Artificial heart valve

Abstract

This specification provides apparatus and methods for the treatment of heart disease. [Solution] The artificial heart valve 100 includes a stent frame 110, a skirt 140, a valve member 160, and a protective cover member 180. The skirt 140 is attached to the stent frame 110 so as to cover the inner and outer portions of the stent frame 110. In the illustrated embodiment, the skirt 140 is attached to the stent frame 110 by sutures used to sew the skirt 140 to itself (while capturing a portion of the stent frame 110).

Description

Technical Field

[0001] This specification relates to devices and methods for the treatment of heart diseases. For example, this specification relates to methods for artificial heart valves and transcatheter heart valve implantation.

Background Art

[0002] Valvular stenosis is a condition in which the heart valve becomes narrow (stenotic). In valvular stenosis, the tissue forming the valve leaflets becomes stiff, the valve opening becomes narrow, and the amount of blood that can flow through the opening decreases. When the stenosis is mild, the overall cardiac output remains normal. However, when the valve becomes severely stenotic, the cardiac output may decrease and cardiac function may be impaired.

[0003] Aortic valve stenosis affects approximately 5% of the total population over 75 years of age. Aortic valve stenosis occurs when the aortic valve of the heart becomes narrow. When the aortic valve is thus blocked, the heart has to work harder to pump blood out to the body. Eventually, this extra work can limit the amount of blood the heart can pump and weaken the myocardium. The left atrium can expand as the pressure increases, and then blood and fluid can accumulate in the lung tissue (pulmonary edema), making breathing difficult. Drug therapy can relieve the symptoms of mild to moderate aortic valve stenosis. However, the only way to treat severe aortic valve stenosis is by surgery to replace the valve.

[0004] Treatments for repairing or replacing the aortic valve include balloon valvuloplasty (valvotomy), surgical aortic valve replacement, and transcatheter aortic valve replacement (TAVR). TAVR involves replacing the aortic valve with an artificial valve that is delivered, for example, via the femoral artery (transfemoral) or the apex of the left ventricle of the heart (transapical). TAVR is also sometimes referred to as transcatheter aortic valve implantation (TAVI).

Summary of the Invention

[0005] This specification describes devices and methods for the treatment of heart disease. For example, this specification describes artificial heart valves and transcatheter heart valve replacement methods. In some embodiments, the artificial heart valve includes a valve member fabricated from a biomaterial molded into a specific three-dimensional ("3D") shape. The shape of the molded valve member is designed to provide improved performance characteristics, as described herein, including, but not limited to, a low mean pressure gradient, low leaflet stress, a large valve opening area, a high junction surface, and a high duration in the open state.

[0006] In some embodiments, the artificial heart valve includes an expandable metal stent frame surrounding a valve member. To prevent direct contact between the valve member and the stent frame when the valve member is in an open position, a local protective cover member may be attached to a portion of the stent frame. Such a protective cover member can extend the effective life of the valve member by protecting it from direct contact with the metal stent frame. Furthermore, a skirt may be attached to the stent frame to cover other portions of the stent frame so that the valve member does not come into contact with other portions of the stent frame. In some embodiments, the combination of a skirt and a local protective cover member prevents the valve member from directly contacting any uncovered portion of the stent frame.

[0007] In one embodiment, the present disclosure relates to an artificial heart valve. Such an artificial heart valve may include a stent frame that is reconfigurable between a thin delivery configuration and an extended, operable configuration, and a valve member attached to the stent frame. The valve member may include three leaflets. Each of the three leaflets has a free edge and a three-dimensional shape. The three-dimensional shape of the leaflet includes (i) a first planar region including a first free edge portion terminating at the center of the free edge of the leaflet, (ii) a second planar region including a second free edge portion terminating at the center of the free edge of the leaflet, and (iii) a concave region located between the first and second planar regions and having its apex at the center of the free edge of the leaflet.

[0008] Such an artificial heart valve may optionally include one or more of the following features. In some embodiments, the valve member is configured to allow blood flow through the artificial heart valve from the inlet end to the outlet end, and to prevent blood flow through the artificial heart valve from the outlet end to the inlet end. In some embodiments, the valve member extends to the edge of the stent frame at the inlet end. The concave region may be joined to a first planar region along a first curved path, or the concave region may be joined to a second planar region along a second curved path. The first free edge may be straight, and the second free edge may be straight. In some embodiments, the first and second free edges are non-parallel to each other. An angle may be defined between the first and second free edges. The angle may be between 80° and 120°. In some embodiments, the first and second planar regions are not coplanar. The valve member may include a biomaterial. In some embodiments, the biomaterial is molded to create a three-dimensional shape.

[0009] In another embodiment, the disclosure relates to an artificial heart valve comprising a valve member having three flexible leaflets and a stent comprising a metal framework reconfigurable between a thin delivery configuration and an extended, operable configuration. The metal framework comprises (i) three commissure posts to which the valve member is attached, and (ii) three frame portions, each of the three frame portions positioned between two of the commissure posts. The artificial heart valve also comprises three separate protective cover members attached to the three frame portions and covering the local valve-facing surfaces of each of the three frame portions.

[0010] Such an artificial heart valve may optionally include one or more of the following features: Three separate protective cover members may comprise bovine pericardium sutured to three frame portions. The artificial heart valve may also include skirts attached to the inside and outside of the inlet end of the stent. In some embodiments, the skirts abut against the protective cover members. The valve member can be configured to allow blood flow through the artificial heart valve from the inlet end to the outlet end, and to prevent blood flow through the artificial heart valve from the outlet end to the inlet end. The valve member may include three free edges. Each of the three free edges may extend between two of the commissure posts. The valve member may be reconfigurable between a fully closed configuration in which the three free edges are in contact with each other, and a fully open configuration in which the three free edges are separated from each other. In the fully open configuration, the middle portions of each of the three free edges may be located closer to the inlet end than the outlet-side edges of each of the three separate protective cover members. In the fully enclosed configuration, all portions of each of the three free edges may be located closer to the outlet end than the respective outlet-side edges of the three separate protective cover members. In some embodiments, each of the three frame portions is located equidistant from two of the connecting posts.

[0011] Specific embodiments of the present invention described herein can be implemented to achieve one or more of the following advantages. In some embodiments, cardiac diseases such as valvular stenosis can be treated using the devices and methods provided herein. Some patients for whom conventional surgical valve replacement is too risky can be treated using the artificial valve devices and transcatheter heart valve replacement methods provided herein. In some embodiments, the valve members of the artificial heart valve are molded in a specific manner to improve various valve performance characteristics. In addition, some embodiments include local protective cover members attached to specific portions of the stent frame to prevent direct contact between the valve members and the stent frame when the valve members are in an open position. The protection provided by the cover members enhances the performance and durability of the valve leaflets.

[0012] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Methods and materials similar to or identical to those described herein may be used to carry out the present invention, but suitable methods and materials are described herein. All publications, patent applications, patents, and other references referenced herein are incorporated in their entirety by reference. In case of any conflict, including definitions, this specification shall prevail. In addition, materials, methods, and examples are illustrative and not intended to limit the invention.

[0013] Details of one or more embodiments of the present invention are described in the accompanying drawings and this description. Other features, purposes, and advantages of the present invention will become apparent from the description and drawings, as well as from the claims.

[0014] Similar reference numbers represent corresponding parts throughout the whole. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view of an exemplary artificial heart valve according to several embodiments. [Figure 2] Figure 1 is a top view of the artificial heart valve in the fully closed position. [Figure 3] Figure 1 is a top view of the artificial heart valve in its fully open position. [Figure 4] Figure 1 is a perspective view of an exemplary stent framework or metal framework for an artificial heart valve. [Figure 5] Figure 1 is a plan view of an exemplary valve leaflet portion of an artificial heart valve. [Figure 6] Figure 1 shows the mold for the artificial heart valve and the resulting molded valve member. [Figure 7] Figure 6 shows the valve member in the fully closed state. [Figure 8] Figure 6 shows the valve member in the fully open state. [Modes for carrying out the invention]

[0016] This specification describes devices and methods for the treatment of heart disease. For example, this specification describes artificial heart valves and transcatheter heart valve replacement methods. Referring to Figures 1 to 3, an exemplary artificial heart valve 100 can be used to replace a patient's natural heart valve. The artificial heart valve 100 is particularly well suited for use in the location of the natural aortic valve, but may also be used in the location of other natural heart valves, such as, but not limited to, the mitral valve, pulmonary valve, and tricuspid valve.

[0017] In some cases, the artificial heart valve 100 may be deployed using a minimally invasive transcatheter technique. Thus, the artificial heart valve 100 can be radially compressed (e.g., crushed) into a low-profile delivery system form for passing through a delivery sheath and entering the patient's vascular system. The delivery system may be percutaneously inserted into the patient's blood vessel (e.g., femoral artery, femoral vein, radial artery, etc.) and then navigated to the target location using imaging techniques such as fluoroscopy, MRI, or ultrasound. In some situations, a guidewire may be initially placed. To improve imaging, radiopaque and / or echogenic markers may be included at one or more locations on the artificial heart valve 100. At the target location, the artificial heart valve 100 can be deployed from the delivery system and then expanded to its original position to be positioned at the target location. The artificial heart valve 100 may be self-expanding or expandable by mechanical means such as a balloon. Other access techniques, such as a transapical approach, are also conceivable.

[0018] Figures 1 to 3 show the artificial heart valve 100 in its expanded state after being deployed from the delivery system. Figure 2 shows the artificial heart valve 100 in the closed state. Figure 3 shows the artificial heart valve 100 in the open state.

[0019] The artificial heart valve 100 operates as a one-way valve. That is, the artificial heart valve 100 functions to allow blood to flow through the artificial heart valve 100 from the inflow end 102 (FIG. 1) in the direction of the outflow end 104. Conversely, the artificial heart valve 100 functions to prevent blood from flowing through the artificial heart valve 100 in the opposite direction, that is, from the outflow end 104 to the inflow end 102. For clarity, FIGS. 2 and 3 are views of the outflow end 104. The artificial heart valve 100 also defines a central longitudinal axis 101.

[0020] The artificial heart valve 100 includes a stent frame 110, a skirt 140, a valve member 160, and a protective cover member 180. The skirt 140 is attached to the stent frame 110 so as to cover the inner and outer portions of the stent frame 110. In the illustrated embodiment, the skirt 140 is attached to the stent frame 110 by suture threads used to sew the skirt 140 to itself (while capturing a portion of the stent frame 110). As will be further described below, in some embodiments, the skirt 140 is a single integral piece of cover material. Alternatively, in some embodiments, the skirt 140 is made from two or more separate portions of cover material.

[0021] The valve member 160 is disposed inside the stent frame 110 and is attached to the stent frame 110 at three cross-linking posts 112. The protective cover member 180 is also attached to the stent frame 110. In particular, in the illustrated embodiment, the protective cover member 180 is attached to the stent frame 110 at three positions of the stent frame 110 that each bisect the position of the cross-linking post 112. In some embodiments, the stent frame 110 may include additional portions between the cross-linking posts 112, and an additional protective cover member 180 may be attached to the additional portions.

[0022] The stent frame 110 consists of an elongated member arranged generally cylindrically and three cross-linking posts 112. In the illustrated embodiment of the stent frame 110, the elongated member is arranged in a cell-like manner. That is, the elongated member defines a plurality of open cells. The stent frame 110 may be composed of stainless steel, a shape memory alloy, a plastically deformable alloy, or a combination thereof. Examples of such alloy materials include, but are not limited to, nickel-titanium alloys such as Nitinol® alloy, cobalt-chromium alloys such as Elgiloy® alloy, platinum-tungsten alloys, tantalum alloys, etc. Other alloys that can be used in fabricating the stent frame 110 include, but are not limited to, other cobalt-chromium alloys, titanium-cobalt-chromium-molybdenum alloys, etc. In addition to these materials, the stent frame 110 may further be composed of a polymer, a biomaterial, or a combination thereof. In some embodiments, the stent frame 110 may initially be a tube (e.g., a Nitinol® tube or an Elgiloy® tube), which is laser cut, expanded into the desired open cylindrical form, and then heat set to form the cylinder into the original form of the elongated member.

[0023] In some embodiments, the elongated member of the stent frame 110 is a wire that is wound, woven, and / or attached together (e.g., welded or adhered) such that a cylindrical form can be fabricated.

[0024] In some embodiments, the stent frame 110 may have a coating on at least a portion of either the outer surface or the inner surface. The coating may include, but is not limited to, polymers including polytetrafluoroethylene (PTFE), silicone, biopolymers, and other suitable polymers. In other embodiments, the coating may include a radiopaque material. In some embodiments, the coating may include a drug-eluting material.

[0025] The artificial heart valve 100 also includes a skirt 140. The skirt 140 covers all or part of the stent frame 110. In the illustrated embodiment, the skirt 140 is a single, integrated piece of cover material that is wrapped around the inlet end 102 of the stent frame 110 to cover the inner and outer portions of the stent frame 110. Alternatively, in some embodiments, the skirt 140 is made from two or more distinct pieces of cover material. For example, in some embodiments, a first piece of the skirt 140 may be used to cover at least a portion of the inner side of the stent frame 110, and a second distinct piece of the skirt 140 may be used to cover at least a portion of the outer side of the stent frame 110. In some such embodiments, the inner portion of the skirt 140 may be made from a different type of material than the type of material used for the outer portion of the skirt 140. In certain embodiments, the skirt 140 may be made from materials including, but not limited to, Dacron, polyester fabric (e.g., PVL), polyethylene terephthalate (PET), Teflon®-based materials, polytetrafluoroethylene (PTFE), stretched polytetrafluoroethylene (ePTFE), polyurethane, silicone, BiO-A®, copolymers, film or foil materials, or combinations of the aforementioned materials and / or similar materials. In some embodiments, the skirt 140 has a material composition and structure that inhibits or prevents tissue endografting into the skirt 140. In some embodiments, the skirt 140 or a portion thereof has a microporous structure that provides a tissue endografting scaffold for durable sealing and supplemental fixation strength of the artificial heart valve 100.

[0026] The skirt 140 may be attached to the stent frame 110 in a variety of suitable ways. For example, in some embodiments, the skirt 140 is sewn to an elongated member of the stent frame 110. In some embodiments, the skirt 140 is bonded to the stent frame 110. In some embodiments, a portion of the stent frame 110 is sandwiched between two layers of the skirt 140 that are sewn together. In some embodiments, a combination of such attachment methods is used. All these and other variations of the type of frame member, material composition, material treatment, construction, manufacturing technique, and method for attaching the skirt 140 to the stent frame 110 are assumed within the scope of the disclosure provided herein.

[0027] The artificial heart valve 100 also includes a valve member 160. The valve member 160 may include tissue material. In some embodiments, the tissue material may be a biomaterial. In some embodiments, the tissue material may be a crosslinked collagen-based biomaterial, including acellular or cellular tissue selected from the group consisting of cardiovascular tissue, cardiac tissue, heart valves, aortic root, aortic wall, aortic valve leaflets, pericardial tissue, connective tissue, dura mater, dermal tissue, vascular tissue, cartilage, pericardium, ligaments, tendons, blood vessels, umbilical cord tissue, bone tissue, fascia, and submucosa and skin. In some embodiments, the tissue material is an implantable biomaterial, such as the biomaterial described in the disclosure of U.S. Patent No. 9,205,172, filed December 21, 2005, entitled “Implantable Biomaterial and Method of Producing Same” (which is incorporated herein by reference in its entirety). In some embodiments, the crosslinked collagen-based biomaterial is processed in an Adapt® processing process. This is an anti-calcification treatment process for biomaterials that leaves no residual DNA and has over 10 years of clinical data demonstrating that it does not exhibit calcification when used in cardiac surgery. In some embodiments, the tissue material may be artificial tissue. In some embodiments, the artificial tissue may comprise a single piece of molded or formed polymer. In some embodiments, the artificial tissue may comprise polytetrafluoroethylene, isotropic silicone, polyethylene terephthalate, other polymers, and other polymer coatings.

[0028] As will be further described below, in some embodiments the valve member 160 may comprise a molded microstructure material. More specifically, at least part or all of the valve leaflets of the valve member 160 may comprise a molded microstructure material (e.g., using a mold and an Adapt® processing process). In some embodiments the valve member 160 is a single-piece three-dimensional valve constructed from a single piece of microstructure material, as will be further described below.

[0029] The valve member 160 is joined to itself so as to attach the valve member 160 to the stent frame 110 at the three commissar posts 112 by capturing the three commissar posts 112. In some embodiments, the valve member 160 has slits into which the three commissar posts 112 are received. This is described, for example, in PCT / US2021 / 040596 filed on July 7, 2021, which is incorporated herein by reference in its entirety. Such joining techniques allow for a large-diameter open state (as depicted in Figure 3) and also reduce valve leaflet stress at the connection point. The valve member 160 may be attached to itself and / or the three commissar posts 112 by means such as sutures, the use of mechanical clips, stitching, the use of hooks or reins, the use of adhesives, joints, mechanical channels, and combinations thereof.

[0030] The artificial heart valve 100 also includes protective cover members 180. In the illustrated embodiment, three protective cover members 180 are included. In some embodiments, fewer than three or more protective cover members 180 may be included. The protective cover members 180 are localized covering materials attached to specific locations on the stent frame 110. The primary purpose of the protective cover members 180 is to prevent or stop the valve member 160 from coming into contact with the stent frame 110 when the valve member 160 is reconfigured to its open state (for example, as shown in Figure 3). By protecting the valve member 160 in this way, the effective life of the valve member 160 can be extended.

[0031] In practice, in the illustrated embodiment, no part of the valve member 160 (except for the portion where the valve member 160 is attached to the stent frame at the three connecting posts 112) directly contacts the stent frame 110. The skirt 140 and protective cover member 180 are in contact with the valve member 160, and the skirt 140 and protective cover member 180 thereby prevent the valve member 160 from directly contacting the stent frame 110. In the illustrated embodiment, as is best seen in Figure 1, the upper edge of the skirt 140 abuts against the respective lower edges of the protective cover member 180. Thus, the inner surface of the stent frame 110 is completely covered in those areas.

[0032] In some embodiments, the protective cover member 180 is a patch made of bovine pericardium sutured to the stent frame 110. In some embodiments, the protective cover member 180 is made of any other suitable biomaterial or synthetic material, such as the materials described above for the skirt 140 or valve member 160, and / or a combination of such materials. For example, in some embodiments, the protective cover member 180 comprises bovine pericardium on the inside of the stent frame 110 and PET on the outside of the stent frame 110.

[0033] Referring to Figure 4, a separate view of the stent frame 110 and protective cover members 180 (without the skirt 140 and valve member 160) is provided. The protective cover members 180 are shown in specific positions inside the stent frame 110. It can be seen that the protective cover members 180 are located in three parts of the stent frame 110, each equidistant between two connecting posts 112. The three separate protective cover members 180 are attached to the three frame parts of the stent frame 110 so as to cover the local valve-facing surfaces of each of the three frame parts.

[0034] The valve member 160 includes three free edges. The three free edges extend between the three connecting posts 112 and join (contact) with each other when the valve member 160 is in a closed configuration (for example, as shown in Figure 2), and spread apart from each other when the valve member 160 is in an open configuration (for example, as shown in the fully open configuration in Figure 3). The protective cover member 180 serves to protect the valve member 160 from direct contact with the stent frame 110 when the valve member 160 is in a fully open configuration (particularly including the intermediate portion of the free edges of the valve member 160).

[0035] In the fully open position, the central portion of each of the three free edges of the valve member 160 is located closer to the inlet end 102 than to the edge of each of the three separate protective cover members 180 that is closest to the outlet end 104. In other words, when the valve member 160 is in its open position, the central portion of each of the three free edges of the valve member 160 is below the upper edge (or, closer to the outlet end 104, hence the "outlet edge") of the protective cover member 180 (closer to the inlet end 102). This arrangement helps to ensure that the free edges of the valve member 160 are not in direct contact with the stent frame 110 by the protective cover member 180 when the valve member 160 is in the fully open position.

[0036] As is best seen in Figure 4, in the illustrated embodiment, the protective cover member 180 is attached to a portion of the stent frame 110 that is directly connected to adjacent diaphragm posts 112 by two elongated members 114 that extend in opposite directions like arches. That is, the two elongated members 114 extend from each portion of the stent frame 110 to which the protective cover member 180 is attached. One of the two elongated members 114 extends directly to the first diaphragm post 112, and the other elongated member 114 extends directly to the second diaphragm post 112. The protective cover member 180 bisects both the first and second diaphragm post 112 locations. Since the elongated member 114 extends directly between the connecting post 112 and the portion of the stent frame 110 to which the protective cover member 180 is attached, a large open cell is defined by the stent frame 110 between the protective cover member 180 and the connecting post 112.

[0037] Referring also to Figure 5, the valve member 160 is composed of three valve leaflets 162. Figure 5 shows an example of a single valve leaflet 162 so that its specific shape can be clearly envisioned. The valve leaflet 162 constitutes the portion of the valve member 160 that extends between the commissar posts 112 of the stent frame 110. The valve leaflet 162 is the portion of the valve member 160 that performs most or all of the reconfiguration movement when the valve member 160 repeatedly moves between a closed state and a fully open state (as shown, for example, in Figures 2 and 3).

[0038] Although the valve leaflet 162 shown in Figure 5 is depicted in two dimensions, the natural shape of the valve leaflet 162 (in an unstressed state) is actually three-dimensional. That is, the valve leaflet 162 includes a first planar region 163, a second planar region 164, and a concave region 165. The first planar region 163 and the second planar region 164 are both planes (but not within the plane of Figure 5). The concave region 165 is concave, curved, dish-shaped, etc. The concave region 165 is located between the first planar region 163 and the second planar region 164. The first planar region 163 and the second planar region 164 are not coplanar with each other. That is, the first planar region 163 defines a first plane, and the second planar region 164 defines a second plane distinct from the first plane. The extension planes defined by the first planar region 163 and the second planar region 164 intersect each other.

[0039] The first planar region 163 and the second planar region 164 include the free edge of the valve leaflet 162. The first planar region 163 includes the first free edge portion 163e, and the second planar region 164 includes the second free edge portion 164e. The first free edge portion 163e and the second free edge portion 164e together constitute the free edge of the valve leaflet 162.

[0040] The first free edge 163e contacts the second free edge 164e at the center position 166 of the free edge of the valve leaflet 162. Although the first free edge 163e and the second free edge 164e are linear in the illustrated embodiment, they are not collinear with respect to each other. The first free edge 163e and the second free edge 164e are not parallel to each other either. Rather, an angle "α" is defined between the first free edge 163e and the second free edge 164e. In some embodiments, the angle α is, but is not limited, in the range of 80° to 120°, 70° to 130°, 90° to 110°, or 100° to 140°.

[0041] The concave region 165 is located between the first planar region 163 and the second planar region 164. The concave region 165 joins the first planar region 163 along the first curved path 163i. The concave region 165 joins the second planar region 164 along the second curved path 164i. The first curved path 163i extends to the center position 166 of the free edge of the valve leaflet 162. The second curved path 164i also extends to the center position 166 of the free edge of the valve leaflet 162. The first curved path 163i intersects the second curved path 164i at the center position 166 of the free edge of the valve leaflet 162. Therefore, it can be said that the concave region 165 includes the apex located at the center position 166 of the free edge of the valve leaflet 162.

[0042] Figure 6 shows one method by which a valve member 160 having three valve leaflets 162 can be manufactured. In this example, the material for the valve member 160 is formed using a mold 170 to have the three-dimensional shape of the valve leaflets 162 as described above. Here, half of the mold 170 is shown, and the other half of the mold 170 is not shown for simplification. Such a mold 170 can be used to form the material for the valve member 160 so that it has three valve leaflets 162 with a first planar region 163, a second planar region 164, and a concave region 165. In some embodiments, the mold 170 may include openings, channels, and ports, or may be made of a porous material, so that fluid can pass through the mold 170 and reach the structural material during the structural molding process.

[0043] In addition to the valve leaflets 162, the valve member 160 may optionally include a base portion 167. In the illustrated embodiment, there is a boundary line 168 between the base portion 167 and the portion of the valve member 160 including the valve leaflets 162. Alternatively, in some embodiments, the base portion 167 is simply a direct extension of the portion of the valve member 160 including the valve leaflets 162 (without a clear boundary line 168). In some embodiments, the valve member 160 is attached to the stent frame 110 such that the base portion 167 extends all the way to the edge of the stent frame 110 at the inlet end 102 of the artificial heart valve 100.

[0044] After forming the three-dimensional shape of the valve member 160 as shown in Figure 6, the valve member 160 may be formed into a substantially cylindrical shape within the stent frame 110. Figures 7 and 8 show the valve member 160 in a closed and fully open state, respectively. Here, the stent frame 110 and other parts of the artificial heart valve 100 are not shown in order to more easily visualize the shape features of the valve member 160.

[0045] The morphological features of the valve member 160 (e.g., the valve leaflet 162 including a first planar region 163, a second planar region 164, and a concave region 165), and how these morphological features are arranged on the valve member 160, as described particularly with reference to Figure 5, are designed and selected by the inventors to achieve certain advantageous performance characteristics for the artificial heart valve 100. For example, the morphological features of the valve member 160 improve the performance characteristics of the artificial heart valve 100, including but not limited to a high leaflet contact surface, a low mean pressure gradient, a large valve opening area, low leaflet stress, and a high duration of the valve 160 in its open state.

[0046] This specification includes many specific implementation details, which should not be construed as limitations on the scope of any invention or claim, but rather as descriptions of features that may be specific to a particular embodiment of a particular invention. Certain features described herein in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented separately in multiple embodiments or in any suitable subcombination. Furthermore, features are described herein as acting in a combination, and may even be initially claimed as such, but in some cases one or more features from a claimed combination may be removed from the combination, and the claimed combination may cover a partial combination or a variation of a partial combination.

[0047] Specific embodiments of the present invention have been described. Other embodiments are within the scope of the following claims. For example, the actions described in the claims can still achieve the desired results even if they are performed in a different order. As an example, the process shown in the accompanying drawings does not necessarily require the specific order or sequence shown to achieve the desired results. In some implementations, multitasking may be advantageous.

Claims

1. It is an artificial heart valve, A stent frame that is reconfigurable between a thin delivery form and an extended, operable form, A valve member having a single piece of collagen-based biomaterial attached to the stent frame and having a plurality of valve leaflets, wherein each valve leaflet is molded and crosslinked to maintain a three-dimensional shape having a free edge and a concave region, The artificial heart valve includes an inlet end and an outlet end, and the valve member is configured to (i) open to allow blood flow from the inlet end to the outlet end, and (ii) close to prevent blood flow from the outlet end to the inlet end. An artificial heart valve in which the concave regions of each valve leaflet are separated from the edge of the stent frame at the inlet end by a portion of the collagen-based biomaterial that is shaped to be non-planar.

2. The artificial heart valve according to claim 1, wherein the concave region of each valve leaflet has its apex at the central position of the free edge of the valve leaflet.

3. Each valve leaflet is, A first planar region including a first free edge portion terminating at the center position of the free edge of the valve leaflet, The valve leaflet comprises a second planar region including a second free edge portion terminating at the center position of the free edge of the valve leaflet, The artificial heart valve according to claim 1, wherein the concave region is disposed between the first planar region and the second planar region.

4. The artificial heart valve according to claim 3, wherein the first free edge is straight and the second free edge is straight.

5. The artificial heart valve according to claim 4, wherein the first free edge and the second free edge are non-parallel to each other.

6. The artificial heart valve according to claim 4, wherein the angle defined between the first free edge and the second free edge is 80° to 120°.

7. The artificial heart valve according to claim 3, wherein the first planar region and the second planar region are not on the same plane.

8. It is an artificial heart valve, A valve member including a flexible valve leaflet, A metal framework comprising (i) a plurality of cells, (ii) a plurality of connecting posts to which the valve member is attached, and (iii) a plurality of frame portions defining one or more openings smaller than the plurality of cells, A skirt attached to the inlet end of the aforementioned metal framework, An artificial heart valve comprising a plurality of protective cover members attached to and covering local valve-facing surfaces of the frame portion, wherein the protective cover members are separated from the skirt.

9. The artificial heart valve according to claim 8, wherein each of the frame portions is directly connected to two adjacent commissure posts by two individual elongated members of the metal framework extending in opposite directions like an arch.

10. The artificial heart valve according to claim 8, wherein the skirt defines a cylinder, and the commissure post and the frame portion all extend from the cylinder toward the outflow end of the metal framework.

11. The artificial heart valve according to claim 10, wherein the plurality of cells comprises a plurality of smaller cells and a plurality of larger cells, the skirt is attached to the plurality of smaller cells so as to define the cylinder, and each of the frame portions is located between two of the commissure posts so as to define two of the plurality of larger cells.

12. The artificial heart valve according to claim 10, wherein the plurality of larger cells are not covered by the skirt.

13. The artificial heart valve according to claim 8, wherein the protective cover member comprises three separate protective cover members, each containing bovine pericardium sutured to the frame portion.

14. The artificial heart valve according to claim 8, wherein the skirt abuts against the protective cover member.

15. The aforementioned skirt, A first skirt material attached to the inside of the aforementioned metal framework, The metal frame comprises a second skirt material attached to the outside of the metal frame, The artificial heart valve according to claim 8, wherein the first and second skirt materials are different types of materials.

16. The artificial heart valve according to claim 8, wherein the valve member comprises three valve leaflets, each including a free edge, and each of the free edges extends between two of the commissure posts.

17. The artificial heart valve according to claim 16, wherein the valve member is reconfigurable between a fully closed state in which the free edges are in contact with each other and a fully open state in which the free edges are separated from each other.

18. The artificial heart valve according to claim 17, wherein in the fully open configuration, the intermediate portions of each of the free edges are located closer to the inlet end than the respective outflow edges of the protective cover member.

19. The artificial heart valve according to claim 18, wherein in the fully closed configuration, all portions of each of the free edges are located closer to the outlet end than each of the outlet-side edges of the protective cover member.

20. The artificial heart valve according to claim 8, wherein each of the frame portions is located equidistant from two of the commissure posts.

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