Method for estimating a value representative of fluid pressure within an inflatable element of an implantable medical device - Patent Application 20070122997

Abstract

The present invention relates to a method for estimating a value representative of a first pressure, the first pressure being a fluid pressure in an inflatable element (3) of an implantable medical device (10) comprising a selectively volume-variable fluid reservoir (5), the reservoir (5) being deformable under the influence of atmospheric pressure changes, the inflatable element (3) being in fluid communication with the reservoir (5). The method, performed by a data control / processing unit (200) of the device, comprises the steps of: a) determining a value representative of a second pressure, the second pressure being the fluid pressure in the reservoir (5); and b) estimating the value representative of the first pressure based on the value representative of the second pressure and a parameter (L) dependent on a value representative of the maximum change in fluid pressure in the inflatable element (3) caused by atmospheric pressure changes.

Description

[Technical Field]

[0001] The present invention relates to a method for estimating a value representative of fluid pressure within an inflatable element of an implantable medical device having a selectively variable volume fluid reservoir. [Background technology]

[0002] Medical devices may take the form of systems that can be implanted within the human or animal body, such as artificial urinary sphincters used to treat urinary incontinence, gastric bands or rings suitable for gastric restriction to treat obesity, and inflatable penile implants used in erectile prostheses, among others.

[0003] In a manner known per se, the implantable system may be hydraulically operated and may in particular consist of a variable volume fluid reservoir and an inflatable element containing a variable amount of fluid, the inflatable element being in fluid communication with the variable volume fluid reservoir and being able to transfer fluid from the reservoir to the inflatable element and vice versa.

[0004] In the case of an implantable occlusion system, such as an artificial urinary sphincter, the inflatable element is an inflatable occlusion cuff that can selectively occlude an anatomical conduit, such as the male urethra or the female bladder neck. Fluid can be transferred from a reservoir to the cuff to increase pressure on the conduit, and conversely, fluid can be transferred from the cuff to decrease pressure on the conduit. This allows the pressure on the occluded anatomical conduit to be increased or decreased depending on the amount of fluid in the cuff.

[0005] Elements of an implantable fluid system may deform in response to changes in atmospheric pressure (e.g., due to changes in altitude). For example, a reservoir of an implantable fluid system may include an elastically deformable portion that deforms in response to changes in atmospheric pressure. This deformation may result in uncontrolled fluid infusion or evacuation from the cuff, causing an increase or decrease in pressure within the cuff.

[0006] However, such fluid pressure changes in the cuff should be avoided. In the case of an artificial urinary sphincter, excessive pressures are likely to damage the tissue in which the cuff is placed. Therefore, these overpressures must be controlled to limit the risk of corresponding tissue damage. To do this, it is necessary to be able to estimate the pressure changes in the inflatable element and compensate for them if necessary. Summary of the Invention

[0007] SUMMARY OF THE INVENTION It is an object of the present invention to reliably calculate fluid pressure within an inflatable element of an implantable medical device.

[0008] Another object of the present invention is to reliably calculate the atmospheric pressure to which an implantable medical device is subjected.

[0009] Therefore, according to a first aspect, the present invention provides a method for estimating a value representative of a first pressure, comprising: the first pressure is a fluid pressure within an inflatable element of an implantable medical device having a selectively volume-variable fluid reservoir, the reservoir being deformable under the influence of atmospheric pressure changes, the inflatable element being in fluid communication with the reservoir; The method is carried out by a data control / processing unit of the instrument, a) determining a value representative of a second pressure, the second pressure being the fluid pressure in the reservoir; b) estimating a value representing the first pressure based on a parameter dependent on a value representing the second pressure and a value representing a maximum change in fluid pressure in the inflatable element caused by a change in atmospheric pressure.

[0010] According to other advantageous and non-limiting features, the following features can be used alone or in combination:

[0011] A value representative of the second pressure is determined based on at least one value representative of fluid pressure in the reservoir measured by a sensor included in the implantable medical device.

[0012] The value representing the first pressure is determined based on a value representing a reference second pressure determined based on a value representing the fluid pressure in the reservoir measured by the sensor.

[0013] The value representing the first pressure is determined based on a value representing a reference first pressure determined based on a value representing a reference second pressure measured by a sensor and a value representing a reference atmospheric pressure measured by a barometer.

[0014] The barometer is located on the outer wall of the housing 1 or within the housing 1 .

[0015] The barometer is provided in an external control element adapted to exchange data with the implantable medical device, and a value representing the reference atmospheric pressure is measured according to commands executed by the individual in whom the device is implanted via the external control element.

[0016] The value representing the reference first pressure is updated each time the command is executed based on the updated value of the reference atmospheric pressure and the updated value of the reference second pressure.

[0017] The value representing the reference first pressure is updated at least once a day based on an updated value of the reference atmospheric pressure and an updated value of the reference second pressure.

[0018] The value representing the reference second pressure is updated at least once a day, preferably at least three times a day, and more preferably at least five times a day.

[0019] The value representing the second pressure is the average or median of multiple values ​​representing the fluid pressure in the reservoir.

[0020] A value representing the second pressure is determined based on the average or median of at least three values ​​representing the fluid pressure in the reservoir.

[0021] A value representing the second pressure is determined based on a value representing a first change in fluid pressure within the reservoir caused by a change in the volume of the reservoir implemented by an actuator of the device.

[0022] A value representing the second pressure is determined based on a value representing a second change in fluid pressure in the reservoir caused by a change in orientation of the device.

[0023] The value representing the first pressure is given by the following terms:

number

[0024] The parameter is predetermined based on one or more measurements of a value representing a third change in fluid pressure in the reservoir caused by one or more changes in atmospheric pressure.

[0025] The value representing the first pressure is given by the following formula:

number

[0026] According to a second aspect, the present invention provides a method for estimating a value representative of atmospheric pressure to which an implantable medical device is subjected, comprising the steps of: Including the estimation method described above, c) estimating the value representative of the atmospheric pressure by subtracting the value representative of the second pressure from the value representative of the first pressure.

[0027] According to a third aspect, the present invention relates to an implantable medical device comprising a variable volume fluid reservoir, an inflatable element in fluid communication with the reservoir, and a data control / processing unit, the unit configured to carry out the method described above.

[0028] According to other advantageous and non-limiting features, the following features can be used alone or in combination:

[0029] The device is configured to be implanted within a human or animal body to selectively occlude an anatomical conduit within the human or animal body selected from at least one of the urethra, gastric tract, colon, and rectum.

[0030] The device comprises an elongated inflatable element configured for use as a penile implant.

[0031] According to a fourth aspect, the present invention relates to an assembly comprising an implantable medical device as described above and an external control element adapted to exchange data with the implantable medical device and configured to be used by an individual in whom the medical device is implanted, the assembly comprising communication means adapted for the implantable medical device and the external control element to communicate with each other.

[0032] According to a fifth aspect, the invention relates to a computer program product comprising code instructions for carrying out the method described above when the program is executed by an electronic control unit.

[0033] According to a sixth aspect, the present invention relates to a computer readable storage medium having stored thereon a computer program product comprising code instructions for carrying out the method described above.

[0034] Other features and advantages of the present invention will become apparent from the following description of the preferred embodiments, which description is made with reference to the accompanying drawings. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a general view of an implantable medical device within an individual's body and control elements external to the individual's body. [Figure 2] 1 is a schematic cross-sectional view of the interior of a housing according to one embodiment. [Figure 3] FIG. 2 illustrates steps of a method for estimating a first pressure. [Figure 4]1 is a graph showing various pressure changes with increasing altitude. [Figure 5] 1 illustrates steps of a method for estimating atmospheric pressure; DETAILED DESCRIPTION OF THE INVENTION

[0036] (device) According to a first aspect, there is provided a medical device implantable in an individual. As used herein, the term "individual" refers to a human or an animal. The device is an implantable active medical device capable of occluding a natural conduit, such as the urethra (in men), the bladder neck (in women), the gastric tract, the colon, or the rectum. In one example applied to the urethra or bladder neck, the device allows for the treatment of, among other things, urinary incontinence by means of an artificial sphincter capable of occluding the urethra or bladder neck. However, the proposed device is more generally a device with a fluid circuit that responds to pressure changes, especially those caused by altitude changes. Other possible forms of the device include, among others, a penile implant or a gastric restriction band.

[0037] A medical device that can be implanted in the human or animal body is shown by way of non-limiting example in FIGS.

[0038] The implantable device 10 comprises: A sealed housing 1 filled with gas, an inflatable element 3 located outside the housing and adapted to be implanted inside the body of an individual; a fluid circuit consisting of a fluid reservoir 5 containing a variable amount of fluid arranged inside the housing and a fluid connection 2 between the reservoir 5 and the inflatable element 3; an actuator 8 disposed within the housing 1 and mechanically coupled to a portion of the fluid reservoir 5 to selectively vary the amount of fluid in the reservoir; a control unit 100 configured to control the actuator 8 to transfer fluid between the reservoir 5 and the inflatable element 3, and A data control / processing unit 200 configured to execute a method for estimating a value representative of the fluid pressure in the inflatable element 3, the so-called "first pressure".

[0039] The fluid circuit is adapted to be filled with a fluid. A change in the volume of the reservoir 5 causes a change in the pressure in the fluid circuit. More specifically, a decrease in the volume of the reservoir 5 causes a transfer of fluid from the reservoir 5 to the inflatable element 3, increasing the pressure in the fluid circuit. Conversely, an increase in the volume of the reservoir 5 causes a transfer of fluid from the inflatable element 3 to the reservoir 5, decreasing the pressure in the fluid circuit.

[0040] The reservoir 5 is preferably a variable volume fluid reservoir that is susceptible to deformation under the influence of atmospheric pressure changes. Thus, the reservoir 5 may include an elastically deformable portion that deforms in response to changes in atmospheric pressure. This deformation changes the volume of the reservoir 5, resulting in a transfer of fluid between the reservoir 5 and the inflatable element 3.

[0041] The reservoir 5 further has an opening for transferring fluid from the reservoir 5 via the fluid connection 2 to the inflatable element 3 or from the inflatable element 3 via the fluid connection 2 to the reservoir 5 .

[0042] The fluid connection 2 may consist of a tube 2 arranged between the reservoir 5 and the inflatable element 3. A first end of the tube 2 opens into the reservoir 5 and a second end of the tube opens into the inflatable element 3.

[0043] The inflatable element 3 may be an inflatable occlusion cuff, particularly when the device 10 is an artificial urinary sphincter. The fluid-filled inflatable occlusion cuff 3 is adapted to completely or partially surround the duct to be occluded.

[0044] Alternatively, the inflatable element 3 may be an inflatable penile implant, having an elongated shape, particularly if the device 10 is an erectile prosthesis.

[0045] The housing 1, fluid connection 2 and inflatable element 3 are adapted to be implanted inside the body of an individual I, and in Figure 1 the profile on either side of this assembly is shown diagrammatically.

[0046] The housing 1, and in particular the interior volume 11 of the housing 1 surrounding the reservoir 5, is filled with a gas, for example an inert gas.

[0047] The actuator 8 is adapted to control the change in volume of the reservoir 5. The actuator 8 is controlled by a control unit 100. In an embodiment, the actuator 8 is adapted to control the linear movement of the movable wall 6, and the bellows 7 is adapted to expand and contract in response to the linear movement of the movable wall 6 controlled by the actuator 8.

[0048] The actuator 8 can be selected from any electromechanical system capable of converting electrical energy into mechanical movement with the required power output to move the movable wall 6 of the variable volume reservoir 5 with the required force and speed. The actuator 8 can in particular be a piezoelectric actuator, an electromagnetic actuator with an electromagnetic motor with or without brushes, coupled with a reduction gear, an electroactive polymer or a shape memory alloy.

[0049] The control unit 100 is configured to control the actuator 8 to move the movable wall 6 of the reservoir 5 to a position corresponding to the determined volume. More specifically, in the example shown in Figure 2, the control unit 100 is configured to send an actuation command to the motor of the actuator 8 in one direction or the other depending on whether an increase or a decrease in the volume of the reservoir 5 is desired.

[0050] Advantageously, the housing 1 incorporates a reservoir sensor 102 adapted to measure a value representative of the fluid pressure in the reservoir 5. The reservoir sensor 102 is for example a force sensor or a pressure sensor.

[0051] In a particularly advantageous embodiment, an external control element 9, such as a remote control outside the patient's body, can be used by the patient or a third party to communicate wirelessly with the medical device 10, for example by radio frequency.

[0052] In one embodiment, a barometer 90, i.e., an atmospheric pressure sensor, is provided within device 10, e.g., housing 1. According to another embodiment, barometer 10 is located on an outer wall of housing 1 and configured to communicate with device 10. According to yet another embodiment, barometer 90 is located on an external control element 9 outside the body of the individual in which device 10 is implanted. Barometer 90 is adapted to measure a value representative of the atmospheric pressure experienced by implantable medical device 10. When barometer 90 is located on external control element 9, the measurement of the value representative of atmospheric pressure can be performed via external control element 9, e.g., by the patient themselves activating a command of external control element 9.

[0053] Alternatively or additionally, the barometer 90 may be configured to perform measurements of atmospheric pressure at a predetermined frequency.

[0054] (assembly) According to a second aspect, an assembly is proposed comprising an implantable medical device 10 as described above and an external control element 9 adapted to be used by the individual in whom the system is implanted, for example. The implantable medical device 10 and the external control element 9 comprise communication means adapted to communicate with each other wirelessly, for example by radio frequency. The communication means of the implantable device 10 can be integrated into the housing 1.

[0055] (method) According to a third aspect, a method is provided for estimating a value representative of a first pressure, which is the fluid pressure within an inflatable element 3 of an implantable medical device 10. This value allows for an estimation of the fluid pressure. Estimating the pressure is particularly useful for issuing a warning if the pressure is too high or too low. Specifically, if the fluid pressure within the inflatable element 3 is too high, it may damage tissue in the anatomical conduit that the inflatable element 3 surrounds. On the other hand, if the fluid pressure within the inflatable element 3 is too low, it may not adequately occlude the anatomical conduit that the inflatable element 3 surrounds, which may cause incontinence, in the example where the conduit is the urethra.

[0056] Furthermore, estimating a value representative of the first pressure allows for estimating a value representative of the atmospheric pressure experienced by device 10. As discussed above, changes in atmospheric pressure can cause deformations in reservoir 5 of device 10. These deformations can cause uncontrolled fluid to enter or exit inflatable element 3, increasing or decreasing the fluid pressure within inflatable element 3.

[0057] Therefore, changes in atmospheric pressure or fluid pressure within the inflatable element 3 are phenomena that should be monitored to avoid tissue damage in the anatomical conduit or failure to occlude the anatomical conduit.

[0058] The method described below includes estimating a value representative of a pressure. In particular, the estimated values ​​include, for example, estimating a value representative of a first pressure, a value representative of a second pressure, and a value representative of atmospheric pressure. The first pressure is the fluid pressure in the inflatable element 3 of the implantable medical device 10. The second pressure is the fluid pressure in the reservoir 5. The atmospheric pressure is the atmospheric pressure to which the device 10 and thus the reservoir 5 are subjected. The value representative of a pressure is a value from which the pressure can be estimated and, in the case of multiple values ​​representative of pressure, a change in pressure can be evaluated. The value representative of a pressure can be, for example, a value of absolute pressure expressed in Pascals. The value representative of a pressure can also be a value of a force (e.g., a force acting on the reservoir 5 or the inflatable element 3). The proposed examples of values ​​representative of pressure are not limiting and other types of related values ​​representative of pressure can also be envisaged.

[0059] For simplicity, in the following description, the concept of a value representing a pressure will be referred to simply as "pressure." For example, a value representing a first pressure will be referred to as a "first pressure," but it will be understood that the expression "first pressure" refers to a value representing the first pressure.

[0060] 3, the method for estimating the first pressure, i.e. the fluid pressure in the inflatable element 3, comprises a step a) of determining a second pressure, i.e. the fluid pressure in the reservoir 5, executed by the data control / processing unit 200. The second pressure will hereinafter be denoted deuxieme_P.

[0061] According to one embodiment, the second pressure is determined based on at least one value representative of the fluid pressure in the reservoir 5 measured by the reservoir sensor 102 .

[0062] Advantageously, the second pressure is the average or median of multiple values ​​representing the fluid pressure in the reservoir 5. In other words, the reservoir sensor 102 acquires multiple values ​​representing the fluid pressure in the reservoir 5 at predetermined time intervals, and the average or median is calculated based on these multiple values ​​to obtain the second pressure. More preferably, the second pressure is determined based on the average or median of at least three values ​​representing the fluid pressure in the reservoir 5. The median or median of the multiple values ​​representing the fluid pressure in the reservoir 5 is denoted M_deuxiemes_P, and in one embodiment, deuxiemes_P is equal to M_deuxiemes_P. In this case, calculating the average or median of multiple values ​​representing the fluid pressure in the reservoir 5 measured consecutively over time allows the second pressure to be evaluated over time as a function of atmospheric pressure changes. The resulting second pressure value is a smoothed value that takes into account changes in the fluid pressure in the reservoir 5 in response to atmospheric pressure changes. Preferably, the values ​​representing the fluid pressure in the reservoir 5 used to calculate the median or average value are measured at intervals of between 10 seconds and 8 minutes, preferably at intervals of about 2 minutes.

[0063] In order to estimate the second pressure as realistically and accurately as possible, various terms that are taken into account in the calculation of the second pressure are advantageously calculated.

[0064] In this regard, according to a preferred embodiment, the second pressure is a value Δ pression More specifically, when an increase or decrease in the volume of the reservoir 5 controlled by the actuator 8 of the device 10 is performed, the change in fluid pressure in the reservoir 5, Δ pression This change Δ pression is estimated by measuring the fluid pressure in the reservoir 5 before and after a first change in the volume of the reservoir 5 controlled by the actuator 8. In this embodiment, the second pressure deuxieme_P is M_deuxiemes_P+Δ pression , i.e. corresponds to the median or average of the values ​​representing the fluid pressure in the reservoir 5 plus a value representing the first change in the fluid pressure in the reservoir 5. Thus, according to this embodiment, the estimate of the second pressure deuxième_P takes into account the change in pressure caused by the last change in the volume of the reservoir 5 controlled by the actuator 8. The estimate of the second pressure is therefore an adjusted / corrected estimate.

[0065] According to another preferred embodiment, the second pressure is a value Δ Orientation Typically, a change in the orientation of the device 10 can occur due to a change in the position or posture of the individual in which the device 10 is implanted. For example, in the case of a human, a change in the orientation of the device 10 can occur due to a change in posture from standing to lying down, or vice versa. A change in the orientation of the device 10 is likely to cause a change in the fluid pressure in the reservoir 5. For example, when a human lies down, the fluid pressure in the reservoir 5 increases. Δ Orientationcan be, for example, a value that changes when a change in the orientation of the device 10 is detected. The change in the orientation of the device may be detected automatically, for example by a sensor, as described in WO 2021 / 255388. In another scenario, the person can activate the "lying down" mode themselves by pressing an appropriate button on the external control element 9, and Δ Orientation takes a different value than before activating the "lying down" mode. Orientation In this embodiment, the second pressure deuxieme_P is M_deuxiemes_P+Δ Orientation , i.e., corresponds to the sum of the median or average of multiple values ​​representing the fluid pressure in the reservoir 5 and a value representing a second change in the fluid pressure in the reservoir 5 caused by a change in orientation of the device 10.

[0066] Considering the two embodiments described above, deuxieme_P is M_deuxiemes_P+Δ pression +Δ Orientation In order to estimate the second pressure as realistically as possible, other terms may be taken into account, and it will be understood that the terms to be taken into account are not limited to those described.

[0067] 3, the method for estimating the first pressure then comprises a step b) of estimating the first pressure on the basis of the second pressure and a parameter L whose value depends on the maximum change in fluid pressure in the inflatable element 3 caused by a change in atmospheric pressure. In fact, preferably, the first pressure is estimated by the term deuxieme_P L It is calculated based on:

[0068] For example, the parameter L represents the fluid overpressure in the inflatable element 3 due to the deformation of the reservoir 5 caused by changes in atmospheric pressure. When atmospheric pressure changes, the reservoir 5 is prone to deformation due to the elastic properties of its components. This leads to a change in the fluid pressure in the inflatable element 3. Figure 4 illustrates what happens when the atmospheric pressure experienced by the fluid in the reservoir 5 decreases. The curve with only dots (first curve from the bottom) plots the change in atmospheric pressure versus altitude. The higher the altitude, the lower the atmospheric pressure. The dotted curve with squares (second curve from the bottom) plots the change in the second pressure, i.e., the change in the fluid pressure in the reservoir 5, versus altitude for a reservoir 5 that does not deform due to changes in atmospheric pressure. This second curve represents an ideal scenario that does not reflect reality. In this case, the second pressure changes linearly and has the same guide factor as the first curve showing changes in atmospheric pressure. The second pressure decreases linearly with increasing altitude, and therefore with decreasing atmospheric pressure. The dashed curve marked with squares (the third curve from the bottom of the graph) plots the change in second pressure, i.e., the change in fluid pressure in reservoir 5, versus altitude for a reservoir 5 that deforms when atmospheric pressure changes. This curve shows what actually happens. It can be seen that this curve is nonlinear, meaning that the fluid pressure in reservoir 5 does not decrease as much as it would for a reservoir 5 that does not deform when atmospheric pressure changes. The nonlinearity of this curve results from the fact that as atmospheric pressure decreases (i.e., altitude increases), reservoir 5 deforms, reducing its volume and increasing the fluid pressure in reservoir 5. Therefore, as shown in the third curve, the fluid pressure in reservoir 5 decreases less in response to a decrease in atmospheric pressure than it would if reservoir 5 did not deform. At the same time, the decrease in volume of reservoir 5 causes an injection of fluid from reservoir 5 into inflatable element 3, increasing the fluid pressure in inflatable element 3. The non-linearity of the third curve therefore represents the fluid overpressure in the inflatable element 3; the greater the gap between the second and third curves, the greater the fluid overpressure in the inflatable element 3. The parameter L makes it possible to mathematically represent this non-linearity.

[0069] For example, in the embodiment shown in Figure 2, a bellows 7 forms part of the wall of a variable volume reservoir. The bellows is formed from a plurality of elastically deformable protrusions. The bellows 7 may be in the form of an accordion bellows, with the protrusions corresponding to the pleats of an accordion. In a static state, i.e., when no stress is applied by an actuator 8 to change the volume of the reservoir, changes in atmospheric pressure cause deformation of the protrusions, which in turn changes the volume of the reservoir.

[0070] It will be appreciated that the above is reciprocally applicable to a scenario in which the altitude decreases and therefore the atmospheric pressure increases. In this case, when the atmospheric pressure increases, the reservoir 5 deforms such that its volume increases, and the fluid pressure within the reservoir 5 decreases. Thus, the fluid pressure within the reservoir 5 increases less in response to the atmospheric pressure than if the reservoir 5 did not deform. In parallel, the increase in the volume of the reservoir 5 causes fluid to be expelled from the inflatable element 3 into the reservoir 5, and the fluid pressure within the inflatable element 3 decreases.

[0071] Parameter L is a predetermined parameter and depends on a variety of factors. The term "predetermined" means that the parameter is set after implantation of device 10 in an individual and is not intended to be changed periodically thereafter, even though it can be changed.

[0072] First, the parameter L depends on a value representing the maximum change in fluid pressure in the inflatable element 3 after deformation of the reservoir 5 due to a change in atmospheric pressure. In practice, this maximum change is empirically determined when the device 10 is implanted in an individual. More specifically, fluid is injected from the reservoir 5 into the inflatable element 3 to simulate a decrease in atmospheric pressure. For example, the maximum decrease in atmospheric pressure can be considered to be the maximum change in atmospheric pressure corresponding to an increase in altitude from sea level to 3,000 meters. The volume of fluid to be injected from the reservoir 5 into the inflatable element 3 after deformation of the reservoir 5 due to this decrease in atmospheric pressure is known and is injected into the inflatable element 3. An estimation of the fluid pressure in the inflatable element 3 is then performed. In this way, the maximum change in fluid pressure in the inflatable element 3 after deformation of the reservoir 5 due to a change in atmospheric pressure is estimated. Note that the parameter L can be obtained from multiple measurements of a value representing a third change in fluid pressure in the reservoir 5 caused by one or more changes in atmospheric pressure. In other words, the calculation procedure described here can be carried out for different simulations of atmospheric pressure changes.

[0073] The parameter L preferably also depends on the deformation rate of the reservoir 5. The deformation rate is a quantity that describes the deformability (or elasticity) of the reservoir 5. The deformation rate depends in particular on the material from which the reservoir 5 is made and the size of the reservoir 5. In principle, two similar reservoirs 5 of the same material and of the same size have the same deformation rate.

[0074] The parameter L also depends on the size of the inflatable element 3 .

[0075] As mentioned above, the first pressure depends on the second pressure and the parameter L. That is, the first pressure is deuxieme_P L It depends on the term.

[0076] Advantageously, the first pressure is estimated based on other quantities. Specifically, the first pressure is preferably determined based on a reference second pressure deuxiemes_P_ref determined based on the fluid pressure in the reservoir 5 measured by the reservoir sensor 102. The reference second pressure initially corresponds to a measurement value measured by the reservoir sensor 102 before the device 10 is activated. The reference second pressure corresponds to a reference value of the fluid pressure in the reservoir 5. Advantageously, the reference second pressure is periodically updated based on the measurement value of the reservoir sensor 102. Preferably, the reference second pressure is updated at least once a day, preferably at least three times a day, and even more preferably at least five times a day. It will be understood that the reference second pressure is updated less frequently than the median or average value M_deuxiemes_P of multiple values ​​representing the fluid pressure in the reservoir 5. Indeed, by way of example, the second reference pressure is measured at time t0, but the value representing the fluid pressure in the reservoir 5 measured for the calculation of the median or average value is calculated at a different time t0+X minutes (or X seconds, X hours, etc.). If the median or average value is calculated based on four values ​​representing the fluid pressure in the reservoir 5, once eight values ​​representing the fluid pressure in the reservoir 5 have been measured, the average or median value calculated based on the first four values ​​is updated and replaced with the average or median value calculated based on the four most recent values. Furthermore, from the time the reference second pressure was measured (and thus the reference second pressure was updated), four new measurements of values ​​representing the fluid pressure in the reservoir 5 are measured in order to calculate the average or median value, and the previous average or median value is therefore updated.

[0077] More preferably, the first pressure is determined based on the reference first pressure. The reference first pressure premiere_P_ref is determined based on the reference second pressure and the reference atmospheric pressure P_atm_ref measured by the barometer 90. The atmospheric pressure, the first pressure, and the second pressure are considered to be numerically related. Specifically, the first pressure is considered to be equal to the second pressure minus the atmospheric pressure. Therefore, it is understood that the reference first pressure can be estimated based on the reference second pressure and the reference atmospheric pressure. The reference atmospheric pressure is preferably measured automatically periodically by the barometer 90 of the external control device 9 and / or when requested by the individual via the external control device 9. Based on the second reference pressure and the reference atmospheric pressure, the reference first pressure is calculated as premiere_P_ref = second pressure - P_atm_ref. Advantageously, the reference first pressure is updated at least once a day. This logically means that the reference second pressure and the reference atmospheric pressure are updated at least once a day. Alternatively, the reference first pressure may not be measured but may correspond to a predetermined value.

[0078] Finally, advantageously, the first pressure is calculated by the control / processing unit on the basis of the following formula:

number

[0079] Preferably, deuxieme_P=M_deuxiemes_P+Δ pression +Δ Orientation is.

[0080] In this way, the first pressure, i.e., the fluid pressure within the inflatable element 3, is estimated by the control / processing unit, which then allows this estimate to be compared with one or more threshold values ​​for the first pressure to determine, for example, whether the first pressure is below or above a threshold value that may represent danger or discomfort to the individual in whom the device 10 is implanted.

[0081] According to a fourth aspect, there is provided a method for estimating atmospheric pressure experienced by implantable medical device 10. Referring to Figure 5, this second method first includes the method for estimating the first pressure described above.

[0082] The second method further comprises a step c) of estimating the atmospheric pressure by subtracting the first pressure from the second pressure. Once the second pressure and the first pressure are known, the atmospheric pressure experienced by the device 10 can be determined by the following subtraction: deuxieme_P - premiere_P. As mentioned above, changes in atmospheric pressure can cause deformations in the reservoir 5 and, consequently, changes in the first pressure, i.e., the fluid pressure in the inflatable element 3. Being able to calculate the atmospheric pressure means that changes in atmospheric pressure can be detected. Steps can then be taken to compensate for these changes in atmospheric pressure.

[0083] (Program products and storage media) According to a fifth aspect, there is provided a computer program product comprising code instructions for performing a method of estimating a value representative of a first pressure and a method of estimating a value representative of atmospheric pressure when the program is executed by an electronic control unit.

[0084] According to a sixth aspect, there is provided a computer readable storage medium having stored thereon a computer program product comprising code instructions for performing a method of estimating a value representative of a first pressure and a method of estimating a value representative of atmospheric pressure.

[0085] The present invention is not limited to the embodiments described above and shown in the accompanying drawings, as modifications are possible, particularly in terms of the construction of the various technical features or by the substitution of technical equivalents, without departing from the general teaching.

Claims

1. 1. A method of estimating a value representative of a first pressure, comprising: the first pressure is a fluid pressure in an inflatable element (3) of an implantable medical device (10) comprising a selectively volume-variable fluid reservoir (5), the reservoir (5) being deformable under the influence of atmospheric pressure changes, the inflatable element (3) being in fluid communication with the reservoir (5); The method is performed by a data control / processing unit (200) of the device, a) determining a value representative of a second pressure, the second pressure being the fluid pressure in said reservoir (5); b) estimating the value representative of the first pressure based on a value representative of the second pressure and a parameter (L) dependent on a value representative of the maximum change in fluid pressure in the inflatable element (3) caused by a change in atmospheric pressure.

2. The estimation method of claim 1, wherein the value representing the second pressure is determined based on at least one value representing a fluid pressure in the reservoir (5) measured by a sensor (102) provided in the implantable medical device.

3. 3. The estimation method according to claim 2, wherein the value representing the first pressure is determined based on a value representing a reference second pressure determined based on a value representing the fluid pressure in the reservoir (5) measured by the sensor (102).

4. 4. The estimation method of claim 3, wherein the value representing the first pressure is determined based on a value representing a reference first pressure determined based on a value representing the reference second pressure measured by the sensor (102) and a value representing a reference atmospheric pressure measured by a barometer (90).

5. The method of claim 4, wherein the barometer (90) is arranged on an outer wall of the housing (1) or inside the housing (1).

6. 5. The method of claim 4, wherein the barometer (90) is provided in an external control element (9) adapted to exchange data with the implantable medical device, and the value representing the reference atmospheric pressure is measured according to commands executed by the individual in whom the device is implanted via the external control element (9).

7. 7. The estimation method according to claim 4, wherein the value representing the reference first pressure is updated each time a command is executed based on an updated value of the reference atmospheric pressure and an updated value of the reference second pressure.

8. 8. The method according to claim 4, wherein the value representing the reference first pressure is updated at least once a day based on an updated value of the reference atmospheric pressure and an updated value of the reference second pressure.

9. 9. The method of claim 3, wherein the value representing the reference second pressure is updated at least once a day, preferably at least three times a day, and more preferably at least five times a day.

10. The method of any one of claims 1 to 9, wherein the value representative of the second pressure is the average or median of a plurality of values ​​representative of the fluid pressure in the reservoir (5).

11. 11. A method according to claim 10, wherein the value representative of the second pressure is determined based on the average or median of at least three values ​​representative of the fluid pressure in the reservoir (5).

12. 12. The method of any one of claims 1 to 11, wherein the value representative of the second pressure is determined based on a value representative of a first change in fluid pressure in the reservoir (5) caused by a change in the volume of the reservoir (5) performed by an actuator (8) of the device (10).

13. 13. The method of any one of claims 1 to 12, wherein the value representative of the second pressure is determined based on a value representative of a second change in fluid pressure in the reservoir (5) caused by a change in orientation of the device.

14. The value representing the first pressure may be expressed in terms of: [Equation 1] (déuxieme_P) is a value representative of said second pressure, and L is said parameter dependent on the maximum change in pressure in said inflatable element (3) caused by a change in atmospheric pressure.

15. 15. The method of any one of claims 1 to 14, wherein the parameter (L) is predetermined based on one or more measurements of a value representative of a third change in fluid pressure in the reservoir (5) caused by one or more changes in atmospheric pressure.

16. The value representing the first pressure is determined by the following formula: [Equation 2] 16. The method of claim 1, wherein the pressure is determined by calculating premiere_P_ref, where premiere_P_ref is a value representing a reference first pressure, and deuxieme_P_ref is a value representing a reference second pressure.

17. 1. A method for estimating a value representative of atmospheric pressure experienced by an implantable medical device, comprising: The estimation method according to any one of claims 1 to 16, c) estimating a value representative of atmospheric pressure by subtracting the value representative of the second pressure from the value representative of the first pressure.

18. An implantable medical device (10) comprising a variable volume fluid reservoir (5), an inflatable element (3) in fluid communication with said reservoir (5), and a data control / processing unit, said unit configured to perform the method of any one of claims 1 to 17.

19. 20. The implantable medical device (10) of claim 18, configured to be implanted within a human or animal body to selectively occlude an anatomical conduit within the human or animal body selected from at least one of the urethra, gastric tract, colon, and rectum.

20. 20. The implantable medical device (10) of claim 19, comprising an elongated inflatable element (3) configured for use as a penile implant.

21. Assembly comprising an implantable medical device according to any one of claims 18 to 20 and an external control element (9) adapted to exchange data with said implantable medical device and configured to be used by an individual in whom said medical device is implanted, An assembly comprising communication means adapted for said implantable medical device and said external control element (9) to communicate with each other.

22. 18. A computer program product comprising code instructions for carrying out the method of any one of 1 to 17 when the program is executed by an electronic control unit.

23. A computer readable storage medium having stored thereon a computer program product comprising code instructions for carrying out the method of any one of 1 to 17.

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