WO2023087110A1

WO2023087110A1 - Ventricular assist implant system and method

Info

Publication number: WO2023087110A1
Application number: PCT/CA2022/051703
Authority: WO
Inventors: Lyes KADEM; Ghassan MARAOUCH; Ahmed Darwish
Original assignee: Valorbec, Societe En Commandite
Priority date: 2021-11-18
Filing date: 2022-11-18
Publication date: 2023-05-25

Abstract

An assistance system for a ventricle(s) may have a ventricular implant including an annular stent configured to be positioned against a surface of a ventricle, and a flexible membrane having a peripheral portion and a central portion circumscribed by the peripheral portion, the peripheral portion being joined to the annular stent, the central portion being displaceable relative to the peripheral portion. The ventricular implant is configured for partitioning the ventricle in a closed subcavity and a ventricular subcavity, the ventricular subcavity in fluid communication with a cardiovascular system. An actuator is arranged for controllably displacing the flexible membrane to emulate a systolic and diastolic movement of the ventricle.

Description

VENTRICULAR ASSIST IMPLANT SYSTEM AND METHOD

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the priority of United States Patent Application Serial No. 63/280,740, filed on November 18, 2021 , and incorporated herein in its entirety by reference.

FIELD OF THE APPLICATION

[0002] The present application relates to ventricular assist devices or like assistance devices.

BACKGROUND OF THE ART

[0003] Congestive heart failure (CHF) is a condition that renders the heart unable to fulfill its function properly. CHF reduces the pumping ability of the heart that is required to distribute blood throughout the body. As the heart gets weaker, other organs may also start deteriorating from lack of oxygenated blood supply. Also, several basic activities, such as walking, may become increasingly demanding. In mild to moderate cases, possible treatments include exercising, dieting and medication. In acute cases, such condition at advanced stages may lead to mortality. Heart transplants remain a preferred treatment to treat such pathology, but the limited availability of healthy donor organs is limited. Accordingly, to treat such acute cases, conventional known ventricular assist devices (VAD) are an alternative solution to aid the heart in restoring at least some of its required pumping ability. Some such conventional VADs have limited effectiveness in aiding the production of a cardiac output meeting physiological requirements. For instance, some such conventional VADs generate flows having characteristics atypical of physiological flows, and thus are ill-adapted to meet the needs of patients afflicted by CHF. Improvements to ventricular assistance are therefore desirable.

SUMMARY OF THE APPLICATION

[0004] It is therefore an aim of the present technology to provide a ventricular assistance device addressing issues related to the prior art.

[0005] Hence, in one aspect, there is provided an assistance system for at least one ventricle comprising : a ventricular implant including an annular stent configured to be positioned against a surface of a ventricle, and a flexible membrane having a peripheral portion and a central portion circumscribed by the peripheral portion, the peripheral portion being joined to the annular stent, the central portion being displaceable relative to the peripheral portion, the ventricular implant configured for partitioning the ventricle in a closed subcavity and a ventricular subcavity, the ventricular subcavity in fluid communication with a cardiovascular system; and an actuator arranged for controllably displacing the flexible membrane to emulate a systolic and diastolic movement of the ventricle.

[0006] Further in accordance with the aspect, for example, the actuator is a pump configured to be in fluid communication with the closed subcavity for pumping a fluid in the closed subcavity.

[0007] Still further in accordance with the aspect, for example, the pump is a diaphragm pump.

[0008] Still further in accordance with the aspect, for example, the pump is an hydraulic pump having a reservoir.

[0009] Still further in accordance with the aspect, for example, the pump is an implant.

[0010] Still further in accordance with the aspect, for example, the system may have two of the ventricular implant, with a first of the ventricular implants configured to be in the left ventricle, and a second of the ventricular implants configured to be in the right ventricle.

[0011] Still further in accordance with the aspect, for example, the pump is configured to be in fluid communication with both the left ventricle and the right ventricle, by a first conduit and a second conduit.

[0012] Still further in accordance with the aspect, for example, the pump operates in an off-phase actuation by which the left ventricle and the right ventricle are in opposing systolic and diastolic movement.

[0013] Still further in accordance with the aspect, for example, the pump operates in an in-phase actuation by which the left ventricle and the right ventricle are in concurrent systolic and diastolic movement.

[0014] Still further in accordance with the aspect, for example, the annular stent has an interlaced structure of strands. [0015] Still further in accordance with the aspect, for example, the strands are made of wire having a diameter of 0.5mm ± 20%.

[0016] Still further in accordance with the aspect, for example, the wire has a pitch of 15mm ± 20%.

[0017] Still further in accordance with the aspect, for example, the annular stent has a height of 15.0mm ± 20%.

[0018] Still further in accordance with the aspect, for example, the annular stent has a diameter between 61 .78 and 62.90mm.

[0019] Still further in accordance with the aspect, for example, the annular stent is made of material exhibiting elastic deformation during diastolic and systolic movements of the myocardium.

[0020] Still further in accordance with the aspect, for example, the ventricular implant is structured so as to be resiliently deformable between a collapsed configuration, configured such that a girth of the ventricular implant fits inside an inner wall of a catheter; and a deployed configuration, configured such that: the girth of the ventricular implant is greater than an outer wall of the catheter and conforms to a girth of a surface of the ventricle proximate an apex of the ventricle.

[0021] Still further in accordance with the aspect, for example, the central portion is displaceable relative to the peripheral portion between a first position in which the flexible membrane extends outwardly of the peripheral portion, and a second position in which the flexible membrane extends inwardly of the peripheral portion.

[0022] Still further in accordance with the aspect, for example, the ventricular implant is biased in the deployed configuration.

[0023] Still further in accordance with the aspect, for example, the actuator is a linear actuator controlling displacement of the central portion so as to selectively vary a volume of the ventricular subcavity partitioned away from the apex upon deployment of the ventricular implant inside the ventricle.

[0024] Still further in accordance with the aspect, for example, the linear actuator is arranged to time decreasing of the central portion relative to a contraction of the ventricle so as to increase a cardiac output flow exiting the ventricle upon the contraction.

[0025] In some such embodiments, the volume of the compartment: decreases as the central portion moves outwardly relative to the channel; and increases as the central portion moves inwardly relative to the channel.

[0026] In some such embodiments, decreasing the volume of the compartment increases a pressure against the inner wall of the ventricle.

[0027] In some other such embodiments, the linear actuator is arranged to time decreasing of the central portion relative to a contraction of the ventricle so as to increase a cardiac output flow exiting the ventricle upon the contraction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Fig. 1 is assembly schematic view of a ventricular assist implant system according to the present disclosure, shown relative to a heart, in a biventricular assistance configuration;

[0029] Fig. 2 is a perspective cutout view of the ventricular assist implant system of Fig. 1 , as implanted;

[0030] Fig. 3 is a perspective cutout view of the ventricular assist implant system in accordance with the present disclosure, in a left ventricle assistance configuration, as implanted;

[0031] Figs. 4A-4C are different views of an annular stent of the ventricular assistance implant system of Fig. 1 , in accordance with an embodiment;

[0032] Fig. 5 is a schematic see-through view of the ventricular assist implant system of Fig. 3, with a first type of actuation;

[0033] Fig. 6 is a schematic see-through view of the ventricular assist implant system of Fig. 3, with a second type of actuation; and

[0034] Fig. 7 is a schematic see-through view of the ventricular assist implant system of Fig. 3, with a third type of actuation.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS [0035] Referring to the drawings and more particularly to Fig. 1 , part of a heart, being in this case a human heart, is schematically represented at 1. A myocardium of the heart 1 is shown at 2, and delimits ventricular cavities . Hence, the left ventricular cavities and the part of the myocardium 2 surrounding said cavities are commonly known as the left ventricle 3A and the right ventricle 3B of the heart 1 . The left ventricle 3A is in fluid connection with a left atrium 4A through mitral valve 4, for blood to reach the left ventricle 3A. The left ventricle 3A is also in fluid communication with an aorta 5A through an aortic valve 5, through which blood exits the left ventricle 3A. The right ventricle 3B is in fluid connection with a right atrium 4B through tricuspid valve 4C. The right ventricle 3B is also in fluid communication with a pulmonary artery 5B through a pulmonary valve 6. In congestive heart failure (CHF), the volume of blood exiting the left ventricle 3A and/or the right ventricle 3B is insufficient, and may be because of deficient function of the myocardium 2, for example. Accordingly, there is also illustrated at 10 a ventricular assist implant system, implanted in the heart 1 in accordance with an embodiment of the present disclosure. The ventricular assistance implant system 10 is tasked with assisting the heart 1 in pumping blood into and out of one or both of the ventricles 3A and/or 3B.

[0036] Referring to Fig. 1 , the ventricular assist implant system 10 includes an implant or implants 20 and an actuator 30. In Fig. 1 , there are two implants 20, i.e., one for each ventricle 3A and 3B, but the ventricular assistance implant system 10 may have a single implant 20 in a single one of the ventricles 3A or 3B, dependent on the patient’s heart function. The implant 20 is used to delimit part of the ventricle 3A and/or 3B, and to emulate a systolic and diastolic movement of a healthy heart, as schematically illustrated in Fig. 1 . The actuator 30 directly or indirectly controls systolic and diastolic movement of the implant 20, such as by being in fluid communication with the ventricles 3A and/or 3B - both in the biventricular configuration of Fig. 1 . In a variant, the actuator 30 may be operatively connected to the implant 20 and extend through the myocardium 2 of the heart 1 to the implant 20 disposed inside the ventricular cavity 3, as detailed below with reference to Fig. 6. In the variant of Fig. 1 , the actuator 30 is a pump having conduits 30A and 30B respectively in fluid communication with the ventricles 3A and/or 3B, via incisions and ports in the myocardium 2. The conduits 30A and 30B are in fluid communication with closed subcavities 3A’ and 3B’ of the ventricular cavities, the subcavities being isolated from fluid communication with the aorta 5A and/or pulmonary artery 5B by the implants 20. The implants 20 indeed segment the respective ventricular cavities into the closed subcavities 3A’ and 3B’, and in reduced-size ventricular subcavities that are part of the cardiovascular system in that blood flows through them. The pump 30 operates to pump a fluid (e.g., bio-fluid, brine, water) in and out of the closed portion(s) to induce the systolic and diastolic movement of the implant 20. As will be appreciated in light of the forthcoming description, the system 10 is configured with respect to the heart 1 to modify flow conditions of one or both ventricles 3A and/or 3B. Structural elements of the system 10 and operation of the system 10 with respect to the heart 1 will be described.

[0037] Referring to Fig. 2, the ventricular assistance implant system 10 may be used in a biventricular configuration, in which a single actuator 30 is shared by a pair of implants 20, each in its own ventricle (3A and 3B). In Fig. 3, the ventricular assistance implant system 10 is shown as being used in a left ventricular configuration, in which the actuator 30 is used to displace an implant 20 in the left ventricle 3A. Though not shown, the ventricular assistance implant system 10 could be used in a right ventricular configuration, in which the actuator 30 would be used to displace an implant 20 in the right ventricle 3B. In Figs. 2 and 3, a hydraulic pump is illustrated, but other types of actuators such as those described herein could be used instead of the hydraulic pump.

[0038] Structural elements of the ventricular assist implant system 10 will now be described. In the forthcoming description, it should be understood that patient-specific characteristics of elements of the system 10 may be derived from medical imaging data. For example, the data may be used to select off-the-shelf components having the patient-specific characteristics or characteristics deemed equivalent, or to manufacture custom components having the patient-specific characteristics. Also, it should be noted that in the figure shown, the implant 20 and portions of the actuator 30 have already been implanted, whereas a remainder of the actuator 30 in some embodiments may be extracutaneous. The system 10 may otherwise be fully implantable, at least in some embodiments.

[0039] Referring now to Figs. 5, 6 and 7, in which a heart model is shown to illustrate a test set up, the ventricular assistance implant system 10 is shown in a left ventricular configuration, but could also have been shown for the right ventricular configuration, of the biventricular configuration. However, to avoid duplications, the ventricular assistance implant system 10 is explained relative to the left ventricular configuration, with similar principles applying to the right ventricular configuration, of the biventricular configuration. The implant 20 is disposed inside the left ventricular cavity and positioned generally intermediate an apex 6 of the left ventricle and the mitral valve 4, aortic valve 5, though the implant 20 may be closer to the apex 6 or closer to the valves 4, 5. The implant 20 has a girth conforming to the inner surface of the left ventricle 3A so as to define a boundary between a closed subcavity 3A’ of the left ventricular cavity 3 located between the implant 20 and the apex 6, and a ventricular subcavity 3A” located between the implant 20 and the valves 4, 5 and opposite the closed subcavity 3A’, the ventricular subcavity 3A” being open to the blood flow in the cardiovascular system of the patient. In an embodiment, positioning of the implant 20 relative to the ventricle(s) may be said to be selectively determined, in that an output of the ventricular assist implant system 10 may be determined as a function of respective volumes of the subcavities of the ventricle(s) and in that the volumes may be determined as a function of the patientspecific shape of the ventricle and of the position of the implant 20.

[0040] The implant 20 of the ventricular assist implant system 10 may include an annulus 21 , via which the implant 20 conforms to an inner surface of the ventricle. The annulus 21 defines part of the boundary between the subcavities of the ventricle 3A and/or 3B. The implant 20 is positioned such that the annulus 21 is spaced away from the apex 6 according to a desired implanting position for implanting the implant 20 in the heart 1. In the present embodiment, the desired implanting position is about 30 mm ± 5 mm inward the left ventricle 3A relative to the apex 6. In some embodiments, the desired implanting position is between 20 mm and 40 mm. Similar positions may be applicable for an implant 20 in the right ventricle 3B. It should be noted that such values provided for the desired implanting position are exemplary as they pertain to typical ventricle cavity sizes. In some embodiments, the desired implanting position may be patient-specific and thus vary from the exemplary values provided.

[0041] According to an embodiment, as shown in Figs. 4A-4C, the annulus 21 may have a stent-like, interlaced structure that is resiliently deformable. Thus, the annulus 21 may be referred to herein as stent annulus or as annular stent. The annulus 21 may be constructed of a composite material (e.g., polycaprolactone), although other materials are possible. For example, the annulus 21 may be constructed of metallic materials. In some embodiments, the annulus 21 is constructed of a memory-shape alloy, such as nitinol. In some such embodiments, deformation of the annulus 21 is activated upon heating of the annulus 21 up to a given temperature (e.g., 37 C), for instance using a balloon catheter or other like means to increase the diametrical dimensions of the annular 21 to conform to the shape of the inner surface of the ventricle 3A or 3B. Also, the annulus 21 may be structured so as to resiliently and elastically deform with the left ventricle 3A for example as the left ventricle 3A is deformed upon pumping of the heart 1.

[0042] The annulus 21 has a deployed annulus configuration (shown in Fig. 1) in which the annulus 21 conforms to a shape of a given annular section of the ventricle 3A and/or 3B defined relative to the desired implanting position. The annulus 21 is configured to be deployable inside the left ventricular cavity from a collapsed annulus configuration (not shown) in which the annulus 21 is deformed so as to fit within a given diameter, to the deployed configuration in which the annulus 21 extends outwardly of the given diameter to engage the ventricle 3A and/or 3B. It should be noted that the annulus 21 is configured to engage the ventricle 3A and/or 3B so as to hold the implant 20 in the desired implanting position. The annulus 21 may have an outer annular border that generally tapers as it extends toward the apex 6. Other shapes are considered as well, and the annulus 21 may have surface features to ensure it remains in the desired implanting position. The annulus 21 may be said to be patient specific, in that in the deployed configuration, the outer annular border defines an annular profile of the annulus 21 consistent with the shape of the given annular section, through for instance 3D printing or like personalized manufacturing methods. In the present embodiment, the annular profile is over dimensioned relative to the given annular section such that the annulus 21 may press against the given annular section upon deployment to securely engage the ventricle 3A and/or 3B. Over dimensioning of other profiles of the annulus 21 (for example, a height of the annulus 21) and/or providing alternative means (for example, artificial chordae) for securing the implant 20 to the ventricle 3A and/or 3B is/are possible. The annulus 21 also has a side annular border extending transversely from the outer annular border to an inner annular border. An opening of the annulus 21 is defined inward of the inner annular border. The outer annular border defines a height of the annulus 21 and the side annular border defines a thickness of the annulus 21 . In this embodiment, the height of the annulus 21 (i.e., 15 mm ± 20%) is greater than its thickness (i.e., 2 mm). It is contemplated that the annulus 21 could be dimensioned such that its height is similar to its thickness. In some embodiments, the height and the thickness of the annulus 21 may be generally similar to those of a coronary stent. Exemplary dimensions are shown in Figs. 4B and 4C, but may be outside of the given ranges (height between 15.00 and 15.20mm, diameter between 61.78 and 62.90mm). The annulus 21 may be deformable into the shape of the ventricle. For example, the stent annulus 21 of Figs. 4A to 4C may be designed to have an oversize of ~10-15% of the landing zone, though other values are possible. Some slight variation in the stent size may occur during heart beats, for instance via elastic deformation, but that may depend on the condition of a patient. Patients eligible for LVADs typically have lower ejection fraction due to a weakened heart, so depending on patient heart condition, the stent annulus 21 may vary slightly in size, if at all. As further exemplary details, the annulus 21 of Figs. 4A-4C may have multiple strands of wire, (e.g., 8 strands as shown), with the wire having 0.5mm of diameter (± 20%). and the pitch of the wire being 15mm (± 20%). Again, these values may be exemplary only, as other values may be possible, notably as a function of the patient condition.

[0043] Also included in the implant 20 is a membrane 22 disposed onto the annulus 21 so as to close the opening, to block any fluid flow or regurgitation through the implant 20 between the subcavities. The membrane 22 is structured to be resiliency deformable yet more flexible than the annulus 21. The membrane 22 may be constructed of silicone, although alternative materials are possible, such as biological tissue (for example, sheets of bovine pericardium, or other forms of pericardial tissue). The membrane 22 is contoured so as to be sealingly attached around the annulus 21. More specifically, a peripheral membrane portion of the membrane 22 is joined to the annulus 21 along the side annular border via stitches, co molding constructions, adhesives, and/or ultrasound welding, etc. Alternative means for joining the membrane 22 to the annulus 21 are possible, including magnetic adhesion.

[0044] The membrane 22 may have a deployed membrane configuration (shown in Fig. 1) in which the peripheral membrane portion follows the shape of the side annular border, for instance by being in a generally planar relation with the border, or by extending outwardly of the given diameter. The membrane 22 is configured to be deployable inside the ventricular cavity from a collapsed membrane configuration (not shown), in which the membrane 22 is deformed so as to fit within the given diameter, to the deployed membrane configuration, in which the membrane 22 extends outwardly of the given diameter. The membrane 22 is arranged relative to the annulus 21 so as to move between the collapsed membrane configuration and the deployed membrane configuration with the annulus 21 as the annulus 21 moves between the collapsed annulus configuration and the deployed annular configuration.

[0045] A central membrane portion of the membrane 22 is disposed inward the peripheral membrane portion. In the deployed membrane configuration (in which the membrane 22 may be biased, optionally), the central membrane portion is arranged so as to be extendable relative to the peripheral membrane portion between a first stroke end position and a second stroke end position, schematically shown in Fig. 1 , respectively located on either sides of the annulus 21. The first and second stroke end positions define a stroke length therebetween, i.e., an amplitude of motion of the membrane 22 relative to the annulus 21. With the implant 20 implanted in the desired implant position relative to the heart 1 , extending the central membrane portion to the first stroke end position extends the central membrane portion upwardly to reduce the size of the ventricular subcavity 3A”. Likewise, extending the central membrane portion to the second stroke end position extends the central membrane portion downwardly to reduce the size of the ventricular subcavity 3A”.

[0046] The membrane 22 is arranged for defining a stroke volume upon movement of the central membrane portion between the first and second stroke end positions. The stroke volume may be representative of a reduction in the volume of the second subcavity as the central membrane portion is moved from the first stroke end position to the second stroke end position.

[0047] It can be said that the stroke volume is a function of the stroke length and of a membrane profile of the membrane 22. In this embodiment, the membrane profile is a cross-sectional profile being downwardly concave upon placing the central membrane portion in the second stroke end position. The membrane profile may have a parabolic profile segment extending away from the peripheral membrane portion and culminating in a flat profile segment. The membrane profile defines a vertex, in this case being defined on the flat profile segment. In each of the first and second stroke end positions, the central membrane portion extends away from the peripheral membrane portion to the vertex. In the second stroke end position, a height of the membrane is defined between the peripheral membrane portion and the vertex. The height of the membrane 22 is 20 mm. The membrane 22 can be said to be patient specific, in that in the first stroke end position, the membrane 22 generally conforms to a shape of the inner surface of the ventricle 3A and/or 3B, although this does not have to be the case. Alternative membrane profiles and different membrane heights are possible.

[0048] The stroke volume is relatable to a volume of the ventricle 3A and/or 3B to define a cardiac output, i.e., a flow of fluid. Fluid parameters and data of the cardiac output (e.g., a pressure achievable in the second subcavity upon operation of the system 10) are provided in exemplary tables below. [0049] Interfaces between the annulus 21 and the membrane 22 and interfaces between the implant 20 and the inner surface of the ventricle 3A and/or 3B upon deployment of the implant 20 therein are generally impermeable.

[0050] The membrane 22 may also have a connector disposed underneath the flat profile segment, via which the implant 20 is connected to the actuator 30. The connector may be constructed of silicone and forms a unitary piece with the central membrane portion, although it does not have to be the case. In some embodiments, the connector is omitted. In some such embodiments, alternative means for connecting the actuator 30 to the implant 20 are used. In a variant, the membrane 22 in its diastole position would be against the surface of the ventricle, i.e., the closed subcavity 3A’ would be as small as possible. In such a configuration the ventricular subcavity 3A” would have a larger volume, and hence the potential of pumping out a larger volume of blood at each heartbeat.

[0051] In Fig. 5, the actuator 30 is shown as being a diaphragm pump in fluid communication with the closed subcavity of the ventricle 3A and/or 3B by conduit 30A, the conduit 30A being biocompatible and sealingly connected to the heart tissue. The diaphragm pump 30 has a diaphragm that oscillates between two positions within a rigid casing of the diaphragm pump 30, resulting in back and forth pumping pressure and suction on the bio-fluid captive in the pump 30 and closed subcavity 3A’. This pressure variation results in the membrane 22 of the implant 20 contributing to systolic and diastolic movements. In a variant, the diaphragm pump 30 is implanted in the body, though it may have parts thereof being extracutaneous. The diaphragm pump may include in its rigid casing any actuator or motorization to displace the diaphragm. Any power source may be in the pump 30, or may be extracutaneous. For example, the diaphragm pump 30 is battery operated, or may operate using pneumatics or hydraulics, with a pressure source being outside of the human body. These are examples among others.

[0052] In Fig. 6, the actuator 30 is shown as being a hydrualic pump in fluid communication with the closed subcavity of the ventricle 3A and/or 3B by conduit 30A, the conduit 30A being biocompatible and sealingly connected to the heart tissue. The hydraulic pump 30 may incorporate a bi-directional rotating and/or translating member that moves within a rigid casing and drawing bio-fluid or any other appropriate fluid from a reservoir 30C (via conduit 30D as a possibility), resulting in back and forth pumping pressure and suction on the bio-fluid captive in the pump 30 and closed subcavity 3A’. This pressure variation results in the membrane 22 of the implant 20 contributing to systolic and diastolic movements. In a variant, the pump 30 is implanted in the body, though it may have parts thereof being extracutaneous. The pump may include in its rigid casing any actuator or motorization to displace the moving component. Any power source may be in the pump 30, or may be extracutaneous. For example, the pump 30 is battery operated, or may operate using pneumatics or hydraulics, with a pressure source being outside of the human body. These are examples among others.

[0053] In a variant, in which a single actuator 30 is used in a biventricular configuration, the actuator 30 may operate in-phase or off-phase actuation between the left and right ventricles. Stated differently, to have the ventricular assistance implant system 10 in phase would mean that the fluid is pumped into both the left and right ventricle, causing them to beat together. This may require the presence of the reservoir 30C. Off-phase would mean that one ventricle would beat, followed by the next one. In such an off- phase configuration, the actuator 30 could be the hydraulic pump 30 without reservoir, as the bio-fluid could circulate from one of the closed subcavities to the other.

[0054] In Fig. 7, the actuator 30 includes a rod 31 , a tube 32 and a control system 33. The control system 33 may be present in the actuators 30 of Figs. 5 and 6 as well, and may include one or more processors and non-transitory computer-readable instructions to execute cardio-vascular assistance as described herein. The rod 31 is an elongated member joined to the membrane 22 via the connector. The rod 31 is generally more rigid than the membrane 22. The rod 31 is arranged for transmitting pushing and pulling forces imparted by the control system 33 to the membrane 22 to move the membrane 22. The rod 31 extends from the control system 33 to the implant 20 via the tube 32. The tube 32 is constructed of silicone, although other materials are possible. The tube 32 may be disposed percutaneously and extends to inside the left ventricular cavity 3 via a surgically-defined opening located at the apex 6. The tube 32 is structured and arranged relative to the cable 31 and the implant 20 such that the implant 20 being in the collapsed configuration can be inserted into the tube 32 and delivered to the left ventricular cavity 3 in the desired implanting position via the tube 32. For instance, the tube 32 has an inner diameter corresponding to the given diameter. Also, with the implant 20 in the desired implanting position, sliding the tube 32 along the rod 31 as the rod 31 is being held in place renders deployment of the implant 20 unhindered.

[0055] Alternative means for actuating the implant 20 are included within the scope of the present technology, for example a hydraulic system (not shown) fluidly connected to the implant 20 via the tube 32 and the first subcavity, soft robots, solenoids, etc. The hydraulic system is arranged for selectively imparting negative pressures and positive pressures to the membrane 22 so as to move the membrane 22 between the first and second stroke end positions.

[0056] In instances in which the actuator 30 is a pump, the objective of the technology is to have a device capable of improving a patient’s quality of life, and as such the actuator pump 30 may be selected depending on the geometry of the heart and how enlarged it is. This may entail that the pump volumetric output is of at least ~5L/min. Given that the pump 30 is pulsatile, the volumetric output can be controlled, notably by increasing the frequency. The volumetric output could be a set value once the pump is implanted. Increasing the frequency would also be a limiting factor depending on the volume displaced/stroke for the membrane 22. Thus, it may be considered to have a volumetric output in a range of 5-7 L/min, though it could be outside of such range.

[0057] The chamber volume for the pump 30 (e.g., reservoir 30C) may also depend on the membrane design. As mentioned above, it would be a possibility to have the membrane 22 shaped to as to that evacuate all bio-fluid during the diastolic phase, and then get fully filled during the systolic phase (l.e., the stroke volume). The other option would be to always keep some fluid in the reservoir 30C. This could also be patient specific, depending on what kind of membrane 22 is suited for a patient’s heart morphology. The ventricular assistance implant system 10 may essentially take over the function of the heart muscles. This may require the pump 30 to operate in the same region as the left (~10-120 mmHg) and right ventricle (~5-30 mmHg). Thus, the pressure range for any pump 30 may be within these ranges of pressure, though not necessarily.

[0058] The system 10 may be generally described as being an assistance system for a ventricle(s), and may have a ventricular implant including an annular stent configured to be positioned against a surface of a ventricle, and a flexible membrane having a peripheral portion and a central portion circumscribed by the peripheral portion, the peripheral portion being joined to the annular stent, the central portion being displaceable relative to the peripheral portion. The ventricular implant may be configured for partitioning the ventricle in a closed subcavity and a ventricular subcavity, the ventricular subcavity in fluid communication with a cardiovascular system. An actuator arranged for controllably displacing the flexible membrane to emulate a systolic and diastolic movement of the ventricle(s). [0059] The present technology also includes a method of controlling the ventricular assist implant system 10. In some embodiments, the method includes sensing a cardiac output and controlling actuator 30 to move the membrane 22 so as to increase the cardiac output to a desired cardiac output.

[0060] Tables 1 and 2 provided below represents fluid parameters during a test phase that may be illustrative to some embodiments associated with the ventricular assistance implant system 10. Table 1 provides a summary of fluid parameters, while Table 2 presents experimental results on a cardiovascular flow simulator and with a flow resistance (i.e., flow-regulating valves of the simulator being calibrated/partially closed so as to achieve a resistance in the flow corresponding to that caused by a healthy left ventricle in a physiological flow). Table 3 provides experimental results on the cardiovascular flow simulator with a system as in Fig. 7 and with the resistance. Table 4 presents experimental results on the cardiovascular flow simulator with the system of Fig. 7, and without the flow resistance (i.e., flow-regulating valves fully open).

TABLE 1

TABLE 2

Table 3:

Table 4:

Claims

CLAIMS:

1 . An assistance system for at least one ventricle comprising : a ventricular implant including an annular stent configured to be positioned against a surface of a ventricle, and a flexible membrane having a peripheral portion and a central portion circumscribed by the peripheral portion, the peripheral portion being joined to the annular stent, the central portion being displaceable relative to the peripheral portion, the ventricular implant configured for partitioning the ventricle in a closed subcavity and a ventricular subcavity, the ventricular subcavity in fluid communication with a cardiovascular system; and an actuator arranged for controllably displacing the flexible membrane to emulate a systolic and diastolic movement of the ventricle.

2. The assistance system according to claim 1 , wherein the actuator is a pump configured to be in fluid communication with the closed subcavity for pumping a fluid in the closed subcavity.

3. The assistance system according to claim 2, wherein the pump is a diaphragm pump.

4. The assistance system according to claim 2, wherein the pump is an hydraulic pump having a reservoir.

5. The assistance system according to any one of claims 2 to 4, wherein the pump is an implant.

6. The assistance system according to any one of claims 2 to 5, including two of the ventricular implant, with a first of the ventricular implants configured to be in the left ventricle, and a second of the ventricular implants configured to be in the right ventricle.

7. The assistance system according to claim 6, wherein the pump is configured to be in fluid communication with both the left ventricle and the right ventricle, by a first conduit and a second conduit.

8. The assistance system according to claim 7, wherein the pump operates in an off-phase actuation by which the left ventricle and the right ventricle are in opposing systolic and diastolic movement.

9. The assistance system according to claim 7, wherein the pump operates in an in- phase actuation by which the left ventricle and the right ventricle are in concurrent systolic and diastolic movement.

10. The assistance system according to any one of claims 1 to 9, wherein the annular stent has an interlaced structure of strands.

11. The assistance system according to claim 10, wherein the strands are made of wire having a diameter of 0.5mm ± 20%.

12. The assistance system according to claim 11 , wherein the wire has a pitch of 15mm ± 20%.

13. The assistance system according to any one of claims 1 to 12, wherein the annular stent has a height of 15.0mm ± 20%.

14. The assistance system according to any one of claims 1 to 13, wherein the annular stent has a diameter between 61 .78 and 62.90mm.

15. The assistance system according to any one of claims 1 to 14, wherein the annular stent is made of material exhibiting elastic deformation during diastolic and systolic movements of the myocardium

16. The assistance system according to any one of claims 1 to 15, wherein the ventricular implant is structured so as to be resiliently deformable between a collapsed configuration, configured such that a girth of the ventricular implant fits inside an inner wall of a catheter; and a deployed configuration, configured such that: the girth of the ventricular implant is greater than an outer wall of the catheter and conforms to a girth of a surface of the ventricle proximate an apex of the ventricle.

17. The assistance system according to any one of claims 1 to 16, wherein the central portion is displaceable relative to the peripheral portion between a first position in which the flexible membrane extends outwardly of the peripheral portion, and a second position in which the flexible membrane extends inwardly of the peripheral portion.

18. The assistance system according to claim 17, wherein the ventricular implant is biased in the deployed configuration.

19. The assistance system according to claim 1 , wherein the actuator is a linear actuator controlling displacement of the central portion so as to selectively vary a volume of the ventricular subcavity partitioned away from the apex upon deployment of the ventricular implant inside the ventricle.

20. The assistance system according to claim 19, wherein the linear actuator is arranged to time decreasing of the central portion relative to a contraction of the ventricle so as to increase a cardiac output flow exiting the ventricle upon the contraction.