Mechanically expandable heart valve
In one embodiment, a method of assembling a prosthetic valve can comprise forming a radially expandable and compressible frame by pivotally joining together a plurality of struts without requiring individual rivets. In some embodiments, the frame is formed by interweaving the struts, which can be joined using integral hinges formed in the struts, such as by performing alternate cuts on the struts, bending the struts to form stopper tabs adjacent to joints and/or drilling holes in the struts to facilitate interconnecting struts at joints, or otherwise forming integral hinges and corresponding holes at junction points between the struts. In other embodiments, separate hinges are provided to interconnect the struts. In still other embodiments, separate flanged rivets are provided to connect the struts.
1. A method of assembling an implantable medical device, the method comprising:
providing a radially expandable and compressible annular frame comprising a plurality of interconnected struts, the plurality of struts comprising a first set of a plurality of first struts and a second set of a plurality of second struts,
connecting the first and second struts to each other to form an annular frame, wherein said connecting comprises overlapping the first struts over adjacent second struts at junctions;
providing a plurality of hinges at the junctions extending from the first struts through corresponding non-circular apertures of the second struts at the junctions, wherein each hinge comprises a cylindrical pivot portion that can rotate in a corresponding aperture of a second strut; and
providing a locking member extending from the pivot portion, wherein the locking member is sized and shaped relative to the corresponding aperture of the second strut so as to prevent radial separation of the first and second struts whenever the locking member is rotationally offset from the corresponding aperture upon radial expansion and compression of the frame; and
mounting one or more actuators on the frame, the one or more actuators configured to radially expand and compress the frame within a predetermined range of diameters corresponding to a predetermined range of angles between the first and second struts; and
expanding or compressing the annular frame, causing the first struts to pivot relative to the second struts at the junctions.
2. The method of claim 1 , wherein the second struts are formed with recessed portions surrounding the non-circular apertures and the locking members of the hinges are disposed within the recessed portions.
3. The method of claim 1 , wherein the actuators are configured to radially expand and compress the frame between a radially compressed state defining a compressed diameter and a radially expanded state defining an expanded diameter, wherein the locking members are rotationally offset from corresponding non-circular apertures in the second struts at the compressed diameter, the expanded diameter, and all diameters in between the compressed and expanded diameters.
4. The method of claim 1 , further comprising integrally forming the hinges on the first struts.
5. The method of claim 1 , further comprising:
providing the hinges as separate components from the first and second struts, wherein each of the first struts comprises a plurality of non-circular apertures; and
connecting the first and second struts comprises extending each hinge through an aperture in a first strut and an adjacent aperture in a second strut at a junction.
6. The method of claim 5 , wherein each of the hinges further comprises a retaining member configured to be retained within the non-circular apertures on the first struts.
7. The method of claim 5 , wherein each of the hinges further comprises a circular base member configured to be retained within a circular recess surrounding one of the non-circular apertures on the first struts.
8. The method of claim 1 , wherein the locking members comprise a non-circular shape.
9. The method of claim 1 , wherein the locking members comprise a non-circular central protrusion with at least two ears extending outward therefrom in a plane parallel to the strut.
10. A method of assembling an implantable medical device, the method comprising:
providing a plurality of first struts;
providing a plurality of second struts, each second strut comprising a plurality of non-circular apertures spaced along a length thereof;
connecting the plurality of first and second struts to each other to form an annular frame by inserting hinges through the non-circular apertures of the second struts, each hinge having a cylindrical pivot portion disposed in a corresponding non-circular aperture and a locking member extending from one end of the pivot portion, wherein the locking members are rotationally aligned with corresponding non-circular apertures when the hinges are inserted into the non-circular apertures;
pivoting the first struts relative to the second struts to cause the locking members to become rotationally offset from their corresponding non-circular apertures; and
mounting one or more actuators on the frame, the one or more actuators configured to radially expand and compress the frame within a predetermined range of diameters corresponding to a predetermined range of angles between the first and second struts, wherein the predetermined range of angles comprises a range of angles through which the locking members are at all times rotationally offset from the non-circular apertures.
11. The method of claim 10 , wherein each first strut comprises a plurality of non-circular apertures spaced along a length thereof, and wherein connecting the first and second struts comprises inserting the hinges through the non-circular apertures of the first struts and the second struts.
12. The method of claim 10 , wherein the hinges are integral to the first struts.
13. The method of claim 10 , further comprising interweaving the first struts with the second struts.
14. The method of claim 10 , further comprising mounting a valve member comprising a plurality of leaflets inside the annular frame.