Mechanical circulatory support cardiac device

Abstract

One aspect of the invention relates to a mechanical circulatory support cardiac device comprising: a pericardial prosthesis including: epicardial surface electrodes configured to measure electrical signals at an epicardial surface, an active layer comprising an electroactive polymer matrix material, a processor connected to a power source, the processor being configured to: obtain, from the signals measured by the epicardial surface electrodes, an electrocardiogram signal, and determine a voltage value as a function of the electrocardiogram signal obtained, and control the power source to apply the determined voltage value to the electroactive polymer matrix material so as to induce a deformation of the active layer. Figure to be published with the abstract: Figure 1

Description

Title of the invention: Mechanical circulatory assistance cardiac device TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of circulatory assistance for people suffering from heart failure.

[0002] The present invention relates to a cardiac device and in particular to a mechanical circulatory assistance cardiac device. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] The heart functions like a pump which, thanks to its regular contractions, propels blood throughout the body and thus ensures the supply of oxygen to the entire body. With each heartbeat, an electrical current passes through the heart. This electrical current causes the heart muscle, called the myocardium, to contract so that it expels blood from the heart. The electrical current originates at a specific point in the heart, called the sinus node, located at the top of the right atrium of the heart. Starting from the sinus node, the electrical current spreads through the heart muscle. It circulates in the two atria to their base, causing them to contract. From this base, it converges towards the partition separating the atria and the ventricles, at the level of an electrical relay called the atrioventricular node. From the atrioventricular node, the impulse progresses simultaneously in the two ventricles, the right and the left, using very fast conductive pathways, i.e.the bundle of His and the Purkinje network, to the apex of the heart, causing the ventricles to contract.

[0004] An electrocardiogram (ECG) is a test that studies the functioning of the heart by measuring its electrical activity. [Fig.7] shows an example of an ECG signal that can be obtained by electrocardiography for a heart that does not present any abnormalities. Thus, an ECG signal, as presented in [Fig.7], includes different characteristic events: • The P wave, which corresponds to the depolarization wave of the atria. It represents the electrical impulse that originates in the sinus node and passes through the atria, causing them to contract. The contraction of the atria allows blood to pass from the atria to the ventricles through the tricuspid and mitral valves. The electrical wave continues its path to the atrioventricular node. • The PR space or PQ space, which corresponds to the atrioventricular conduction time, i.e. from the atria to the ventricles. This short pause allows blood to pass through the valves to the ventricles. • The QRS complex, which corresponds to the depolarization of the ventricles and therefore to the contraction of the ventricles. The electrical impulse travels through the two ventricles through the bundle of His and its branches and causes the ventricles to contract. • The ST segment, which corresponds to the start of repolarization of the ventricles. • The T wave, which is the repolarization wave of the ventricles. The ventricular myocytes relax and recharge in order to be able to depolarize again.

[0005] Heart failure is the inability of the heart to provide a cardiac output adequate to the body's metabolic needs. Heart failure can affect the left ventricle and / or the right ventricle of a patient's heart. Heart failure is a major public health problem as it represents the leading cause of death worldwide. Moreover, despite a wide variety of therapeutic treatments available, the morbidity and mortality of heart failure is high.

[0006] Heart failure can be expressed in different ways in clinical practice. For example, heart failure can be expressed in a very acute and sudden manner in the context of a heart attack. This first example, also called cardiogenic shock, results in mortality of patients in approximately 40 to 50% of cases. Heart failure can also develop in a more chronic manner. End-stage chronic heart failure represents a situation in which the patient is hampered by the slightest effort for the activities of daily living.The patient may also, during the course of his illness, present decompensations ranging from simple hospitalization with a need to take diuretics, to refractory cardiogenic shock requiring the implantation of extracorporeal mechanical circulatory assistance, commonly noted ECMO-VA for "veno-arterial ECMO" (ECMO meaning "extracorporeal membrane oxygenation" in English, or "oxygenation by extracorporeal membrane" in French). It is known to offer extracorporeal mechanical circulatory assistance to people suffering from heart failure. Extracorporeal mechanical circulatory assistance thus temporarily makes it possible to restore blood flow to other organs in a patient hospitalized in intensive care.

[0007] Various solutions are possible so that a patient can emerge from an acute resuscitation situation or from terminal chronic heart failure with a suitable quality of life. A first solution is, for example, a heart transplant. A second solution is the use of a long-term mechanical circulatory support device (MCAD), i.e., for example, a duration of use greater than or equal to 30 days. These long-term mechanical circulatory support devices are medical devices Active plantable devices intended to supplement a major failure of the heart pump. These devices are used either for a temporary period while awaiting transplantation or while awaiting myocardial recovery, or as definitive therapy. A prime example of a long-term mechanical circulatory support device is the Heartmate III device developed by Abbott®. The Heartmate III device is a single-left ventricular device, i.e. it only assists the left ventricle of a patient's heart. Another example is a total artificial heart such as that proposed by Syncardia®.

[0008] These different solutions can help a large number of patients but do not meet all needs. Indeed, a certain number of patients do not have access to a compatible graft or are not in a condition to receive a heart transplant. In addition, heart transplantation is a major cardiac surgery with a subsequent treatment which is also major. Mechanical assistance solutions also have many disadvantages such as major cardiac surgery, the refusal of certain patients to have such an invasive device, the impossibility of suitable post-operative treatment linked to a contraindication to a blood thinner or a precarious general condition. Finally, a device such as the Abbott® Heartmate III does not allow the management of failure of both ventricles of the heart.

[0009] There is therefore a need for a mechanical circulatory assistance cardiac device which does not have, or at least limits, the disadvantages of the currently available solutions. Summary of the invention

[0010] The invention provides a solution to the problems mentioned above, by proposing an implantable device partially or totally assisting the cardiac muscle in its role for the ejection of blood. Thus, the device comprises an electroactive material with a polymer matrix which deforms when an electric field is applied to it. This property of the electroactive material with a polymer matrix makes it possible to provide assistance to cardiac contraction in systole and therefore an increase in the volume of blood ejected by the heart. Thus, by integrating an electroactive material with a polymer matrix, which has significant electromechanical coupling, the device according to the invention makes it possible to achieve an efficiency and generation of a cardiac output meeting the needs of a large majority of patients suffering from heart failure.

[0011] One aspect of the invention relates to a mechanical circulatory support cardiac device comprising: • a pericardial prosthesis comprising: • epicardial surface electrodes configured to measure electrical signals at an epicardial surface, • an active layer comprising an electroactive material with a polymer matrix, • a processor connected to a power source, the processor being configured to • obtain, from the signals measured by the epicardial surface electrodes, an electrocardiogram signal, and • determine a value of an electrical voltage based on the electrocardiogram signal obtained, and • control the energy source to apply the determined electrical voltage value to the polymer matrix electroactive material so as to induce deformation of the active layer.

[0012] Thanks to the invention, the volume of blood ejected from a patient's heart is increased. Indeed, the active layer, comprising the electroactive polymer matrix material, assists or even replaces the patient's heart muscle in its role as a pump allowing the circulation of blood throughout the patient's body. In addition, the pericardial prosthesis makes it possible to avoid major surgery and allows simplified therapeutic monitoring compared to currently available solutions since it is affixed to the outside of the patient's heart. The pericardial prosthesis is in fact adapted to be affixed to the external surface of the heart, for example at the epicardium, by minimally invasive surgery without the heart being stopped and without significant risk of hemorrhage.

[0013] A second advantage of the invention is that the pericardial prosthesis can assist not only the left part but also the right part of the patient's heart without requiring removal of the native heart. This allows for the possibility of native myocardial recovery depending on the pathologies and treatments administered to the patient. Thus, when significant myocardial recovery occurs, the device can be removed or left in place. If the device is left in place, it can be switched off, i.e. in a mode in which the device does not assist the patient's heart, in order to allow the native heart to function without assistance and without risk related to the prosthesis. Alternatively, the device according to the invention can be active only in certain situations in the patient's life, such as during phases of physical exertion.

[0014] A third advantage of the device according to the invention is that no part of the device is in contact with the patient's blood. Thus, the implantation of the device does not induce any thrombotic risk or introduction of embolus into the systemic circulation.

[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the mechanical circulatory assistance cardiac device according to one aspect of the invention may have one or more complementary characteristics among the following, considered individually or in all technically possible combinations: • the device further comprises an electrically insulating biocompatible layer enveloping the active layer, • the epicardial surface electrodes are integrated into the electrically insulating biocompatible layer, • the electrically insulating biocompatible layer further comprises biosensing mechanoreceptors configured to obtain information on variations in the volume of a heart wall and the value of the electrical voltage is further determined based on the information on variations in the volume of a heart wall, • the active layer comprises several sub-layers, each sub-layer comprising a respective membrane of electro-active material with a polymer matrix, • for the determination of the value of the electrical voltage, the processor is configured to: • identify an event of a cardiac cycle from the electrocardiogram signal obtained, and • determine the value of the electrical voltage from the identified event, • the identified event is the start of a QRS complex of the cardiac cycle, • the processor is further configured to: • before identifying the event, command the energy source to apply a reference value of electrical voltage to the polymer matrix electroactive material, and • upon identification of the event, command the energy source to apply the determined value of the electrical voltage, in which the determined value of the electrical voltage is strictly lower than the reference value, • the determined value of the electrical voltage is applied to the polymer matrix electroactive material for a predetermined duration after the event has been identified, • the electroactive polymer matrix material is an electroactive polymer, • the polymer matrix electroactive material is a ferroelectric and / or elect- trostrictive, • the electroactive polymer matrix material is a PVDF- terpolymer TrFE-CFE.

[0016] A second aspect of the invention relates to a method for manufacturing a mechanical circulatory assistance cardiac device according to the invention comprising: • obtaining cardiac measurements of a patient, • determining dimensions of the pericardial prosthesis as a function of the cardiac measurements obtained, and • 3D printing of the pericardial prosthesis according to the determined dimensions.

[0017]

[0018]

[0019]

[0020] In an exemplary manufacturing method according to one aspect of the invention, the patient's cardiac measurements include measurements of the patient's cardiac ventricles and the dimensions of the pericardial prosthesis are determined such that the pericardial prosthesis envelops at least half of the patient's cardiac ventricles. A third aspect of the invention relates to a method, implemented by a processor, for controlling a pericardial prosthesis and an energy source, the pericardial prosthesis comprising an active layer, the active layer comprising an electroactive polymer matrix material, the method comprising, for each cardiac cycle of a patient's heart: • Sending a control signal to the energy source to apply a determined value of electrical voltage to the electroactive polymer matrix material of the active layer, • Reception of electrical signals of cardiac activity from the patient's heart, • Obtaining an electrocardiogram signal from the electrical signals of cardiac activity, • Identification of an event in a cardiac cycle from the electrocardiogram signal obtained, • When the cardiac cycle event is identified, reduction of the determined value of electrical voltage based on information regarding the patient's cardiac activity, and • Sending a control signal to the energy source to apply the reduced electrical voltage value to the polymer matrix electroactive material of the active layer. By "processor-implemented" is meant that the steps, or substantially all of the steps, of the method for controlling a pericardial prosthesis are performed by a processor or other similar system. A fourth aspect of the invention relates to a method of implanting the device according to the invention, the method comprising a step of minimally invasive surgery so that the pericardial prosthesis at least partially envelops a heart of a patient.

[0021] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0022] The figures are presented for information purposes only and in no way limit the invention. • [Fig.l] is a schematic representation of an example of the device according to the invention when it is implanted on a patient. • Figures 2, 3 and 4 are schematic representations of an example of the pericardial prosthesis according to the invention. • Figures 5 and 6 are schematic representations of a cross-section of an example of the pericardial prosthesis according to the invention. • [Fig.7] is an illustration of an example ECG signal. • [Fig.8] is a block diagram illustrating the steps of an example of the manufacturing method according to the invention. DETAILED DESCRIPTION

[0023] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0024] [Fig. 1] is a schematic representation of an example of the device 100 according to the invention when it is implanted on a patient. [Fig. 1] illustrates an example of a device 100 according to the invention comprising a pericardial prosthesis 101 connected to a housing 113 by a cable 102. [Fig. 1] also illustrates an example of such a housing 113 comprising a processor 112 and an energy source 108. Finally, [Fig. 1] illustrates a display means 109, to which the device 100 according to the invention can send information to be displayed.

[0025] The device 100 is a mechanical circulatory support cardiac device. It is designed to allow a long duration of use, typically greater than 30 days.

[0026] [Fig. 4] is a schematic representation of an example of the pericardial prosthesis according to the invention. [Fig. 4] illustrates in particular a pericardial prosthesis 101 as well as the cable 102 connecting the pericardial prosthesis 101 to the other components of the device. [Fig. 4] also illustrates a heart 300 of a patient on which a pericardial prosthesis 101 is affixed.

[0027] The pericardial prosthesis 101 of the device 100 is affixed around the patient's heart, i.e. the pericardial prosthesis 101 envelops at least a portion of the patient's heart 300. In a first example, the pericardial prosthesis 101 envelops at least half of the patient's heart ventricles. In a second example, the pericardial prosthesis 101 envelops at least two-thirds of the patient's heart ventricles. In a third example, the pericardial prosthesis 101 covers at least three-quarters of the patient's heart ventricles. The term "wrap" here means "surround or cover the heart" using the prosthesis. Thus, the prosthesis is implanted so as to be in contact with an epicardial surface of the heart. As illustrated in [Fig. 4], the prosthesis can therefore be considered as a prosthesis having the shape of a pocket enveloping the heart 300. The resting shape, i.e. when no electric field is applied to the electroactive polymer matrix material, of the pericardial prosthesis 101 is close to a cone having no base. In addition, the pericardial prosthesis 101 may have a notch in order to allow significant deformation of the prosthesis. Indeed, when implanting the cardiac prosthesis around the heart 300, it may be necessary to deform the prosthesis significantly to place it around the heart. [Fig.4] schematically illustrates the displacement of the pericardial prosthesis 101 relative to the heart 300 during implantation of said prosthesis. It should be noted that the notch that may be present on the pericardial prosthesis 101 is not shown in [Fig.4] for the sake of clarity. This notch is for example located along a generatrix of the cone. A generatrix of a cone is a segment connecting the apex of the cone to a point on the circle forming the base of this cone.

[0028] The implantation of the pericardial prosthesis 101 is therefore not a complex operation and is a minimally invasive cardiac surgery procedure which does not require stopping the heart. The device 100 according to the invention can therefore be implanted in unstable critically ill patients. In one example, the pericardial prosthesis 101 can be implanted in the pericardial space by thoracotomy and glued to a wall of the epicardium using a biological glue or a pericardial patch.

[0029] [Fig. 5] is a schematic representation of a cross-section of an example of the pericardial prosthesis according to the invention. It illustrates in particular epicardial surface electrodes 105 included in the pericardial prosthesis 101. These epicardial surface electrodes 105 are adapted to measure electrical signals at the epicardial surface of the patient's heart. Thus, these electrodes can be arranged on the internal face of the pericardial prosthesis 101. The internal face corresponds to the face of the pericardial prosthesis 101 located on the side of the patient's heart while the external face corresponds to the face of the pericardial prosthesis 101 located opposite the heart. In other words, the internal face of the pericardial prosthesis 101 is the face located towards the inside of the baseless cone, when the pericardial prosthesis 101 has the shape of a baseless cone.These epicardial surface electrodes 105 may, when the prosthesis is implanted on a patient, be in contact with the epicardial surface of the heart. These epicardial surface electrodes 105 may also be located close to the epicardial surface, i.e. at a distance less than a maximum distance of less than 20 millimeters. The maximum distance corresponds to the . distance at which the epicardial surface electrodes 105 no longer allow electrical signals to be measured at the epicardial surface. In one example, compatible with the previous examples, the number of epicardial surface electrodes 105 is between 1 and 5, preferably between 3 and 5. For example, for a number of electrodes 105 of 3, the first electrode is placed at the level of the right ventricle, the second electrode is placed at the level of the interventricular septum, the third is placed at the level of the left ventricle.

[0030] The pericardial prosthesis 101, as illustrated in [Fig. 5], comprises an active layer 103. The terms "active layer" mean in the present application that the layer is adapted to deform in response to an application of an electrical voltage. Thus, the active layer 103 could also be called a deformation layer 103. This capacity to deform in response to an application of an electrical voltage is enabled by the presence, in the active layer 103, of an electroactive polymer matrix material. An electroactive polymer matrix material is a material whose shape or size changes when stimulated by an electric field. In one example, consistent with the previous examples, the electroactive polymer matrix material present in the active layer 103 is a membrane with a thickness of between 50 micrometers and 2 millimeters and preferably 0.5 millimeters.

[0031] There are different types of electroactive polymer matrix materials suitable for shape control. In one example, compatible with the previous examples, an electroactive polymer matrix material compatible with the invention is a material having a compromise between a large deformation under an electric field, for example between 0.5% and 1.5%, preferably 1%, and a significant blocking force, for example greater than 8 newtons and preferably 10 newtons. The blocking force of a material is the force at which the deformation of the material is zero.

[0032] In one example, compatible with the preceding examples, an electroactive polymer matrix material compatible with the invention is a material having a modulus of elasticity of between 0.1 and 200 megapascals, for example 45 megapascals.

[0033] Examples of electroactive polymer matrix materials compatible with the invention are, for example: • an electroactive polymer, and / or • a silicone and its composite derivatives, and / or • an elastomer polyurethane and its composite derivatives.

[0034] An electroactive polymer, commonly referred to as EAP for “electro active polymer” in English, is a polymer whose shape or size changes when stimulated by an electric field. Ferroelectric and / or electrostrictive polymers are examples of electroactive polymers suitable for the device 100. In one example, compatible with the previous examples, the electroactive polymer included in the active layer 103 is a PVDF-TrFE-CFE terpolymer. also noted P(VDF-TrFE-CFE). The PVDF-TrFE-CFE terpolymer has a modulus of elasticity of 45 megapascals. In addition, it has a compromise between its deformation under an electric field and its blocking force which is particularly suitable for the operation of the pericardial prosthesis. In addition, it is suitable for operating in direct electromechanical conversion, i.e. when an electrical voltage is applied to the material this induces a displacement of the material, but also in reverse electromechanical conversion, i.e. a displacement of the material induces the generation of an electrical voltage by the material. In one example, compatible with the previous examples, the PVDF-TrFE-CFE terpolymer present in the active layer 103 is a membrane with a thickness of between 30 micrometers and 1 millimeter.The term "membrane" here refers to the fact that the electroactive polymer matrix material is membraniform, that is to say that it has the characteristics of a membrane. A membrane being defined, in the present application, as being a thin and flexible material, which forms or covers an organ, or which lines a cavity.

[0035] In one example, compatible with the preceding examples, the electroactive polymer matrix material can also serve as an additional sensor for analyzing a displacement of one or more heart walls and a contraction force of one or more heart walls. In another example, compatible with the preceding examples, a second electroactive polymer matrix material, different from the electroactive polymer matrix material used to deform the pericardial prosthesis, can serve as an additional sensor for analyzing a displacement of one or more heart walls and / or a contraction force of one or more heart walls. For example, the PVDF-TrFE-CFE terpolymer, due to its direct electromechanical conversion property, is suitable for serving as an additional sensor for analyzing a displacement of one or more heart walls and a contraction force of one or more heart walls.This allows the material to operate in pseudo-piezoelectric mode.

[0036] [Fig. 6] illustrates a cross-sectional plan of an example, compatible with the previous examples, of a pericardial prosthesis 101 whose active layer 103 comprises several sub-layers 107. The active layer 103 of the device 100 may comprise several sub-layers 107, for example between 2 and 10 sub-layers 107. Each sub-layer 107 may have a thickness of less than 100 pm. Each sub-layer 107 comprises electro-active material with a polymer matrix, for example in the form of a membrane of electro-active material with a polymer matrix. The different sub-layers 107 may be superimposed on each other. Each sub-layer 107 may be adapted to deform differently from at least one other sub-layer 107. For example, the difference in deformation between the different sub-layers 107 may relate to the length and / or the shape and / or the orientation of the deformation obtained for the same applied voltage value. This difference in deformation may be obtained in particular by varying the thickness of at least one sub-layer or by varying the electroactive polymer matrix material used in at least one sub-layer.

[0037] An example of a pericardial prosthesis 101, compatible with the previous examples and as illustrated in FIGS. 5 and 6, also comprises an electrically insulating biocompatible layer 104.

[0038] In one example, consistent with the previous example, the epicardial surface electrodes 105 are integrated, at the inner face, into the electrically insulating biocompatible layer 104. For example, as illustrated in [Fig. 5], the epicardial surface electrodes 105 are disposed, at least partially, in the electrically insulating biocompatible layer 104 so as to be in contact with the epicardium of the patient's heart.

[0039] This electrically insulating biocompatible layer 104 envelops the active layer 103, that is to say it surrounds the active layer 103 so that no part of the active layer 103 is in contact with an organ of the patient. Figures 5 and 6 illustrate an example of a pericardial prosthesis 101 in which the electrically insulating biocompatible layer 104 envelops the active layer 103. Thus, as illustrated in Figures 5 and 6, the electrically insulating biocompatible layer 104 almost completely covers the active layer 103. In particular, it covers both faces of the active layer 103, i.e. internal and external, with the possible exception, for example: • areas comprising epicardial surface electrodes 105 and / or biosensing mechanoreceptors 106 when the epicardial surface electrodes 105 and / or the biosensing mechanoreceptors 106 are at least partly outside the electrically insulating biocompatible layer 104, and • an area in which one or more cables 102 connect the pericardial prosthesis 101 to other elements of the device 100, such as a processor 112 and an energy source 108.

[0040] This electrically insulating biocompatible layer 104 comprises, for example, biocompatible silicone. This electrically insulating biocompatible layer 104 makes it possible to protect the patient's organs from receiving the electrical voltage applied to the active layer 103. This electrically insulating biocompatible layer 104 is also adapted to allow the prosthesis not to be affected by the risk of rejection. Thus, the implantation of the device 100 does not require the taking of an immunosuppressant. by the patient.

[0041] The device 100 also comprises a processor 112 connected to an energy source 108. The term “processor” designates, in the present application, a single processor or a multitude of processors. For example, each processor can be dedicated to a task among the tasks necessary for the operation of the device 100 or a processor can perform several or even all of the tasks necessary for the operation of the device 100. The energy source 108 is for example an electric battery. The processor is connected to the energy source 108 by one or more cables 102. The cables 102 make it possible to supply the processor with energy and allow the processor to control the energy source 108 to apply a predetermined value of electrical voltage to the electroactive polymer matrix material. Thus, one or more cables 102 also connect the energy source 108 to the active layer 103.In addition, one or more cables 102 connect the energy source 108 to the epicardial surface electrodes 105 in order to supply them with energy. Finally, one or more cables 102 connect the epicardial surface electrodes 105 to the processor in order to send the electrical signal captured by the electrodes 105 to the processor. At the pericardial prosthesis 101, the cable or cables 102 can be fixed at the tip of the prosthesis, as illustrated for example in figures 1, 2, 3 or 4. .

[0042] In one example, consistent with the preceding examples, the processor and the energy source 108 are adapted to be implanted under the skin of the patient at a subdiaphragmatic epigastric area. In addition, as illustrated in [Fig.l], the processor 112 and the energy source 108 may be included in a housing 113, itself implanted under the skin of the patient, for example at the subdiaphragmatic epigastric area. In one example, consistent with the preceding example, the energy source 108 may be recharged by transcutaneous electromagnetic means.

[0043] The processor of the device 100 is configured to perform different functions. The first function consists of obtaining, from the signals measured by the electrodes, an ECG signal. The second function is to determine a value of an electrical voltage as a function of the obtained ECG signal. For example, the determination of the value of the electrical voltage can be performed by the processor in two sub-steps: • identify an event of a cardiac cycle from the ECG signal obtained, • determine the value of the electrical voltage from the identified event.

[0044] By "identifying an event of a cardiac cycle from the obtained ECG signal" is meant "identifying any predefined event that can be detected in the ECG signal". For example, the event may correspond to an ascending or descending peak in the ECG signal, which may be detected by noting that a rising or falling edge of the ECG signal reaches a predefined threshold.

[0045] The third function is to control the energy source 108 to apply the determined electrical voltage value to the polymer matrix electroactive material so as to induce deformation of the active layer.

[0046] In one example, consistent with the preceding examples, the processor may further be configured to control the energy source 108 to apply a reference value of electrical voltage to the polymer matrix electroactive material before the identification of an event. In this example, the processor is also configured to control the energy source 108 to apply a determined value of the electrical voltage, strictly lower than the reference value of the electrical voltage, when the event is identified. By applying the reference value of electrical voltage to the polymer matrix electroactive material of the active layer 103, a deformation of the active layer 103 is obtained. This deformation of the active layer 103 further allows a deformation of the pericardial prosthesis assembly 101. [Fig. 2] illustrates in particular an example of deformation of the pericardial prosthesis 101 when an electrical voltage is applied.In [Fig. 2], such a deformation is illustrated by the various arrows 110. Then, by applying a determined value of the electrical voltage strictly lower than the reference value of electrical voltage, the deformation of the active layer 103, and therefore of the pericardial prosthesis assembly 101, is reduced. Indeed, when the electrical voltage is reduced, the electroactive polymer matrix material of the active layer 103 exerts an elastic return which allows the active layer 103 to approach its resting shape. [Fig. 3] illustrates, using the various arrows 111, an example of movement induced by the elastic return exerted by the electroactive polymer matrix material of the active layer 103 of the pericardial prosthesis 101 when the value of the electrical voltage applied to the electroactive polymer matrix material is reduced.In one example, consistent with the previous examples, the reference voltage value is between 10 and 2000 volts and the determined value of voltage strictly lower than the reference voltage value is between 0 and 1900 volts.

[0047] In one example, consistent with the preceding example, the electrical voltage strictly lower than the electrical voltage reference value is applied for a predetermined period after the event has been identified. The duration of this predetermined period must be less than the duration of the patient's cardiac cycle. For example, the predetermined period of application of the electrical voltage strictly lower than the electrical voltage reference value may be between 1% and 99%, preferably between 10 and 60% of the duration of the patient's cardiac cycle or between 1 and 599 milliseconds, preferably between 100 and 400 milliseconds.

[0048] In one example, consistent with the preceding examples, the event identified by the processor is the start of the QRS complex of a cardiac cycle. The QRS complex functionally corresponds to ventricular contraction. Thus, in this example, for each cardiac cycle, before the start of the QRS complex is identified, a reference electrical voltage value is applied. When the start of the QRS complex is identified, the electrical voltage applied to the electroactive polymer matrix material is reduced. With this reduction in the electrical voltage applied to the electroactive polymer matrix material, the elastic return of the active layer 103 makes it possible, by assisting the cardiac muscle, to increase the volume of blood ejected during systole.Indeed, the electroactive polymer matrix material, when it deforms, allows the active layer 103, and therefore the pericardial prosthesis 101, to expand, that is to say to move the epicardial prosthesis 101 away from the patient's heart. When the electrical voltage is reduced, the elastic return of the active layer 103 makes it possible, during systole, to assist or even replace ventricular contraction and therefore to increase the volume of blood ejected by the patient's heart. For example, the volume of blood ejected with the assistance of the device is increased by at least 10% and / or can make it possible to regain a systolic ejection volume of 30 to 40 milliliters per meter2 of the patient's body surface area.

[0049] In one example, compatible with the preceding examples, events other than the start of the QRS complex of the cardiac cycle can be identified by the processor. For example, it is possible to identify one or more events from a signal corresponding to the movement of the cardiac wall. In this example, the identified event can be the start of the movement of the cardiac wall in the systole phase. The triggering of the assistance of the pericardial prosthesis, by the elastic return of the active layer 103, cannot therefore take place when the heart is still completely distended at the end of the filling phase (diastole). Thus, it is possible to carry out this triggering of the pericardial prosthesis with lower constraints for the prosthesis, thus allowing less difficulty and resistance of the device in the ejection of blood by the patient's heart.In addition, a delay between the identification of the event and the modification of the value of the reference electrical voltage can be respected.

[0050] In one example, consistent with the preceding examples, the processor is further configured to detect an absence of electrical activity for a certain duration. In this example, the processor controls the energy source 108 to rhythmically apply the reference electrical voltage value and the electrical voltage value strictly lower than the reference electrical voltage value to the polymer matrix electroactive material so as to induce deformation of the active layer at a predetermined rhythm. The rhythm value may for example be predetermined during the configuration of the processor and / or predetermined after the implantation of the device 100. The rate is for example 80 commands per minute in order to allow 80 beats of the patient's heart per minute.

[0051] In one example, consistent with the preceding examples, the electrically insulating biocompatible layer 104 further comprises biosensing mechanoreceptors 106 configured to obtain information on volume variations of one or more cardiac walls. In this example, the processor is further configured to control the energy source 108 in order to modify the reference value of the electrical voltage applied to the polymer matrix electroactive material as a function of the information on volume variations of one or more cardiac walls obtained. Similarly, the electrical voltage value lower than the electrical voltage reference value can also be adapted by the processor taking into account the information on volume variations of one or more cardiac walls obtained.In this example, the device 100 can therefore automatically adapt to the patient's heart by modifying the assistance provided to the heart to eject blood from the heart. For example, if the patient's heart, at a given moment, is functioning normally, i.e. it allows sufficient cardiac output to ensure the circulation of blood in the body, the device 100 will adapt to reduce or even stop its assistance. Indeed, the biosensor mechanoreceptors 106 will detect a change in the volume variations of one or more heart walls and the processor will process this information to modify the electric field applied to the electroactive polymer matrix material accordingly. This therefore makes it possible to adapt the level of assistance provided by the device 100 to the native heart to ensure the circulation of blood in the body.In addition, it allows an assessment of volume variations of one or more cardiac walls including the left and right parts of the heart.

[0052] In this example, the biosensing mechanoreceptors 106 and the epicardial surface electrodes 105 provide a set of data for monitoring the functioning of the patient's heart. Thus, the device 100 can be used as a monitoring tool to obtain continuous data on the functioning of the heart. This can therefore allow a patient suffering from heart failure to avoid numerous medical examinations such as cardiac ultrasounds.

[0053] In one example, compatible with the previous examples, the device 100 may be connected to a display means 109 such as a screen. This display means may for example make it possible to display various information such as the ECG signal captured by the epicardial surface electrodes 105 and / or the remaining battery level and / or the level of assistance currently provided by the device 100. Thus, in this example, the device is adapted to send information relating to the state of the patient's heart and the operation of the device 100 to the display means. For example, the processor included in the device 100 is configured to process the information relating to the state of the patient's heart and the operation of the device 100 and send it to the display means.

[0054] A second aspect of the invention relates to a method for manufacturing the device 100 according to any one of the preceding examples. [Fig. 8] is a block diagram illustrating the steps of an example of the manufacturing method 200. A first step 210 of the method 200 consists of obtaining the cardiac measurements of the patient. The cardiac measurement information includes in particular the size of the heart as well as the shape of the external surface of the heart, in particular at the level of the left and right ventricles. The cardiac measurements of the patient can for example be obtained by cardiac ultrasound or cardiac magnetic resonance imaging.

[0055] A second step 220 of the method 200 consists of determining the dimensions of the pericardial prosthesis based on the obtained cardiac measurements. For example, the patient's cardiac measurements may include measurements of the patient's cardiac ventricles. Thus, the dimensions of the pericardial prosthesis (101) may be determined, using these measurements of the cardiac ventricles, such that the pericardial prosthesis envelops at least half of the patient's cardiac ventricles.

[0056] A third step 230 of the method 200 consists of printing in three dimensions (3D) the pericardial prosthesis 101 according to the determined dimensions. In one example, compatible with the previous examples, electrically conductive electrodes are deposited on the electroactive polymer matrix material, or when the electroactive polymer matrix material is in the form of a membrane on each face of the membrane. These electrically conductive electrodes allow the transmission of the electrical pulse. The electroactive polymer matrix material is metallized in air in order to apply the electric field in the thickness of the active layer.

Claims

Claims

1. A mechanical circulatory assistance cardiac device (100) comprising: - a pericardial prosthesis (101) comprising: • epicardial surface electrodes (105) configured to measure electrical signals at an epicardial surface, • an active layer (103) comprising an electroactive polymer matrix material, - a processor connected to a power source (108), the processor being configured to: • obtain, from the signals measured by the epicardial surface electrodes (105), an electrocardiogram signal, and • determine a value of an electrical voltage as a function of the electrocardiogram signal obtained, and • control the power source (108) to apply the determined electrical voltage value to the electroactive polymer matrix material so as to induce a deformation of the active layer (103).

2. The device (100) of claim 1 further comprising an electrically insulating biocompatible layer (104) surrounding the active layer (103).

3. Device (100) according to claim 2 wherein the epicardial surface electrodes (105) are integrated into the electrically insulating biocompatible layer (104).

4. Device (100) according to claim 2 or 3 wherein the electrically insulating biocompatible layer (104) further comprises biosensor mechanoreceptors (106) configured to obtain information on variations in the volume of a heart wall and wherein the value of the electrical voltage is further determined as a function of the information on variations in the volume of a heart wall.

5. Device (100) according to any one of the preceding claims wherein the active layer (103) comprises several sub-layers (107), each sub-layer comprising a respective membrane of electroactive material with polymer matrix.

6. Device (100) according to any one of the preceding claims, wherein, for determining the value of the electrical voltage, the processor is configured to: - identify an event of a cardiac cycle from the electrocardiogram signal obtained, and - determine the value of the electrical voltage from the identified event.

7. The device (100) of claim 6, wherein the identified event is an initiation of a QRS complex of the cardiac cycle.

8. Device (100) according to the preceding claim wherein the processor is further configured to: - before identifying the event, control the energy source (108) to apply a reference value of electrical voltage to the polymer matrix electroactive material, and - upon identifying the event, control the energy source (108) to apply the determined value of the electrical voltage, wherein the determined value of the electrical voltage is strictly lower than the reference value.

9. A device (100) according to any preceding claim wherein the polymer matrix electroactive material is an electroactive polymer.

10. Device (100) according to any one of the preceding claims in which the polymer matrix electroactive material is a ferroelectric and / or electrostrictive polymer.

11. A device (100) according to any preceding claim wherein the polymer matrix electroactive material is a PVDF-TrFE-CFE terpolymer.

12. Method (200) for manufacturing a mechanical circulatory assistance cardiac device (100) according to any one of the preceding claims comprising: - Obtaining (210) cardiac measurements of a patient, - Determining (220) dimensions of the pericardial prosthesis as a function of the cardiac measurements obtained, and - 3D printing (230) of the pericardial prosthesis (101) as a function of the determined dimensions.

13. A manufacturing method (200) according to the preceding claim wherein the patient's cardiac measurements comprise measurements of the patient's cardiac ventricles and the dimensions of the pericardial prosthesis (101) are determined such that the pericardial prosthesis envelops at least half of the patient's cardiac ventricles.

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