Heart assist device

Abstract

A cardiac assist device (1) having a cup-shaped element (2), an inner spherical element (5), and a tubular element (6). The cup-shaped element (2) has a cup wall (2a), one or more inflow openings (3), and an outflow element (4) having a small hole (4a). The inner spherical element (5) is positioned inside the cup-shaped element (2) and is not connected to the outflow element (4). The tubular element (6) is arranged to inflate and deflate the inner spherical element (5) during operation. During operation in a pumping mode, a combination of a first material, the size of the cup wall (2a), and the size of the outflow element (4) provides a restraining force on the cup-shaped element (2) to counteract the outward force of the inner spherical element (5).

Description

Technical Field

[0001] This application relates to a cardiac assist device, which includes a cup-shaped element, an internal ball-shaped element, and a tubular element. Background Technology

[0002] US Patent Publication US-B-5,169,378 describes an intraventricular assist pump. The pump includes a body pump or external chamber with double-lumen walls, which is expandable and has variable rigidity, and an inflatable but stationary external cup. In operation, the (inflatable) external chamber is rigid and stationary during operation. A transvalvular segment or flexible neck of the pump is provided, which makes it conform to the "open" or "closed" condition or position of the aortic or pulmonary valve and avoids the need for valve use when draining blood from the pump. An internal bulb with progressively thickened walls is provided, resulting in a sequential rhythm of inflation and deflation.

[0003] International Patent Publication WO2015 / 131879 discloses a catheter device for directionally conducting fluids, particularly bodily fluids. The catheter device is described as being positioned in the aorta and comprising a housing having an interior and including a frame, wherein the housing includes at least three openings and is designed as a fluid line in the region between a first and a second opening, and wherein a check valve is disposed at the second opening. During operation, the housing is in an inflated state and is fully rigid (e.g., implemented as a stent). The check valve includes a diaphragm that is at least partially fixed to the housing such that the second opening can be completely covered by the diaphragm.

[0004] International patent application WO2020 / 022905 discloses a cardiac support device with a chamber body for circulatory assistance, the chamber body having a first opening. A dynamic volume body is provided for increasing and decreasing the internal volume of the chamber body. A directional flow structure is used for the direction of blood flow during operation. Summary of the Invention

[0005] This application seeks to provide an improved cardiac assist device to allow for proper and effective operation.

[0006] According to the present invention, a cardiac assist device as defined above is provided, wherein the cardiac assist device includes a cup-shaped element having a cup wall comprising a first material and defining an internal cup volume, one or more inflow openings disposed in the cup wall to allow a first fluid (such as blood) to flow into the cup-shaped element during operation, and an outflow element fluidly connected to the cup wall and having an orifice for draining the first fluid during operation. An internal spherical element exists having a spherical wall comprising a second material and defining an internal spherical volume, the internal spherical element being positioned inside the cup-shaped element and not connected to the outflow element. A tubular element is provided fluidly connected to the internal spherical element for inflating and deflating the internal spherical element during operation, thereby generating a pumping operation mode and a filling operation mode, respectively. During operation in the pumping operation mode, a combination of the first material, the dimensions of the cup wall, and the dimensions of the outflow element provides a restraining force on the cup-shaped element to counteract the outward force of the internal spherical element.

[0007] The implementation of this application allows for very good and effective operation of a cardiac assist device with a very limited number of components.

[0008] Brief description of the attached figures

[0009] The invention will now be discussed in more detail with reference to the accompanying drawings, wherein,

[0010] Figure 1A and Figure 1B A cross-sectional view of a first embodiment of the present invention is shown;

[0011] Figures 2A to 2D A cross-sectional view of a second embodiment of the present invention is shown;

[0012] Figure 3A A perspective view of a third embodiment of the present invention is shown, and Figure 3B Showing Figure 3A The cross-sectional view of the skeleton structure of the embodiment shown in the figure is an alternative embodiment.

[0013] Figure 4 A side view of another embodiment of the cardiac assist device according to the present invention is shown.

[0014] Figure 5 Showing along Figure 4 A cross-sectional view of line VV in the middle.

[0015] Figure 6 Showing along Figure 4 Cross-sectional view of line VI-VI in the middle.

[0016] Figure 7A and Figure 7B Showing along Figure 4Cross-sectional views of line VII-VII in two operating states.

[0017] Figures 8A to 8C A perspective view showing (partial) of another embodiment of the invention is displayed.

[0018] Figure 9 An exploded perspective view of a check valve used in other embodiments of the present invention is shown.

[0019] Figure 10 A side view of another embodiment of the cardiac assist device according to the present invention is shown.

[0020] Figure 11 A perspective view showing an implementation of a cardiac assist device with details regarding the retrieval of components, and

[0021] Figure 12 A cross-sectional view of an embodiment of the cardiac assist device of the present invention is shown. Detailed Implementation

[0022] The present invention seeks to provide an intracardiac cardiac assist device that more closely approximates the natural function of the heart. A cardiac assist device produced according to embodiments of the present invention can function in a patient by pumping blood from the cardiovascular lumen (e.g., the left ventricle) with a sufficiently high stroke volume and effective placement to provide circulatory assistance.

[0023] In an embodiment of the invention, two pumping mechanisms are implemented that work together to make the function of the cardiac assist device more effective.

[0024] Figure 1A and Figure 1B Two cross-sectional views of a first embodiment of the cardiac assist device 1 of the present invention are shown. Figure 1A The image shows the cardiac assist device 1 at the start of the pump operation mode, and Figure 1B The image shows the cardiac assist device 1 at the start of the filling operation mode, where two operation modes alternate. The cardiac assist device 1 has, for example, an overall elliptical or oval shape with a symmetrical longitudinal axis.

[0025] The cardiac assist device 1 includes a cup-shaped element 2 and an internal spherical element 5, which is inflated during a pumping operation mode and deflated during a filling operation mode. The internal spherical element 5 has a spherical wall 5a, and the cup-shaped element 2 has a cup wall 2a with an inlet opening 3, allowing a first fluid (blood) to enter the space between the cup wall 2a and the spherical wall 5a. The cup-shaped element 2 also includes an outlet element 4 fluidly connected to the cup wall 2a and having a small orifice 4a for draining the first fluid during operation. A tubular element 6 is present, fluidly connected to the internal spherical element 5, and used to inflate and deflate the internal spherical element 5 during operation, generating the pumping operation mode and the filling operation mode, respectively. Figure 1A As shown, the cup-shaped element 2 has an internal cup volume Vc1, which is substantially the same during both the pumping operation mode and the filling operation mode. The internal spherical element has an initial internal volume Vb1 at the start of the pumping operation mode, as... Figure 1A As shown, and having an expanded internal volume Vb2 at the start of the filling operation mode, as Figure 1B As shown in the diagram. Therefore, the achievable stroke volume SV of the cardiac assist device 1 in this embodiment is Vb2-Vb1.

[0026] To achieve this pumping and filling operation mode, one or more inflow openings 3 need to be closed during the pumping operation mode and opened during the filling operation mode. This can be achieved as described below, or through a further set of embodiments, wherein the one or more inflow openings 3 include a check valve.

[0027] Furthermore, in one set of embodiments, the outflow element 4 has a tubular structure. The tubular structure can be long enough to extend through the aortic valve when the cardiac assist device 1 is positioned in the left ventricle (e.g., having a length of at least 20 mm), thereby ensuring that the orifice 4a is in the aorta during operation. Alternatively or additionally, the outflow element 4 is a directional flow element. This allows for directional flow of the first fluid during pumping operation, for example, oriented towards the aortic valve during operation.

[0028] In fact, the cardiac assist device 1 of the present invention combines two pumping mechanisms to achieve the smallest possible external volume of the cardiac assist device 1 with the highest possible stroke volume, and the most unobstructed possible outflow of the first fluid through the outflow element 4, which is made possible by the (dynamic) balance of forces during alternating pumping operation mode and filling operation mode.

[0029] More specifically, during operation in pumping mode, the combination of the first material of the cup wall 2a, the dimensions of the cup wall 2a, and the dimensions of the outflow element 4 provides the restraining force of the cup-shaped element 2 to counteract the outward force of the internal spherical element 5 during inflation. These structural features of the cup wall 2a (first material properties, dimensions of the cup wall 2a (thickness, radius, surface area)) and dimensions of the outflow element 4 (opening area 4a, diameter and / or length of the outflow element 4) determine the restraining force. It should be noted that other parameters may be relevant during operation, such as the rate of volumetric change of stroke volume, resistance on the outflow element 4, viscosity of the first fluid, and / or back pressure from the external environment of the cardiac assist device (such as aortic pressure in the case of ventricular assist type of cardiac assist device 1). However, these parameters can be taken into account when setting the structural features of the cup-shaped element 2.

[0030] Furthermore, during the filling operation mode, the structure and material of the cup-shaped element 2 ensure that the shape of the cup wall 2a remains substantially the same (i.e., with the internal cup volume Vc1), thereby counteracting the force generated by the contracting internal spherical element 5. It should be noted that in this case, other parameters may be relevant during operation, such as the resistance on the total inflow surface area of ​​the inflow opening 3 in the cup wall 2a, the degassing rate of the internal spherical element 5, and the viscosity of the first fluid. Similarly, these further parameters can be considered when selecting the structural features of the cup-shaped element 2 for the overall design of the cardiac assist device 1.

[0031] Therefore, in general, the present invention provides a cardiac assist device 1, comprising a cup-shaped element 2 having a cup wall 2a comprising a first material and defining an internal cup volume Vc1; one or more inflow openings 3 disposed in the cup wall 2a to allow a first fluid to flow into the cup-shaped element 2 during operation; and an outflow element 4 fluidly connected to the cup wall 2a and having a small hole 4a for discharging the first fluid during operation. An internal spherical element 5 is present, having a spherical wall 5a comprising a second material and defining internal spherical volumes Vb1, Vb2, the internal spherical element 5 being positioned inside the cup-shaped element 2 and not connected to the outflow element 4; and a tubular element 6 fluidly connected to the internal spherical element 5 for inflating and deflating the internal spherical element 5 during operation, thereby generating a pumping operation mode and a filling operation mode, respectively. During operation in the pumping operation mode, the combination of the first material, the dimensions of the cup wall 2a, and the dimensions of the outflow element 4 provides a restraining force on the cup-shaped element 2 to counteract the outward force of the internal spherical element 5.

[0032] In one set of embodiments, during pumping and filling operation modes, the cup-shaped element 2 has a substantially constant internal cup volume Vc1.

[0033] In addition, Figure 1A and Figure 1BIn the exemplary embodiment shown, the cup-shaped element 2 is provided with a skeleton (or reinforcing) structure 7b, for example, as an integral part of the cup wall 2a, providing rigidity to the cup wall 2a. In other words, in a further embodiment, the cup-shaped element 2 includes skeleton structures 7a, 7b integrated with the cup wall 2a.

[0034] In another set of embodiments, the cup-shaped element 2 has a dynamic internal cup volume Vc1-Vc2, such as Figures 2A to 2D An exemplary embodiment is shown in the mid-section. During operation, the cup wall 2a will cooperate synchronously with the inflating / deflating spherical element 5 to achieve an even more efficient stroke volume SV. In sequence, Figures 2A to 2D The display shows that the cardiac assist device 1 has two main actions, namely, in Figure 2A In the middle, the cup-shaped element 2 remains fully open (i.e., maximum internal cup volume Vc1) until the internal spherical element 5 is completely degassed, and the internal volume is filled with the first fluid through one or more inflow openings 3. Then, Figure 2B The next step in the sequence is shown, where the cup wall 2a contracts (or tightens) to the minimum internal cup volume Vc2, and the internal spherical element 5 expands from the internal spherical volume Vb1 to Vb2, thereby combining the two forces Fc and Fb for the pumping operation mode. Subsequently, the internal spherical element 5 is allowed to deflate again, and the internal volume of the heart assist device 1 is once again filled with the first fluid (filling operation mode), and the operation continues as the internal cup volume increases again to its maximum level Vc1. Figure 2D Then a new cycle can begin again.

[0035] In one set of implementations, the dynamic volume of the cup-shaped element 2 can be varied by appropriately selecting structural features of the cup-shaped element 2, such as selecting a first material, the size of the cup wall 2a, and the size of the outflow element 4.

[0036] In another set of embodiments, this dynamic volume of the cup-shaped element 2 is achieved by having skeleton structures 7a and 7b, which are flexible skeleton structures arranged to control the cup volume during operation. Note that... Figure 1A and Figure 1B The skeleton structure 7b shown in the exemplary embodiment can also be applied to Figures 2A to 2D The exemplary implementation plan shown is as follows.

[0037] In other embodiments, the flexible skeleton structures 7a, 7b include hollow channels that can be inflated and deflated, for example, to obtain varying inner cup volumes Vc1-Vc2. For this purpose, in another embodiment, the hollow channels are in fluid communication with the tubular element 6. Optionally, the cardiac assist device 1 also includes a secondary tubular element in communication with the hollow channels. All these components allow the cardiac assist device 1 according to these embodiments to operate at relatively high pressures, for example, between 0.5 bar and 20 bar. Because this is higher than prior art systems operating at inflation pressures of 0.5 to 1 bar (see, for example, U.S. Patent Publication US-B-5,169,378), faster and more robust operation of the cardiac assist device 1 is possible.

[0038] In another set of embodiments, to obtain a restraining force to counteract the expansion force of the internal sphere, the skeleton structures 7a, 7b include a shape memory material. The shape memory material is, for example, linear and may include nitinol as the memory material. For example, the skeleton structure 7b can then be implemented as a spiral included in the cup wall 2a, such as... Figure 1A and Figure 1B The implementation scheme is shown below.

[0039] Figure 3A A perspective view of another embodiment of the cardiac assist device 1 of the present invention is shown. In this embodiment, the skeleton structure 7b includes a spiral wire mesh element integrated with the cup wall 2a. Figure 3B A cross-sectional view of another embodiment is shown, wherein the skeletal structures 7a, 7b include a ridge element 7a and a plurality of rib elements 7b arranged along the longitudinal direction of the cardiac assist device 1, each of the rib elements 7b being connected to the ridge element 7a on one side. The rib elements 7b extend from the ridge element 7a, for example, in a substantially vertical manner, forming a rib cage-like skeletal structure. Another advantage of this embodiment is that the rib elements 7b can be easily folded, thereby allowing the cardiac assist device to be more easily inserted and removed before being placed in operation (e.g., into the left ventricle via a vascular catheter). In even further alternative embodiments, the ridge element 7a and / or the rib elements 7b may be partially made of a solid material (e.g., nitinol) and partially open (e.g., hollow polyurethane material).

[0040] In a further set of embodiments, the cardiac assist device also includes a control unit 10 arranged to control the fluid flow of a second fluid through the tubular element 6 during operation. This allows for the periodic inflation / deflation of the internal spherical element 5 to achieve the pumping and filling operating mode described above. The second fluid can be (compressed) air, gas, liquid, water, etc. The tubular element 6 is implemented, for example, as a conduit (capable of delivering the second fluid), allowing for remote control of the inflation / deflation of the internal spherical element 5 using a remote pressure source. The hollow channels of the aforementioned skeleton structures 7a, 7b can also be controlled in this manner, if present. For example, when using a high-pressure fluid, the hollow channels will eventually harden, thereby providing shape consistency for the cup-shaped element 2. By adding impedance elements and selecting the internal volume of the hollow channels relative to the size of the internal sphere 5, the same second fluid source and control unit 10 can be used to first inflate the skeleton structures 7a, 7b and subsequently inflate the internal spherical element 5.

[0041] In a further embodiment, the cup-shaped element 2 is provided with inflatable skeleton structures 7a, 7b, wherein the internal volume of the inflatable skeletons 7a, 7b is smaller than the (possible) internal volume of the internal spherical element 5, for example, 1 cc versus 20 cc. This allows the inflatable skeletons 7a, 7b and the internal spherical element 5 to be connected to a single (remote) pressure source via a tubular element 6, since the lower volume will first ensure the inflation of the skeleton structure and subsequently ensure the inflation of the internal spherical element 5. To enable operational application of embodiments of the invention using dynamic internal cup volumes, in another embodiment, a control unit 10 is arranged to independently control the internal cup volumes Vc1, Vc2 and the internal spherical volumes Vb1, Vb2.

[0042] The control unit 10 can be arranged to apply specific synchronization timing between the inflation / deflation of the cup-shaped element 2 and the inflation / deflation of the internal spherical element 5. The cup-shaped element 2 can change from an internal cup volume Vc1 to Vc2 shortly before, simultaneously with, or shortly after the internal spherical volume form Vb1 changes to Vb2. In a particular embodiment, the maximum internal cup volume Vc1 can be timed shortly before the internal spherical element 5 is inflated, thereby ensuring optimal stroke volume.

[0043] Furthermore, in a further exemplary embodiment, the pumping frequency can be set by the control unit 10 to obtain optimal performance. This pumping frequency can be controlled to be synchronized with the actual (sensed) heartbeat. Even further, the pumping frequency can be higher, for example, 2-10 times higher than the actual heartbeat, to obtain a higher initial fluid flow rate.

[0044] like Figure 3AAs shown in the exemplary embodiment, in another embodiment, the tubular element 6 contacts the outflow element 4 along a predetermined length. This off-center positioning of the tubular element 6 allows the first fluid to flow substantially unimpeded in the outflow element 4 and out of the orifice 4a.

[0045] In another embodiment, the combination of the cup-shaped element 2 and the inner spherical element 5 is adjustable to a transport mode in which the maximum diameter of the combination is less than 7 mm, for example less than 5 mm. This, for example, allows the cardiac assist device to be delivered to the left ventricle reliably and safely via the aorta and conventional catheter systems. The combination is elongated, for example, in the transport mode and elliptical in the operating mode.

[0046] exist Figure 3A In the exemplary embodiment shown, the tubular element 6 is a multi-lumen (e.g., dual-lumen) catheter. One lumen 6a is used, for example, for the expansion / contraction of the internal bulbous element 5, and the other lumen 6b provides space for the guidewire 8, which extends along or even from the cardiac assist device 1, for example, for proper positioning of the cardiac assist device 1 in the left ventricle.

[0047] As another alternative embodiment, the internal spherical element 5 comprises a multi-stage spherical assembly having at least two spherical portions made of different rigid materials. The multi-stage spherical assembly is, for example, a shaped balloon, or has controlled volume expansion (or directional thrust). Even further, the shaped balloon 5 can be positioned relative to the outflow element 4 such that directional expansion occurs from the apex of the cup-shaped element 2 toward the outflow element 4. Optionally, or additionally, the size and position of the shaped balloon 5 can be configured to close the inflow opening 3 in the early stages of inflation, thereby creating a one-way valve assembly. In other words, one of the two spherical portions is positioned to close one or more inflow openings 3 in pumping operation mode.

[0048] Figure 4 A side view of another embodiment of the cardiac assist device 1 according to the present invention is shown, which has a cup-shaped element 2 and an outflow element 4, similar to the embodiments described above. In this exemplary embodiment, the skeleton structure 7b is provided as a wire mesh structure, for example using nitinol or another shape memory material. For example, the skeleton structure 7b is manufactured similarly to a laser-cut stent. The skeleton structure 7b in this embodiment allows for a reduction in the diameter of the cardiac assist device 1 when stretched along its longitudinal axis (see also...). Figure 10 and Figure 11(Description of the description). Once positioned in the heart, the cup-shaped element 2 returns to its intended shape, wherein the mesh structure ensures that the cup-shaped element 2 has an internal volume Vc1. During operation (inflation and deflation), the skeleton structure 7b of this embodiment provides radial stiffness to maintain the internal volume Vc1. At the ends of the cup-shaped element 2, the skeleton structure 7b and other local components of the cardiac assist device 1 are held together and protected by end caps 19, which are, for example, shaped or rounded to provide the least possible damage to the (cardiac) tissue during use of the cardiac assist device 1.

[0049] To prevent excessive stretching of the outer surface of the cup-shaped element 2 during operation, the skeleton structure 7b has a wire mesh structure with one or more circumferential constraint elements 11. The constraint elements 11 are made of, for example, a non-compliant material, thereby ensuring the local maximum diameter of the cup-shaped element 2.

[0050] Figure 5 Showing along Figure 4 The cross-sectional view of line VV in the middle, and Figure 6 Showing along Figure 4 A cross-sectional view of line VI-VI in the diagram. In one set of embodiments, the cup wall 2a includes an inner layer 12 and / or an outer layer 13. The inner and / or outer layers 12, 13 are made of a compliant, high-tensile-strength material, or even a non-compliant material (or a combination of compliant and non-compliant materials). Furthermore, the outer layer 13, which spans the wire mesh skeleton structure 7b (and the restraint element 11), also provides a (more) smooth outer surface, allowing the cardiac assist device 1 to interfere with cardiac tissue as little as possible (during insertion and operation).

[0051] exist Figures 4 to 6 In the exemplary embodiment shown, the cup-shaped element 2 further includes a transvalvular segment 14 communicating with the outflow element 4. In use, this portion (in which the skeleton structure 7b extends) can be positioned, for example, at the height of the aortic valve, thereby providing an always-open passage from the internal volume Vc1 of the cup-shaped element 2 to the outflow element 4.

[0052] Figure 7A and Figure 7B Showing along Figure 4 Cross-sectional views of centerline VII-VII under two operating conditions show the operation of the outflow element 4, including the collapsible tubular element 15, made of a material that provides radial stiffness (the collapsible tubular element 15 has a maximum diameter even when fluid is pumped through the tubular element at high pressure and / or high speed) but has sufficient flexibility to allow the collapsible tubular element 15 to fold for use as a check valve. The open position of the collapsible tubular element 15 is as follows... Figure 7A As shown, and the closing position is as follows Figure 7BAs shown. The foldable tubular element 15 has a length of, for example, 0.5-4 cm, such as 2 cm, and a diameter of, for example, 5-15 mm, such as 12 mm. The foldable tubular element 15 is made of, for example, a flexible material such as Tecotane 85.

[0053] In the illustrated exemplary embodiment, the outflow element 4 includes an outflow skeleton structure 7c formed by an extension of the skeleton structure 7b. This provides partial support for the outflow element 4, compatible with the intended function of the foldable tubular element 15 and the intended retrieval mechanism function. Additionally or alternatively, the foldable tubular element 15 is at least partially secured to the outflow skeleton structure 7c. Additionally or alternatively, the foldable tubular element 15 may be provided with a shaped outer end to further improve the one-way valve function, for example by providing an angle (e.g., 40 degrees to the longitudinal direction of the cardiac assist device 1) at the upper end of the foldable tubular element 15.

[0054] This exemplary embodiment of the cardiac assist device 1 has a rigid portion (cup-shaped element 2) positioned in the ventricle during operation, including a transvalvular segment 14 passing through the aortic valve during operation, and a one-way valve mechanism formed by a collapsible tubular element 15 of the outflow element 4. During systole, the rigid portion converts energy provided by the action of the internal ball-shaped element 5 to push fluid toward the outflow element 4. At the end of this phase, as the fluid flow decreases, the collapsible tubular element 15 begins to close, causing the pressure inside the collapsible tubular element 15 to be lower than the surrounding pressure. During diastole, the outflow skeleton structure 7c prevents the collapse of the outflow element 4; however, the collapsible tubular element 15 remains closed, thereby preventing possible fluid backflow.

[0055] In addition, such as Figure 4 , Figure 7A and Figure 7B As shown, an attachment element 16 is provided at the upper end of the skeleton structure 7B (or only at the upper end of the outflow skeleton structure 7c), which is effective when the cardiac assist device 1 is retrieved. Figure 10 A partial side view of a further embodiment of the cardiac assist device 1 according to the invention is shown, which plays a role in positioning and retrieving the cardiac assist device 1. A wire mesh 16a can be attached to an attachment element 16 of the skeleton structure 7b / outflow skeleton structure 7c. This attachment to the tip of the outflow element 4 allows tension to be applied to the cup-shaped element 2 while retrieving, elongating, and reducing its width.

[0056] Figure 11 A perspective view of an embodiment of the cardiac assist device 1 is shown, including details of the retrieval elements. The perspective view also shows the internal spherical element 5 and tubular element 6, as well as the guidewire 8 and outer shaft 18 (forming part of a catheter for positioning and retrieving the cardiac assist device 1).

[0057] The tapered shape of the outflow element 4 (more specifically, the outflow skeleton structure 7c) allows the cardiac assist device 1 to retract into the outer shaft 18. The tubular element 6 can serve as a fastener for the end cap 19 (also attached to the inner spherical element 5), allowing sufficient force to be applied to stretch the cardiac assist device 1 to reduce its diameter so that it can be (re)fitted into the outer shaft 18.

[0058] Figures 8A to 8C A perspective view showing (partial) of another embodiment of the invention relates to the inflow opening 3 of the cardiac assist device 1, and Figure 9 An exploded perspective view of an embodiment of the one-way valves 12, 17 used in another embodiment of the invention is shown. In these embodiments, one or more inflow openings 3 include a one-way valve 17.

[0059] Figure 8A The cup wall 2a of the cup-shaped element 2 is shown, which has a row of inflow openings 3 (drawn as thick lines), and Figure 8B The blade-like element 17, which mates with the outer surface 2a as a one-way inlet valve, is shown. Figure 8C The image shows mutual positioning, where the blade-like element 17 is attached to the inner surface of the cup wall 2a along the dashed line, thereby creating an engagement area with the blade in the region below the drain opening 3.

[0060] Figure 9 An exploded view of a simplified embodiment of a one-way inlet valve is shown. The cup wall 2a is formed by a skeleton structure 7b (partially shown), an inner layer 12 (with an inlet opening 3), and a blade-like element 17. The blade-like element 17 is positioned to allow the closure of the inlet opening 3. The resulting engagement area has a size of, for example, 0.5-4 mm, such as 2.5 mm, to allow the formed one-way inlet valve to open and close sufficiently quickly. The diameter of the inlet opening 3 is at least 2 mm, such as 3.5 mm. The engagement area also provides directional inflow of fluid within the cup-like element 2, where the helical flow helps to close the one-way inlet valve quickly enough. Multiple such one-way inlet valve lines can be arranged parallel to each other along the longitudinal direction of the cup wall 2a, which has the additional benefit of increased directional and helical flow within the cup-like element 2. The inlet opening 3 can also have an orientation in the same direction to obtain a more directional fluid inflow. Fluid flowing through the blade-like element 17 in this way helps to close them more quickly.

[0061] Figure 12A cross-sectional view of an embodiment of the cardiac assist device of the present invention is shown, illustrating another embodiment of the internal spherical element 5. In this embodiment, during operation, the internal spherical volume Vb2 is smaller than the internal cup volume Vc1. During inflation, this ensures that the internal spherical element 5 does not trap or encapsulate any fluid between the inner surfaces of the internal spherical element and the cup-shaped element 2. During deflation, fluid will be present between the inner surfaces of the internal spherical element 5 and the cup-shaped element 2, thereby preventing a “vacuum” and possible adhesion in the area between the two surfaces.

[0062] In the exemplary embodiment shown, the internal spherical element 5 is positioned at the distal end within the cup-shaped element 2, i.e., closer to the end cap 19 than the outflow element 4. This prevents increased outflow resistance generated by the internal spherical element 5 itself.

[0063] Alternatively, the internal spherical element 5 can be configured as a cone. This results in a predetermined fluid flow toward the outflow element 4.

[0064] Usage Reference Figure 12 One or more of the above features can be used to inflate the internal spherical element 5 in two stages, for example by using the variable compliance of the material of the internal spherical element 5, using a specific shape (e.g., a cone shape), or a combination thereof.

[0065] In the above embodiment, the tubular element 6 is used in communication with the internal spherical element 5. A fluid (air or helium) can be used to inflate and deflate the internal spherical element 5. To obtain a sufficiently high frequency and duration of inflating / deflating actions, the tubular element 6 may be provided with specific technical features. For example, to maintain sufficiently low flow resistance, the inner diameter of the tubular element 6 is 4 mm. 2 Up to 8 mm 2 For example, 5.3 mm 2 A length of 100 cm to 150 cm (e.g., 110 cm) is advantageous. This can be compared with 80 mm. 2 The optimized inflation area of ​​the internal spherical element 5 is combined with this. In addition, the material of the tubular element 6 can be selected to obtain sufficiently high radial stiffness (allowing for rapid flow of, for example, helium in both directions) and simultaneously sufficiently high longitudinal push / pull strength, thereby allowing for placement, positioning, and retrieval of the cardiac assist device 1.

[0066] The invention has been described above with reference to several exemplary embodiments illustrated in the accompanying drawings. Modifications and alternative implementations of some parts or elements are possible and are included within the scope of protection as defined in the appended claims.

Claims

1. A cardiac assist device, comprising: The cup-shaped element has the following characteristics: A cup wall comprising a first material and defining an internal cup volume, wherein the cup wall comprises a skeleton structure, an inner layer extending through the inside of the skeleton structure, and an outer layer extending through the outside of the skeleton structure, the skeleton structure comprising a shape memory material; One or more inlet openings that allow a first fluid to flow into the cup-shaped element during operation; An outflow element is connected to the cup wall and has a small hole for discharging the first fluid during operation; and An internal spherical element having a spherical wall and defining an internal spherical volume, the internal spherical element being positioned inside the cup-shaped element and not connected to the outflow element; and A tubular element connected to the internal spherical element for inflating and deflating the internal spherical element during operation, thereby generating a pumping operation mode and a filling operation mode, respectively. During operation in the pumping mode, the combination of the first material, the size of the cup wall, and the size of the outflow element provides a restraining force on the cup-shaped element to counteract the outward force generated by the inflation of the internal spherical element.

2. The cardiac assist device of claim 1, wherein the cup-shaped element has a substantially constant internal cup volume during the pumping and filling operation mode.

3. The cardiac assist device of claim 1, wherein the skeleton structure is integrated with the cup wall.

4. The cardiac assist device of claim 1, wherein the skeletal structure comprises a wire mesh structure.

5. The cardiac assist device of claim 1, wherein the cup-shaped element further comprises a transvalvular segment in communication with the outflow element.

6. The cardiac assist device of claim 1, wherein the outflow element comprises a foldable tubular element.

7. The cardiac assist device of claim 6, wherein the outflow element comprises an outflow skeleton structure formed through an extension of the skeleton structure.

8. The cardiac assist device of claim 7, wherein the outflow skeleton structure extends along the outflow element.

9. The cardiac assist device of claim 7, wherein the foldable tubular element is at least partially fixed to the outflow skeleton structure.

10. The cardiac assist device of claim 1, wherein the tubular element is configured to contact the outflow element along its predetermined length.

11. The cardiac assist device of claim 1, wherein the combination of the cup-shaped element and the internal spherical element is adjustable to a transport mode, wherein the maximum diameter of the combination is less than 7 mm.

12. The cardiac assist device of claim 11, wherein the assembly is elongated in the transport mode and elliptical in the operating mode.

13. The cardiac assist device of claim 1, wherein the tubular element is a multi-lumen catheter.

14. The cardiac assist device of claim 1, wherein the internal sphere volume is smaller than the internal cup volume during operation.

15. The cardiac assist device of claim 1, wherein the internal spherical element is positioned distally within the cup-shaped element.

16. The cardiac assist device of claim 1, wherein the internal spherical element has a conical shape.

17. The cardiac assist device of claim 1, wherein the internal spherical element comprises a multi-stage spherical assembly.

18. The cardiac assist device of claim 1, wherein the one or more inflow openings comprise a one-way valve.

19. The cardiac assist device of claim 3, wherein the skeleton structure is a flexible skeleton structure arranged to control the volume of the cup during operation.

20. The cardiac assist device of claim 19, wherein the flexible skeleton structure includes a hollow channel.

21. The cardiac assist device of claim 20, wherein the hollow channel is in fluid communication with the tubular element.

22. The cardiac assist device of claim 21, wherein the cardiac assist device further comprises a secondary tubular element communicating with the hollow channel.

23. The cardiac assist device of claim 17, wherein the multi-stage spherical assembly comprises at least two spherical portions, and one of the spherical portions is positioned to close the one or more inflow openings in the pumping operation mode.

24. The cardiac assist device of claim 1, wherein the internal spherical element is configured to inflate and deflate at a pumping frequency synchronized with the sensed heartbeat.

25. The cardiac assist device of claim 1, wherein the internal spherical element is configured to inflate and deflate at a pumping frequency 2-10 times higher than the sensed heart rate.

26. The cardiac assist device of claim 4, wherein the cup includes one or more circumferential restraint elements.

27. The cardiac assist device of claim 1, wherein a portion of the skeletal structure is configured to pass through the aortic valve when the cardiac assist device is placed in the patient's left ventricle.

28. The cardiac assist device of any one of claims 1-27, further comprising a control unit arranged to control fluid flow through the tubular element during operation.

29. The cardiac assist device of claim 28, wherein the control unit is arranged to independently control the internal cup volume and the internal spherical volume.

30. The cardiac assist device of claim 28, wherein the control unit is arranged to periodically inflate and deflate the internal spherical element at a certain pumping frequency.

31. The cardiac assist device of claim 30, wherein the control unit is arranged to set the pumping frequency to synchronize with the sensed heartbeat.

32. The cardiac assist device of claim 30, wherein the control unit is arranged to set the pumping frequency to be 2-10 times higher than the actual heart rate.

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