Electronic lead for a medical implant device, method of making same, and method and apparatus for inserting same

• US 6,671,554 B2
• Filed: 12/27/2001
• Issued: 12/30/2003
• Est. Priority Date: 09/07/2001
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Chernoff, Edward, Byers, Charles, Gibson, Scott R.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US10/033,720
• Publication Number:
  US 20030050680A1
• Time in Patent Office: 733 Days
• Field of Search: 607/116, 607/2, 607/37, 607/122, 607/123, 607/126, 439/827, 439/370, 439/345, 439/775, 439/816, 439/825, 439/909, 600/374, 600/375, 600/377, 600/395, 600/396
• US Class Current: 607/37
• 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 1/3752 Details of casing-lead connections
• CPC Class Codes: Y10S 439/909 Medical use or attached to human body

Abstract

An implantable coaxial lead includes a cable with male and female connectors. The cable includes inner and outer helical coils separated by an inner insulator tube, with an outer insulator tube surrounding the outer helical coil. The male connector includes an outer conductive cylinder, a conductive pin and an insulator molded in between. For increased strength, a braided cylinder, infused with rubber, is included at the juncture of the male connector and the cable. The female connector includes a cylinder formed by two conducting body elements and an intervening insulating body element. The female connector includes respective conductive tension elements configured to engage the male connector. A first seal is provided between the conductive tension members for electrical isolation and tactile feedback. An insertion tool includes a cylinder with a hollow bore and detachable head, and a rod for pulling the lead through the cylinder.

Claims

1. An electrical connecting system comprising:

a first connector having an electrically conductive element and an electrically conductive surface and an insulating member configured to electrically insulate the conductive element from said conductive surface;

a second connector comprising;

a connector body defining an inner cavity with a first end and a second end, wherein said inner cavity is open at said first end, said inner cavity configured to receive said first connector;

a first electrically conductive tension member within said inner cavity, said first conductive tension member configured to engage said conductive element to form a first electrical channel; and

a second electrically conductive tension member within said inner cavity, said second conductive tension member configured to engage said conductive surface to form a second electrical channel.

2. The system of claim 1, wherein said second connector has an insertion force of no greater than fourteen Newtons with respect to said first connector.

3. The system of claim 1, wherein said second connector has a retention force of at least five Newtons with respect to said first connector.

4. The system of claim 1, wherein said first connector and said second connector are configured for unidirectional mechanical engagement.

5. The system of claim 1, wherein:

the second connector further comprises a first seal within said inner cavity, said first seal configured to engage said insulating member to isolate said first electrical channel from said second electrical channel.

6. The system of claim 5, wherein:

said first seal comprises an umbrella-shaped ridge; and

said insulating member comprises a seal catch configured to engage said umbrella-shaped ridge.

7. The system of claim 6, wherein said first seal and said seal catch form a tactile feedback mechanism.

8. The system of claim 5, wherein said second connector further comprises a second seal configured to engage said first connector to isolate said inner cavity.

9. The system of claim 8, wherein said second seal comprises an annular ring of flexible material, said annular ring having a plurality of annular ridges that contact said first connector while said first connector is within said inner cavity.

10. The system of claim 9, wherein said flexible material is molded rubber.

11. The system of claim 8, wherein said second seal is located within a first annular groove substantially adjacent to said first end of said inner cavity.

12. The system of claim 5, wherein said connector body comprises:

a first conductive body member defining said first end of said inner cavity;

a second conductive body member defining said second end of said inner cavity; and

a middle insulator coupled between said first conductive body member and said second conductive body member.

13. The system of claim 12, wherein said first conductive body member is comprised of steel.

14. The system of claim 12, wherein said second conductive body member is comprised of steel.

15. The system of claim 12, wherein said middle insulator is comprised of a resilient, nonconductive material.

16. The system of claim 15, wherein said resilient, nonconductive material is polysulfone.

17. The system of claim 12, wherein the interior of said first conductive body member comprises an annular groove wherein said first conductive tension member is located.

18. The system of claim 17, wherein said second connector further comprises a wear-resistant member fitted into said annular groove between said first conductive tension member and said middle insulator.

19. The system of claim 18, wherein said wear resistant member comprises a washer.

20. The system of claim 17, wherein said first conductive tension member comprises a toroidal spring.

21. The system of claim 12, wherein said middle insulator comprises an annular groove in which said first seal is seated.

22. The system of claim 12, wherein the interior of said second conductive body member comprises an annular groove wherein said second conductive tension member is located.

23. The system of claim 22, wherein said second connector further comprises a wear-resistant member fitted into said annular groove between said second conductive tension member and said middle insulator.

24. The system of claim 23, wherein said wear resistant member comprises a washer.

25. The system of claim 24, wherein said second conductive tension member comprises a toroidal spring.

26. The system of claim 12, further comprising a two-conductor electrical cable coupled to said second connector.

27. The system of claim 26, wherein said cable comprises:

an outer coil comprising a first helical ribbon conductor;

an inner coil within said outer coil, said inner coil comprising a second helical ribbon conductor;

an inner insulating tube between said inner coil and said outer coil; and

an outer insulating tube encompassing said outer coil.

28. The system of claim 27, wherein said first helical ribbon conductor comprises a plurality of adjacent conductive wires configured in a ribbon strip that is twisted about a central axis to form a helix.

29. The system of claim 28, wherein each of said conductive wires comprises a silver core surrounded by a cobalt alloy layer.

30. The system of claim 28, wherein said ribbon strip is configured to have a maximum distance by which any one of said plurality of adjacent wires may be offset from said ribbon strip.

31. The system of claim 27, wherein:

said inner coil is coupled to said first conductive body member;

said outer coil wraps around an exterior surface of said connector body; and

said outer coil is electrically coupled to an external surface of said second conductive body member.

32. The system of claim 31, further comprising an electrically insulating layer around said exterior surface of said connector body and said outer coil.

33. The system of claim 32 applied to an implant patient, wherein said insulating layer comprises means for suturing said second connector within said implant patient.

34. The system of claim 1, further comprising a two-conductor electrical cable coupled to said first connector.

35. The system of claim 34, wherein said cable is coupled to said first connector through a braided tube adjacent to said first connector.

36. The system of claim 35, wherein said braided tube is infused with a flexible insulating material.

37. The system of claim 36, wherein said braided tube is overmolded with said flexible insulating material to have about the same diameter as said cable.

38. The system of claim 37, wherein said first connector has a diameter less than or about equal to the diameter of said cable.

39. The system of claim 35, wherein said braided tube comprises a steel mesh.

40. The system of claim 34, wherein said cable comprises:

an outer coil comprising a first helical ribbon conductor;

an inner coil within said outer coil, said inner coil comprising a second helical ribbon conductor;

an inner insulating tube between said inner coil and said outer coil; and

an outer insulating tube encompassing said outer coil.

41. The system of claim 40, wherein said first helical ribbon conductor comprises a plurality of adjacent conductive wires configured in a ribbon strip that is twisted about a central axis to form a helix.

42. The system of claim 41, wherein each of said conductive wires comprises a silver core surrounded by a cobalt alloy layer.

43. The system of claim 41, wherein said ribbon strip is configured to have a maximum distance by which any one of said plurality of adjacent wires may be offset from said ribbon strip.

44. The system of claim 40, wherein said inner coil is coupled to said conductive element and said outer coil is coupled to said conductive surface.

45. A female connector for receiving a male connector having an electrically conductive element and an electrically conductive surface, comprising:

a connector body defining an inner cavity with a first end and a second end, wherein said inner cavity is open at said first end, said inner cavity configured to receive said male connector;

a first electrically conductive tension member within said inner cavity, said first conductive tension member configured to engage said conductive element to form a first electrical channel;

a second electrically conductive tension member within said inner cavity, said second conductive tension member configured to engage said conductive surface to form a second electrical channel; and

a first seal within said inner cavity, said first seal configured to engage said male connector to isolate said first electrical channel from said second electrical channel;

wherein said first seal comprises an umbrella-shaped ridge.

46. The female connector of claim 45 having an insertion force of no greater than fourteen Newtons with respect to said male connector.

47. The female connector of claim 45 having a retention force of at least five Newtons with respect to said male connector.

48. The female connector of claim 45 being mechanically unidirectional with respect to said male connector.

49. The female connector of claim 45, wherein said umbrella-shaped ridge has a forward angle and a rearward angle.

50. The female connector of claim 45, wherein said first seal is a tactile feedback mechanism.

51. A female connector for receiving a male connector having an electrically conductive element and an electrically conductive surface, comprising:

a connector body defining an inner cavity with a first end and a second end, wherein said inner cavity is open at said first end, said inner cavity configured to receive said male connector;

a first electrically conductive tension member within said inner cavity, said first conductive tension member configured to engage said conductive element to form a first electrical channel;

a second electrically conductive tension member within said inner cavity, said second conductive tension member configured to engage said conductive surface to form a second electrical channel;

a first seal within said inner cavity, said first seal configured to engage said male connector to isolate said first electrical channel from said second electrical channel; and

a second seal configured to engage said male connector to isolate said inner cavity

wherein said first seal comprises an umbrella-shaped ridge and said second seal comprises an annular ring of flexible material, said annular ring having a plurality of annular ridges.

52. The female connector of claim 51, wherein said flexible material is molded rubber.

53. The female connector of claim 52, wherein said second seal is located within a first annular groove substantially adjacent to said first end of said inner cavity.

54. A female connector for receiving a male connector having an electrically conductive element and an electrically conductive surface, comprising:

a connector body defining an inner cavity with a first end and a second end, wherein said inner cavity is open at said first end, said inner cavity configured to receive said male connector;

a first electrically conductive tension member within said inner cavity, said first conductive tension member configured to engage said conductive element to form a first electrical channel;

a second electrically conductive tension member within said inner cavity, said second conductive tension member configured to engage said conductive surface to form a second electrical channel; and

a first seal within said inner cavity, said first seal configured to engage said male connector to isolate said first electrical channel from said second electrical channel;

wherein said connector body comprises;

a first conductive body member defining said first end of said inner cavity;

a second conductive body member defining said second end of said inner cavity; and

a middle insulator coupled between said first conductive body member and said second conductive body member.

55. The female connector of claim 54, wherein said first conductive body member is comprised of steel.

56. The female connector of claim 54, wherein said second conductive body member is comprised of steel.

57. The female connector of claim 54, wherein said middle insulator is comprised of a resilient, nonconductive material.

58. The female connector of claim 57, wherein said resilient, nonconductive material is polysulfone.

59. The female connector of claim 58, wherein the interior of said first conductive body member comprises an annular groove wherein said first conductive tension member is located.

60. The female connector of claim 59, further comprising a wear-resistant member fitted into said annular groove between said first conductive tension member and said middle insulator.

61. The female connector of claim 60, wherein said wear resistant member comprises a washer.

62. The female connector of claim 59, wherein said first conductive tension member comprises a toroidal spring.

63. The female connector of claim 54, wherein said middle insulator comprises an annular groove in which said first seal is seated.

64. The female connector of claim 54, wherein the interior of said second conductive body member comprises an annular groove wherein said second conductive tension member is located.

65. The female connector of claim 64, wherein said second connector further comprises a wear-resistant member fitted into said annular groove between said second conductive tension member and said middle insulator.

66. The female connector of claim 54, wherein said wear resistant member comprises a washer.

67. The female connector of claim 66, wherein said second conductive tension member comprises a toroidal spring.

68. The female connector of claim 54, further comprising a two-conductor electrical cable coupled to said second connector.

69. The female connector of claim 68, wherein said cable comprises:

an outer coil comprising a first helical ribbon conductor;

an inner coil within said outer coil, said inner coil comprising a second helical ribbon conductor;

an inner insulating tube between said inner coil and said outer coil; and

an outer insulating tube encompassing said outer coil.

70. The female connector of claim 69, wherein said first helical ribbon conductor comprises a plurality of adjacent conductive wires configured in a ribbon strip that is twisted about a central axis to form a helix.

71. The female connector of claim 70, wherein each of said conductive wires comprises a silver core surrounded by a cobalt alloy layer.

72. The female connector of claim 69, wherein said ribbon strip is configured to have a maximum distance by which any one of said plurality of adjacent wires may be offset from said ribbon strip.

73. The female connector of claim 69, wherein:

said inner coil is coupled to said first conductive body member;

said outer coil wraps around an exterior surface of said connector body; and

said outer coil is electrically coupled to an external surface of said second conductive body member.

74. The female connector of claim 73, further comprising an electrically insulating layer around said exterior surface of said connector body and said outer coil.

75. The female connector of claim 74 applied to an implant patient, wherein said insulating layer comprises means for suturing said second connector within said implant patient.