IMPLANTABLE LEAD

• US 20100137928A1
• Filed: 10/23/2009
• Published: 06/03/2010
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Duncan, Jeffrey B., McDaniel, Thomas R., Wiersdorf, Jason M., Vonesh, Michael J., Hopkinson, Aaron J.
• Granted Patent: US 8,364,281 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0563 specially adapted for defibrillation or cardioversion
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing

Abstract

A highly flexible implantable lead that offers improved flexibility, fatigue life and fatigue and abrasion resistance improved reliability, effective electrode tissue contact with a small diameter and low risk of tissue damage during extraction. In one embodiment the lead is provided with both defibrillation electrodes and pacing/sensing electrodes. For defibrillation/pacing leads, the lead diameter may be as small as six French or smaller. The construction utilizes helically wound conductors. For leads incorporating multiple separate conductors, many of the helically wound conductors are arranged in a multi-filar relationship. Preferably, each conductor is a length of wire that is uninsulated at about the middle of its length to create an electrode, wherein the conductor is folded in half at about the middle of the length to create first and second length segments that constitute parallel conductors.

Claims

1. An electrode for an implantable lead comprising

a length of a first electrically conductive wire provided with an outer insulating covering,

said covered first wire being further provided with a length of a second, uninsulated, electrically conductive wire helically wound tightly around the outer insulating covering of said first wire such that said first and second wires are in electrical communication.

2. An electrode according to claim 1 wherein said first and second wires are of dissimilar metals.

3. An electrode according to claim 2 wherein said second wire is a noble metal.

4. An electrode according to claim 3 wherein said second wire comprises platinum.

5. An electrode according to claim 3 wherein said second wire comprises an alloy of platinum and iridium.

6. An electrode according to claim 1 wherein said first wire is a multiply stranded wire.

7. An electrode according to claim 1 wherein said second wire is a solid wire.

8. An electrode according to claim 1 wherein said electrode is provided with an outer covering of a conductive polymeric material over said first and second wires.

9. An electrode according to claim 8 wherein said conductive polymer is a fluoropolymer.

10. An electrode according to claim 9 wherein said conductive polymer comprises expanded polytetrafluoroethylene having void spaces containing carbon.

11. An electrode according to claim 1 wherein said insulating covering is a fluoropolymer.

12. An electrode according to claim 11 wherein said fluoropolymer comprises polytetrafluoroethylene.

13. An electrode according to claim 11 wherein said fluoropolymer comprises polytetrafluoroethylene and fluorinated polypropylene.

14. An electrode according to claim 1 wherein said first wire is a stranded wire with strands laid up at a first pitch and said second wire is a solid wire helically wound at a second pitch that is finer than said first pitch.

15. A method of making an electrode for an implantable lead wire comprising:

a) providing a first wire having a length and having a thin outer insulation covering at least a portion of said length, said first wire being held under tension;

b) providing a second wire and helically winding said second wire around the thin outer insulation while heating said second wire before it comes into contact with said first wire.

16. A method according to claim 15 wherein said outer insulation has a melt point and second wire is heated above said melt point.

17. A method according to claim 15 wherein said outer insulation is a fluoropolymer.

18. A method according to claim 17 wherein said fluoropolymer comprises polytetrafluoroethylene.

20. A method according to claim 17 wherein said outer insulation has a melt point and second wire is heated above said melt point.

21. A method according to claim 15 wherein said first and second wires are in electrical communication.

22. A method according to claim 15 wherein said first wire is a stranded wire and said second wire is a solid wire.

23. A method according to claim 15 wherein said second wire comprises a noble metal.

24. A method according to claim 23 wherein said second wire comprises platinum.

19. A method according to 18 wherein said outer insulation has a melt point and second wire is heated above said melt point.

25. An implantable lead having a length, comprising:

a conductive wire having a length and a first end and a second end, said wire being folded at a point along the length of the wire to form a bent end located between said first and second ends,

said conductive wire including electrically insulated portions adjacent to each of said first and second ends and at least one electrically exposed portion,

said conductive wire including said electrically insulated portions and said at least one electrically exposed portion being helically wound along a substantial portion of the length of said lead,

wherein said at least one electrically exposed portion is configured for use as an electrode.

26. An implantable lead according to claim 25 wherein said electrically exposed portion includes said bent end.

27. An implantable lead according to claim 25 wherein said bent end is an electrically insulated portion.

28. An implantable lead according to claim 25 wherein said bent end is secured to the lead by an electrically non-conductive filament.

29. An implantable lead according to claim 25 wherein said filament is helically wound in a direction extending distally from said bent end.

30. An implantable lead according to claim 25 wherein one or more of said at least one electrically exposed portions is provided with a covering of an electrically conductive polymer.

31. An implantable lead according to claim 30 wherein said electrically conductive polymer comprises carbon-impregnated ePTFE.

32. An implantable lead according to claim 25 wherein said conductive wire is continuous between the first and second ends, without any wire-connecting components located between the ends.

33. An implantable lead according to claim 25 wherein said first and second ends are in electrical communication.

34. An implantable lead according to claim 25 wherein said electrically exposed portion comprises a portion of the length of said conductive wire having been provided with a thin layer of insulation wire, over which insulation is a tightly helically wound uninsulated second wire that is in electrical communication with said conductive wire.

35. An implantable lead according to claim 34 wherein said second wire comprises a noble metal.

36. An implantable lead according to claim 25 wherein said lead has a distal length portion having a larger diameter than a proximal lead portion.

37. An implantable lead according to claim 25 wherein said lead has lead body with a maximum diameter of about 2.0 mm or less.

38. An Implantable cardioverter defibrillator lead body comprising a length having an insulated portion and an electrically conductive portion, wherein the Implantable cardioverter defibrillator lead body has a maximum diameter of about 2 millimeters or less.

39. An Implantable cardioverter defibrillator lead body according to claim 38 wherein said insulated portion comprises a fluoropolymer.

40. An Implantable cardioverter defibrillator lead body according to claim 39 wherein said fluoropolymer comprises polytetrafluoroethylene.

41. An Implantable cardioverter defibrillator lead body according to claim 38 wherein said electrically conductive portion comprises a covering of a conductive polymer.

42. An Implantable cardioverter defibrillator lead body according to claim 41 wherein said conductive polymer comprises expanded polytetrafluoroethylene impregnated with carbon.

43. An implantable lead comprising a distal tip wherein said tip includes a rotatable helical fixation member and a thread guide comprising a copolymer containing an elutable therapeutic agent.

44. An implantable lead according to claim 43 further comprising a lead body affixed to said distal tip.

45. An electrical connector, said connector comprising at least one contact ring, said contact ring having an integral leg extending distally from said contact ring for connection with a conductor wire.