Lead electrode for use in an MRI-safe implantable medical device

• US 20050222658A1
• Filed: 12/10/2004
• Published: 10/06/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Olsen, James M., Bolea, Stephen L., Wahlstrand, Carl D., Hrdlicka, Gregory A., Hoegh, Thomas Barry
• Granted Patent: US 7,877,150 B2
• Time in Patent Office: Days
• US Class Current: 607/116
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents

Abstract

A neurostimulation lead is configured to be implanted into a patient'"'"'s body and has at least one distal electrode. The lead comprises at least one conductive filer electrically coupled to the distal electrode, a jacket for housing the conductive filer and a shield surrounding at least a portion of the filer for reducing electromagnetic coupling to the filer.

Claims

1. A neurostimulation lead configured to be implanted into a patient'"'"'s body and having at least one distal electrode, the lead comprising:

at least one conductive filer electrically coupled to the distal electrode;

a jacket for housing said conductive filer; and

a shield surrounding at least a portion of said filer for reducing electromagnetic coupling to said filer.

2. A neurostimulation lead according to claim 1 wherein said shield resides on the exterior surface of the stimulation lead.

3. A neurostimulation lead according to claim 1 wherein said shield resides proximate an interior surface of said jacket.

4. A neurostimulation lead according to claim 3 further comprising a plurality of openings in a region of said jacket to provide coupling between said shield and the patient'"'"'s body.

5. A neurostimulation lead according to claim 4 wherein said shield is configured for electrical coupling with the patient'"'"'s body.

6. A neurostimulation lead according to claim 1 wherein said shield is at least partially imbedded in said jacket.

7. A neurostimulation lead according to claim 2 wherein said shield is configured for electrical coupling with the patient'"'"'s body tissue.

8. A neurostimulation lead according to claim 1 wherein said neurostimulation lead is configured for coupling to an implantable medical device having an encasement and wherein said shield is coupled to said encasement.

9. A neurostimulation lead according to claim 2 wherein said shield comprises a plurality of separate shield segments.

10. A neurostimulation lead according to claim 9 wherein said segments are substantially one-quarter wavelength in length.

11. A neurostimulation lead according to claim 1 wherein said shield comprises at least one contact configured for electrical coupling with the patient'"'"'s body tissue.

12. A neurostimulation lead according to claim 11 wherein said encasement comprises said at least one contact.

13. A neurostimulation lead according to claim 10 further comprising a plurality of contacts, each residing between adjacent ones of said plurality of segments.

14. A neurostimulation lead according to claim 1 wherein said shield comprises a metal selected from the group consisting of titanium, stainless steel, platinum, chromium cobalt, nitinol, tantalum, iridium, and alloys thereof.

15. A neurostimulation lead according to claim 14 wherein said shield comprises metal along substantially its entire length.

16. A neurostimulation lead according to claim 14 wherein said shield comprises a braid.

17. A neurostimulation lead according to claim 14 wherein said shield comprises a foil.

18. A neurostimulation lead according to claim 14 wherein said shield comprises a coil.

19. A neurostimulation lead according to claim 18 wherein said coil has a non-uniform pitch along the length of said coil.

20. A neurostimulation lead according to claim 18 wherein said shield comprises a wire.

21. A neurostimulation lead according to claim 1 wherein said shield is completely imbedded in said jacket.

22. A neurostimulation lead according to claim 6 wherein said jacket is doped with conductive particles.

23. A neurostimulation lead according to claim 22 wherein said conductive particles are conductive microspheres.

24. A neurostimulation lead according to claim 22 wherein conductive particles are metal flakes.

25. A neurostimulation lead according to claim 22 wherein conductive particles are metal fibers.

26. A neurostimulation lead according to claim 6 wherein a conductive braided wire is imbedded in said jacket.

27. A neurostimulation lead according to claim 21 wherein a conductive foil is imbedded in said jacket.

28. A neurostimulation lead according to claim 22 wherein said jacket is doped at one or more selected regions of said jacket.

29. A neurostimulation lead according to claim 22 wherein said jacket is doped with carbon powder.

30. A neurostimulation lead according to claim 22 wherein said jacket is doped with carbon fibers.

31. A neurostimulation lead according to claim 22 wherein said jacket is doped with a conductive polymer.

32. A neurostimulation lead according to claim 1 wherein said shield comprises alternating layers of conductive and non-conductive material.

33. A neurostimulation lead according to claim 32 wherein the outer layer of said alternating layers is conductive.

34. A neurostimulation lead according to claim 1 wherein said shield comprises a biocompatible organic layer infused with a shielding material on said jacket.

35. A neurostimulation lead configured to be implanted into a patient'"'"'s body and having at least one distal electrode, the lead comprising:

at least one conductive filer electrically coupled to the distal electrode; and

a multi-layer jacket surrounding said filer and shielding said filer from electromagnetic energy, said multi-layer jacket comprising alternating layers of conductive and non-conductive material.

36. A neurostimulation lead according to claim 35 wherein an outer layer of said multi-layer jacket is configured for electrical coupling with the patient'"'"'s body tissue.

37. A neurostimulation lead according to claim 35 wherein an outer layer of said jacket is conductive.

38. A neurostimulation lead according to claim 35 wherein said jacket is wrapped and comprises alternating strips of conductive and insulative materials.

39. A neurostimulation lead according to claim 38 wherein said alternating strips have abutting edges.

40. A neurostimulation lead according to claim 38 wherein said alternating strips are overlapping.

41. A pulse stimulation system configured for implantation into a patient'"'"'s body, the system comprising:

a conductive encasement;

a pulse generator within said encasement;

at least one conductive filer having a proximal end electrically coupled to said pulse generator and having a distal end;

at least one stimulation electrode electrically coupled to said distal end;

a jacket for housing said conductive filer; and

a shield surrounding at least a portion of said filer for reducing electromagnetic coupling to said filer.

42. A pulse stimulation system according to claim 41 wherein said shield resides on the exterior surface of the stimulation lead.

43. A pulse stimulation system according to claim 42 wherein said shield is configured for electrical coupling with the patient'"'"'s body tissue.

44. A pulse stimulation system according to claim 43 wherein said shield is coupled to said encasement.

45. A pulse stimulation system according to claim 42 wherein said shield comprises a plurality of separate shield segments.

46. A pulse stimulation system according to claim 45 wherein each of said segments is substantially one-quarter wavelength in length.

47. A pulse stimulation system according to claim 46 further comprising a plurality of floating electrodes, each floating electrode residing between adjacent ones of said plurality of segments.

48. A pulse stimulation system according to claim 41 wherein said shield is at least partially imbedded in said jacket.

49. A pulse stimulation system according to claim 41 wherein said shield comprises alternating layers of conductive and non-conductive material.

50. A pulse stimulation system according to claim 49 wherein the outer layer of said alternating layers is conductive.

51. A pulse stimulation system according to claim 41 wherein said shield comprises a biocompatible organic layer infused with a shielding material on said jacket.

52. A pulse stimulation system according to claim 41 wherein said shield resides proximate an interior surface of said jacket.

53. A neurostimulation lead configured to be implanted into a patient'"'"'s body and having at least one distal stimulation electrode, the lead comprising:

at least one insulated filer electrically coupled to said stimulation electrode; and

a shield surrounding at least a portion of said at least one insulated filer for reducing electromagnetic coupling to said filer.