis for an output that selects to prompt to skip step (i) and (re)evaluate the static pressure.

[0092] In an embodiment, if the difference between two consecutively evaluated static pressures after re-evaluating the static pressure is above the second threshold, an output is selected to terminate the feedback loop. Thus, if the difference remains above the second threshold after implementing an output to skip step (i) and continue to evaluate the static pressure, an output is selected to terminate the feedback loop. If, after re-evaluating the static pressure, the difference between the static pressure evaluated in the current cycle and the static pressure evaluated in the previous cycle is above the second threshold, it may indicate the permanent presence of an object causing the increased pressure (e.g., feces or scar tissue), rather than a temporary object (e.g., peristaltic movement). In such a case, according to this embodiment, an output is selected to terminate (i.e., not restart) the feedback loop, thereby terminating the entire inflation process. Thus, although the specified maximum volume has not been reached, the inflation process can be terminated. In such a case, the final volume in the balloon becomes the product of the predetermined amount of liquid and the number of times step (i) has been applied (i.e., the number of times the balloon has been inflated with the predetermined amount of liquid).

[0093] In an embodiment, if the evaluated static pressure of the current cycle after re-evaluating the static pressure is above the first threshold, the output terminating the feedback loop is selected. Thus, the absolute value of the static pressure forms the basis for selecting the output terminating the feedback loop.

[0094] In an embodiment, the method further comprises the step of continuously evaluating the pressure inside the balloon. Thus, during the inflation process including during step (i) of the feedback loop (i.e., during the process of inflating the balloon with a predetermined amount of liquid and during any intermediate periods), the pressure inside the balloon is always monitored. Thus, the evaluation comprises both the dynamic pressure evaluated during the inflation step (step (i)) of the feedback loop and the static pressure as previously described. Continuously means that the pressure inside the balloon is evaluated at a sampling rate of at least 1 Hz or at least 10 Hz. Thus, regardless of the current step of the feedback loop, an output can be selected based on the pressure inside the balloon. In an embodiment, the step of continuously evaluating the pressure inside the balloon runs in parallel with the feedback loop.

[0095] In an embodiment, if the assessed pressure inside the balloon at any time during the inflation process exceeds a third threshold, the output of the feedback loop is selected to terminate. Thus, the feedback loop can be terminated based on the pressure inside the balloon, regardless of the current step of the feedback loop. Therefore, if the pressure at any point in time exceeds the third threshold, the feedback loop is terminated. In an embodiment, the third threshold is greater than the first threshold, both of which are related to the absolute value of the pressure inside the balloon. During inflation, the (dynamic) pressure may be significantly higher than the static pressure, and therefore the third threshold is selected so that such foreseen high dynamic pressures do not cause termination unless significantly high pressures are formed. However, if the dynamic pressure exceeds the third threshold, it may indicate a sudden change or the presence of an object in the rectum that causes an increase in pressure. In such a case, the method is adapted to select to terminate the feedback loop based on the pressure assessment and thus terminate the output of the inflation process, regardless of the activity / current step of the feedback loop.

[0096] In an embodiment, the predetermined amount of liquid is nominally 20 ml. Thus, during each cycle of the feedback loop, in particular during step (i) of the feedback loop, the balloon is inflated by 20 ml. Such a volume provides for convenient inflation without the risk that inflating the balloon by an additional 20 ml increases the risk of exceeding any threshold alarm value. In an embodiment, if the specified maximum volume is not an integer multiple of the volume of the predetermined amount of liquid, the final inflation is adjusted to the predetermined amount of liquid.

[0097] In an embodiment, the predetermined amount of liquid is selected from the range between 10 ml and 50 ml, or between 15 ml and 30 ml, or between 15 ml and 25 ml, such as 20 ml.

[0098] In an embodiment, the predetermined amount of liquid is reduced during each cycle of the feedback loop. Thus, subsequent inflations of the predetermined amount of liquid are less likely to cause any non-compliance with the threshold value, because such subsequent inflations introduce less liquid into the balloon than the liquid inflated during the previous cycle. In an embodiment, the initial (i.e., relating to the first cycle of the feedback loop of the inflation process) predetermined amount of liquid is 20 ml. In an embodiment, the initial predetermined amount of liquid is between 20 ml and 40 ml, such as 30 ml. In an embodiment, the subsequent inflation cycle (step (i) of the feedback loop) introduces 1 ml less than the previous cycle, or 2 ml less than the previous cycle, or 3 ml less than the previous cycle, or 4 ml less than the previous cycle, or 5 ml less than the previous cycle. In an embodiment, the volume introduced by the subsequent inflation cycle (step (i) of the feedback loop) is a fraction of the predetermined amount of liquid of the previous cycle, such as between 50% and 99% of the previous predetermined amount of liquid, or such as 90% of the previous predetermined amount of liquid, or such as 80% of the previous predetermined amount of liquid, or such as 50% of the previous predetermined amount of liquid. As an example, where the initial predetermined liquid volume is 20 ml and the predetermined liquid volume is reduced by 80% during each cycle of the feedback loop, the subsequent four cycles inflate the balloon (in step (i)) with 16 ml, 12.8 ml, 10.2 ml and 8.2 ml of liquid respectively.

[0099] In an embodiment, the predetermined amount of liquid is one Nth of the maximum volume, where N is an integer. Therefore, the predetermined amount of liquid satisfies the following relationship

[0100] ,

[0101] Where N is an integer, and Where V1 is a predetermined amount of liquid, and V max is the maximum volume. Thus, the balloon can be inflated through multiple cycles, wherein no final adjustment of the predetermined liquid amount is required to reach the maximum volume, i.e., there is no residual volume. For example, for a specified maximum volume of 100 ml, the predetermined liquid amount according to this embodiment can be 50 ml (N=2), or 33 ml (N=3), or 25 ml (N=4), or 20 ml (N=5), or 17 ml (N=6), and so on. Therefore, the balloon can be inflated in multiple cycles (e.g., 2 to 6 cycles), wherein all cycles (step (i) of the feedback loop) inflate the balloon with the same predetermined liquid amount (e.g., 50 ml, or 33 ml, or 25 ml, or 20 ml, or 17 ml, for a maximum volume of 100 ml), regardless of the maximum volume.

[0102] In an embodiment, the integer N is between 2 and 20, such as 2, or 3, or 4, or 5, or 6, or 7, or 8, or 9, or 10, or 11, or 12, or 13, or 14, or 15, or 16, or 17, or 18, or 19, or 20. When the specified maximum volume is large, a large integer may be preferred, and when the specified maximum volume is small, a small integer may be preferred. Thus, the predetermined amount of liquid is adjusted to the maximum volume. Inflating the balloon with a small predetermined amount of liquid (e.g., less than 20 ml or less than 15 ml) during each cycle may be beneficial for users with particularly sensitive rectums (for whom special attention must be paid to the rectum). By using a small predetermined amount of liquid, the inflation process may take longer than using a large predetermined amount of liquid. Using a large predetermined liquid volume (e.g., more than 20 ml or more than 25 ml) can be beneficial for users with non-sensitive rectums and / or to speed up the inflation process so that the system can quickly proceed with irrigating the intestine (such as the steps of the intestinal irrigating procedure described herein after balloon inflation).

[0103] In summary, after a single assessment of static pressure (i.e., during the first cycle of the feedback loop), the following can be expected:

[0104] The static pressure evaluated complies with the first threshold, i.e., the static pressure in the balloon is equal to or lower than the first threshold. In this case, an output is selected to restart the feedback loop. Thus, a second loop is started.

[0105] The evaluated static pressure does not comply with the first threshold, i.e. the static pressure in the balloon is above the first threshold. In this case, two outputs can be selected, depending on how the system is configured. In the first case, an output is selected that terminates the feedback loop, i.e. an output equivalent to not selecting to restart the feedback loop. In the second case, an output is selected that skips the first step and proceeds with evaluating the static pressure. Thus, the (re)evaluated pressure forms the basis for a new check of compliance. In case of compliance, an output that restarts the feedback loop can be selected. In case of persistent non-compliance, an output that terminates the feedback loop can be selected, thereby leaving the partially inflated balloon acting as a retaining device sufficient for a subsequent lavage procedure.

[0106] In summary, after at least two evaluations of the static pressure (i.e. once the feedback loop has run at least twice) the following can be foreseen:

[0107] The evaluated static pressure complies with a first threshold value, and the difference between two consecutively evaluated static pressures complies with a second threshold value. In this case, an output is selected to restart the feedback loop. Thus, a new loop is started.

[0108] The evaluated static pressure does not comply with a first threshold and / or the difference between two consecutively evaluated static pressures does not comply with a second threshold. In this case, two outputs can be selected, depending on how the system is configured. In the first case, an output is selected that terminates the feedback loop, i.e., an output that is equivalent to not selecting to restart the feedback loop. In the second case, an output is selected that skips the first step and continues to evaluate the static pressure. Thus, the (re)evaluated pressure forms the basis for a new check of compliance with the first threshold and / or the second threshold. In the case of compliance, an output that restarts the feedback loop can be selected. In the case of non-compliance, an output that terminates the feedback loop can be selected, thereby allowing the partially inflated balloon to act as a sufficient retaining device.

[0109] If a maximum volume has been specified, compliance may be checked and outputs similar to those specified above may be selected depending on compliance / non-compliance. For example, if the current volume in the balloon has reached the maximum volume, an output is selected that terminates the feedback loop.

[0110] In an embodiment, in case the pressure (static and / or dynamic) does not comply with (i.e. exceeds) a third threshold, an output is selected to terminate the feedback loop. During inflation, the dynamic pressure is evaluated, and during the intermediate period between two inflations, the static pressure is evaluated. The pressure may be evaluated continuously during the entire inflation procedure. Thus, compliance with the threshold may be continuously checked by the processor. Continuously means that the pressure sensor / processor has a sampling rate higher than 1 Hz or higher than 10 Hz.

[0111] Detailed description with drawings

[0112] Figure 1 A graph depicting the internal pressure P of a balloon as a function of time t during the inflation process when the balloon is inflated in an unconfined space is shown. Figure 1 The inflation process involves a feedback loop. Figure 1The inflation process shown in comprises four cycles of a feedback loop, the third cycle C3 being highlighted by a dashed box and curly brackets for illustrative purposes. Each cycle begins by inflating a predetermined amount of liquid at time t1, as illustrated by the grey box and curly brackets covering the first step (step (i)) C1a of the first cycle. During the inflation process, the pressure increases, which is referred to herein as the dynamic pressure. Once the predetermined amount of liquid (e.g., nominally 20 ml) has been pumped into the balloon, the pump is turned off / paused (or equivalent effect) at time t2 and the pressure in the balloon stabilizes for a predetermined period of time ∆t. At time t3, the pressure inside the balloon is evaluated, which is now referred to as the static pressure due to the stabilization of the pressure inside the balloon during period ∆t. A processor of the system selects an output based on the evaluated static pressure, which output indicates a future operating state of the feedback loop. In the event that the processor has established that the static pressure assessed at time t3 complies with the relevant (multiple) predetermined threshold values, a new cycle of the feedback loop begins at time t3, the new cycle following the same procedure as described above in relation to the first cycle, so that time t3 of the first cycle coincides with time t1' of the second cycle (assuming for illustrative purposes that the output is immediately selected and routed to step (i) of the feedback loop).

[0113] according to Figure 1 , four cycles are applied before the inflation process is terminated at time tX. Termination may be the result of the volume inside the balloon having reached a specified maximum volume. For example, if the maximum volume has been set to 80 ml, each step (i) of each cycle may have inflated the balloon with 20 ml of liquid.

[0114] Figure 2 A graph depicting the pressure P as a function of time t when a balloon is inflated in a confined space is shown. Figure 2 . As demonstrated by the static pressures P1, P2, P3 that increase over time, during each of the three cycles C1', C2', C3', the restriction causes the static pressure inside the balloon to gradually increase. Such a gradual increase in static pressure indicates that the balloon encounters resistance in its inflation, such as due to feces or scar tissue in the rectum. Ignoring such presence may result in the balloon exerting high back pressure on the rectal wall and / or increased intestinal pressure, both of which potentially constitute a health risk to the user. According to an embodiment of the present invention, a first threshold value T1 for the static pressure is applied. The first threshold value T1 specifies an upper limit value for the static pressure allowed in the balloon. Therefore, exceeding (non-compliance with) the first threshold value T1 may potentially constitute a health risk. Therefore, the feedback loop may choose to re-evaluate the static pressure or terminate the output of the feedback loop / inflation process. As Figure 2As shown, the estimated static pressure P1 of the first cycle C1' and the estimated static pressure P2 of the second cycle C2' comply with the first threshold value T1 (the estimated static pressure is below the first threshold value T1). Compliance with the threshold value is checked after a stable period of pressure, and in case of non-compliance (i.e. the estimated static pressure is above the first threshold value T1), the output of the feedback loop can be terminated so that the balloon is not further inflated even though the maximum volume has not yet been reached. This situation is in Figure 2 2 is shown for the third cycle C3 ′, wherein the evaluated static pressure P3 of the third cycle C3 ′ exceeds (does not comply with) the first threshold value T1 .

[0115] A second threshold is applied to the relative change in static pressure between the static pressure evaluated in the current cycle and the static pressure evaluated in the previous cycle. Figure 2 The relative changes are shown by a first difference ∆P1 between the assessed static pressure P1 of the first cycle C1' (the "previous cycle" relative to the second cycle C2') and the assessed static pressure P2 of the second cycle C2 (the "current cycle" when the first difference ∆P1 is assessed), and a second difference ∆P2 between the assessed static pressure P2 of the second cycle C2 (the "previous cycle" relative to the third cycle C3') and the assessed static pressure P3 of the third cycle C3 (the "current cycle" when the second difference ∆P2 is assessed). Large differences / relative changes may indicate sudden resistance (e.g., due to feces or scar tissue), and as such, further inflation may potentially constitute a health risk.

[0116] Figure 3 A graph depicting the pressure P as a function of time t for an inflation process comprising seven cycles is shown. Figure 3 The static pressure P7 evaluated for each of the seven cycles is similar in magnitude and complies with the first threshold value T1. Figure 3 No significant changes in static pressure between cycles were observed. A third threshold value T3 is included in the figure, which limits the maximum allowed pressure inside the balloon at any time. Since the pressure during none of the seven cycles neither exceeded the third threshold value T3 nor violated the first T1 or the second threshold value, the cycle was restarted after each evaluation of the static pressure until the maximum volume was reached after seven cycles.

[0117] Figure 4A A flow chart of a method for inflating an inflatable balloon is shown. The method includes specifying a maximum volume "V M==" and a feedback loop comprising three steps 1001, 1002, 1003. In an embodiment, specifying a maximum volume is optional, and in the absence of a maximum volume, the feedback loop may restart until non-compliance with one or more thresholds results in an output that selects to terminate the feedback loop. In the following, it is assumed that a maximum volume has been specified, so that compliance with such a maximum volume is checked.

[0118] In a first step 1001 of the feedback loop, the balloon is inflated with a predetermined amount of fluid "+V1". In a second step 1002, the static pressure P of the balloon interior is evaluated by means of a pressure sensor in fluid communication with the interior of the balloon and a processor in communication with the pressure sensor. a (Alternatively stylized as P_a). The first step 1001 and the second step 1002 may be separated by a predetermined period of time to ensure a static state of the fluid in the balloon at the time of the pressure assessment, so that the assessed pressure may be considered a static pressure. The third step 1003 is processed by the processor and the assessed pressure P of the second step 1002 is converted to a In a third step 1003, the processor performs the evaluation of the static pressure P a The comparison with the first threshold value T1 and the determination of the estimated pressure P a Whether it complies with the first threshold T1, that is, P a ≤ T1 is true. In addition, assuming that at least two cycles have been performed, the processor calculates the static pressure P evaluated in the current cycle (ie, in the second step 1002 of the current / active cycle) a The difference ∆P from the static pressure evaluated in the previous cycle a (ie, relative change). The processor performs the calculation of the difference ∆P a The difference is compared with the second threshold value T2 and determines whether the calculated difference complies with the second threshold value, ie, ∆P a ≤ T2 is true. Finally, check whether the current volume V in the balloon is less than the target volume V M , that is, V < V M Is true. Figure 4A In the example of , all conditions are met, and the processor therefore selects an output that restarts the cycle (i.e., inflates the balloon with a predetermined amount of liquid + V1), and continues with the steps as described above. The selected output is routed to the first step 1001 of the feedback loop via route 1004. In an embodiment, the pressure inside the balloon is monitored during the entire inflation process (including during the first step 1001). Thus, a check for compliance with the third threshold can be performed in the feedback loop, wherein non-compliance can result in a prompt to select an output that terminates the feedback loop.

[0119] Figure 4B Shows something similar to what is described above Figure 4A , but it is found that the second threshold T2 is not complied with, that is, ∆P a > T2. In this case, the processor chooses to skip the first step 1001' (step (i)) and proceed to the second step 1002' (step (ii)) to evaluate the static pressure P before selecting a subsequent output (e.g., whether to restart the feedback loop from step (i) or terminate the feedback loop). a The output of skipping the first step 1001' and continuing to evaluate the static pressure is routed to the second step 1002', as shown by route 1004'. Skipping the first step 1001' can be considered as a re-evaluation of the static pressure. Failure to comply with the second threshold value T2 may be due to the presence of vanishing peristaltic motion, and by re-evaluating the pressure P again after a short period of time (e.g., less than 3 seconds). a , compliance can be found to be reestablished, and the feedback loop can be as Figure 4A The feedback loop is terminated as described. In the event of persistent non-compliance, there is an option to terminate the output of the feedback loop. Terminating the feedback loop is equivalent to not restarting the feedback loop, and thus terminating the inflation of the balloon. Termination of the feedback loop results in the balloon including less liquid than initially expected when the maximum volume was set. When the feedback loop is terminated before the maximum volume has been reached, the current volume in the balloon acts as a retaining device for the catheter during the subsequent irrigation process.

[0120] If the current volume V in the balloon is found to be greater than the difference V M - V1, the method / system can adapt (reduce) the volume of the predetermined amount of liquid in the last inflation step to meet and reach the maximum volume and not over-inject. Thus, predetermined means that the volume can be adjusted between cycles, but in such a way that this is allowed by or as a result of calculations made by the processor. Thus, the processor is allowed to calculate and potentially change the predetermined amount of liquid during each cycle of the feedback loop. For example, if the maximum volume V M is 90 ml, V1 is 20 ml, and the current volume in the balloon is 80 ml, the processor may adjust the volume of the predetermined amount of liquid for the final cycle to 10 ml, thereby reaching the maximum volume. However, in an embodiment, the maximum volume may be selected to be an integer multiple of the predetermined amount of liquid, thereby avoiding the need for adjustment. Correspondingly, the predetermined amount of liquid may be selected to be one Nth of the maximum volume, where N is an integer.

[0121] Figure 5AA volume scale 4 is shown for visualizing the inflation process according to the present invention. In this example, a maximum volume "L" (large) has been specified / selected. The inflation process according to one embodiment of the present invention comprises a feedback loop comprising a first step of inflating the balloon with a predetermined amount of liquid V1 less than the maximum volume. Once the balloon has been inflated with the predetermined amount of liquid V1, the static pressure P inside the balloon is evaluated. a , and the processor 11 of the system executing the method selects an output based on the static pressure. a If at least one threshold value is complied with (such as a first threshold value limiting the maximum allowed static pressure), an output is selected to restart the feedback loop, thereby inflating the balloon again with a predetermined amount of liquid V1. If at least one threshold value is complied with during the entire inflation process, the amount of liquid in the balloon eventually reaches a maximum volume, and an output is selected to terminate (not restart) the feedback loop.

[0122] Figure 5B Shows something like Figure 5A The volume scale of the volume scale is 4. Figure 5B In the case of a non-compliance established in the third cycle C3 ″, the inflation process according to the invention is visualized. The non-compliance may be due to the difference between two consecutively evaluated static pressures exceeding a second threshold value. In this case, it is chosen to skip the first step (step (i)) and thus re-evaluate the static pressure P a ' output, and re-evaluate the pressure P a ' forms the basis for a new output selected by the processor 11. Compliance with the second threshold is reestablished as demonstrated by a new series of cycles / inflations, and the output selected by the processor 11 prompts the restart of the feedback loop. Ultimately, this series of inflations (one per cycle) causes the volume in the balloon to reach a maximum volume.

[0123] Figure 6A cross-sectional view of a user's rectum 103 and a catheter 110 of a bowel irrigation system inserted therein through the anus 102 is shown. The catheter 110 comprises an inflatable balloon 111 which can be inflated through an inflation channel 115. The inflation channel 115 is in fluid communication with a container holding a liquid for inflating the balloon 111. The inflatable balloon 111 is considered a retaining means for holding the catheter 110 in a fixed position within the rectum 103 and further for blocking the anus 102 during an irrigation procedure. The proximal end of the catheter 110 is provided with an eyelet 112 communicating with an irrigation channel (not shown) inside the catheter 110, so that liquid pumped into the catheter 110 in the distal end of the catheter can exit the catheter at the proximal end through the eyelet 112 and enter the rectum 103. The liquid can be held in a container in fluid communication with the irrigation channel. In the lower part of the rectum 103 there is naturally a chamber 106 which allows the inflatable balloon 111 to inflate without pushing the rectal wall 104 excessively. Once the inflatable balloon 111 has been inflated inside the chamber 106, the irrigation liquid can be pumped through the catheter 110 and further through the eyelet 112 into the rectum 103. During such a procedure, and during subsequent procedures of letting the irrigation liquid stimulate the intestine for a specified period of time, peristaltic motion 101 can be generated. Peristaltic motion can be defined as the radially symmetrical contraction and relaxation of muscles that propagate waves. Thus, the peristaltic motion 101 can propagate towards the anus 102 and eventually exert pressure on the balloon 111 inflated by the (incompressible) liquid. Due to the incompressible nature of the liquid, the exerted pressure can cause counterpressure on the rectal wall 104 and thus potentially constitute a health risk for the user. For example, the specified period of time left for the irrigation liquid to stimulate the intestine is between 1 minute and 30 minutes, for example, 15 minutes. During this period, the catheter 110 remains in place inside the rectum and the balloon 111 remains inflated to prevent irrigating liquid from escaping through the anus 102 .

[0124] Figure 7A bowel irrigation system 400 is shown. The system 400 includes a container 401 for holding a liquid, a catheter 410, a conduit 402 connecting the container 401 and the catheter 410, a pump 403 (not shown, but preferably incorporated in the container, such as at the bottom), and a control unit 404 for controlling the flow of fluid in the system 400. The catheter 410 includes an inflatable balloon 411. The conduit 402 may include a first lumen and a second lumen, so that a separate fluid communication may be established between the container 401 and the balloon 411 through the first lumen, and a separate fluid communication may be established between the container 401 and the proximal end 413 of the catheter 410 through the second lumen. Thus, the liquid held in the container 401 may be selectively pumped into the balloon 410 and through an eyelet provided in the proximal end 413 of the catheter 410. By pumping the liquid through the eyelet, the liquid irrigates the intestine when the catheter 410 is inserted into the rectum of the user. A liquid sensor 419 for sensing the presence of liquid in the container 401 may be included in the container 401 or incorporated into the pump 403. A pressure sensor 414 for evaluating / measuring the pressure inside the balloon 411 may be arranged at any point between the balloon 411 and the pump 403, provided that the pressure sensor 414 is in fluid communication with the interior of the balloon 411. In an embodiment, the pressure sensor 414 is arranged by the control unit 404 (e.g., via an articulated coupling 404'), wherein the control unit 404 is in fluid communication with the interior of the lumen of the conduit 402 and as such is in fluid communication with the interior of the balloon 411. Thus, the pressure evaluation performed by the control unit 404 indicates the pressure inside the balloon 411. In an embodiment, the pressure sensor 414 is arranged in the control unit 404.

[0125] Figure 8A cross-sectional view of a catheter 510 of a bowel irrigation system is shown. The catheter 510 comprises a proximal end 513 and a distal end 514. The proximal end 513 is provided with one or more eyelets 512 for facilitating irrigation of the intestine when the proximal end 513 is inserted into the rectum of a user. The distal end 514 is provided with a connector 517 for connecting the catheter 510 to a tube (not shown). The catheter 510 comprises an inflatable balloon 511. The balloon 511 surrounds the catheter 510. In an embodiment, the inflatable balloon 511 is annular, i.e., similar to a ring body. The diameter d of the balloon 510 can be measured as indicated, which is the outer diameter of the ring body. The balloon 511 can be inflated by a liquid, for example, a liquid pumped through a tube from a container of the bowel irrigation system. The catheter 510 comprises two channels: an inflation channel 515 and an irrigation channel 516. These channels can be in separate fluid communication with the container. The inflation channel 515 facilitates communication between the interior of the balloon 511 and the container of the intestinal irrigation system, so that the balloon 511 can be inflated by liquid from the container. The irrigation channel 516 facilitates communication between the eyelet 512 of the proximal end 513 and the container of the intestinal irrigation system, so that liquid can be pumped through the eyelet 512 and thereby promote irrigation of the intestine under the use condition. The balloon 511 is made of a flexible / elastic material to allow a tight fit around the catheter in the non-inflated state, and for a flexible balloon in the inflated state. Therefore, in the non-inflated state, the material of the balloon 511 is tightly wrapped around the catheter 510. Thus, no folds are formed when the balloon is not inflated. A pressure sensor in fluid communication with the interior of the balloon 511 can be included in the catheter 510 for evaluating the pressure inside the balloon 511.

[0126] Although specific features have been shown and described, it should be understood that they are not intended to limit the claimed invention, and that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed invention. Accordingly, the description and drawings should be regarded as illustrative rather than restrictive. The claimed invention is intended to cover all alternatives, modifications and equivalents.

[0127] In an embodiment, a system for inflating an inflatable balloon of a catheter for a bowel irrigation system is provided, the system comprising: a container adapted to contain a liquid; a catheter adapted to be inserted into a user's rectum, the catheter comprising an inflatable balloon; a conduit connecting the container and the catheter; a pump adapted to pump liquid from the container through the conduit to the balloon; a control unit comprising a processor; and a pressure sensor in fluid communication with an interior of the inflatable balloon; wherein the system further comprises: a quantity of liquid contained in the container for inflating the balloon, and

[0128] The control unit is configured to control the inflation process by means of a feedback loop, the feedback loop comprising the following steps: (i) inflating the balloon with a predetermined amount of liquid by means of the pump; (ii) evaluating the static pressure inside the balloon by means of the pressure sensor; and (iii) restarting the feedback loop in accordance with the static pressure being lower than a first threshold, or re-evaluating the static pressure in accordance with the static pressure being higher than the first threshold and terminating the inflation process in accordance with the re-evaluated static pressure being higher than the first threshold, or restarting the feedback loop in accordance with the re-evaluated static pressure being lower than the first threshold.

[0129] Example

[0130] Embodiments of the present disclosure are set forth in the following clauses:

[0131] 1. A system for inflating an inflatable balloon of a catheter for a bowel irrigation system, the system comprising:

[0132] - a container adapted to contain a liquid;

[0133] - a catheter adapted for insertion into the rectum of a user, the catheter comprising an inflatable balloon;

[0134] - a pipe connecting the container and the conduit;

[0135] - a pump adapted to pump liquid from the container through the conduit to the balloon;

[0136] - a control unit comprising a processor; and

[0137] - a pressure sensor in fluid communication with the interior of the inflatable balloon;

[0138] Wherein, the system further comprises:

[0139] - a quantity of liquid contained in the container for inflating the balloon, and

[0140] - means for initiating an inflation process comprising a feedback loop comprising the steps of:

[0141] (i) inflating the balloon with a predetermined amount of liquid by means of the pump,

[0142] (ii) evaluating the static pressure inside the balloon by means of the pressure sensor, and

[0143] (iii) selecting, with the aid of the processor, an output based on the static pressure evaluated according to step (ii), the output being selected from:

[0144] - restarting the feedback loop according to step (i),

[0145] - skipping step (i) and continuing with step (ii) to evaluate said static pressure, and

[0146] - terminating the feedback loop.

[0147] 2. A system according to claim 1, wherein the system is adapted to receive a specification of a maximum volume, and wherein the system includes means for determining the current volume in the balloon in addition to evaluating the static pressure inside the balloon during step (ii) of the feedback loop.

[0148] 3. A system according to clause 2, wherein the processor is adapted to compare the current volume in the balloon with the maximum volume and select an output that terminates the feedback loop if the current volume has reached the maximum volume.

[0149] 4. A system according to any of clauses 1 to 3, wherein the processor is adapted to select, in step (iii) of a first cycle of the feedback loop, an output for restarting the feedback loop, thereby establishing two consecutively assessed static pressures.

[0150] 5. A system according to clause 4, wherein the processor is adapted to calculate the difference between two consecutive assessed static pressures.

[0151] 6. The system of clause 5, wherein the processor is adapted to select the output based on the assessed static pressure of the current cycle and the difference between two consecutive assessed static pressures.

[0152] 7. A system according to claim 6, wherein the processor is adapted to compare the assessed static pressure of the current cycle with a first threshold and / or to compare the difference between two consecutive assessed static pressures with a second threshold, and wherein the processor is adapted to select an output for restarting the feedback loop if the assessed static pressure of the current cycle is lower than or equal to the first threshold and / or the difference between two consecutive assessed static pressures is lower than or equal to the second threshold.

[0153] 8. A system according to claim 6, wherein the processor is adapted to compare the assessed static pressure of the current cycle with a first threshold and / or to compare the difference between two consecutive assessed static pressures with a second threshold, and wherein the processor is adapted to select an output that terminates the feedback loop if the assessed static pressure of the current cycle is higher than the first threshold and / or the difference between two consecutive assessed static pressures is higher than the second threshold.

[0154] 9. A system according to claim 6, wherein the processor is adapted to compare the difference between two consecutive evaluated static pressures with a second threshold, and wherein the processor is adapted to select to skip step (i) and continue to evaluate the output of the static pressure according to step (ii) if the difference between two consecutive evaluated static pressures is higher than the second threshold.

[0155] 10. The system of clause 9, wherein the processor is adapted to select an output terminating the feedback loop if, after re-evaluating the static pressure, the difference between two consecutively evaluated static pressures is above the second threshold.

[0156] 11. The system according to any of clauses 1 to 10, wherein the pressure sensor is adapted for continuously assessing the pressure inside the balloon during the inflation process.

[0157] 12. A system according to claim 11, wherein the processor is adapted to compare the assessed pressure inside the balloon to a third threshold, and wherein, if the assessed pressure inside the balloon exceeds the third threshold at any time during the inflation process, the processor is adapted to select an output that terminates the feedback loop.

[0158] 13. A system according to any one of clauses 1 to 12, wherein the predetermined amount of liquid is nominally 20 ml.

[0159] 14. A system according to any one of clauses 1 to 12, wherein the processor is adapted to reduce the predetermined amount of liquid during each cycle of the feedback loop.

[0160] 15. A system according to any one of clauses 1 to 12, wherein the predetermined amount of liquid is one Nth of the maximum volume, where N is an integer.

Claims

1. A system for inflating an inflatable balloon of a catheter for a bowel irrigation system, the system comprising: - a container adapted to contain a liquid; - a catheter adapted for insertion into the rectum of a user, the catheter comprising an inflatable balloon; - a pipe connecting the container and the conduit; - a pump adapted to pump liquid from the container through the conduit to the balloon; - a control unit comprising a processor; and - a pressure sensor in fluid communication with the interior of the inflatable balloon; Wherein, the system further comprises: - a quantity of liquid contained in the container for inflating the balloon, and - means for initiating a stepwise inflation process comprising a feedback loop comprising the steps of: (i) inflating the balloon with a predetermined amount of liquid by means of the pump, (ii) evaluating the static pressure inside the balloon by means of the pressure sensor, and (iii) selecting, with the aid of the processor, an output based on the static pressure evaluated according to step (ii), the output being selected from: - restarting the feedback loop according to step (i), - skipping step (i) and continuing with step (ii) to evaluate said static pressure, and - terminate said feedback loop, wherein the processor is adapted to select, in step (iii) of a first cycle of the feedback loop, an output of the feedback loop to be restarted, thereby establishing two consecutively assessed static pressures, wherein the processor is adapted to calculate a difference between two consecutively assessed static pressures, and Therein, the processor is adapted to select an output based on the assessed static pressure of a current cycle and a difference between two consecutive assessed static pressures.

2. The system according to claim 1, wherein: The system is adapted to receive a specification of a maximum volume and wherein the system comprises means for determining the current volume in the balloon in addition to assessing the static pressure inside the balloon during step (ii) of the feedback loop.

3. The system according to claim 2, wherein: The processor is adapted to select an output terminating the feedback loop if a current volume in the balloon has reached the maximum volume.

4. The system according to claim 1, wherein: The processor is adapted for selecting an output for restarting the feedback loop if the assessed static pressure of the current cycle is lower than or equal to a first threshold and / or a difference between two consecutive assessed static pressures is lower than or equal to a second threshold.

5. The system according to any one of claims 1 to 4, wherein: The processor is adapted for selecting an output terminating the feedback loop if the assessed static pressure of the current cycle is above a first threshold and / or a difference between two consecutive assessed static pressures is above a second threshold.

6. The system according to any one of claims 1 to 4, wherein: The processor is adapted to select to skip step (i) and to proceed with evaluating the output of the static pressure according to step (ii) if the difference between two consecutive evaluated static pressures is above a second threshold value.

7. The system according to claim 6, wherein: The processor is adapted to select an output terminating the feedback loop if, after re-evaluating the static pressure, a difference between two consecutively evaluated static pressures is above the second threshold.

8. The system according to any one of claims 1 to 4, wherein: The pressure sensor is adapted for continuously evaluating the pressure inside the balloon during the inflation process.

9. The system according to claim 8, wherein: The processor is adapted to select an output terminating the feedback loop if the assessed pressure inside the balloon exceeds a third threshold at any time during the inflation process.

10. The system according to any one of claims 1 to 4, wherein: The predetermined liquid volume is nominally 20 ml.

11. The system according to any one of claims 1 to 4, wherein: The processor is adapted to reduce the predetermined amount of liquid during each cycle of the feedback loop.

12. The system according to any one of claims 2 to 3, wherein: The predetermined amount of liquid is one Nth of the maximum volume, where N is an integer.

13. The system according to any one of claims 1 to 4, wherein: Before initiating the inflation process, a maximum volume is specified to be pumped into the balloon.

14. The system according to claim 13, wherein: The predetermined amount of liquid is less than the maximum volume.

15. The system of claim 14, wherein: Step (ii) is separated from step (i) by a predetermined period of time.

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