Prosthetic heart valve

Abstract

A prosthetic valve assembly includes a radially expandable and compressible annular frame. The frame includes a plurality of interconnected struts including a plurality of inner struts and a plurality of outer struts. The inner struts overlap adjacent outer struts at a plurality of pivot joints. Radial expansion or compression of the annular frame causes the inner struts to pivot relative to the outer struts at the pivot joints. The assembly also includes a valve structure within the frame having a plurality of leaflets that regulate blood flow through the frame. Some struts include recessed portions, and other struts that cross the recessed portions include segments that reside in the recessed portions at the pivot joints. This provides a continuous or flush inner or outer surface of the frame.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 893,621, filed August 29, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to artificial heart valves, as well as related systems and methods. Technical Background

[0004] Current designs for the mechanical framework of artificial heart valves consist of multiple intersecting struts that attach to each other at junctions to form a grid. The grid of struts forms the walls of the framework, which are generally cylindrical, but may not be perfectly cylindrical in any particular framework design. The grid has two layers of struts—an inner radial layer and an outer radial layer. All struts in each layer are generally parallel to each other and intersect with struts in the other layer. All inner surfaces of the inner layer struts form the inner diameter surface of the framework. All outer surfaces of the outer layer struts form the outer diameter surface of the framework. Summary of the Invention

[0005] This document describes examples of artificial valves, their components, and related methods for assembling, delivering, and using them. The artificial valves disclosed herein can be implanted within any autologous valve of the heart (e.g., aortic, mitral, tricuspid, and pulmonary valves). In some embodiments, the artificial valve can be delivered via the vascular system and implanted into a patient's heart using a delivery device such as a catheter-based delivery device. The frameworks disclosed herein can also be used for artificial valves in other catheters of the body or as stents for structures without valves.

[0006] Some embodiments of this disclosure relate to artificial heart valves. The assembly may include a radially expandable and compressible annular frame. The frame can expand within the implantation site by applying radially outward forces, such as by a balloon or mechanical tool, or by applying circumferential dissociation forces, or by applying axial shortening forces.

[0007] The frame may include multiple interconnected pillars. These interconnected pillars may include multiple inner pillars and multiple outer pillars. Inner pillars may overlap adjacent outer pillars at multiple pivot joints, connected together by pins or other fasteners that allow the pillars to pivot relative to each other. The interconnected pillars may be arranged in a lattice or grid, with each pillar extending diagonally or helically around the frame. Radial expansion or compression of the annular frame may cause the inner pillars to pivot relative to the outer pillars at the pivot joints.

[0008] Further details regarding the general structure of such a prosthetic valve assembly and mechanical frame can be found in U.S. Provisional Application 62 / 854,702, filed May 30, 2019, which is incorporated by reference herein in its entirety. Referring to U.S. Provisional Application 62 / 854,702, FIG. 1 shows an entire prosthetic valve using a mechanical frame that includes interconnected struts pivotably coupled at pivot joints. Figure 2A and 2B Only the frame is shown and the radially expanded and compressed configurations are illustrated. Figure 3 and Figure 4 Examples of how other components are attached to the frame are shown, and Figure 6A and 6B Individual struts are shown, and FIG. 6C shows the pivot joint in detail. Other components and details of the valve and frame are also described in U.S. Provisional Application 62 / 854,702, such as valve leaflets, inner skirt, outer skirt, frame expansion mechanism, delivery device, exemplary materials and dimensions, and related methods of assembly and use. The valves and frames disclosed herein can have similar structures to those shown in U.S. Provisional Application 62 / 854,702, except as described herein. Further details regarding transcatheter prosthetic heart valves, including the manner in which valve structures can be mounted to prosthetic valve frames, can be found in, for example, U.S. Patent Nos. 6,730,118; 7,393,360; 7,510,575; 7,993,394; and 8,252,202; and U.S. Publication No. 2018 / 0325665, all of which are incorporated by reference herein in their entireties. Further details regarding the construction of frames and prosthetic valves are described in U.S. Patent Publication Nos. 2018 / 0153689 and 2018 / 0344456; and U.S. Patent Application Nos. 16 / 105,353 and 62 / 748,284, all of which are incorporated by reference herein.

[0009] In embodiments disclosed herein, at least some struts include a recessed portion at a pivot joint, and segments of other struts are located in the recessed portion at the pivot joint. In some embodiments, at least some outer struts include a recessed portion, and segments of at least some inner struts are located in the recessed portion, and in some embodiments, at least some inner struts include a recessed portion, and segments of at least some outer struts are located in the recessed portion. In some embodiments, at least some inner struts include a recessed portion that receives segments of outer struts, and at least some outer struts include a recessed portion that receives segments of inner struts.

[0010] Pivot joints segmented in recessed portions can be configured such that they have a substantially continuous inner or outer surface, which can facilitate attachment of leaflets or skirts to the frame and provide other benefits. In some embodiments, pivot joints segmented in recessed portions have a substantially continuous inner surface such that the inner surface of a seated segment and the adjacent inner surface of a strut joined to the seated segment have approximately equal radial dimensions from the centerline of the frame. This can help attachment of leaflets and inner skirts to the interior of the frame. In some embodiments, pivot joints segmented in recessed portions have a substantially continuous outer surface such that the outer surface of a seated segment and the adjacent outer surface of a strut joined to the seated segment have approximately equal radial dimensions from the centerline of the frame. This can help attachment of outer skirts and / or help prevent paravalvular leakage.

[0011] Struts can include a plurality of recessed portions at respective pivot joints, and all intersecting strut segments can be located in recessed portions at respective pivot joints.

[0012] Recesses defined by recessed portions can be sized to receive intersecting strut segments while allowing pivoting motion between struts. The recesses of the recessed portions can have a radial depth approximately equal to the radial thickness of a segment located in the recessed portion, such that their radially facing surfaces can be flush or coplanar, thereby providing a continuous overall frame surface. The recesses of the recessed portions can have a length greater than the width of a segment located in the recessed portion to allow space for a seated segment to pivot within the recess.

[0013] Also disclosed herein are methods of forming a mechanical frame by coupling inner struts to outer struts at pivot joints, such as via pivot pins. Also disclosed herein are methods of crimping or radially compressing a prosthetic heart valve including a mechanical frame, where the struts move closer to parallel to the axial dimension within the same circumferential plane, such that shearing of the internal valve structure can be avoided. Also disclosed herein are methods of implanting a prosthetic heart valve, where the mechanical frame is radially expanded and uniformly pressed against surrounding autologous tissue to prevent paravalvular leakage pathways between the frame and autologous tissue.

[0014] Further details of the disclosed technology are described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1A and 1B are views of the interior of a prosthetic heart valve showing how leaflets and skirts are connected to the struts of the frame.

[0016] Figure 2A is a schematic view of the intersection between struts of a frame showing an uneven frame surface that engages with leaflets.

[0017] Figure 2B is a schematic view of a frame showing how the struts can create a shearing shear force.

[0018] Figure 3 is a cross-sectional view of a heart valve showing the radial and circumferential positioning of the inner and outer struts of the frame when the frame is crimped.

[0019] Figure 4 shows the outboard side of a heart valve without an outer skirt showing the paravalvular leak pathway.

[0020] Figure 5 shows a junction between two frame struts where one strut has a recessed portion that receives a crossing strut, thereby providing a relatively continuous or flush overall surface.

[0021] Figure 6A shows a pair of strut junctions similar to Figure 5 where the continuous surface is an inner surface facing the valve leaflets.

[0022] Figure 6B is a schematic view of a frame incorporating recessed strut junctions as shown in Figure 5 showing the alignment between the struts that mitigates shear forces on the leaflets and skirt. DETAILED DESCRIPTION

[0023] Described herein are examples of a prosthetic heart valve that can be implanted within any native valve of the heart (e.g., the aortic valve, the mitral valve, the tricuspid valve, and the pulmonary valve). The present disclosure also provides frames for use with such prosthetic implants. The prosthetic valves disclosed herein are radially compressible and expandable between a radially compressed state and a radially expanded state. Thus, the prosthetic valve can be held in the radially compressed state by an implant delivery device during delivery, and then expanded to the radially expanded state once the prosthetic valve reaches the implant site.

[0024] Conventional designs for mechanical frames for prosthetic heart valves suffer from several drawbacks, which can include some or all of the following drawbacks: Among other things, (1) each leaflet can be connected to an inner strut at one edge and to an outer strut at its other edge. The edge of the leaflet connected to the inner strut can be attached to a uniform surface, while the edge connected to the outer strut lies on a non-uniform surface (e.g., a "meandering" shape along varying diameters with respect to the center of the frame, as it has to "climb" over the intersecting inner and outer struts). This pattern can affect the accuracy and uniformity of the leaflet attachment because: (a) it can create folds in the leaflet, thereby changing its shape and interfering with its ability to move, and (b) the attachment to different diameters can create an asymmetric leaflet, such that the leaflet coaptation is not optimal. (2) The overall wall thickness of the frame can be equal to or greater than twice the strut thickness, which is an important factor in crimping. (3) During crimping, the relative motion between adjacent inner and outer struts creates a scissor-like shear force, which can compromise the integrity of the leaflet tissue. (4) In designs that do not include an outer cloth component or a paravalvular sealing component, it is likely that the parallel outer struts create a channel for paravalvular leakage.

[0025] The present application discloses new strut geometries that can avoid the above-mentioned drawbacks. The valve frames disclosed herein can include struts having recessed mid-sections configured to accommodate respective straight mid-sections of adjacent intersecting struts. The junction between the intersecting struts can be convex only along one surface (outer or inner) of the frame, while the opposite surface remains relatively flat or continuous.

[0026] Determining which surface is provided as the flat / continuous surface, whether the inner surface of the frame (which coapts with the leaflets) or the outer surface (which coapts with the anatomical environment), can be based on the arrangement of the intersecting struts. In some embodiments, the outer struts can be formed with recessed mid-sections that cover the "straight" inner struts, so as to form an inner continuous surface, enabling both edges of the leaflets to attach to a continuous inner surface of equal diameter. In other embodiments, the inner struts can be formed with recessed mid-sections that cover the "straight" outer struts, so as to form an outer continuous surface, enabling the provision of additional free lumen volume in the crimped frame to accommodate internal soft components.

[0027] The recessed portions of the struts can be formed by stamping the straight struts in the desired areas. Both geometries (continuous outer surface or continuous inner surface) can provide a tight interface with the vessel wall anatomy, resulting in a single layer mesh that does not form a leakage channel.

[0028] Figure 1A and 1B A frame 10 of a prosthetic heart valve is shown, which includes a plurality of interconnected struts 40a, 40b, 40c, 40d, etc. Figure 2A and2B A schematic view of the frame 10 is shown. Each strut comprises a plurality of segments disposed between its two ends, and intermediate segments 42a, 42b, etc. disposed between each pair of adjacent segments in the strut. The ends and intermediate segments of each strut can comprise holes through which the struts can be connected to each other, e.g. via fasteners (e.g. pins through the holes), to form the pivot joints J1, J2, etc. As Figures 1A-1B shown, the width of the joints J1, J2 is twice the width of a single strut, and the resulting frame geometry forms an uneven outer and / or inner surface, with the joints protruding radially with respect to the straight segments of the struts. Figure 2A It is illustrated how the frame protrudes at the joints J1, J2, J3.

[0029] Figures 1A-1B A valve leaflet 20 and an outer skirt 30 are shown attached at the scalloped sutures 22 to the skirt portion or cloth, with the valve leaflet 20 and the outer skirt 30 attached to the outer strut 40a of the frame 10 via the suture loops 32a, 32b, etc., and with the valve leaflet 20 contacting the inner surface of the frame 10 and the outer skirt 30 contacting the outer surface of the frame 10. Figure 1A An example of overlapping outer and inner struts 40a, 40b is shown, which are connected to each other at the joint J1, such that the joint J1 protrudes radially inward, i.e. towards the centerline 12 of the frame 10 (see Figure 2B ). The edges of the valve leaflet 20 are attached to the outer strut 40a via the suture loops 32a, 32b, and the radial inward protrusion of the joint J1 between the suture loops 32a and 32b forms a discontinuous interface between the leaflet 20 and the strut 40a.

[0030] Figure 1B An example of overlapping inner and outer struts 40c, 40d is shown, which are connected to each other at the pivot joint J2, such that the joint J2 protrudes radially outward. The edges of the leaflet 20 are attached to the inner strut 40c via the suture loops 32c, 32d, and in this region a continuous interface is formed between the leaflet 20 and the strut 40a. However, the radial outward protrusion of the joint J2 between the suture loops 32c and 32d forms a discontinuous interface between the outer skirt 30 and the strut 40c.

[0031] Figure 2B Further challenges of the structure of the frame 10 are shown, where the position of adjacent struts 40, e.g. struts 40f, 40g, 40h, 40i, can change during crimping of the frame 10, such that they come close to each other while the frame 10 is compressed or crimped, thereby creating undesired folding of the leaflets 20 or outer skirts 30 attached thereto, and even possibly exerting a scissor-like shear force that can further damage the leaflets 20 or outer skirts 30.

[0032] Figure 3 A cross-sectional view showing the radial displacement of adjacent struts 40f, 40g, 40h, 40i during valve compression, which can exert shear forces that can damage the tissue of the leaflets 20 or skirt 30.

[0033] Figure 4 An exemplary prosthetic heart valve is shown, wherein no outer skirt is included. Figure 4 The leaflets in the embodiment of FIG. 1 are connected to the frame via an inner skirt. A disadvantage of this design is that leakage channels can form between the parallel outer struts 40a and the surrounding blood vessel wall against which the expanded valve rests, directing blood flow through these channels in the direction of arrows 92, resulting in overall paravalvular leakage flow in the direction of arrows 90.

[0034] The novel frame disclosed herein can provide an improved strut geometry, wherein some or all of the intermediate struts segments are curved to form recessed intermediate segments configured to accommodate straight or also curved intermediate segments of overlapping struts.

[0035] Figure 5 A schematic view of straight strut segments 40 overlaid on curved struts 50 with recessed intermediate segments 52 is shown, such that the recessed intermediate segments 52 at the junctions JN receive and couple with the intermediate segments 44 of the straight struts. Although Figure 5 Not shown in the

[0036] According to some embodiments, the recessed intermediate segments 52 or recessed ends can be formed by providing straight struts and stamping (e.g., plastically deforming) them at such desired recessed areas. Advantageously, the relatively straight struts are overlaid on the struts with recessed intermediate segments such that at least one surface of the resulting frame is continuous or flush, such that the continuous surface does not include any substantial radial protrusion at the junctions JN (and at the apex).

[0037] As Figure 6A schematically shown in FIG. 1, the struts 50 with recessed intermediate segments are coupled to the struts 40 such that when the junctions JN1 and JN2 are convex towards one side (the lower side, the radially outer side of the frame in this view), the surface of the opposite side (the upper side, the radially inner side of the frame in this view) is substantially continuously adjacent to the leaflets 20. According to some embodiments, by coupling a set or layer of parallel outer struts 50 with recessed intermediate segments 52 to a set or layer of parallel intersecting inner (straight) struts 40 in the manner shown in FIG. 1, the inner surface of the frame is substantially continuously adjacent to the leaflets 20. Advantageously, the leaflets 20 can be connected to the continuous inner surface of the frame via both edges in this geometry. Figure 6A schematically shown in FIG. 1, the struts 50 with recessed intermediate segments are coupled to the struts 40 such that when the junctions JN1 and JN2 are convex towards one side (the lower side, the radially outer side of the frame in this view), the surface of the opposite side (the upper side, the radially inner side of the frame in this view) is substantially continuously adjacent to the leaflets 20. According to some embodiments, by coupling a set or layer of parallel outer struts 50 with recessed intermediate segments 52 to a set or layer of parallel intersecting inner (straight) struts 40 in the manner shown in FIG. 1, the inner surface of the frame is substantially continuously adjacent to the leaflets 20. Advantageously, the leaflets 20 can be connected to the continuous inner surface of the frame via both edges in this geometry.

[0038] According to some embodiments, the frame is formed by connecting one or more layers of parallel inner struts 50 with recessed intermediate segments 52 with one or more layers of parallel intersecting outer (straight) struts 40, such that the outer surface of the frame is substantially continuous. Advantageously, additional free internal volume can be achieved in the crimped frame of this geometry to accommodate internal soft components such as leaflets and inner skirt.

[0039] A further advantage of the disclosed embodiments is that they enable artificial heart valves that lack an outer skirt, without the risk of forming a leak channel along the outer surface of the frame. This can be achieved in a combination of the two proposals described above, such that: (a) if the outer surface is continuous (i.e. the junctions JN are protruding inwardly towards the inner lumen of the frame), then no space is formed between the fully expanded frame against the vessel wall, thus avoiding the formation of a leak channel, and (b) if the inner surface is continuous (i.e. the junctions JN are protruding outwardly towards the vessel wall), then the frame can be further expanded such that the junctions JN are pressed against the vessel wall (i.e. slightly piercing the vessel inner surface), until the segments of the struts are tightly pressed against the vessel wall, thus avoiding the formation of a leak channel therebetween.

[0040] A further advantage of the disclosed technology is that it mitigates the risk of shear forces acting on the leaflets or skirt (see e.g. Figure 2B and 3 ) during compression or crimping. As shown in Figure 6B , since the adjacent struts 40 and 50 are brought close to each other along the same circumferential plane during frame compression, shear of the soft layer disposed therebetween is avoided, while substantially avoiding radial displacement between the adjacent struts, which can result in harmful shear or “shear-like” forces.

[0041] General Considerations

[0042] It is to be understood that the disclosed embodiments can be applied to deliver and implant artificial devices in any native annulus of the heart (e.g. aortic, pulmonary, mitral and tricuspid annulus), and can be used with any of a variety of delivery devices that deliver artificial valves using any of a variety of delivery methods (e.g. retrograde, antegrade, trans-septal, trans-ventricular, trans-atrial, etc.).

[0043] For purposes of this summary, certain aspects, advantages, and novel features of the implementations of the present disclosure are described. The disclosed methods, apparatus, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed implementations, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any particular aspect or feature or combination of aspects and features, nor do the disclosed implementations require the presence of any particular advantage or resolve any problem. Techniques from any example can be combined with techniques described in any one or more other examples. In view of the many possible embodiments to which the principles of the disclosed technology can be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosed technology.

[0044] Although the operations of some disclosed implementations are described in a particular, sequential order for convenience, it should be understood that this manner of description encompasses rearrangement, save to the specific order required by particular words described herein. For example, operations described sequentially can in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures can not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “provide” or “achieve” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms can vary depending on the particular implementation and are readily recognized by one of ordinary skill in the art.

[0045] As used in this application and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the term “includes” means “comprises.” As used herein, “and / or” means “and” or “or,” as well as “and” and “or.” Furthermore, the term “coupled” and “connected” generally mean electrically, electromagnetically, and / or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between coupled or associated items absent specific contrary language.

[0046] Directions and other related references (e.g., inner, outer, upper, lower, etc.) can be used to facilitate discussion of the drawings and principles of the present description, but are not intended to be limiting. For example, certain terms can be used, such as “inboard,” “outboard,” “top,” “bottom,” “inner,” “outer,” etc. Where applicable, these terms are used to provide some clarity in dealing with relative relationships, particularly with respect to the illustrated implementations. However, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, an “upper” part can become a “lower” part if an object is turned over. Nonetheless, it is still the same part, and the object is still the same.

[0047] The valves and frames disclosed herein are described using axial, radial, and circumferential directions, with the axial direction defined by the centerline of the annular frame and the overall blood flow direction from the inflow end to the outflow end, the radial direction defined as radiating perpendicularly from the centerline of the frame, and the circumferential direction perpendicular to both axial and radial and extending around the centerline of the frame. The term "inner" refers to objects, surfaces, and regions close to the centerline of the frame, while the term "outer" refers to objects, surfaces, and regions away from the centerline of the frame.

[0048] In view of the many possible embodiments to which the principles of the disclosed technology can be applied, it should be recognized that the examples described herein are not limited in scope to the exemplary embodiments disclosed. Indeed, various changes can be made to the embodiments without departing from the scope of the technology.

Claims

1. An artificial heart valve, comprising: A radially expandable and compressible annular frame comprising a plurality of pillars, each of the plurality of pillars comprising a plurality of segments disposed between two ends of each pillar and a respective intermediate segment disposed between two of the respective segments, the plurality of pillars comprising inner pillars and outer pillars separated from each other, wherein the outer pillars overlap with adjacent inner pillars at a pivot joint, and radial expansion or compression of the annular frame causes the inner pillars to pivot relative to the outer pillars at the pivot joints. and A valve structure installed within the frame that regulates blood flow through the artificial heart valve; At least some of the intermediate segments of the plurality of pillars are bent to form a recessed intermediate segment at the pivot joint to accommodate the respective straight or also bent intermediate segments of the respective overlapping pillars of the other pillars among the plurality of pillars, such that the other pillars of the plurality of pillars are located in the recessed intermediate segment at the pivot joint.

2. The valve of claim 1, wherein at least some of the outer struts include a recessed intermediate segment, and at least some of the inner struts have segments located within the recessed intermediate segment.

3. The valve of claim 1, wherein at least some of the inner struts include a recessed intermediate segment, and at least some of the outer struts have segments located within the recessed intermediate segment.

4. The valve of claim 1, wherein at least some of the inner struts include a recessed intermediate segment that receives a segment of the outer strut, and at least some of the outer struts include a recessed intermediate segment that receives a segment of the inner strut.

5. The valve according to any one of claims 1-4, wherein the pivot joint located in the middle segment of the recess has a substantially continuous inner or outer surface.

6. The valve of claim 5, wherein the pivot joint located in the recessed intermediate segment has a continuous inner surface such that the inner surface of the seated segment and the adjacent inner surface of the strut connected to the seated segment have radial dimensions equal to the centerline of the frame.

7. The valve of claim 5, wherein the pivot joint located in the recessed intermediate segment has a continuous outer surface such that the outer surface of the seated segment and the adjacent outer surface of the strut connected to the seated segment have radial dimensions equal to the centerline of the frame.

8. The valve according to any one of claims 1-4, wherein at least some of the struts include two or more recessed intermediate segments located at their respective pivot joints, and the segments of the other struts are located in the two or more recessed intermediate segments at their respective pivot joints.

9. The valve according to any one of claims 1-4, wherein the frame further comprises a pin that connects the recessed intermediate segment to the segment in the recessed intermediate segment located at the pivot joint.

10. The valve according to any one of claims 1-4, wherein the depth of the intermediate segment of the recess is equal to the thickness of the segment located in the intermediate segment of the recess.

11. The valve according to any one of claims 1-4, wherein the width of the intermediate segment of the recess is greater than the width of the segment located in the intermediate segment of the recess.

12. The valve according to any one of claims 1-4, wherein the leaflet of the valve structure is attached to the strut including the intermediate segment of the recess.

13. The valve according to any one of claims 1-4, wherein at least some of the struts include recessed ends, and the end segments of the other struts are located in the recessed ends, forming a pivot joint at the top of the frame.

14. A mechanical frame for an artificial valve, comprising: A plurality of interconnected pillars forming a radially expandable and compressible annular lattice, each of the plurality of interconnected pillars comprising a plurality of segments disposed between two ends of each pillar and a respective intermediate segment disposed between each of two segments, the plurality of interconnected pillars comprising a set of inner pillars parallel to each other and a set of outer pillars parallel to each other, wherein the outer pillars overlap with adjacent inner pillars at pivot joints, and the radial expansion or compression of the annular lattice causes the inner pillars to pivot relative to the outer pillars at the pivot joints; At least some of the interconnected struts have their intermediate segments bent to form recessed intermediate segments at the pivot joint to accommodate the respective straight or bent intermediate segments of the respective overlapping struts of the other interconnected struts, such that the other struts of the interconnected struts are located in the recessed intermediate segments at the pivot joint.

15. The frame of claim 14, wherein at least some of the outer pillars include a recessed intermediate segment, and at least some of the inner pillar segments are located within the recessed intermediate segment.

16. The frame according to claim 14 or claim 15, wherein at least some of the inner pillars include a recessed intermediate segment, and at least some of the outer pillar segments are located within the recessed intermediate segment.

17. The frame according to claim 14 or claim 15, wherein at least some of the inner pillars include a recessed intermediate segment receiving a segment of the outer pillar, and at least some of the outer pillars include a recessed intermediate segment receiving a segment of the inner pillar.

18. The frame according to claim 14 or claim 15, wherein the pivot joint located in the recessed intermediate segment has a continuous inner or outer surface.

19. The frame of claim 18, wherein the pivot joint of the segment located in the recessed intermediate segment has a continuous inner surface such that the inner surface of the seated segment and the adjacent inner surface of the support connecting to the seated segment have radial dimensions equal to those from the centerline of the frame.

20. The frame of claim 18, wherein the pivot joint of the segment located in the recessed intermediate segment has a continuous outer surface such that the outer surface of the seated segment and the adjacent outer surface of the support connecting to the seated segment have radial dimensions equal to those from the centerline of the frame.

21. The frame according to claim 14 or claim 15, wherein at least some of the interconnected pillars include two or more recessed intermediate segments located at their respective pivot joints, and the segments of the other interconnected pillars are located in the two or more recessed intermediate segments at their respective pivot joints.

22. The frame of claim 14 or claim 15, wherein the frame further includes a pin that connects the recessed intermediate segment to the segment in the recessed intermediate segment located at the pivot joint.

23. The frame according to claim 14 or claim 15, wherein the depth of the intermediate segment of the recess is equal to the thickness of the segment located in the intermediate segment of the recess.

24. The frame according to claim 14 or claim 15, wherein the width of the intermediate segment of the recess is greater than the width of the segment located in the intermediate segment of the recess.

25. The frame according to claim 14 or claim 15, wherein at least some of the pillars include recessed ends, and the end segments of the other pillars are located in the recessed ends, forming a pivot joint at the top of the frame.

26. A method of forming a mechanical framework for an artificial valve, the method comprising: A set of inner pillars is connected to a set of outer pillars at multiple pivot joints to form a radially expandable and compressible annular grid. Each of the set of inner pillars and the set of outer pillars includes multiple segments disposed between two ends of each pillar, and a respective intermediate segment disposed between each of the multiple segments. The inner pillars are parallel to each other and the outer pillars are parallel to each other. The outer pillars overlap with the inner pillars at the pivot joints such that radial expansion or compression of the annular grid causes the inner pillars to pivot relative to the outer pillars at the pivot joints. in: The intermediate segments of the outer pillars are bent to form respective recessed intermediate segments at the pivot joint to accommodate respective straight or also bent segments of the respective overlapping inner pillars, such that the inner pillars are located within the recessed intermediate segments of the outer pillars at the pivot joint; or The intermediate segment of the inner pillar is bent to form a respective recessed intermediate segment at the pivot joint to accommodate the respective straight or also bent segments of the respective overlapping outer pillar, such that the outer pillar is located in the recessed intermediate segment of the inner pillar at the pivot joint.

27. The method of claim 26, wherein the connection comprises attaching the straight segment to the recessed intermediate segment with a pivot pin to form the pivot joint.

28. The method of claim 26 or 27, wherein the outer strut includes a recessed intermediate segment at the pivot joint, and each straight or curved segment of the respective overlapping inner strut is located in the recessed intermediate segment of the outer strut at the pivot joint.

29. The method of claim 28, wherein the pivot joint has a substantially continuous radial inner surface.

30. The method of claim 28, wherein the respective straight or curved segmented inner surfaces and the adjacent inner surfaces of the outer pillars have radial dimensions equal to the centerline of the frame.

31. The method of claim 26 or 27, wherein the inner support includes a recessed intermediate segment at the pivot joint, and a straight segment of the outer support is located in the recessed intermediate segment of the inner support at the pivot joint.

32. The method of claim 31, wherein the pivot joint has a substantially continuous radial outer surface.

33. The method of claim 31, wherein the outer surface of the straight segment and the adjacent outer surface of the inner support have radial dimensions equal to the centerline of the frame.

34. The method of claim 26 or 27, wherein at least some of the struts include two or more recessed intermediate segments located at their respective pivot joints, and the segments of the other struts are located in the two or more recessed intermediate segments at their respective pivot joints.

35. The method of claim 26 or claim 27, wherein the depth of the intermediate segment of the recess is equal to the thickness of the straight segment located in the intermediate segment of the recess.

36. The method of claim 26 or claim 27, wherein the width of the intermediate segment of the recess is greater than the width of the straight segment located in the intermediate segment of the recess.

37. The method of claim 26 or claim 27, wherein at least some of the pillars include recessed ends, and the end segments of the other pillars are located in the recessed ends and connected by pivot pins to form a pivot joint at the top of the frame.

38. A method for radially compressing an artificial heart valve, comprising: A set of outer struts and a set of inner struts of the mechanical frame of the artificial heart valve are pivoted relative to each other at multiple pivot joints where the outer struts and the inner struts overlap, such that the outer struts and the inner struts are closer to being parallel to the axial dimension of the frame and the radius of the frame is reduced. Each of the set of inner struts and the set of outer struts includes multiple segments disposed between two ends of each strut and a respective intermediate segment disposed between each two of the multiple segments. The intermediate segments of the outer struts are bent to form respective recessed intermediate segments at the pivot joints to accommodate respective straight or bent segments of the respective overlapping inner struts, such that the inner struts are located in the recessed intermediate segments of the outer struts at the pivot joints, such that the radially inner surface of the outer struts between the pivot joints has an inner radius equal to the radially inner surface of the inner struts between the pivot joints. The reduction in the radius of the frame results in radial compression of the valve structure mounted within the frame; and When the outer and inner struts become closer to being parallel to the axial dimension of the frame, the radially inner surfaces of both the outer and inner struts between the pivot joints maintain substantially continuous radial contact with respect to the valve structure.

39. The method of claim 38, wherein the substantially continuous radial contact with respect to the valve structure prevents the pivot strut from exerting shear forces on the valve structure during radial compression of the artificial heart valve.

40. The method of claim 38, wherein the inner surface of the seated segment of the inner support and the adjacent inner surface of the outer support connected to the seated segment have radial dimensions equal to those from the axial centerline of the frame.

41. The method according to any one of claims 38-40, wherein each of the outer pillars comprises two or more recessed intermediate segments located at its respective pivot joint, and the inner pillar is located in the intermediate segments of the two or more recesses of the outer pillar at its respective pivot joint.

42. The method according to any one of claims 38-40, wherein the frame further comprises a pin that connects the recessed intermediate segment of the outer pillar to the seated segment of the inner pillar at the pivot joint.

43. The method according to any one of claims 38-40, wherein the depth of the intermediate segment of the recess is equal to the thickness of the segment located in the intermediate segment of the recess.

44. The method according to any one of claims 38-40, wherein the width of the intermediate segment of the recess is greater than the width of the segment located in the intermediate segment of the recess.

45. The method according to any one of claims 38-40, wherein the leaflets of the valve structure are attached to the outer struts between the pivot joints.

46. ​​The method according to any one of claims 38-40, wherein at least some of the outer pillars include recessed ends, and the end segments of the inner pillars are located in the recessed ends, forming a pivot joint at the top of the frame.

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