US4490859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artificial heart valves
Assignee: University of Sheffield
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Filing: 1983-01-18
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Granted: 1985-01-01
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Expires: 2003-01-18
Abstract
Abstract A bioprosthetic mitral valve replacement comprises a flexible frame (1) having a ring-shaped base (2) and at least a pair of upstanding posts (3), which divide the base into at least two portions (2A, 2B) of varying flexibility, together with animal tissue leaflets (4) each having a periphery consisting of a free portion (4A) extending between the tips (3X) of posts (3) and a fixed portion (4B) secured and sealed to corresponding sides of the posts and the adjacent portion of the base. A bicuspid mitral valve replacement has a pair of posts (3) disposed at opposite ends of a diameter of the undistorted base (2), or displaced therefrom towards the portion (2A) of lesser flexibility to accommodate leaflets (4) of unequal size. The frame (1) is formed of Delrin covered with Dacron cloth, the Delrin having differing thicknesses to either side of the posts (3) which merge into the base (2) by way of a continuous curve (6) on each side. The leaflets (4) are cut from flat sheet in a special way to avoid stress-fixing.
Inventors
- 👤 Martin M. Black
- 👤 Philip J. Drury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:55
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/24; A61F2/2412
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
234 words
A bioprosthetic mitral valve replacement comprising a frame having a ring-shaped base and at least a pair of upstanding posts merging into the base by way of a continuous curve from the tip of one post to the tip of the other post, valve leaflets each having a free portion extending between the tips of the posts and a fixed portion secured and sealed to corresponding sides of the posts and the adjacent portion of the base, the valve leaflets being cut from a flat sheet of fully fixed animal tissue and the shape of each leaflet corresponding to a portion of a surface of a cone which portion is defined by the intersections on the conical surface of two parallel flat planes having peripheries on the conical surface corresponding in length respectively to the circumference of the ring-shaped base and the distance between the tips of the posts of the frame, and a third intersection on the conical surface of a curved plane concave towards the apex of the cone and intersecting the two parallel flat planes at opposite sides of the cone, the spacing of the flat planes and the curvature of the curved plane being such that the development of the curved plane on the conical surface matches in length and curvature the continuously blending curve of one arcuate portion of the ring-shaped base and the adjacent sides of the posts.
Claim 2
Dependent Claim
234 words
A bioprosthetic mitral valve replacement comprising a frame having a ring-shaped base and at least a pair of upstanding posts merging into the base by way of a continuous curve from the tip of one post to the tip of the other post, valve leaflets each having a free portion extending between the tips of the posts and a fixed portion secured and sealed to corresponding sides of the posts and the adjacent portion of the base, the valve leaflets being cut from a flat sheet of fully fixed animal tissue and the shape of each leaflet corresponding to a portion of a surface of a cone which portion is defined by the intersections on the conical surface of two parallel flat planes having peripheries on the conical surface corresponding in length respectively to the circumference of the ring-shaped base and the distance between the tips of the posts of the frame, and a third intersection on the conical surface of a curved plane concave towards the apex of the cone and intersecting the two parallel flat planes at opposite sides of the cone, the spacing of the flat planes and the curvature of the curved plane being such that the development of the curved plane on the conical surface matches in length and curvature the continuously blending curve of one arcuate portion of the ring-shaped base and the adjacent sides of the posts.
Claim 3
Dependent Claim
45 words
A mitral valve replacement as in claim 1, wherein the base is flexible and a pair of upstanding posts divide the base into two portions of differing flexibility, with lesser flexibility at one side between the posts than at the other side between the posts.
Claim 4
Dependent Claim
23 words
A mitral valve replacement as in claim 2, wherein the posts are disposed at opposite ends of a diameter of the undistorted base.
Claim 5
Dependent Claim
38 words
A mitral valve replacement as in claim 2, wherein the posts are displaced from the opposite ends of a diameter of the undistorted base towards the portion of lesser flexibility, and the leaflets are of correspondingly equal size.
Claim 6
Dependent Claim
19 words
A mitral valve replacement as in claim 1, wherein three posts are disposed at regular intervals round the base.
Claim 7
Dependent Claim
20 words
A mitral valve replacement as in claim 1, wherein the frame is formed of polyformaldehyde covered with polyethylene terephthalate cloth.
Claim 8
Dependent Claim
26 words
A mitral valve replacement as in claim 2, wherein the differential flexibility is afforded by providing differing thicknesses of polyformaldehyde to either side of the posts.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-01 | 1988-07-02 | 1989-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-01 | 1992-07-02 | 1993-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-01 | 1996-07-02 | 1997-01-01 | $7700.00 | Window Closed / Lapsed |