Mandrel for use in forming valved prostheses having polymer leaflets by dip coating

• US 6,953,332 B1
• Filed: 11/28/2000
• Issued: 10/11/2005
• Est. Priority Date: 11/28/2000
• Status: Expired due to Term

• Current Assignee: St Jude Medical Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: St Jude Medical Incorporated (Abbott Laboratories Incorporated)
• Inventors: Woo, Yi-Ren, Kurk, James L., Cai, Chad Q., Kruse, Steven D.
• Primary Examiner(s): Staicovici, Stefan
• Application Number:
  US09/724,007
• Time in Patent Office: 1,778 Days
• Field of Search: 264/302, 264/303, 264/305, 264/299, 264/DIG.60, 425/269, 425/270, 425/275, 249/52
• US Class Current: 425/275
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2475 Venous valves
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 41/14 Dipping a core B29C41/10 takes precedence
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses
• CPC Class Codes: Y10S 264/60 Processes of molding plastisols

Abstract

Improved dip coating methods and mandrels for forming polymer leaflets and valve prostheses generally involve one or more features on the mandrel that facilitate the processing. The mandrel has a top surface and an outer surface comprising a plurality of ridges and contoured surfaces extending to the ridges. An edge on the mandrel separates the top surface and the contoured surfaces, with the mandrel edge corresponding to the free edge of the leaflet. In preferred embodiments, the edge separating the top surface from the contoured surfaces is sharp. The polymer formed on the top surface can be efficiently separated from the remaining portions of the polymer structure to form the free edges of the leaflets.

Claims

1. A mandrel comprising a top surface, and an outer surface comprising a plurality of ridges and contoured surfaces extending between the ridges corresponding to polymer leaflets, wherein an edge on the mandrel separates the top surface and the contoured surfaces, with the mandrel edge corresponding to the free edge of the leaflets, said mandrel edge having a radius of curvature of no more than about 0.25 millimeters.

2. The mandrel of claim 1 wherein the mandrel comprises three ridges connected by three scallops to form three contoured surfaces.

3. The mandrel of claim 1 wherein the mandrel edge has a radius of curvature of no more than about 0.15 millimeters.

4. The mandrel of claim 1 wherein the angle between the top surface and the contoured surfaces is no larger than about 135 degrees.

5. The mandrel of claim 1 wherein the angle between the top surface and the contoured surfaces is no larger than about 90 degrees.

6. The mandrel of claim 1 wherein the top surface of the mandrel is flat.

7. The mandrel of claim 1 wherein the top surface of the mandrel has flat portions and curved portions.

8. The mandrel of claim 1 wherein the top surface of the mandrel has flat portions adjacent the edge and a protruding portion away from the edge.

9. The mandrel of claim 1 wherein the contoured surfaces are on an outside surface of the mandrel.

10. The mandrel of claim 1 wherein the contoured surfaces are on an interior surface of the mandrel.

12. The mandrel of claim 1 wherein the top surface of the mandrel is convex.

13. The mandrel of claim 1 wherein the top surface of the mandrel is concave.

14. The mandrel of claim 1 comprising a groove parallel to the edge of the top surface.

15. The mandrel of claim 14 wherein the groove has a depth from about 0.01 millimeter to about 1 millimeter.

16. The mandrel of claim 1 wherein the mandrel edge has a radius of curvature of no more than about 0.1 millimeter.

17. The mandrel of claim 1 comprising a polymer on the contoured surfaces.

11. A mandrel comprising an outer surface having a plurality of ridges and contoured surfaces extending between the ridges corresponding to polymer leaflets in a closed configuration, wherein contoured surfaces corresponding to the leaflets meet contoured surfaces of adjacent leaflets at an edge, said edge having a radius of curvature of no more than about 0.25 millimeters.

18. The mandrel of claim 11 comprising a polymer on the contoured surfaces.

19. A mandrel for forming leaflets of valved prostheses, the mandrel comprising:

an end surface; and

a sidewall surface comprising a contoured surface section conformal with a shape of a leaflet, the leaflet having a free edge, the contoured surface section having a curvature which varies and at least a portion of which curves outwardly relative to the mandrel;

wherein the contoured surface section and at least an adjacent region of the end surface have a predetermined wetting property for receiving a polymer composition having a predetermined viscosity; and

wherein the contoured surface section intersects the end surface to form a boundary that corresponds to the free edge of the leaflet, the boundary generally having a radius of curvature.

20. The mandrel of claim 19 wherein the contoured surface section intersects the end surface generally at no more than about a 135 degree angle and generally with the radius of curvature being no more than about 0.25 mm.

21. The mandrel of claim 19 wherein the contoured surface section intersects the end surface generally at no more than about a 90 degree angle and generally with the radius of curvature being no more than about 0.1 mm.

22. The mandrel of claim 19 wherein the contoured surface section intersects the end surface generally at no more than about a 135 degree angle.

23. The mandrel of claim 19 wherein the contoured surface section intersects the end surface generally at no more than about a 105 degree angle.

24. The mandrel of claim 19 wherein the contoured surface section intersects the end surface generally at no more than about a 90 degree angle.

25. The mandrel of claim 19 wherein the radius of curvature is no more than about 0.25 mm.

26. The mandrel of claim 19 wherein the radius of curvature is no more than about 0.15 mm.

27. The mandrel of claim 19 wherein the radius of curvature is no more than about 0.1 mm.

28. The mandrel of claim 19 wherein the mandrel is a male mandrel.

29. The mandrel of claim 19 wherein the mandrel is a female mandrel.

30. The mandrel of claim 19 wherein the contoured surface section comprises a groove parallel to the boundary.

31. The mandrel of claim 19 wherein:

the sidewall surface further comprises an additional surface section conformal with the shape of the leaflet in a relaxed state;

the additional contoured surface section has the predetermined wetting property; and

the additional contoured surface section intersects the end surface to form an additional boundary that corresponds to the free edge of the leaflet, the additional boundary generally having a radius of curvature comparable to the predetermined polymer coating thickness.

32. The mandrel of claim 19 wherein the contoured surface section includes at least a portion which curves inwardly relative to the mandrel.