Pulsatile flow device for assisting a heart

Abstract

A pulsatile flow device configured to be implanted in a ventricle of a heart, has: an enclosure having an internal volume, the enclosure having a wall side for facing a myocardium of the heart and a ventricle side for being exposed to blood flowing in the ventricle, the ventricle side defined at least partially by a membrane, the membrane movable between a diastolic position and a systolic position, the internal volume greater in the systolic position than in the diastolic position; a frame located within the enclosure, the frame engaging the wall side of the enclosure, the frame exerting a force on the wall side to resist deformation of the wall side of the enclosure; and an actuator operatively connected to the enclosure, the actuator operable to move the membrane between the diastolic position and the systolic position.

Description

PULSATILE FLOW DEVICE FOR ASSISTING A HEARTCROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims benefit from United States provisional application no. 63 / 707,388 filed on October 15, 2024, the entire contents of which are incorporated by reference herein.TECHNICAL FIELD

[0002] The present application relates to medical devices and, more particularly, to ventricular assist devices or like assistance devices.BACKGROUND

[0003] Congestive heart failure (CHF) is a condition that renders the heart unable to fulfill its function properly. CHF reduces the pumping ability of the heart that is required to distribute blood throughout the body. As the heart gets weaker, other organs may also start deteriorating from lack of oxygenated blood supply. Also, several basic activities, such as walking, may become increasingly demanding. In mild to moderate cases, possible treatments include exercising, dieting and medication. Heart transplants remain a preferred treatment to treat such pathology, but the limited availability of healthy donor organs prevents their more frequent use.

[0004] Accordingly, to treat such acute cases, conventional known ventricular assist devices (VAD) are an alternative solution to aid the heart in restoring at least some of its required pumping ability. Some such conventional VADs are capable of producing the required physiological cardiac output, but are associated with adverse events. For instance, some such conventional VADs generate flows having characteristics atypical of physiological flows, which has been associated with gastrointestinal bleeding. Conventional VADs are also still plagued with other adverse events, notably right ventricular failure, stroke and renal dysfunction. Improvements to ventricular assistance are therefore desirable.SUMMARY

[0005] In one aspect, there is provided a pulsatile flow device configured to be implanted in a ventricle of a heart, comprising: an enclosure having an internal volume, the enclosure having a wall side for facing a myocardium of the heart and a ventricle side for being exposed to blood flowing in the ventricle, the ventricle side defined at least partially by a membrane, the membrane movable between a diastolic position and a systolic position, the internal volume greater in thesystolic position than in the diastolic position; a frame located within the enclosure, the frame engaging the wall side of the enclosure, the frame exerting a force on the wall side to resist deformation of the wall side of the enclosure; and an actuator operatively connected to the enclosure, the actuator operable to move the membrane between the diastolic position and the systolic position.

[0006] The pulsatile flow device described above may include any of the following features, in any combinations.

[0007] In some embodiments, the ventricle extends from an apex to a valve along a ventricle axis, the enclosure extending along the ventricle axis from a bottom end at the apex to a top end proximate the valve.

[0008] In some embodiments, the enclosure converges towards the ventricle axis towards the top end.

[0009] In some embodiments, the wall side has a stiffness greater than the membrane.

[0010] In some embodiments, the bottom end is shaped to sealingly engage the apex.

[0011] In some embodiments, the frame is made of a superelastic material.

[0012] In some embodiments, the superelastic material is nickel-titanium.

[0013] In some embodiments, the frame includes an upper frame section and a lower frame section both defining a respective closed loop.

[0014] In some embodiments, the wall side of the enclosure includes an apical portion configured to abut an inner face of an apical of the ventricle.

[0015] In some embodiments, the enclosure includes a sub-cavity fluidly separated from the internal volume, the sub-cavity filled with a fluid.

[0016] In some embodiments, the pulsatile flow device configured to be implanted in a ventricle of a heart includes a conduit fluidly connected to the internal volume, the actuator being a fluid actuator fluidly connected to the internal volume via the conduit, the fluid actuator configured to vary a pression of a fluid inside the internal volume.

[0017] In some embodiments, the fluid actuator is a pneumatic actuator.

[0018] In some embodiments, the enclosure is made of a biocompatible material.

[0019] In some embodiments, the biocompatible material is one or more of polyurethane, silicone, polytetrafluoroethylene, polyester.

[0020] In some embodiments, the pulsatile flow device configured to be implanted in a ventricle of a heart further includes a sensor configured to detect heart pulsation of the heart; and a controller operatively connected to the sensor and to the actuator, the controller having a processing unit operatively connected to a computer-readable medium having instructions stored thereon executable by the processing unit to: receiving a signal from the sensor indicative of a frequency of the heart pulsations of the heart; and cause the actuator to move the membrane between the systolic and diastolic positions at the frequency of the heart pulsations of the heart.

[0021] In some embodiments, the computer-readable medium further has instructions stored thereon to: determine, from the signal received from the sensor, that the frequency of the heart pulsations is irregular; and cause the actuator to move the membrane between the systolic and diastolic positions at a set frequency independent of the heart pulsations.

[0022] In another aspect, there is provided a method for operating a pulsatile flow device having an enclosure defining a membrane operatively connected to an actuator, the method comprising: determining a frequency of heart pulsations of a heart; and assisting the heart by causing an internal volume of the enclosure to vary by moving the membrane with the actuator between a systolic position and a diastolic position at the frequency of the heart pulsations.

[0023] The method for operating a pulsatile flow device described above may include any of the following features, in any combinations.

[0024] In some embodiments, the method further includes determining that the frequency of the heart pulsations is irregular; and assisting the heart by causing the internal volume to vary at a set frequency being independent of the heart pulsations.

[0025] In some embodiments, the actuator is a fluid actuator, the causing of the internal volume of the enclosure to vary by moving the membrane with the actuator includes: using the actuator to periodically vary a pression inside the internal volume to move the membrane between the diastolic position and the systolic position.

[0026] In some embodiments, the method includes : expanding the enclosure to conform to a shape of a ventricle of the heart using a frame embedded within the enclosure, the frame made of a superelastic material.DESCRIPTION OF THE DRAWINGS

[0027] Reference is now made to the accompanying figures in which:

[0028] Fig. 1 is a cutaway view of a human heart;

[0029] Fig. 2A is a cutaway view of the human heart of Fig. 1 with a pulsatile flow device installed in one of the ventricles of the heart and shown in a diastolic configuration;

[0030] Fig. 2B is a cutaway view of the human heart of Fig. 1 with the pulsatile flow device shown in a systolic configuration;

[0031] Fig. 3A is a three dimensional partially transparent view of the pulsatile flow device of Fig. 2A;

[0032] Fig. 3B is a side partially transparent view of the pulsatile flow device of Fig. 2A;

[0033] Fig. 3C is a front view of a frame of the pulsatile flow device of Fig. 3A;

[0034] Figs. 4A is a three dimensional partially transparent view of a pulsatile flow device in accordance with another embodiment;

[0035] Fig. 4B is a side view of the pulsatile flow device of Fig. 4A in a systolic configuration;

[0036] Fig. 4C is a side view of the pulsatile flow device of Fig. 4A in a diastolic configuration;

[0037] Fig. 4D is a front view illustrating a frame of the pulsatile flow device of Fig. 4A;

[0038] Fig. 5A is a three dimensional partially transparent view of a pulsatile flow device in accordance with another embodiment;

[0039] Fig. 5B is a side view of the pulsatile flow device of Fig. 5A in a systolic configuration;

[0040] Fig. 5C is a side view of the pulsatile flow device of Fig. 5A in a diastolic configuration;

[0041] Fig. 5D is a front view illustrating a frame of the pulsatile flow device of Fig. 5A;

[0042] Fig. 6 is a cutaway view of a patient having the pulsatile flow device of any one of Figs. 3A, 4A, 5A ;

[0043] Fig. 7 A is a graph illustrating a variation of an aortic pressure as a function of time;

[0044] Fig. 7B is a graph illustrating a variation of a left ventricular outflow tract flow rate as a function of time;

[0045] Fig. 8 is a flowchart illustrating steps of a method for operating a pulsatile flow device; and

[0046] Fig. 9 is a schematic representation of a controller for the pulsatile flow device.DETAILED DESCRIPTIONIntroduction

[0047] Referring to the drawings and more particularly to Fig. 1 , part of a heart, being in this case a human heart, is schematically represented at 1. A myocardium of the heart 1 is shown at 2, and delimits ventricular cavities. Hence, the left ventricular cavities and the part of the myocardium 2 surrounding said cavities are commonly known as the left ventricle 3A and the right ventricle 3B of the heart 1 . The left ventricle 3A is in fluid connection with a left atrium 4A through mitral valve 4, for blood to reach the left ventricle 3A. The left ventricle 3A is also in fluid communication with an aorta 5A through an aortic valve 5, through which blood exits the left ventricle 3A. The right ventricle 3B is in fluid connection with a right atrium 4B through tricuspid valve 4C. The right ventricle 3B is also in fluid communication with a pulmonary artery 5B through a pulmonary valve 6. In congestive heart failure (CHF), the volume of blood exiting the left ventricle 3A and / or the right ventricle 3B is insufficient, and may be because of deficient function of the myocardium 2, for example.

[0048] Heart failure is a disease that lowers the functionality of the heart. During the endstage of the disease, the quality of life for the patients reduces drastically; simple activities such as walking can be tiresome. The treatment of heart disease is preferably done with medications, but the efficacy of that tends to eventually plateau. The gold standard for treating advanced heart failure is with a heart transplant; patients receiving a heart transplant tend to live on average twelve years following the operation. Unfortunately, the shortage of heart donors compared tothose who could benefit from one makes the selection criteria incredibly selective. For instance, older patients are not eligible for heart transplants as the priority goes to those of younger age.

[0049] To offer an alternative option for patients that are not eligible for heart transplants, or for those awaiting a heart transplant, but who are at risk of medical emergencies while waiting, ventricular assist devices have been developed. Ventricular assist devices are typically classified as either pulsatile flow, mimicking the natural pulsatility of the heart, or continuous flow, a flow with no pulse. A patient with an older generation continuous flow device would have no pulse if the heart was to stop beating, but blood would still be circulated through the body. Modern continuous flow devices have a feature to periodically drop the pump RPM and then rapidly increase it to generate some pulsatility, increasing washout. In other words, it may be desirable to have pulsatility to mitigate blood stagnation. Pulsatile flow devices have been historically bulky and unreliable; as a result, continuous flow devices have become the popular ventricle assist device of choice.

[0050] Continuous flow devices come with the disadvantage that they typically require a median sternotomy surgery (e.g., sternum has to be opened) to be implanted. Minimally invasive approaches have seen an increase in popularity due to the small incision size required in transcatheter aortic valves compared to the surgical ones. A smaller incision size improves a patient’s recovery time, reduces the chance of infections, and improves patient’s overall survivability. Minimally invasive surgery has been done with modern continuous flow devices, but their size makes them unsuitable for a percutaneous delivery, which would be desirable.Pulsatile flow device

[0051] Referring to Figs. 2A and 2B, a pulsatile flow device is shown at 10. The device 10 is configured to be received within one of the ventricles of the heart 1. In some embodiments, each of the ventricles may receive a respective device. In the embodiment shown, the device 10 is shaped to fit into the left ventricle 3A although its shape may be modified to fit into the right ventricle 3B. The device 10 has a shape that substantially matches that of the left ventricle 3A and is configured to expand and contract between a diastolic configuration depicted in Fig. 2A and a systolic configuration depicted in Fig. 2B. Changes in the shape of the device 10 between these two configurations contributes in helping the heart 1 pumping a required flow of blood.

[0052] The device 10 may have the potential to be implanted in a minimally invasive way through a transapical approach. In other words, the device 10 may be inserted via a left apex 7Aor a right apex 7B (Fig. 1) of the left and right ventricles 3A, 3B. More specifically, the device 10 may be collapsed and contained within a catheter for insertion into the left ventricle 3A. Once in place, the catheter may be removed to deploy the device 10. As the technology develops, a less invasive way may be explored. The device pumps blood via an actuating membrane. The device also has a frame, which may be made of a nickel-titanium alloy (e.g., nitinol™), a copper- aluminum-nickel alloy, a copper-zinc-aluminum alloy, a iron-manganese-silicon alloy, a titaniumniobium alloy, and a titanium-tantalum alloy, to name a few. Any material able to exhibit superelastic properties may be contemplated. The material selected for the frame has superelastic properties while imparting some rigidity to the frame. A superelastic material is a material that exhibits an ability to recover large strains through a reversible, stress-induced phase transformation between two solid phase (e.g., austenite, martensite), rather than through conventional elastic deformation. For instance, for a nickel-titanium alloy, when stretched, the cubic (austenite) lattice transforms to a monoclinic (martensite) lattice and on unloading, the reverse transformation occurs, and the material returns to its original shape. Put differently, a superelastic material is one that behaves “elastically” over very large strains by transforming its crystal structure under stress and reverting upon unloading — rather than merely stretching its atomic bonds. One way to characterize superelastic material is with a property called “transformation strain”, which is defined as the recoverable strain associated with the phase transformation. It characterizes how much deformation is recoverable through phase change. Typical value of transformation strain are from 6% to 8% for a nickel-titanium alloy, from 4% to 6% for a copper-aluminum-nickel alloy, and from 2% to 4% for a iron-manganese-silicon alloy.

[0053] The device 10 may be made of polyurethane, but a combination with other materials, such as pericardial tissue, is being considered. Silicone or any suitable biocompatible materials may be used such as ePTFE (polytetrafluoroethylene), Dacron™ (polyester), etc. In this disclosure, the expression “biocompatible” implies the material may also be “blood compatible”. The device 10 is placed in the ventricle. To prevent migration of the device and to prevent any leaking at the apex 7A, a contained liquid, gas or gel is being considered as will be explained below.

[0054] Referring more particularly to Figs. 3A to 3C, the device 10 includes an enclosure 20 defining an internal volume V for receiving a fluid as will be explained below. Although the device 10 is designed to be received in the left ventricle 3A of the heart 1 , the device 10 may be adapted to fit at any suitable location in the heart (e.g., right ventricle or both ventricles). The enclosure 20 has a wall side 20A for facing the myocardium 2 of the heart 1 and a ventricle side 20B for being exposed to blood flowing in the left ventricle 3A. The wall side 20A is configured to be in abutmentagainst the myocardium 2 whereas the ventricle side 20B is configured to be exposed to the blood, that is, exposed to a volume of the left ventricle 3A. The wall side 20A may have a shape that substantially matches that of the myocardium 2 in the left ventricle 3A.

[0055] In the embodiment shown, the ventricle side 20B is defined at least partially by a membrane 21. The membrane 21 corresponds to the moving part of the device 10 and moves between two positions each associated with a respective one of the diastolic and systolic configurations of the device 10. Thus, the membrane 21 is movable between a diastolic position shown in Fig. 2A and a systolic position shown in Fig. 2B. The membrane 21 is expanded from the side to avoid interfering with papillary muscles in the ventricle. The membrane 21 may be manufactured in any of the diastolic or systolic shape. If manufactured in the systolic shape, the device 10 may be deflated prior to its insertion in a patient. A pump may be used forthat purpose as further described below. The membrane 21 can also be designed in different shapes as the one illustrated. The internal volume V varies with movements of the membrane 21. The internal volume V is greater in the systolic position than in the diastolic position. Movements of the membrane 21 alters an inner volume of the left ventricle 3A able to receive blood. Thus, movements of the membrane 21 between those two positions create a pumping effect to circulate the blood in and out of the left ventricle 3A. In the embodiment shown, the wall side 20A of the enclosure 20 has a stiffness greater than the membrane 21 . The enclosure 20 and the membrane 21 may be manufactured of a biocompatible material, such as silicone (i.e., silicone rubber) or any other suitable biocompatible material as described above. In some embodiments, the thickness of the membrane 21 is less than that of a remainder of the enclosure 20 to permit the movement of the membrane 21 between the two positions. Alternatively, or in combination, the material of the membrane 21 may be less stiff, even for the same thickness, than that of the remainder of the enclosure 20 to permit its moving between the two positions.

[0056] As shown in Fig. 1 , the left ventricle 3A extends from the apex 7 A to the aortic valve 5 along a ventricle axis A1. As shown in Figs. 3A-3B, the enclosure 20 also extends along the ventricle axis A1 from a bottom end 20C at the apex 7A to a top end 20D proximate the aortic valve 5. In the embodiment shown, the enclosure 20 converges towards the ventricle axis A1 and towards the top end 20D. In other words, a cross-sectional area of the enclosure 20, taken along a plane normal to the ventricle axis A1 , decreases towards the top end 20D. This shape may be used to better conform to the heart 1 . However, other shapes are contemplated.

[0057] Referring more particularly to Fig. 3C, the device 10 includes a frame 30 located within the enclosure 20. The frame 30 is depicted in Fig. 3C in the systolic position, that is, in an expanded configuration. The frame 30 engages the wall side 20A of the enclosure 20 and exerts a force on the wall side 20A to resist deformation of the wall side 20A of the enclosure 20. The frame 30 may be made of nitinol™ (i.e., nickel-titanium) or any other suitable material as described herein above. Any superelastic material may be used. The frame 30 is used to constrain the device 10 into a certain shape and prevent it from collapsing during the diastolic phase. The frame 30 may be a wire frame. The frame 30 is collapsible in a collapsed configuration for its insertion into the heart 1 via an artery. The collapsed configuration is different than the diastolic position of the device 10. Indeed, the frame 30 is in the expanded configuration in both of the systolic and diastolic positions, but is in the collapsed configuration when being inserted in the heart 1 .

[0058] In the depicted embodiment, the frame 30 includes two frame sections, namely an upper frame section 30A and a lower frame section 30B being separated from each other. They may alternatively be connected to each other. In this embodiment, the two sections are connected via the enclosure 20, but not directly connected to each other. They may alternatively be directly connected to each other. The two frame sections 30A, 30B each define a closed loop, but of different shape. The upper frame section 30A has a substantially triangular shape in that in includes two longitudinal frame members 31 each extending away from the lower frame section 30B and towards each other towards the top end 20D of the enclosure 20. The two longitudinal frame members 31 are interconnected via transversal frame members 32 that extend substantially transversally to the longitudinal frame members 31 . In some embodiments, the transversal frame members 32 may be arcuate, but other shapes are contemplated.

[0059] The lower frame section 30B is shaped to mate with the bottom end 20C of the enclosure 20. To this end, the lower frame section 30B defines two wing-shaped members 33 that impart a U-shape to the lower frame section 30B. The two wing-shaped members 33 are interconnected by a rear transversal member 34 and a front transversal member 35. The rear transversal member 34 abuts the wall side 20A of the enclosure 20 whereas the front transversal member 35 is closer to the ventricle side 20B of the enclosure 20. In the depicted embodiment, the rear transversal member 34 is arcuate whereas the front transversal member 35 defines a sinusoidal shape including two apexes 36 spaced apart by a valley 37. The different members of the upper frame section 30A and the lower frame section 30B are disposed such as to allow the frame 30 to be collapsed to allow the insertion of the device 10 into the heart 1. To this end, thetwo longitudinal frame members 31 of the upper frame section 30A may move towards each other via a bending of the transversal frame members 32. Similarly, the two wing-shaped members 33 of the lower frame section 30B may move towards each other via bending of the rear and front transversal members 34, 35. Understandably, other shapes are contemplated as will be discussed below.

[0060] To compress the frame 30 to the collapsed configuration, the longitudinal members 31 and the wing-shaped members 33 are folded towards each other and towards the ventricle axis A1 . Hence, in the collapsed configuration of the frame 30, a cross-sectional area of the device 10 taken across the ventricle axis A1 is reduced to be smaller than that of an artery via which the device 10 is inserted into the heart 1 .

[0061] Referring back to Figs. 3A-3B, in the embodiment shown, the wall side 20A of the enclosure 20 includes an apical portion 20E at the bottom end 20C. The apical portion 20E is shaped to abut an inner face of the apex 7 A of the left ventricle 7. The apical portion 20E may define a sealing engagement with the inner face of the apex 7A to prevent leakage via the apex 7. The apical portion 20E encloses a chamber 22, also referred to as a sub-cavity or sub-volume, located within the inner volume V of the enclosure 20. The chamber 22 is fluidly separated from the internal volume V. The chamber 22 is fluidly connected to a filling port 23 to inject a fluid, such as a gas, a liquid, a gel, and so on into the chamber 22. The filling port 23 is sealed shut after the chamber 22 is filled with the fluid. The chamber 22 is used to expand the apical portion 20E of the enclosure 20 until it sealingly engages the wall of the left ventricle 3A to prevent leakage therefrom and to constrain the device 10 to prevent any migration. The chamber 22 is typically empty during an installation procedure of the device 10, that is, when the frame 30 is in the collapsed configuration. Once the device 10 is located in the ventricle, the chamber 22 may be filled with the fluid, such as a saline solution or any other suitable fluid, to expand in a suitable way to engage the myocardium 2. The external wall of chamber 22 may also be coated with a biocompatible sticky coating to improve the fixture of the device to the ventricular wall. Such a coating may include, for instance, polydimethylsiloxane, silicone pressure-sensitive adhesive, polyacrylamide hydrogels, and so on to name a few.

[0062] The internal volume V of the enclosure 20 is fluidly connected to an inlet conduit 24. The inlet conduit 24 is fluidly connected to an actuator 40 that is operable to move the membrane 21 between the diastolic and systolic positions. In the depicted embodiment, the actuator 40 is a pneumatic actuator operable to inject and withdraw a volume of a gas to and from the internalvolume V of the enclosure 20. The gas may be air or any suitable gas (e.g., helium). Alternatively, the actuator40 is a hydraulic actuator configured to inject and withdraw a volume of a liquid, such as water or any other suitable liquid. The actuator 40 may alternatively be located into the internal volume V and engaged to the membrane 21 to cause its moving between the diastolic and systolic positions. In other words, the actuator 40 may be a magnetic actuator, such as a solenoid or any suitable actuator. In the embodiment shown, the actuator 40 is external to the heart 1 and to the patient. The actuator 40 may be internal in an alternate embodiment. Stated otherwise, the actuator 40 may cause the movement of the membrane 21 between the systolic and diastolic configurations using a fluid that is injected and withdrawn from the internal volume V, or may be a mechanical actuator that engages the membrane 21 to cause its movements.

[0063] In the case where the actuator 40 is a pneumatic actuator, such as a pulsatile pump, it is configured to vary a pressure of a gas inside the internal volume V. In the case of a hydraulic actuator, it is configured to inject and withdraw a liquid to and from the internal volume V. For a mechanical actuator, it may directly engage the membrane 21 to move it between its two opposed positions.

[0064] In the embodiment shown, the actuator 40 is operatively connected to a controller 50. A sensor 51 may be operatively connected to the controller 50 and configured to detect residual heart pulsations. The sensor 51 may be a pressure sensor, or a ECG sensor. The controller 50 may be configured to receive a signal from the sensor 51 indicative of the heart pulsations, and indicative of a frequency of heart beats (e.g., beats per minute); and cause the actuator 40 to move the membrane 21 between the systolic and diastolic positions at a frequency that matches the heart pulsations of the heart 1 . The device may be configured to match the heart beat for every second or third beat for weaning purposes. Thus, the frequency of the movements of the membrane 21 may be adjusted dynamically as a function of the heart beats of the patient. For instance, if the patient performs an activity that elevates his or her heart rate, the device 10 may increase its frequency to continue in assisting the heart 1 in pumping the blood regardless of the heart beat. In other words, the flow rate generated by the device 10 in the ventricle may be varied as needed.

[0065] It will be appreciated that the disclosed devices need not match the frequency of the heart rate since, in the case the heart has no pulse or when an arrhythmia is detected, the devices may take overthe pumping function of the heart 1 . The heart 1 may be equipped with two of those devices, one in each ventricles, to work in tandem or alternatively activated (i.e., the device in the left ventricle may be operated in systole and the device in the right ventricle may be operated indiastole). When two devices are used in an alternating configuration, at least one of the ventricles may be dyssynchronous with the heart rate. In other words, the sensor 51 may detect arrhythmia and, upon the detecting of arrhythmia, the controller 50 may cause the actuator 40 to impose a selected heart beat independently of the heart beat of the heart 1.

[0066] Referring now to Figs. 4A to 4D, a pulsatile flow device in accordance with another embodiment is shown at 1 10. For the sake of conciseness, only features differing from the device 10 described above are described below.

[0067] In the embodiment shown, the frame 130 includes two frame sections, namely a first frame section 130A and a second frame section 130B. Both frame sections extend along a longitudinal direction between the bottom end 20C and the top end 20D of the enclosure 20. A width of the first frame section 130A, along a direction transverse to the longitudinal direction, is less than that of the second frame section 130B. A length of the first frame section 130A, taken along the longitudinal direction, is greaterthan that of the second frame section 130B. Each frame sections include two longitudinal frame members 131 interconnected proximate the top end 20D of the enclosure 20 via a respective transversal frame member 132. The inner-most longitudinal frame members are connected together via an inner transversal frame member 133. The outermost longitudinal frame members are connected together via an outer transversal frame member 134. As shown, the inner most longitudinal member 131 of the first frame section 130A defines a concave shape adapted to mate with the inner most longitudinal member 131 of the second frame section 130B. Such a configuration may allow the frame 130 to be collapsed to the diastolic configuration when the pulsatile flow device 1 10 is inserted in the heart 1 while minimizing interaction between the different frame members. This shape of the frame 130 may allow its collapsing in the collapsed configuration while minimizing interaction between its different members while ensuring a proper expansion of the frame in the expanded configuration once the device is received in the heart.

[0068] The geometry of this frame was made such that the shorter section would deform into the curve of the enclosure. The geometry of this frame 130 may also accommodate the use of a thicker wire (thicker wires are harder to bend into shape), providing more rigidity to the frame. Lastly, the frame for this embodiment is a single monolithic piece and defines a closed loop, which may provide more support to the lateral section (i.e., part that is along the septum) since it is coupled with the transverse section (i.e., lower section at the apex).

[0069] Referring now to Figs. 5A to 5D, a pulsatile flow device in accordance with yet another embodiment is shown at 210. For the sake of conciseness, only features differing from the device 10 described above are described below.

[0070] In the embodiment shown, the enclosure 220 has a cup shape extending from a bottom end 220C to a top end 220D. The enclosure 220 is closed at the bottom end 220C but for an aperture sized to receive the filling port 23 and the inlet conduit 24. The enclosure 220 is opened at the top end 220D and defines a side opening 220F at the ventricle side 220B. The side opening 220F is substantially U-shaped and extend from the top end 220D towards the bottom end 220C although other shapes are contemplated. The bottom of the side opening 220F is located approximately at midway between the top end 220D and the bottom end 220C. The top end 220D being opened and the side opening 220F cooperate to allow access to an inner volume of the enclosure 220 that receives the membrane 221 . The membrane 221 expands and contracts as shown in Figs. 5B and 5C between the systolic (Fig. 5B) and diastolic (Fig. 5C) configurations. The membrane 221 expands towards the side opening 220F to push blood out of the inner volume and contracts away from the side opening 220F to draw blood into the inner volume to create the pumping action.

[0071] As shown in Fig. 5D, the frame 230 defines a plurality of loops 230B distributed around a longitudinal axis of the device 210; the longitudinal axis extending between the bottom end 220C and the top end 220D of the enclosure 220. The frame 230 defines a frame opening 230A in register with the side opening 220F of the enclosure 220. Each of the loops 230B includes two longitudinal frame members 231 interconnected by a top transversal frame member 232. Each loops 230B is secured to an adjacent loop via a bottom transversal frame member 233. The frame 230 at least partially encloses the membrane 221 .

[0072] In the embodiment shown, the loops 230B include long loops and short loops having a length less than that of the long loops relative to the longitudinal axis. The short loops are circumferentially aligned with the side opening 220F of the enclosure 220 such that the side opening 220F is devoid of the frame 230.

[0073] Having a cup shape frame may provide the advantage of having a radial force applied along the circumference of the ventricle, which may improve the anchoring of the device. The increased surface area may also reduce the likelihood of having some blood leaking through the apex because of a better seal. The short loops of the frame are made in such a way that they may not interfere with the papillary muscles.

[0074] Referring to Fig. 6, an exemplary alternate installation of any of the pulsatile flow devices 10, 110, 210 described above is illustrated. The device has been implanted using a trans arterial retrograde approach via the common femoral artery. The device is placed in an inverted fashion through the aortic valve and may or may not be connected with an intra-aortic pump 61 , which may be an intra-aortic counter pulsation balloon 61 , to further enhance flow. However, the pulsatile flow device may work without the intra-aortic counter pulsation balloon 61. In the embodiment shown, the device is inserted in the ventricle via the aortic valve as opposed to via the apex of the ventricle. In such an embodiment, the filling port 23 and inlet conduit 24 of the devices are located at the top end of the device, rather than at the bottom end. A drive line 60 is connected to the device 10 via an artery that reaches the aortic valve. The intra-aortic pump 61 , which may be omitted in some embodiments, is fluidly connected to the device 10 and drive line 60. Pump 61 may be included to enhance flow. The drive line 60 would therefore also operatively connect the pump 61 and the device 10 to the controller 50. In such an embodiment, the pump 61 is located inside the patient in an extracardiac position, that is, inside the aorta in this example. Additionally, the device may also be inserted through a transseptal approach, passing through the mitral valve into the left ventricle. In this latter configuration, there may be no counter pulsation balloon.

[0075] In this embodiment, the device 10 and the pump 61 conjointly enclose a given volume of a fluid (e.g., gas). The fluid is exchanged between the pump 61 and the device 10 to move the membrane 21 of the device 10 between the systolic and diastolic positions in a complementary alternating fashion. In some embodiments, the system depicted in Fig. 6 also includes the actuator 40, which is external to the patient. The controller 50 is operatively connected to the actuator 40. The controller 50 may cause the actuator to inject gas into either the intra-aortic balloon 61 or the device 10. Various methods may be used to achieve this. For example, a unidirectional valve may be used, with the controller 50 operatively connected to the valve to reverse its directionality using a membrane or other suitable means to direct the gas to either the balloon 61 or the device 10. In another embodiment, two parallel lines may be used to selectively inflate the balloon 61 or the device 10. A switching means may be used so that only one of the balloon orthe device is inflated at a time, allowing for alternating inflation. In yet another embodiment, the actuator may be used to deflate the balloon while injecting the withdrawn gas into the device, and vice versa when it is desired to inflate the balloon.

[0076] Additionally, it is also possible to configure the device to inflate only in the ventricle or the aorta according to changing patient conditions or to allow weaning to device support.

[0077] Referring to Figs. 7A and 7B, results of the pressure (Fig. 7A) and flow rate (Fig. 7B) of the device 10 as a function of time are shown. For Fig. 7A, the pressure is measured downstream of the aortic valve 5. For Fig. 7B, the flow rate is measured at the left ventricle outflow tract and upstream of the aortic valve 5. The pressure measurements and flow rate are indicative that a pulsatile flow with a physiological characteristic can be generated with this device.

[0078] The pulsatile flow devices described above may be inserted in both of the right ventricle, either via the apex or via the tricuspid valve, and the left ventricle, either via the apex, via the aortic valve, or via a transseptal approach using the mitral valve.

[0079] Referring now to Fig. 8, a method for operating the pulsatile flow device 10, 110, 210 is shown at 800. The method 800 includes determining (e.g., measuring) a frequency of heart pulsations of the heart 1 at 802; and assisting the heart by causing the internal volume V of the enclosure 20 to vary by moving the membrane 21 with the actuator 40 between the systolic position and the diastolic position at the frequency of the heart pulsations at 804, i.e., varying the internal volume V of the enclosure 20 by moving the membrane 21 with the actuator 40.

[0080] In some embodiments, the method 800 includes determining that the frequency of the heart pulsations is irregular; and assisting the heart by causing (i.e., varying)the internal volume V to vary at a set frequency being independent of the heart pulsations. In other words, when it is determined that a heart 1 is irregular, the controller 50 may decide to ignore the heart beats of the heart 1 and impose its own independent heart beat 1.

[0081] As previously described, the actuator 40 may be a fluid actuator. The causing of the internal volume V of the enclosure 20 to vary by moving the membrane 21 with the actuator 40 may include: using the actuator 40 to periodically vary a pression inside the internal volume V to move the membrane 21 between the diastolic position and the systolic position.

[0082] In some embodiments, the method 800 includes expanding the enclosure 20 to conform to a shape of a ventricle of the heart 1 using the frame 30, 130, 230 embedded within the enclosure. The frame may be made of a superelastic material.Conclusions

[0083] Accordingly, there is also illustrated at 10, 110, 210 ventricular assist implant systems, implanted in the heart 1 in accordance with embodiments of the present disclosure. Theventricular assistance implant systems 10, 110, 210 are tasked with assisting the heart 1 in pumping blood into and out of one or both of the ventricles 3A and / or 3B.

[0084] The disclosed device may be safe, durable, may improve quality of life by pumping the required cardiac output, and may be transplanted via a mini-invasive procedure at a lower cost per device and transplantation than existing solutions. The devices 10, 110, 210 may permit to prolong life expectancy, reduce recovery time, decrease hospital stay, enable a return to an active life, an d accelerate the return to the active life.

[0085] With reference to Fig. 9, an example of a computing device 900 is illustrated. For simplicity only one computing device 900 is shown but the system may include more computing devices 900 operable to exchange data. The computing devices 900 may be the same or different types of devices. The controller 50 may be implemented with one or more computing devices 900.

[0086] The computing device 900 comprises a processing unit 902 and a memory 904 which has stored therein computer-executable instructions 906. The processing unit 902 may comprise any suitable devices configured to implement the method such that instructions 906, when executed by the computing device 900 or other programmable apparatus, may cause the functions / acts / steps performed as part of the method as described herein to be executed. The processing unit 902 may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.

[0087] The memory 904 may comprise any suitable known or other machine-readable storage medium. The memory 904 may comprise non-transitory computer readable storage medium, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory 904 may include a suitable combination of any type of computer memory that is located either internally or externally to device, for example random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magnetooptical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. Memory 904 may comprise any storage means (e.g., devices) suitable for retrievably storing machine-readable instructions 906 executable by processing unit 902.

[0088] The methods and systems described herein may be implemented in a high level procedural or object oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of a computer system, for example the computing device 900. Alternatively, the methods and systems described herein may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems described herein may be stored on a storage media or a device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or special-purpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. Embodiments of the methods and systems described herein may also be considered to be implemented by way of a non-transitory computer-readable storage medium having a computer program stored thereon. The computer program may comprise computer-readable instructions which cause a computer, or more specifically the processing unit 902 of the computing device 900, to operate in a specific and predefined manner to perform the functions described herein, for example those described in the method.

[0089] Computer-executable instructions may be in many forms, including program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0090] The embodiments described herein are implemented by physical computer hardware, including computing devices, servers, receivers, transmitters, processors, memory, displays, and networks. The embodiments described herein provide useful physical machines and particularly configured computer hardware arrangements. The embodiments described herein are directed to electronic machines and methods implemented by electronic machines adapted for processing and transforming electromagnetic signals which represent various types of information. The embodiments described herein pervasively and integrally relate to machines, and their uses; and the embodiments described herein have no meaning or practical applicability outside their use with computer hardware, machines, and various hardware components. Substituting the physical hardware particularly configured to implement various acts for non-physical hardware, using mental steps for example, may substantially affect the way the embodiments work. Such computer hardware limitations are clearly essential elements of the embodiments describedherein, and they cannot be omitted or substituted for mental means without having a material effect on the operation and structure of the embodiments described herein. The computer hardware is essential to implement the various embodiments described herein and is not merely used to perform steps expeditiously and in an efficient manner.

[0091] The term “connected” or "coupled to" may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0092] The technical solution of embodiments may be in the form of a software product. The software product may be stored in a non-volatile or non-transitory storage medium, which can be a compact disk read-only memory (CD-ROM), a USB flash disk, or a removable hard disk. The software product includes a number of instructions that enable a computer device (personal computer, server, or network device) to execute the methods provided by the embodiments.

[0093] It is noted that various connections are set forth between elements in the preceding description and in the drawings. It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities. The term “connected” or "coupled to" may therefore include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0094] It is further noted that various method or process steps for embodiments of the present disclosure are described in the preceding description and drawings. The description may present the method and / or process steps as a particular sequence. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the description should not be construed as a limitation.

[0095] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process,method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0096] While various aspects of the present disclosure have been disclosed, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the present disclosure. For example, the present disclosure as described herein includes several aspects and embodiments that include particular features. Although these particular features may be described individually, it is within the scope of the present disclosure that some or all of these features may be combined with any one of the aspects and remain within the scope of the present disclosure. References to “various embodiments,” “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. The use of the indefinite article “a” as used herein with reference to a particular element is intended to encompass “one or more” such elements, and similarly the use of the definite article “the” in reference to a particular element is not intended to exclude the possibility that multiple of such elements may be present.

[0097] The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. Yet, further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.

Claims

CLAIMS1 . A pulsatile flow device configured to be implanted in a ventricle of a heart, comprising: an enclosure having an internal volume, the enclosure having a wall side for facing a myocardium of the heart and a ventricle side for being exposed to blood flowing in the ventricle, the ventricle side defined at least partially by a membrane, the membrane movable between a diastolic position and a systolic position, the internal volume greater in the systolic position than in the diastolic position; a frame located within the enclosure, the frame engaging the wall side of the enclosure, the frame exerting a force on the wall side to resist deformation of the wall side of the enclosure; and an actuator operatively connected to the enclosure, the actuator operable to move the membrane between the diastolic position and the systolic position.

2. The pulsatile flow device of claim 1 , wherein the ventricle extends from an apex to a valve along a ventricle axis, the enclosure extending along the ventricle axis from a bottom end at the apex to a top end proximate the valve.

3. The pulsatile flow device of claim 2, wherein the enclosure converges towards the ventricle axis towards the top end.

4. The pulsatile flow device of claim 1 , wherein the wall side has a stiffness greater than the membrane.

5. The pulsatile flow device of claim 2, wherein the bottom end is shaped to sealingly engage the apex.

6. The pulsatile flow device of claim 1 , wherein the frame is made of a superelastic material.

7. The pulsatile flow device of claim 6, wherein the superelastic material is nickel-titanium.

8. The pulsatile flow device of claim 1 , wherein the frame includes an upper frame section and a lower frame section both defining a respective closed loop.

9. The pulsatile flow device of claim 1 , wherein the wall side of the enclosure includes an apical portion configured to abut an inner face of an apical of the ventricle.

10. The pulsatile flow device of claim 9, wherein the enclosure includes a sub-cavity fluidly separated from the internal volume, the sub-cavity filled with a fluid.1 1 . The pulsatile flow device of claim 1 , comprising a conduit fluidly connected to the internal volume, the actuator being a fluid actuator fluidly connected to the internal volume via the conduit, the fluid actuator configured to vary a pression of a fluid inside the internal volume.

12. The pulsatile flow device of claim 11 , wherein the fluid actuator is a pneumatic actuator.

13. The pulsatile flow device of claim 1 , wherein the enclosure is made of a biocompatible material.

14. The pulsatile flow device of claim 13, wherein the biocompatible material is one or more of polyurethane, silicone, polytetrafluoroethylene, polyester.

15. The pulsatile flow device of claim 1 , further comprising: a sensor configured to detect heart pulsation of the heart; and a controller operatively connected to the sensor and to the actuator, the controller having a processing unit operatively connected to a computer-readable medium having instructions stored thereon executable by the processing unit to: receiving a signal from the sensor indicative of a frequency of the heart pulsations of the heart; and cause the actuator to move the membrane between the systolic and diastolic positions at the frequency of the heart pulsations of the heart.

16. The pulsatile flow device of claim 15, wherein the computer-readable medium further has instructions stored thereon to: determine, from the signal received from the sensor, that the frequency of the heart pulsations is irregular; and cause the actuator to move the membrane between the systolic and diastolic positions at a set frequency independent of the heart pulsations.

17. A method for operating a pulsatile flow device having an enclosure defining a membrane operatively connected to an actuator, the method comprising:determining a frequency of heart pulsations of a heart; and assisting the heart by causing an internal volume of the enclosure to vary by moving the membrane with the actuator between a systolic position and a diastolic position at the frequency of the heart pulsations.

18. The method of claim 17, further comprising: determining that the frequency of the heart pulsations is irregular; and assisting the heart by causing the internal volume to vary at a set frequency being independent of the heart pulsations.

19. The method of claim 17, wherein the actuator is a fluid actuator, the causing of the internal volume of the enclosure to vary by moving the membrane with the actuator includes: using the actuator to periodically vary a pression inside the internal volume to move the membrane between the diastolic position and the systolic position.

20. The method of claim 17, comprising: expanding the enclosure to conform to a shape of a ventricle of the heart using a frame embedded within the enclosure, the frame made of a superelastic material.

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