Method and apparatus for forming a heart valve wireform
First Claim
1. An apparatus for forming a three-dimensional wireform for use in a heart valve, comprising:
- a first mandrel having a forming surface with a varying curvature;
a second mandrel having a forming surface with a varying curvature; and
a forming tool having clamps for cooperating with the mandrels and rigidly holding a two-dimensional wire and displacing the forming surfaces of the mandrels with respect to one another to bend the wire into a three-dimensional shape.
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Accused Products
Abstract
A system and method for forming a three-dimensional wireform for heart valves from a two-dimensional starting shape. The wireform has multiple arcuate cusps and oppositely directed commissure tips therebetween, the cusps and commissure tips being oriented generally in a tube about an axis. The two-dimensional wire has three cusps and two commissure tips, with two free ends having bent segments. The wireforming system and process holds the commissure tips, or one commissure tip and one bent segment, and forms the cusp therebetween. The wire is held by two axially-parallel mandrels and cooperating clamps which axially rotate and move toward one another. A forming surface on each mandrel bends one half of the cusp, the forming surfaces being mirror images of one another. The forming surface has a complex curvature specifically designed to shape a particular size of wireform into a desired final three-dimensional shape. After bending all the cusps, the free ends of the wire are joined, such as with a tubular crimp, and the wireform assembled into a tissue-type heart valve.
42 Citations
17 Claims
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1. An apparatus for forming a three-dimensional wireform for use in a heart valve, comprising:
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a first mandrel having a forming surface with a varying curvature;
a second mandrel having a forming surface with a varying curvature; and
a forming tool having clamps for cooperating with the mandrels and rigidly holding a two-dimensional wire and displacing the forming surfaces of the mandrels with respect to one another to bend the wire into a three-dimensional shape. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A subassembly for bending a wire for a heart valve wireform, the wireform having alternating arcuate cusps and arcuate commissure tips, comprising:
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a pair of mandrels having forming surfaces that have non-cylindrical cross-sectional shapes. - View Dependent Claims (9, 10, 11)
a shaft sized to fit within the throughbore having an axial groove; and
a key sized to fit within the groove in the shaft and within the keyway and couple rotation of the shaft and mandrel.
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10. The subassembly of claim 9, further including, for each mandrel, a clamp having a throughbore and a keyway sized to receive the shaft and key, respectively, and couple rotation of the shaft, mandrel and clamp.
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11. The subassembly of claim 10, wherein each mandrel further includes an axial channel on one side adjacent the forming surface, and the clamp includes an external recess aligned with the channel, the subassembly further including a retaining pin projecting into the channel and sized to receive therearound one of the arcuate commissure tips of the two-dimensional wire, the commissure tip being retained by overlapping of the channel and recess.
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12. A method for forming a three-dimensional wireform for use in a heart valve, comprising:
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bending a wire into a flat (2-dimensional) undulating pattern of the alternating cusps and commissures; and
bending the flat pattern into a three dimensional shape using;
a pair of mandrels having forming surfaces that have non-cylindrical cross-sectional shapes. - View Dependent Claims (13, 14, 15, 16, 17)
providing a forming tool having clamps for cooperating with the mandrels and rigidly holding a two-dimensional wire;
displacing the forming surfaces of the mandrels with respect to one another to bend the wire into a three-dimensional shape.
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14. The method of claim 13, wherein the forming tool includes first and second shafts arranged to rotate along parallel axes, the mandrels including throughbores sized to receive the respective shafts, and further including
rotating the shafts to cause the displacement of the forming surfaces of the mandrels. -
15. The method of claim 14, wherein the forming tool includes a linear slide for translating one of the shafts in a direction perpendicular to the parallel axes and the displacement of the forming surfaces of the mandrels further includes:
translating one of the shafts and forming surface toward the other shaft and forming surface.
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16. The method of claim 15, further including:
coordinating the rotation of the shafts and translation of the one shaft using motors and a programmable controller.
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17. The method of claim 12, further including:
holding two of the commissures of the wire with a cusp therebetween and using the pair of mandrels to bend one cusp at a time.
Specification