Implantable medical device conductor insulation and process for forming

• US 20040215299A1
• Filed: 04/23/2003
• Published: 10/28/2004
• Est. Priority Date: 04/23/2003
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Zhao, Yong David, Sommer, John L.
• Application Number:
  US10/421,182
• Publication Number:
  US 20040215299A1
• Time in Patent Office: Days
• US Class Current: 607/116
• 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 1/056 Transvascular endocardial electrode systems

Abstract

A composite redundant insulation is formed about each of a plurality of conductors extending within a lead body of an implantable medical device. The insulation includes a first insulative layer, a second insulative layer having a lower durometer and a lower flexural modulus than the first insulative layer, and a third insulative layer having a higher durometer and a higher flexural modulus than the second insulative layer.

Claims

1. An implantable medical device, comprising:

a lead body extending from a proximal end to a distal end;

a plurality of conductors extending within the lead body from the proximal end to the distal end; and

a composite redundant insulation formed about each of the plurality of conductors and including a first insulative layer, a second insulative layer having a lower durometer and a lower flexural modulus than the first insulative layer, and a third insulative layer having a higher durometer and a higher flexural modulus than the second insulative layer.

2. The implantable medical device of claim 1, wherein the first insulative layer comprises a hydrolytically stable polyimide material.

3. The implantable medical device of claim 2, wherein the hydrolytically stable polyimide material is an SI polyimide.

4. The implantable medical device of claim 1, wherein the second insulative layer comprises a fluoropolymer.

5. The implantable medical device of claim 4, wherein the fluoropolymer is an ETFE.

6. The implantable medical device of claim 1, wherein the second insulative layer comprises polyurethane.

7. The implantable medical device of claim 1, wherein the third insulative layer comprises a fluoropolymer.

8. The implantable medical device of claim 1, wherein the third insulative layer comprises polyurethane.

9. The implantable medical device of claim 1, wherein the first insulative layer has a thickness between approximately 0.0001 inch and approximately 0.001 inch.

10. The implantable medical device of claim 1, wherein the composite redundant insulation has a thickness between approximately 0.002 inch and approximately 0.005 inch.

11. The implantable medical device of claim 1, wherein the second layer is free to slide against the first layer and the third layer is free to slide against the second layer.

12. An implantable medical device, comprising:

a lead body extending from a proximal end to a distal end;

a plurality of conductors extending within the lead body from the proximal end to the distal end;

a first insulative layer formed about each of the plurality of conductors by a dip coating process and comprised of a hydrolytically stable polyimide;

a second insulative layer formed about the first insulative layer by a co-extrusion process and having a lower durometer and a lower flexural modulus than the first insulative layer; and

a third insulative layer formed about the second insulative layer by a co-extrusion process and having a higher durometer and a higher flexural modulus than the second insulative layer.

13. The implantable medical device of claim 12, wherein the hydrolytically stable polyimide material is an SI polyimide.

14. The implantable medical device of claim 12, wherein the second insulative layer comprises a fluoropolymer.

15. The implantable medical device of claim 14, wherein the fluoropolymer is an ETFE.

16. The implantable medical device of claim 12, wherein the second insulative layer comprises polyurethane.

17. The implantable medical device of claim 12, wherein the third insulative layer comprises a fluoropolymer.

18. The implantable medical device of claim 12, wherein the third insulative layer comprises polyurethane.

19. The implantable medical device of claim 12, wherein the first insulative layer has a thickness between approximately 0.0001 inch and approximately 0.001 inch.

20. The implantable medical device of claim 12, wherein the composite redundant insulation has a thickness between approximately 0.002 inch and approximately 0.005 inch.

21. The implantable medical device of claim 12, wherein the second layer is free to slide against the first layer and the third layer is free to slide against the second layer.

22. The implantable medical device of claim 12, wherein the second layer has a melt temperature between approximately 400°

F. and approximately 500°

F.; and

the third insulative layer has melt temperature less than approximately 400°

F.

23. An implantable medical device, comprising:

a housing adapted to generate electrical signals and including a connector block;

a lead body extending from a proximal end to a distal end and including a connector assembly terminating the proximal end and adapted to be coupled to the connector block of the housing;

a plurality of conductors coupled to the connector assembly and extending within the lead body, the plurality of conductors adapted to deliver the electrical signals from the housing, via the connector assembly, to an implant site; and

a composite redundant insulation formed about each of the plurality of conductors and including a first insulative layer, a second insulative layer having a lower durometer and a lower flexural modulus than the first insulative layer, and a third insulative layer having a higher durometer and a higher flexural modulus than the second insulative layer.

24. The implantable medical device of claim 23, wherein the first insulative layer comprises a hydrolytically stable polyimide material.

25. The implantable medical device of claim 23, wherein the hydrolytically stable polyimide material is an SI polyimide.

26. The implantable medical device of claim 23, wherein the second insulative layer comprises a fluoropolymer.

27. The implantable medical device of claim 26, wherein the fluoropolymer is an ETFE.

28. The implantable medical device of claim 23, wherein the second insulative layer comprises polyurethane.

29. The implantable medical device of claim 23, wherein the third insulative layer comprises a fluoropolymer.

30. The implantable medical device of claim 23, wherein the third insulative layer comprises polyurethane.

31. The implantable medical device of claim 23, wherein the first insulative layer has a thickness between approximately 0.0001 inch and approximately 0.001 inch.

32. The implantable medical device of claim 23, wherein the composite redundant insulation has a thickness between approximately 0.002 inch and approximately 0.005 inch.

33. The implantable medical device of claim 23, wherein the second layer is free to slide against the first layer and the third layer is free to slide against the second layer.