DEVICE FOR SUPPORTING THE HEART MUSCLE OF A LIVING BEING

Description

SCOPE OF DISCLOSURE

[0001] The present invention relates to a device for assisting the heart muscle of a living being. STATE OF THE ART

[0002] The invention is particularly applicable to the treatment of heart failure, a disease of the heart muscle or myocardium.

[0003] Heart failure is the leading cause of death in industrialized countries. In its terminal stage, the disease is characterized by dilation of the ventricular chambers, coupled with a decrease in the contractile capacity of the heart muscle fibers, which become progressively weaker. This results in reduced cardiac output and impaired ability of the heart muscle to perform its essential pumping function, vital for propelling blood throughout the body.

[0004] To treat heart failure, heart transplantation is a solution that only a tiny proportion of patients with end-stage heart failure have access to.

[0005] An alternative solution is to use a circulatory support device.

[0006] Known circulatory support devices rely on either a complete replacement of the heart with an artificial heart or the implantation of a turbine that draws blood from the left ventricle and ejects it into the aorta.

[0007] However, this alternative solution is still only available to a tiny fraction of patients with end-stage heart failure. Furthermore, it is not entirely satisfactory given the serious complications and impaired quality of life it can cause. In particular, when blood flows through a foreign body, it coagulates and forms clots that can migrate and cause embolic events (strokes, gastrointestinal or limb ischemia). To prevent clot formation, long-term anticoagulant therapy is then essential, requiring close biological monitoring and itself a source of hemorrhagic complications.The heart muscle's autoregulatory mechanisms are no longer possible, and heart valves are replaced with prostheses that require anticoagulation in the case of mechanical prostheses or are associated with a risk of degeneration in the case of biological prostheses. The diastolic dimension of cardiac function (the ability to adapt to variations in blood volume and filling of the heart chambers) is not, or is poorly, taken into account. Furthermore, circulatory support devices are only partially implantable. The electronic controllers and power sources are external to the patient, requiring the device to be connected to these components via a cable passing through the patient's skin, which is a source of infection that can lead to death.

[0008] Other known circulatory support devices consist of cardiac muscle compression systems acting from its external surface, of the type described in documents WO98 / 55165 A1 and US 6 464 655. Such circulatory support devices make it possible to assist the cardiac muscle while preserving other structures of the heart, and in particular the internal lining of the chambers in contact with the blood, the heart valves or the nervous (connection of the heart to the autonomic nervous system) and hormonal autoregulatory systems.

[0009] However, known compression systems are bulky and therefore difficult to implant and have limited effectiveness. DISCLOSURE SUMMARY

[0010] The invention aims to solve the problems mentioned above.

[0011] For this purpose, the disclosure relates to a cardiac muscle assist device for a living being, the cardiac muscle having a cardiac muscle axis between an apex and a base, and an external surface, the cardiac muscle having a variable volume during a cardiac cycle between a diastolic volume and a systolic volume, the assist device comprising: an implantable envelope having an envelope axis intended to be placed along the axis of cardiac muscle, the envelope having a plurality of annular actuation organs around the envelope axis, each actuation organ having a contact surface configured to be placed in contact with at least a portion of the outer surface of the cardiac muscle, and a control system comprising at least one actuator configured to move the actuation organs along the envelope axis such that the envelope has a deployed state in which the actuation organs are far apart from each other and the contact surfaces delimit the diastolic volume of the cardiac muscle, and a retracted state in which the actuation organs are close together and the contact surfaces delimit the systolic volume of the cardiac muscle.

[0012] The assistive device provides active support to assist, and potentially amplify and reinforce, the systolic and diastolic movements of the heart muscle during the cardiac cycle. The device is an implantable exo-muscle that envelops the heart muscle, thus reducing its bulk. The contact surfaces can also be distributed to improve the support of systolic and diastolic movements and better adapt them to the natural movements of the heart muscle.

[0013] Diastolic and systolic volumes can be determined in any appropriate manner. This may include the patient's natural diastolic and systolic volumes of the heart muscle prior to the implantation of the assistive device and, if applicable, before the heart muscle was affected by the disease. It may also include average diastolic and systolic volumes defined from a population belonging to the same category as the patient. Of course, it may also include any other diastolic and systolic volumes deemed appropriate by the healthcare team.

[0014] The cardiac muscle may exhibit a plurality of adjacent zones of interest along the cardiac muscle axis, each zone of interest having an external surface that can be moved through a range of motion between a systole and a diastole of the cardiac cycle. The contact surface of each of the actuation devices may be configured to be in contact with at least a portion of the external surface of one of the zones of interest, and said at least one actuator may be configured to move each of the contact surfaces through a stroke corresponding to at least a portion of the range of motion of the zone of interest with which said contact surface is in contact.

[0015] Just like diastolic and systolic volumes, the amplitudes of the various areas of interest in the heart muscle can be determined in any appropriate way. This may include the patient's natural heart muscle amplitudes prior to the implantation of the assistive device and, if applicable, before the heart muscle was affected by the pathology. It may also include average amplitudes defined from a population belonging to the same category as the patient. Of course, it may also include any other amplitudes deemed appropriate by the healthcare professionals.

[0016] These arrangements allow us to respect the physiognomy of cardiac muscle contraction by applying efforts distributed over all areas of interest according to the specific orientations of each of the areas of interest of the cardiac muscle which have a convergence allowing us to eject the necessary volume of blood.

[0017] The plurality of zones of interest of the cardiac muscle may present at least one apical zone of interest and one basal zone of interest, the movement of the apical zone of interest having an essentially axial component and the movement of the basal zone of interest having an essentially radial component.The plurality of actuation members may then include at least one apical actuation member whose contact surface is configured to be placed in contact with at least a part of the outer surface of the apical area of ​​interest, and one basal actuation member whose contact surface is configured to be placed in contact with at least a part of the outer surface of the basal area of ​​interest, the stroke of the contact surface of the apical actuation member being essentially axial along at least a part of the essentially axial component of the deflection of the apical area of ​​interest, the stroke of the contact surface of the basal actuation member being essentially radial along at least a part of the essentially radial component of the deflection of the basal area of ​​interest.

[0018] Each actuation member may comprise an annular body around the envelope axis and having an inner surface, and a plurality of plates distributed over the inner surface of the body, the plates having elementary contact surfaces opposite the inner surface of the body, the elementary contact surfaces of the plates forming the contact surface of the actuation member.

[0019] Said at least one actuator may include at least one main actuator, in particular electromagnetic or piezoelectric, configured to move the bodies of the actuation members relative to each other along the envelope axis.

[0020] The elementary contact surface of each of the pads can be displaced relative to the inner surface of the body of the actuation member.

[0021] Each of the plates can be mounted on the inner surface of the body of each of the actuating members by means of a connecting rod arrangement comprising a first connecting rod having opposite ends articulated respectively on said plate and on said inner surface of the body of the actuating member, and at least a second connecting rod having opposite ends articulated respectively on said plate and on the inner surface of the body of the adjacent actuating member along the envelope axis, so that the displacement of the actuating members along the envelope axis induces a displacement of the plate relative to the inner surface of the body of the actuating member.

[0022] Said at least one actuator may include at least one local actuator, in particular electromagnetic or piezoelectric, configured to move the pad relative to the inner surface of the body of the actuating member.

[0023] The plurality of actuating organs may include at least one pair of actuating organs comprising an external actuating organ and an internal actuating organ, the body of the internal actuating organ extending partly into the body of the external actuating organ at least in the retracted state of the casing.

[0024] Under specific conditions, the assistance device can be synchronized with the heart's activity. Mechanical activity can thus be combined with electrical synchronization to achieve mechanical resynchronization.

[0025] The heart muscle can exhibit a plurality of activity parameters. The control system may then include a sensing device configured to detect at least one of the activity parameters and to activate said at least one actuator based on said at least one detected activity parameter.

[0026] Said at least one actuator may be electrically activatable and the control system may include an electrical power supply source connected to said at least one actuator.

[0027] The electrical power supply source may include at least one implantable battery.

[0028] The disclosure also proposes a method for assisting the cardiac muscle of a living organism, the cardiac muscle having a cardiac muscle axis between an apex and a base, and an external surface, the cardiac muscle having a variable volume during a cardiac cycle between a diastolic volume and a systolic volume, the assisting method implementing the assisting device as defined above and providing for: implant the envelope, the contact surface of each of the actuation organs being placed in contact with at least a part of an external surface of the cardiac muscle, at least one actuation zone being placed opposite at least one zone of interest of the cardiac muscle, move the actuation organs along the envelope axis between the deployed state of the envelope in which the actuation organs are far apart from each other and the contact surfaces delimit the diastolic volume of the cardiac muscle, and the retracted state of the envelope in which the actuation organs are close together and the contact surfaces delimit the systolic volume of the cardiac muscle.

[0029] The heart muscle can have multiple adjacent areas of interest along its axis, each area of ​​interest having an external surface that can be moved by a stroke between systole and diastole of the cardiac cycle. The contact surface of each actuation device can be configured to be in contact with at least a portion of the external surface of one of the areas of interest. The assistance method can then move each of the contact surfaces by a stroke corresponding to at least a portion of the stroke of the area of ​​interest with which that contact surface is in contact.

[0030] The assistance method may provide for detecting at least one cardiac muscle activity parameter and activating said at least one actuator based on said at least one detected activity parameter. DESCRIPTION OF THE FIGURES

[0031] Other objects and advantages of the invention will become apparent from the following description of a particular embodiment of the invention, given by way of illustration only and not limitation, the description being made in relation to the accompanying drawings in which: there figure 1 represents an assistive device configured to perform active restraint of the cardiac muscle, the assistive device comprising an implantable sheath configured to be placed in contact with at least a portion of an external surface of the cardiac muscle, and a control system, the figure 2 represents the envelope of the assistance device of the figure 2 The casing comprises annular actuation elements around a casing axis and movable relative to each other in translation along the casing axis, figure 3 represents a cross-sectional view according to the orientation referenced III-III on the figure 2of the envelope of the figure 2 Each actuation organ comprises an annular body and platelets on which a contact surface between the actuation organs and the outer surface of the cardiac muscle is distributed. figure 4 schematically represents the steps of an assistance process implementing the assistance device of the figure 1 the actuation organs being moved along the envelope axis by the control system to vary the volume of the cardiac muscle between a diastolic volume and a systolic volume. DETAILED DESCRIPTION

[0032] There figure 1 represents an assisting device 10 of the cardiac muscle 1, or myocardium, of a living being, in particular of a patient, suffering from a pathology, in particular of heart failure.

[0033] The assistive device 10 is configured as an implantable exo-muscle providing active support to the cardiac muscle 1. The assistive device 10 can thus assist the cardiac muscle 1 in its movements, thereby varying its volume during a cardiac cycle between a diastolic volume (diastole) and a systolic volume (systole). The diastolic and systolic volumes can be determined in any appropriate manner. These may include the patient's natural diastolic and systolic volumes prior to the implantation of the assistive device 10 and, if applicable, before the cardiac muscle 1 was affected by the pathology. They may also be average diastolic and systolic volumes defined from a population belonging to the same category as the patient. Of course, they may also be any other diastolic and systolic volumes deemed appropriate by the healthcare professionals.

[0034] The cardiac muscle 1 has a cardiac muscle axis 2 between an apex 3 and a base 4, and an external surface 5. It comprises a plurality of areas of interest 6 identified by any appropriate means, including in the literature, through trials or observations, medical imaging, or otherwise. Each area of ​​interest 6 has an external surface that can be moved according to a range of motion between diastole and systole of the cardiac cycle. The ranges of motion of the different areas of interest 6 of the cardiac muscle 1 can be determined in any appropriate manner. These may include the natural ranges of motion of the patient's cardiac muscle 1 at a stage prior to the implantation of the assistive device 10 and, where applicable, before the cardiac muscle 1 is affected by the pathology. They may also include average ranges defined from a population belonging to the same category as the patient.This can of course include any other discussions deemed appropriate by the healthcare staff.

[0035] In particular, for the embodiment shown, the 6 areas of interest considered are adjacent along the cardiac muscle axis 2 and include an apical area of ​​interest 7, at the apex 3, and a basal area of ​​interest 9 at the base 4. The 6 areas of interest considered also include an intermediate area of ​​interest 8 between the apical 7 and basal 9 areas of interest. As seen in the figure 4 , the movement of the apical interest zone 7 has an essentially axial component, identified by the references b and b', and the movement of the basal interest zone 9 has an essentially radial component, identified by the references a and a'.

[0036] The invention is not limited to a cardiac muscle 1 segmented into three zones of interest 6. In other embodiments, more than one intermediate zone of interest 8 may be provided between the apical 7 and basal 9 zones of interest.

[0037] On the Figures 1 And 2 , the assistive device 10 includes an implantable envelope 11 having an envelope axis 12 intended to be placed along the axis of cardiac muscle 2.

[0038] The casing 11 comprises a plurality of annular actuation members 16 around the casing axis 12. Each actuation member 16 has a contact surface 25 configured to be in contact with at least a portion of the outer surface of one of the areas of interest 6. The plurality of actuation members 16 thus comprises at least one apical actuation member 17 whose contact surface is configured to be in contact with at least a portion of the outer surface of the apical area of ​​interest 7, and one basal actuation member 19 whose contact surface is configured to be in contact with at least a portion of the outer surface of the basal area of ​​interest 9. The plurality of actuation members 16 also comprises an intermediate actuation member 18 whose contact surface is configured to be in contact with at least a portion of the outer surface of the intermediate area of ​​interest. 8.In other embodiments, the number of intermediate actuation members 18 is adapted according to the number of intermediate interest zones 8.

[0039] On the figure 3Each actuating member 16 comprises an annular body 20 about the axis of the casing 12 and having an inner surface 21. The actuating members 16 are nested within one another. In particular, they can be considered as a pair of actuating members, each comprising an external actuating member and an internal actuating member. In each pair of actuating members, the body 20 of the internal actuating member extends partially into the body 20 of the external actuating member. In the embodiment shown, the intermediate actuating member 18 and the apical actuating member 17 form a pair of actuating members in which the intermediate actuating member 18 is the external actuating member and the apical actuating member 17 is the internal actuating member.The apical actuation organ 17 and the basal actuation organ 19 form another pair of actuation organs in which the apical actuation organ 17 is the external actuation organ and the basal actuation organ 19 is the internal actuation organ.

[0040] In the embodiment shown, the apical actuation member 17 has an axial dimension, along the envelope axis 12, greater than the axial dimension of the intermediate actuation member 18.

[0041] On the inner surface 21 of the body 20, each actuation member 16 further comprises a plurality of plates 22 distributed and having elementary contact surfaces 26 opposite to the inner surface 21 of the body 20. The elementary contact surfaces 26 of the plates 22 form the contact surface 25 of the actuation member 16.

[0042] The elementary contact surface 26 of each of the platelets 22 can be moved relative to the inner surface 21 of the body 20 of the actuation organ 16 and, in particular, orientable to ensure intimate and permanent contact with the outer surface 5 of the cardiac muscle 1.

[0043] In the embodiment shown, each of the plates 22 can be mounted on the inner surface 21 of the body 20 of one of the actuating members 16 by means of a connecting rod arrangement 30. The connecting rod arrangement 30 comprises a first connecting rod 31 having opposite ends articulated respectively on the plate 22 and on the inner surface 21 of the body 20 of the actuating member 16. The connecting rod arrangement 30 also comprises a second connecting rod 32 having opposite ends articulated respectively on the plate 22 and on the inner surface 21 of the body 20 of the adjacent actuating member along the envelope axis 12, namely the apical actuating member 17 for the plates 22 of the basal actuating member 19 and one of the intermediate and basal actuating members 18 for the member apical actuation 17.Alternatively, each connecting rod arrangement could include several first connecting rods 31 and / or several second connecting rods 32.

[0044] In addition to the casing 11, the actuation device 10 includes a control system 35 shown in the figure 1 .

[0045] On the figure 4 , the control system 35 includes one or more actuators 36 configured to move each of the contact surfaces 25 along a stroke corresponding to at least a part of the travel of the area of ​​interest 6 with which the contact surface 25 is in contact.

[0046] In the embodiment shown, the control system includes at least one main actuator 37, in particular electromagnetic or piezoelectric, configured to move the bodies 20 of the actuating members 16 relative to each other in translation along the envelope axis 12. Due to the linkage arrangements 30, the movement of the actuating members 16 along the envelope axis 12 induces a displacement of the pads 22 relative to the inner surfaces 21 of the bodies 20 of the actuating member 16. In particular, the stroke of the contact surface 25 of the apical actuating member 17 is essentially axial along at least a part of the essentially axial component b - b' of the deflection of the apical area of ​​interest 7.Furthermore, the stroke of the contact surface 25 of the basal actuation member 19 is essentially radial along at least part of the essentially radial component a - a' of the deflection of the basal interest zone 9.

[0047] The envelope 11 can then have a deployed state in which the actuation organs 16 are far apart from each other and the contact surfaces 25 delimit the diastolic volume of the cardiac muscle 1, and a retracted state in which the actuation organs 16 are close together and the contact surfaces 25 delimit the systolic volume of the cardiac muscle 1. In the embodiment shown, the actuation organs 16 are nested within each other in the retracted and deployed states of the envelope 12.

[0048] These provisions allow us to respect the physiology of cardiac muscle contraction 1 by applying efforts, illustrated by arrows F on the figure 4 , distributed over all the areas of interest 6 according to orientations conforming to a natural convergence of the efforts of the cardiac muscle 1 to successively aspirate and eject the necessary volumes of blood.

[0049] The actuator(s) 36 may be electrically activatable and the control system 35 may include an electrical power supply connected to the actuator(s) 36. The electrical power supply may then include at least one implantable battery 41.

[0050] The battery 41 can also be integrated into an implantable unit 40 of the control system 35 comprising: a memory 42 in which is stored a control software, a power board 43 connected to the actuators 36, and a microcontroller 44 connected to the memory 42 and to the power board, and configured to activate the power board 43 in accordance with instructions from the control software to actuate the actuators appropriately.

[0051] In this respect, the assistance device 10 can be synchronized with the heart's activity, which is characterized by a plurality of activity parameters. The control system 35 can then include a detection device 45 configured to detect one or more of the activity parameters and to activate the actuators based on the detected activity parameters.

[0052] The control system 35 may then include a bidirectional communication interface 46 configured to receive new instructions or updates to the control software and to send data measured by the implantable unit to a remote server 50.

[0053] The assistance device 10 as described above can be implemented in an assistance method involving implanting the casing 11 on the cardiac muscle 1, the contact surface 25 of each of the actuation members 16 being placed in contact with at least a part of the outer surface of the corresponding area of ​​interest 6 of the cardiac muscle 1. The intermediate actuation member 18 is for example configured to be secured by any type of anchoring system suitable for the cardiac muscle 1.Once the envelope 11 is implanted, the assistance process continues by moving, where appropriate in coordination with the activity of the heart, the actuation organs 16 along the axis of the envelope 12, in particular in translation, between the deployed state of the envelope 11 in which the actuation organs 16 are away from each other and the contact surfaces 25 delimit the diastolic volume of the cardiac muscle 1, and the retracted state of the envelope 11 in which the actuation organs 16 are close together and the contact surfaces 25 delimit the systolic volume of the cardiac muscle 1. In particular, each of the contact surfaces 25 is moved by a stroke corresponding to at least a part of the movement of the area of ​​interest 6 with which it is in contact. In the embodiment shown, the apical actuating members 17 and basal actuating members 19 are displaced relative to the intermediate actuating member 18.

[0054] The description was made with interest zones 6 arranged successively along the cardiac muscle axis 2 and annular actuation elements 16, displaced entirely in translation along the envelope axis 12. However, the invention applies to any other arrangement of interest zones 6, any other conformation, and any other suitable displacement of the actuation elements 16 along the envelope axis 12, provided that such arrangements are covered by the attached claims. For example, only a portion of each of the actuation elements 16 may be displaced along the envelope axis 12. Displacement along the envelope axis 12 may be combined with another displacement, in particular a rotation about the envelope axis 12.

[0055] Furthermore, the relative arrangement of the actuation members 16 between the retracted and deployed states of the envelope 12 could be different, the actuation members 16 being nested within each other only in the retracted state of the envelope 12. Alternatively, the actuation members 16 could not be nested and be at a distance in the retracted state as in the deployed state, their relative displacement varying this distance.

[0056] In other embodiments, which are not part of the claimed invention, instead of the connecting rod arrangements 30, the control system 35 could include local actuators, in particular electromagnetic or piezoelectric, each configured to move one of the plates 22 relative to the inner surface 21 of the body 20 of the actuating member 16.

[0057] According to other embodiments, the contact surface 25 of each of the actuation members 16 could be configured in any other suitable way, in particular directly on the inner surface 21 of the body 20.

Claims

1. Assistance device (10) for the heart muscle (1) of a living being, the heart muscle (1) having a heart muscle axis (2) between an apex (3) and a base (4), and an outer surface (5), the heart muscle (1) having a variable volume during a cardiac cycle between a diastolic volume and a systolic volume, the assistance device (10) comprising: - an implantable envelope (11) having an envelope axis (12) intended to be placed along the heart muscle axis (2), the envelope (11) including a plurality of annular actuation members (16) around the envelope axis (12), each actuation member (16) having a contact surface (25) configured to be placed in contact with at least a portion of the outer surface (5) of the heart muscle (1), the assistance device (10) for the heart muscle (1) being characterised by - a control system (35) comprising at least one actuator (36) configured to move the actuation members (16) along the envelope axis (12) in such a way that the envelope (11) has a deployed state in which the actuation members (16) are away from each other and the contact surfaces (25) delimit the diastolic volume of the heart muscle, and a retracted state in which the actuation members (16) are close to each other and the contact surfaces (25) delimit the heart-muscle systolic volume (1).

2. Assistance device (10) according to claim 1, the heart muscle (1) having a plurality of adjacent areas of interest (6) along the heart muscle axis (2), each area of interest (6) having an outer surface movable in a deflection between a systole and a diastole of the cardiac cycle, wherein the contact surface (25) of each of the actuation members (16) is configured to be placed in contact with at least a portion of the outer surface of one of the areas of interest (6), and wherein said at least one actuator (36) is configured to move each of the contact surfaces (25) in a travel corresponding to at least a portion of the movement of the area of interest (6) with which said contact surface (25) is in contact.

3. Assistance device (10) according to claim 2, the plurality of areas of interest (6) of the heart muscle (1) having at least one apical area of interest (7) and one basal area of interest (9), the movement of the apical area of interest (7) having an essentially axial component and the movement of the basal area of interest having an essentially radial component, wherein the plurality of actuation members (16) includes at least one apical actuation member (17) the contact surface (25) of which is configured to be placed in contact with at least a portion of the outer surface of the apical area of interest (7), and a basal actuation member (19) the contact surface (25) of which is configured to be placed in contact with at least a portion of the outer surface of the basal area of interest (9), the travel of the contact surface (25) of the apical actuation member (17) being essentially axial along at least a part of the essentially axial component of the movement of the apical area of interest (7), the travel of the contact surface (25) of the basal actuating member (19) being essentially radial along at least a part of the essentially radial component of the movement of the basal region of interest (9).

4. Assistance device (10) according to any one of claims 1 to 3, wherein each actuating member (16) includes an annular body (20) around the envelope axis (12) and having an inner surface (21), and a plurality of pads (22) distributed on the inner surface (21) of the body (20), the pads (22) having elementary contact surfaces (26) opposite the inner surface (21) of the body (20), the elementary contact surfaces (26) of the pads (22) forming the contact surface (25) of the actuating member (16).

5. Assistance device (10) according to claim 4, wherein said at least one actuator (36) comprises at least one main actuator (37), in particular electromagnetic or piezoelectric, configured to move the bodies (20) of the actuation members (16) relative to one another along the envelope axis (12).

6. Assistance device (10) according to any one of claims 4 and 5, wherein the elementary contact surface (26) of each of the pads (22) is movable with respect to the inner surface (22) of the body (20) of the actuating member (16).

7. Assistance device (10) according to claim 6, wherein each of the pads (20) is mounted on the inner surface (21) of the body (20) of each of the actuating members (16) by means of an arrangement of connecting rods (30) comprising a first connecting rod (31) having opposite ends articulated respectively on said pad (22) and on said inner surface (21) of the body (20) of the actuating member (16), and at least one second connecting rod (32) having opposite ends articulated respectively on said plate (22) and on the inner surface (21) of the body (20) of the adjacent actuating member (16) along the envelope axis (12), such that the movement of the actuating members (16) along the envelope axis (12) causes a movement of the pad (22) relative to the inner surface (21) of the body (20) of the actuating member (16).

8. Assistance device (10) according to claim 6, wherein said at least one actuator (36) comprises at least one local actuator, in particular electromagnetic or piezoelectric, configured to move the pad (22) relative to the inner surface (21) of the body (20) of the actuating member (16).

9. Assistance device (10) according to any one of claims 4 to 8, wherein the plurality of actuation members (16) comprises at least one pair of actuation members including an external actuation member and an internal actuation member, the body (20) of the internal actuation member extending partially into the body (20) of the external actuation member at least in the retracted state of the envelope (11).

10. Assistance device (10) according to any one of claims 1 to 9, the heart muscle (1) having a plurality of activity parameters, wherein the control system (35) comprises a detection device (45) configured to detect at least one of the activity parameters and to activate said at least one actuator (36) using said at least one detected activity parameter.

11. Assistance device (10) according to any one of claims 1 to 10, wherein said at least one actuator (36) is electrically activatable and the control system (36) comprises an electrical energy supply connected to said at least one actuator (36).

12. Assistance device (10) according to claim 11, wherein the electrical energy supply source comprises at least one implantable battery (41).