Polymeric implements for torque transmission

• US 6,436,056 B1
• Filed: 07/13/1998
• Issued: 08/20/2002
• Est. Priority Date: 02/28/1996
• Status: Expired due to Term

• Current Assignee: Boston Scientific Corporation
• Original Assignee: Boston Scientific Corporation
• Inventors: Wang, James C., Svatek, Thomas A., Daniels, Douglas J., Daigle, James B., Demello, Richard M., Reid, Robert E., Hartnett, John F., Warich, Charles, Chin, Albert, Rowland, Christopher A.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US09/114,458
• Time in Patent Office: 1,499 Days
• Field of Search: 600/434, 600/435, 600/585, 264/339
• US Class Current: 600/585
• CPC Class Codes: A61M 25/104 used for angioplasty
• CPC Class Codes: B29K 2021/00 Use of unspecified rubbers as moulding material
• CPC Class Codes: B29L 2031/7542 Catheters

Abstract

Implements, particularly medical instruments, formed at least in part of elongated polymer members, exhibit high torque fidelity after processing with tension, heat, and twisting. The processing orients the polymer in generally helical paths so that torque imposed at the proximal end can be transmitted to the distal end without substantial whipping, even if the implement follows a long and tortuous pathway. Applications include medical guidewires, catheters, and driveshafts.

Claims

1. An elongated medical instrument formed at least in part of an extended element, said element being a structural body that is composed of polymer and which is the product of the process comprising:

providing an elongated polymer member,

heating said polymer member above its glass transition temperature but below its melting temperature,

simultaneously twisting and tensioning said member, and

cooling said member to set the effect of said twisting and tensioning into said member,

wherein said member is a part of the medical instrument.

2. The instrument of claim 1 comprising stretching said member by said tensioning.

3. The instrument of claim 2 comprising placing said polymer member in tension and rotating one end of said polymer member while holding the other end rotationally stationary.

4. The instrument of claim 2 wherein said process includes simultaneously heating, twisting, and stretching.

5. The instrument of claim 3 wherein said process includes providing a member having differential stiffness along its length.

6. The instrument of claim 1, wherein the cooled member is substantially straight.

7. The instrument of claim 1, further comprising heating the polymer member under sufficient tension to prevent the member from shrinking.

8. The instrument of claim 1, wherein the polymer member comprises a plurality of polymers along its length.

9. The instrument of claim 1, wherein tensioning the member comprises translating ends of the polymer member at different speeds.

10. The instrument of claim 1, wherein the polymer member comprises

a core comprising a first material, and

an outer portion comprising a second material different than the first material.

11. The instrument of claim 10, wherein the first material comprises a metal.

12. The instrument of claim 10, wherein the outer portion has differential stiffness along its length.

13. The instrument of claim 1, further comprising:

positioning the cooled polymer member into a tubular member,

heating the tubular member, and

twisting the tubular member in a direction different than a twisting direction of the polymer member.

14. The instrument of claim 1, wherein the polymer member defines a lumen.

15. The instrument of claim 14, further comprising positioning an inner core in the lumen.

16. The instrument of claim 15, wherein the inner core is oriented in a direction different than a twisting direction of the polymer member.

17. The instrument of claim 15, wherein the inner core is axially oriented.

18. The instrument of claim 14, further comprising positioning the polymer member over a mandrel.

19. The instrument of claim 18, wherein the mandrel comprises a polymer coating.

20. The instrument of claim 1, capable of exhibiting substantially 1:

1 torque fidelity between proximal and distal ends.

21. The instrument of claim 1, wherein the member is in the form of a solid polymer rod.

22. The instrument of claim 1, wherein the polymer comprises a semi-crystalline polymer.

23. The instrument of claim 1, in the form of a guidewire.

24. The instrument of claim 1, in the form of a catheter.

25. An elongated medical instrument formed at least in part of an extended element, said element being a structural body that is composed of polymer and which is the product of the process comprising:

heating an elongated polymer member above its glass transition temperature but below its melting temperature,

tensioning the member,

twisting the member, and

cooling the member,

wherein the member is a part of the medical instrument.

26. The instrument of claim 25, wherein twisting is performed after tensioning.

27. The instrument of claim 25, wherein twisting is performed under sufficient tension to prevent the member from shrinking and without stretching the member.

28. The instrument of claim 25, wherein tensioning the member comprises stretching the member.

29. The instrument of claim 25, wherein cooling sets the effect of the twisting and tensioning into the member.

30. The instrument of claim 25, wherein tensioning and twisting are performed while heating.

31. The instrument of claim 25, comprising placing said polymer member in tension and rotating one end of said polymer member while holding the other end rotationally stationary.

32. The instrument of claim 25, wherein said member has differential stiffness along its length.

33. The instrument of claim 25, wherein the cooled member is substantially straight.

34. The instrument of claim 25, further comprising heating the polymer member under sufficient tension to prevent the member from shrinking.

35. The instrument of claim 25, wherein the polymer member comprises a plurality of polymers along its length.

36. The instrument of claim 25, wherein tensioning the member comprises translating ends of the polymer member at different speeds.

37. The instrument of claim 25, wherein the polymer member comprises

a core including a first material, and

an outer portion including a second material different than the first material.

38. The instrument of claim 37, wherein the first material comprises a metal.

39. The instrument of claim 37, wherein the outer portion has differential stiffness along its length.

40. The instrument of claim 25, further comprising:

positioning the cooled polymer member into a tubular member,

heating the tubular member, and

twisting the tubular member in a direction different than a twisting direction of the polymer member.

41. The instrument of claim 25, wherein the polymer member defines a lumen.

42. The instrument of claim 41, further comprising positioning an inner core in the lumen.

43. The instrument of claim 42, wherein the inner core is oriented in a direction different than a twisting direction of the polymer member.

44. The instrument of claim 32, wherein the inner core is axially oriented.

45. The instrument of claim 31, further comprising positioning the polymer member over a mandrel.

46. The instrument of claim 45, wherein the mandrel comprises a polymer coating.

47. The instrument of claim 25, capable of exhibiting substantially 1:

1 torque fidelity between proximal and distal ends.

48. The instrument of claim 25, wherein the member is in the form of a solid polymer rod.

49. The instrument of claim 25, wherein the polymer comprises a semi-crystalline polymer.

50. The instrument of claim 25, in the form of a guidewire.

51. The instrument of claim 25, in the form of a catheter.