Method of testing bioprosthetic heart valve leaflets
First Claim
1. A method of selecting leaflets for an implantable heart valve, comprising the steps of:
- providing a collection of similarly sized leaflets;
applying a load to each leaflet;
observing the strain response in each leaflet from applying the load; and
sorting the leaflets based on their respective strain responses.
1 Assignment
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Accused Products
Abstract
Heart valve leaflet selection methods and apparatuses which subject individual leaflets to loads and measure the resulting deflection to more reliably group leaflets of similar physical characteristics for later assembly in prosthetic heart valves. The deflection testing may be accomplished using a variety of test set ups which are designed to impart a load on the leaflet which simulates the actual loading within a heart valve. The results from a number of deflection tests are used to categorize individual leaflets, which data can be combined with other data regarding the characteristics of the leaflet to better select leaflets for assembly into a multi-leaflet heart valve. In one embodiment, the deflection test is combined with an intrinsic load test, and leaflets having similar deflection and intrinsic load values used in the same heart valve. One apparatus for testing the leaflets includes a frame for securing the arcuate cusp of the leaflet while the straight coapting edge remains free, to simulate the actual leaflet mounting configuration within the heart valve prosthesis. The frame may include a lower portion having a recess for the leaflet and plurality of receptor holes around the peripheral edge of the recess, and an upper portion having a plurality of needles which extend downward through the leaflet and into the receptor holes and secure the edges of the leaflet.
118 Citations
41 Claims
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1. A method of selecting leaflets for an implantable heart valve, comprising the steps of:
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providing a collection of similarly sized leaflets;
applying a load to each leaflet;
observing the strain response in each leaflet from applying the load; and
sorting the leaflets based on their respective strain responses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
performing an intrinsic load test on the leaflets; and
sorting the leaflets based on the intrinsic load test results.
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12. The method of claim 1, wherein the step of sorting the leaflets comprises forming subgroups of leaflets having a strain response within a predetermined range.
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13. The method of claim 12, wherein the step of forming subgroups of leaflets having a strain response within a predetermined range comprises a measuring a deflection of each leaflet resulting from applying a load thereto, and forming a subgroup of leaflets each having a deflection within about 0.030 inches of the others.
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14. A method of testing a leaflet for use in an implantable heart valve, comprising the steps of:
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mounting the leaflet in a framing assembly so that portions which are to be sutured in the valve are held stationary, wherein the leaflet defines a cusp edge and a coapted edge generally opposite the cusp edge, and the framing assembly includes an upper member and a lower member, the lower member having a recess for receiving at least the cusp edge of the leaflet, the upper member being shaped to mate over the recess, and the framing assembly defining a cavity circumscribed by the recess, the step of mounting including positioning the leaflet in the recess and piercing the leaflet cusp edge with needles extending between and supported from movement by the upper and lower members, to hold at least the cusp edge of the leaflet stationary;
applying a load to the leaflet in a location adapted to simulate a point at which an average load is applied in the valve; and
sensing the resulting strain in the leaflet. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of testing a leaflet for use in an implantable heart valve, wherein the leaflet defines a cusp edge and a coapting edge generally opposite the cusp edge, comprising the steps of:
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positioning the leaflet in a frame assembly including an upper member and a lower member, the lower member having a recess for receiving and securing the cusp edge of the leaflet the user member being shaped to mate over the recess, and the framing assembly further defining a cavity circumscribed by the recess;
supporting the leaflet by piercing the leaflet cusp edge with needles extending between and supported from movement by the upper and lower members to hold at least the cusp edge of the leaflet stationary such that a mid-portion remains unsupported;
applying a load to the mid-portion of the leaflet; and
sensing the resulting strain at the mid-portion of the leaflet. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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Specification