AID DEVICE BY DIRECT CARDIAC COMPRESSION

Description

[0001] The present invention relates to a direct cardiac compression assist device (i.e., Direct Cardiac Compression in English), intended for the treatment of heart failure.

[0002] More specifically, the invention relates to an implantable pericardial assistance device advantageously fixed to the apex of the heart and capable of exerting localized pressure at specific locations on the outer wall of the heart in order to improve cardiac function. This device can operate synchronously with the patient's native rhythm, or according to a rhythm imposed by a pacing device such as a previously implanted pacemaker, or according to a rhythm imposed by a control unit.

[0003] The device is powered by an energy storage system, implanted in a preferential manner in the patient's body, and which is preferably designed to be recharged transcutaneously.

[0004] Ventricular assist devices used clinically to assist failing hearts typically require direct contact between the devices and the patient's blood.

[0005] The risks of thromboembolic events, hemolysis, immune reactions, and infections contribute significantly to the morbidity and mortality of these devices.

[0006] Therefore, direct cardiac compression (DCC), which involves applying pressure to the pericardial surface of the heart, could provide ventricular support and prevent interactions between blood and a foreign body.

[0007] In 1965, Georges Anstadt developed a pericardial compression device for cardiopulmonary resuscitation (CPR). This device, known as the Anstadt cup, is an elliptical cup that fits over the right and left ventricular chambers. It has a semi-rigid outer shell and an inflatable inner diaphragm that delivers compression forces to the heart.

[0008] Later, Cardio Technologies, Inc. developed the CardioSupport® system, described in document EP1030701 A1, which is a ventricular cuff designed to assist the heart in pumping blood by applying uniform pressure to a majority of the heart's outer ventricular surface. The ventricular cuff comprises an outer shell, an inflatable inner bladder, and a fastening assembly (not shown). The bladder has an opening for communication with a pressurized fluid source, so the bladder is cyclically inflated and deflated at a predetermined rate to assist the heart's ventricles in contracting properly.

[0009] Other work described in US patent 6464655 A1 focused on a multi-finger device for selectively assisting the ventricles, particularly the left ventricle, of a weak heart by exerting pericardial pressure and pumping blood to one or more sides, in synchronization with the ventricle's natural systolic contraction. This implantable device includes a microprocessor to supervise the multiple fingers, which contract once the solenoid is electrically energized and rapidly release the heart when the solenoid is de-energized. Another direct cardiac compression device, comprising multiple fingers with gel-filled contact pads, is described in US patent 5098369.

[0010] However, it has become necessary to improve existing devices by proposing a solution in which the pressure exerted on the epicardium by direct cardiac assistance devices can be very precisely controlled, at least in terms of frequency, intensity, and location.

[0011] Therefore, the invention relates to an implantable cardiac assistance device using direct compression, characterized in that it comprises: a base forming a receptacle suitable for receiving the lower part of a heart, a support for fixing the lower part of the heart to the base, said support comprising a fixing arm and attachments to the base, allowing adjustment of the position of said support on said base, the support comprising an attachment area shaped for an apical suture ring, said device being shaped to be fixed by suture between the apex of the heart and the heart fixing support.at least one finger extending longitudinally between a first upper free end and a second lower end curved inside the base, said finger being mounted on said base by means of a first pivot joint, a contact interface mounted in an adjustable and removable manner on said free end so that said interface can exert adjustable pressure on a localized area of ​​the epicardium when said finger is moved in a rocking motion around said pivot joint, means for actuating the rocking motion of said finger around said pivot joint, a control unit for said actuating means.

[0012] The term "epicardium" refers to the inner layer of the inner (visceral) pericardium. It forms the serosa of this layer and extends over the entire external surface of the heart and the proximal part of the great vessels.

[0013] Optional features of the invention, complementary or alternative, are set out below.

[0014] According to certain characteristics, the means for actuating the rocking motion of said at least one finger around said pivot joint may comprise a connecting rod and a sliding member, one end of which is in a second pivot joint with said connecting rod, itself in a third pivot joint with the second lower end of said finger, the other end of said sliding member being connected by means of a rigid or semi-rigid cable to a linear actuator belonging to the control unit.

[0015] According to a first embodiment, the device may comprise six fingers distributed so that the first six upper ends form the vertices of a hexagon, each second lower end of the six fingers being in pivot connection with a connecting rod, itself in pivot connection with one end of a sliding member, the other end of said sliding member being connected by means of a rigid or semi-rigid cable to a linear actuator belonging to the control unit, so that the fingers are actuated independently.

[0016] According to a second embodiment, the device may comprise a pair of fingers arranged oppositely, each lower second end of the fingers being in pivot connection with a connecting rod, itself in pivot connection with one end of a sliding member common to each finger, the other end of said common sliding member being connected by means of a single rigid or semi-rigid cable to a linear actuator belonging to the control unit, so that the fingers are actuated in the same way.

[0017] Depending on other characteristics, the control unit may include an electrical storage unit to power the linear actuator(s) and an antenna to allow transcutaneous recharging of said electrical storage unit.

[0018] Depending on other characteristics, the control unit may include a computer to control the power supply of the linear actuator(s).

[0019] According to other features, the support for fixing the lower part of the heart to the base may include an attachment area for the apical suture ring.

[0020] According to other features, the support for fixing the lower part of the heart to the base may include at least one sensor for measuring intracardiac pressure.

[0021] According to other features, the device includes flow-type sensors suitable for installation on vessels emerging from the heart, such as the aorta, to allow feedback control of said device.

[0022] According to other features, each contact interface can be fixed to the first free end of the finger by means of a fastener cooperating with a groove made in said end so as to adjust the position of said interface along said end and thus vary the location of the pressure.

[0023] Depending on other characteristics, the interface with the epicardium may be equipped with at least one sensor allowing, for example, the measurement of contact pressure.

[0024] According to other features, the calculator can be connected to a set of sensors internal or external to the cardiac assistance device, in order to adapt the frequency and intensity of the contact pressure exerted by the first fingertip on the epicardium.

[0025] Other advantages and features of the invention will become apparent upon reading the detailed description of implementations and embodiments, which are by no means limiting, and the following attached drawings: [ Fig.1 This figure represents a schematic view of a cardiac assist device implanted in a patient according to the invention. Fig.2 This figure shows in detail a portion of the cardiac assistance device according to one embodiment of the invention. Fig.3 This figure shows in detail a portion of the cardiac assistance device according to another embodiment of the invention. Fig.4 This figure represents an overall diagram of the cardiac assistance device according to one embodiment of the invention.

[0026] The embodiments described below are not exhaustive; variants of the invention may include, in particular, a selection of the described features, isolated from the other described features (even if this selection is isolated within a sentence containing these other features), provided that this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one feature, preferably a functional feature without structural details, or with only a portion of the structural details if this portion alone is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0027] The device according to the invention is intended for implantation in patients suffering from end-stage heart failure, particularly in cases where other therapies cannot be applied.

[0028] The invention may also replace existing therapeutic solutions if it proves to be more suitable and demonstrates increased benefit for the patient.

[0029] The device according to the invention is intended for implantation in patients suffering from end-stage heart failure, particularly in cases where other therapies cannot be applied.

[0030] The invention may also replace existing therapeutic solutions if it proves to be more suitable and demonstrates increased benefit for the patient.

[0031] The cardiac assistance device according to the invention generates a mechanical deformation of the external wall of the organ in a synchronous manner and in accordance with the needs of the failing organ.

[0032] The device makes it possible to compensate for the inadequacy of the heart's pumping function without being in direct contact with the patient's circulating blood and without creating a rupture of the skin barrier, a classic source of infection.

[0033] The cardiac assistance device according to the invention and as shown in the figures 2 , 3 , 4 includes at a minimum: a base 1 forming a receptacle suitable for receiving the lower part of a heart 9, a support 2 for fixing the lower part of the heart to the base, said support comprising a fixing arm 21 and fasteners 15 to the base 1, allowing adjustment of the position of said support on said base, at least one finger 3 extending longitudinally between a first free upper end 35 and a second lower end 36 curved inside the base, said finger being mounted on said base according to a first pivot joint 12, a contact interface 4 mounted in an adjustable and removable manner on said free end so that said interface can exert adjustable pressure on a localized area of ​​the epicardium when said finger is moved by a rocking motion about said pivot joint, means 5, 6 for actuating the rocking motion of said finger about said pivot joint, a control unit 10 of said actuating means 5, 6.

[0034] Of course, the device according to the invention may include one or more fingers.

[0035] The fact that the second lower end 36 of at least one finger is curved inside the base allows it to conform to the shape of the heart and thus make the device less bulky.

[0036] The first pivot joint 12 of at least one finger, which is made for example by means of a drilling 32 in the body 31 of said finger, is not disposed at the lower end of said finger, but rather preferably somewhere between the middle of said finger and its lower end.

[0037] Thus, through leverage, the tilting motion consumes less energy.

[0038] In all cases, it is the adjustment of the position of the contact interfaces at the fingertips that allows the contact pressure on the epicardium and the precise area to be stimulated to be adjusted.

[0039] The device is therefore designed to exert pressure on the heart (systole) and to remain open and away from the heart inactively if the actuation means are no longer powered.

[0040] This deactivation of the actuation means allows the heart to expand freely (diastole) after compression to allow blood to return naturally and freely to the cardiac ventricles and the coronary vascular network (arteries and veins).

[0041] The external pressure exerted by the myocardium during ventricular systole compresses the heart muscle (myocardium) and reduces blood flow to the coronary arteries that supply the heart, even though aortic pressure is increased. Thus, more than 70% of coronary arterial flow occurs during diastole.

[0042] According to preferred embodiments represented on the figures 2 And 3, the means 5, 6 for actuating the rocking movement of a finger around said pivot joint, comprise a connecting rod 5 and a sliding member 6, one end of which 61 is in pivot joint 62 with said connecting rod, itself in pivot joint 34 with the second end 36 of the finger 3.

[0043] The other end of the sliding member 6 is then connected by means of at least one rigid or semi-rigid cable 8 to a linear actuator 103 of the control unit 10.

[0044] Thus, cable 8, housed in a sheath 7, allows the motor part, the power source and the electronic unit to be moved away from the rib cage where space is very limited.

[0045] The translational movement generated by the linear actuator(s) 103 is transmitted by one or more rigid or semi-rigid cables 8 contained in the sheath 7 to the part of the device surrounding the core. The translation of the sliding element 6 in the base 1 is transmitted to the finger 3 via the connecting rod 5 at the pivot joint 62 between the sliding element 6 and the connecting rod 5, and then at the pivot joint 34 between the connecting rod 5 and the second end 36 of the finger 3.

[0046] This movement generates a rocking motion, i.e. a rotation of the finger around its pivot joint 12 with the base 1, resulting in a concentric reduction of the gap between the tips of the fingers.

[0047] According to the first embodiment represented in [ Fig.2 ], the device consists of a pair of fingers arranged in opposite directions.

[0048] Each second lower end 36 of the two fingers 3 is in pivot connection 34 with a connecting rod 5 specific to each of the fingers, itself in pivot connection 62 with an end 61 of a sliding member 6 common to each finger.

[0049] The other end of the common sliding member 6 is connected by means of a single rigid or semi-rigid cable 8 to a linear actuator 103 belonging to the control unit 10, so that the fingers are actuated in the same way.

[0050] According to the second embodiment represented in [ Fig.3 ], the device has six fingers arranged so that the six upper ends form the vertices of a hexagon.

[0051] Each lower second end 36 of the six fingers 3 is connected by a pivot joint 34 to a connecting rod 5 specific to each finger, which is itself connected by a pivot joint 62 to an end 61 of a sliding member 6, specific to each finger. The sliding movement of each member 6 is guided along at least one axis 13 through an orifice 64 located near the end 61.

[0052] The other end of each sliding member 6 is connected by means of a rigid or semi-rigid cable 8 to a linear actuator 103 belonging to the control unit 10, so that the fingers are actuated independently.

[0053] A single sheath 7 then contains all six cables 8.

[0054] Depending on the requirements, it is possible to group the sliding parts together, to make them interlocking or to have them share the same actuation cable or the same linear actuator.

[0055] Advantageously and as represented on the [ Fig.1 ], the control unit 10 includes an electrical storage unit 101 to power the linear actuator 103 and an antenna 11 to allow transcutaneous recharging of said electrical storage unit.

[0056] Of course, other power supply configurations can be considered, for example, connecting the control unit externally.

[0057] The preferred location for this pilot unit 10 is the abdomen, with the possibility of recharging the integrated battery by transcutaneous induction.

[0058] Preferably, the support 2 for fixing the lower part of the heart to the base includes an attachment area 22 of the apical suture ring.

[0059] In other words, the device is ideally fixed by suture between the apex 91 of the heart and the heart fixation support 2. This support 2 is mounted on the base 1 by through fasteners 15 at the level of the fixation arms 21.

[0060] The assembly formed by the base 1 and the fingers 3 is thus secured to the heart at the level of the apex, and closely follows its lower part.

[0061] The apical suture ring, which is known to those skilled in the art, is in this case an accessory device to the cardiac assistance device described in the invention, acting as an interface between the organ and the device. Indeed, one of the key conditions for ensuring the effectiveness of the heart compression provided by the invention is to prevent organ escape and external deformation at the points of interest and not elsewhere.

[0062] The feasibility of fixing a cardiac assist device in the apical region of the heart has already been studied in the publication "Chalon A, Favre J, Piotrowski B, Landmann V, Grandmougin D, Maureira JP, Laheurte P, Tran N. Contribution of computational model for assessment of heart tissue local stress caused by suture in LVAD implantation. J Mech Behav Biomed Mater. 2018 Jun;82:291-298. doi: 10.1016 / j.jmbbm.2018.03.032. Epub 2018 Mar 28. PMID: 29649657."

[0063] The apical suture ring is generally made up of two parts.

[0064] The outer part is manufactured, according to one method, from medical-grade Teflon® (PTFE), Dacron®, or another biocompatible, non-absorbable synthetic fabric. A second method allows the use of pericardial tissue from another species (bovine, ovine, or other) treated to ensure tolerance by the recipient's body. This outer part (outer ring) is attached to the inner ring by crimping, gluing, and / or suturing to ensure the two components remain securely connected over time.

[0065] The inner ring is made of a biocompatible material, such as, but not limited to, nitrogen-doped stainless steel, titanium and titanium alloys (e.g., Ti-Nb), or a polymer (e.g., PEEK, UHMWPE, or PP). This section comprises a fixed segment that connects to the outer ring and a circular flange segment that ensures a firm connection with the cardiac assist device. A screw or an adjustment lever allows this circular flange to be tightened onto the attachment point of the cardiac assist device according to the invention. Tightening and / or locking prevents the device from rotating relative to the organ.

[0066] According to another embodiment, it is possible to provide a non-circular flange (hexagonal for example) allowing the elements to be locked together and limiting the risks of rotation of the suture ring relative to the cardiac assistance device.

[0067] Thus, the external part is sutured to the apex of the heart and the internal part is locked to the cardiac assistance device to ensure that the invention remains in place and functions properly.

[0068] Regarding the attachment zone 22 of the apical ring on the device, it emerges from the support 2 and is connected via fasteners 15 to the frame 1. This attachment zone can be cylindrical or of a shape complementary to the flange described previously in order to prevent any unwanted rotation of the elements relative to each other. This attachment element is hollow to accommodate tubing and / or pressure sensors. A window in one of the protrusions of the base 1) allows the necessary tubing and / or cables to pass through without hindering the operation of the invention.

[0069] A rigid or flexible cannula, tubing, or needle 23 emerges from the attachment zone 22 and is sized so that its free end opens inside the left ventricle. Connected directly to a sensor in the recess of the attachment zone 22 or via tubing to a remote sensor (particularly at the control unit 10), the sensor 23 enables continuous measurement of left ventricular pressure, which is used by the control unit 10 to adapt the device's action to the patient's needs. In either case, tubing or cables run along the frame 1 and follow the path of the sheath 7 to reach the control unit 10.

[0070] Advantageously, the device includes flow-type sensors suitable for installation on vessels emerging from the heart, such as the aorta, to allow feedback control of said device.

[0071] Advantageously, the contact interface 4 is fixed to the first free end 35 of the finger 3 by means of a fastener 42 cooperating with a groove 33 formed in said end so as to adjust the position of said interface along said end, and also to adjust its distance from the epicardium. The removable nature of the interface also allows it to be replaced before implantation of the device in the patient.

[0072] These interface elements 4, adjustable, removable and custom-made, are therefore fixed according to a fastener 42 in the groove 33 of the upper part of the fingers and make contact with the epicardium.

[0073] This movement generates a compression phenomenon on the external surface of the heart which induces an increase in pressure in the ventricles and promotes the ejection of blood towards the pulmonary and systemic circulations.

[0074] Advantageously, these interface elements 4 with the epicardium can be equipped with at least one sensor enabling the measurement of contact pressure.

[0075] Similarly, the support 2 for fixing the lower part of the heart to the base may include at least one sensor 23 for measuring intracardiac pressure. Thus, pressure sensors may be installed in the heart fixation support 2 and connected to cannulas 23 surgically placed in the ventricles.

[0076] Therefore, it is possible to condition the amplitude and / or force of finger pressure according to the signals collected by this set of sensors, in particular to synchronize the action of the device with the contraction of the heart.

[0077] To do this, the control unit 10 includes a computer 102 to control the power supply of the linear actuator 103.

[0078] This calculator 102 is connected to a set of sensors internal or external to the cardiac assistance device, in order to adapt the frequency and intensity of the contact pressure exerted by the first fingertip on the epicardium.

[0079] The acquisition and management of these signals is therefore carried out in the control unit 10 and more specifically by the computer 102.

[0080] Flow sensors can also be installed on vessels emerging from the heart, typically the aorta, to allow feedback control of the action of the invention.

[0081] Returning to the reverse position allows for the relaxation of all joints and a return to the initial "open" position. This initial position can be calibrated to exert minimal pressure on the organ to compensate for its pathological dilation.

[0082] The materials that make up the invention and that are implanted in the patient are all designed with materials recognized scientifically and industrially as biocompatible, or, where appropriate, are isolated from the patient by such materials.

[0083] The device can be manufactured in whole or in part by 3D printing from TiNb or PEEK powder.

[0084] Mechanical tests on a test bench and on an ex vivo organ under isovolumetric conditions were performed to determine the forces and pressures generated by the device, as well as the energy required to create these forces. The results clearly demonstrated the device's ability to restore hemodynamic parameters, even in a completely stopped heart, namely intraventricular pressure and aortic arterial pressure, to levels identical to normal physiological function.

[0085] Furthermore, this has shown that the energy deployed by the device for this cardiac assistance work remains at a sufficiently low level to consider its miniaturization and complete implantation.

[0086] The first tests carried out using prototypes of the described invention made it possible to establish a first estimate of the performance of the device.

[0087] Firstly, trials on explanted hearts under isovolumic conditions (no fluid circulation, the cardiac chambers were filled with a blood analog) showed the possibility of achieving intracardiac pressures of up to 110 mm Hg, which corresponds to the typical blood pressure in a healthy adult.

[0088] Further tests demonstrated the possibility of going even further.

[0089] However, these physiologically excessively high values ​​only illustrate the reserve of force that the device can develop and do not relate to its intended use in clinical settings.

[0090] The device can maintain a contraction rate of up to 80 beats per minute without any loss of contractile efficiency. Beyond that, it is possible to reach values ​​of 120 beats per minute, but this comes with premature wear of the device, a potential detrimental effect on the heart, and significantly degraded performance.

[0091] The time required to obtain the maximum force of the device was recorded at around 100+ / 25 ms but can be greatly improved to 20+ / -10 ms.

[0092] Energy consumption was estimated at 155 kJ for 24 hours of continuous use at a rate of 60 beats per minute. For comparison, this is the amount of energy contained in a laptop battery.

[0093] Compared to other conventional therapies, the implantable direct compression cardiac support device according to the invention offers the following advantages: Organ-conserving technique Preservation of pulsatility of flow Decrease in cardiac cavity volume Increase in cardiac output No direct blood contact Total implantation of the device (via mini-thoracotomy) and its annexes in the patient (reduction of infectious risks).

[0094] In other words, the implantable direct compression cardiac assistance device according to the invention is adjusted as closely as possible to the morphology of the heart, respecting healthy support areas as well as fragile and infarcted areas.

[0095] Note that the different characteristics, forms, variants and embodiments of the invention can be associated with each other, according to various combinations insofar as they are not incompatible or exclusive of each other.

Claims

1. Implantable device for cardiac assistance by direct compression, characterized in that it includes: - a base (1) forming a receptacle capable of receiving the lower part of a heart (9), - a support (2) for fixing the lower part of the heart to said base, said support comprising a fixing arm (21) and fasteners (15) at the base (1), making it possible to adjust the position of said support on said base, the support (2) comprising an area for fastening (22) configured to an apical suture ring, said device being configured to be fixed by suturing between the apex (91) of the heart and the fixing support of the heart (2), - at least one finger (3) extending longitudinally between a free upper first end (35) and a curved lower second end (36) inside the base, said finger being mounted on said base by virtue of a first pivot connection (12), - a contact interface (4) mounted adjustably and movably on said free end so that said interface can exert an adjustable pressure on a localized area of the epicardium, when said finger is moved by a tilting movement about said pivot connection, - means (5, 6) for actuating the tilting movement of said finger about said pivot connection, - a unit for controlling (10) said actuating means (5, 6).

2. Implantable device for cardiac assistance by direct compression, according to claim 1, characterized in that the means (5, 6) for actuating the tilting movement of said at least one finger about said pivot connection include a connecting rod (5) and a sliding member (6) one of the ends (61) of which is in a second pivot connection (62) with said connecting rod, itself in a third pivot connection (34) with the lower second end (36) of said finger (3), the other end of the sliding member (6) being connected by means of a rigid or semi-rigid cable (8) to a linear actuator (103) belonging to the control unit (10).

3. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the device includes six fingers distributed so that the six upper ends form the vertices of a hexagon, each lower second end (36) of the six fingers (3) being in a pivot connection (34) with a connecting rod (5), itself in a pivot connection (62) with an end (61) of a sliding member (6), the other end of the sliding member (6) being connected by means of a rigid or semi-rigid cable (8) to a linear actuator (103) belonging to the control unit (10), so that the fingers are actuated independently.

4. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the device includes a pair of fingers arranged opposite one another, each lower second end (36) of the fingers (3) being in a pivot connection (34) with a connecting rod (5), itself in a pivot connection (62) with an end (61) of a sliding member (6) common to each finger, the other end of the common sliding member (6) being connected by means of a single rigid or semi-rigid cable (8) to a common linear actuator (103) belonging to the control unit (10), so that the fingers are actuated identically.

5. Implantable device for cardiac assistance by direct compression, according to the preceding claim, characterized in that the control unit (10) comprises an implantable electrical storage unit (101) to power the linear actuator(s) (103) and an antenna (11) to allow recharging of said electrical storage unit by the transcutaneous route.

6. Implantable device for cardiac assistance by direct compression, according to any one of claims 2 to 5, characterized in that the control unit (10) comprises a computer (102) for controlling powering of the linear actuator(s) (103).

7. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the support (2) for fixing the lower part of the heart to the base comprises at least one sensor (23) for measuring the intracardiac pressure.

8. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the device includes sensors of the flow type capable of being installed on the vessels emerging from the heart, such as the aorta, to allow feedback from said device.

9. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the contact interface (4) is fixed on the free first end (35) of its finger (3) by means of a fastener (42) cooperating with a groove (33) made in said end, so as to adjust the position of said interface along said end.

10. Implantable device for cardiac assistance by direct compression, according to any one of the preceding claims, characterized in that the interface for contact (4) of each finger with the epicardium is equipped with at least one sensor making it possible for example to measure the contact pressure.

11. Implantable device for cardiac assistance by direct compression, according to claim 6, characterized in that the computer (102) is connected to an assembly of sensors internal or external to the cardiac assistance device, in order to adapt the frequency and the intensity of the contact pressure exerted by the first end of the fingers on the epicardium.