Cochlear implant electrode and method of making same

• US 7,319,906 B2
• Filed: 05/28/2004
• Issued: 01/15/2008
• Est. Priority Date: 09/19/2002
• Status: Active Grant

• Current Assignee: Advanced Bionics AG (Sonova Holding AG)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Smith, Lani A, Kuzma, Janusz A, Thenawara, Chuladatta
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/857,389
• Publication Number:
  US 20040220651A1
• Time in Patent Office: 1,327 Days
• Field of Search: 607/2, 607/55, 607/57, 607116-119, 607/137, 600373-379
• US Class Current: 607/137
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

A cochlear stimulation lead and method of making an aggressively curved electrode array are provided. In one embodiment of the lead, while the curved section of the lead is curled further beyond the originally molded curvature and held in this position, a filling channel is filled up with a filling material that is hardened or cured in this held position. The resulting lead has a tip curvature that is more curved than the originally molded curvature.

Claims

1. An implantable medical lead for use with electrical stimulation, the lead comprising:

a proximal lead end, a distal lead end, a medial lead side and a lateral lead side;

a pre-curved lead section at the distal lead end, the pre-curved lead section comprised of a first material and a second material, wherein the first material is further curved from a less curled, original, molded position, which first material tends to uncurl the pre-curved lead section to the original, molded position, whereas the second material opposes this tendency of the pre-curved lead section to uncurl to the original, molded position, to thereby maintain the pre-curved lead section in the further curved position;

at least one electrode located on the pre-curved lead section; and

at least one conductor wire embedded within the lead, the at least one conductor wire connected to the at least one electrode contact.

2. The lead of claim 1, wherein the second material is more flexible than the first material.

3. The lead of claim 1, wherein the second material and first material are the same material.

4. The lead of claim 1, wherein the second material is along the lateral side of the distal, curved section of the lead, and which second material is formed into an elongate piece.

5. The lead of claim 4, wherein the second material is inside a channel formed by the first material.

6. The lead of claim 5, wherein the channel is open along a substantial part of its length, before the channel is filled by the second material.

7. The lead of claim 1, wherein the distal lead end is dimensionally tapered and sized so that the lead can be implanted inside a human cochlear duct.

8. The lead of claim 7, wherein the pre-curved lead section has a curvature, taper and size to provide medial contact with the cochlear duct which is the scala tympani.

9. The lead of claim 7, wherein the pre-curved lead section has a curvature, taper and size to provide lateral contact with the cochlear duct which is the scala tympani.

10. The lead of claim 1, wherein the second material is liquid silicone rubber that hardens after curing.

11. The lead of claim 1, further comprising a stylet insertion channel.

12. A method of manufacturing an implantable medical lead, the method comprising:

(a) providing a partially formed, molded lead having at least one electrode at the distal section of the partially formed lead, which distal section is molded to an original curvature and which distal section has a fillable channel;

(b) applying a curling force to the partially formed, molded lead to further curve the distal section exceeding the original, molded curvature; and

(c) while the lead is further curved beyond its original molded curvature, placing a filling material into the fillable channel and allowing the filling material to cure or harden, thereby providing a lead with a distal section having a final curvature exceeding the original, molded curvature.

13. The method of claim 12, wherein the fillable channel in step (a) is located along the lateral side of the lead at the distal section of the lead.

14. The method of claim 12, wherein the fillable channel in step (a) is located along the lead in the distal curve section and the fillable channel has at least one opening.

15. The method of claim 12, wherein the fillable channel in step (a) is open along a substantial part of the channel length.

16. The method of claim 12, wherein the filling material is more flexible than the distal section of the partially formed lead.

17. The method of claim 12, wherein the filling material is the same material as the distal section of the partially formed lead.

18. The method of claim 12,

wherein the lead is a cochlear lead with an array of electrodes;

and

wherein the lead curvature permits insertion of the lead into a human cochlear duct.

19. The method of claim 18, wherein the distal, lead section has a taper and size, and the final curvature to provide medial contact with the human cochlear duct which is the scala tympani.

20. The method of claim 18, wherein the distal, lead section has a taper and size, and the final curvature to provide lateral contact with the human cochlear duct which is the scala tympani.

21. The method of claim 12, wherein the filling material is liquid silicone rubber that hardens after it cures.

22. An implantable medical lead for use with electrical stimulation, the lead comprising:

a proximal lead end, a distal lead end, a medial lead side and a lateral lead side;

a pre-curved lead section at the distal lead end, the pre-curved lead section comprised of a first material and a second material, wherein the first material is further curved from a less curled, original, molded position, which first material tends to uncurl the pre-curved lead section to the original, molded position, whereas the second material opposes this tendency of the pre-curved lead section to uncurl to the original, molded position, to thereby maintain the pre-curved lead section in the further curved position;

a fillable channel located on the lateral side of the distal lead end, wherein the second material is formed in the channel, and wherein the second material is an integral part of the first material;

at least one electrode located on the pre-curved lead section; and

at least one conductor wire embedded within the lead, the at least one conductor wire connected to the at least one electrode contact.

23. The lead of claim 22, wherein the second material is more flexible than the first material.

24. The lead of claim 22, wherein the second material and first material are the same material.

25. The lead of claim 22, wherein the channel is open along a substantial part of its length, before the channel is filled by the second material.

26. The lead of claim 22, wherein the distal lead end is dimensionally tapered and sized so that the lead can be implanted inside a human cochlear duct.

27. The lead of claim 26, wherein the pre-curved lead section has a curvature, taper and size to provide medial contact with the cochlear duct which is the scala tympani.

28. The lead of claim 26, wherein the pre-curved lead section has a curvature, taper and size to provide lateral contact with the cochlear duct which is the scala tympani.

29. The lead of claim 22, wherein the second material is liquid silicone rubber that hardens after curing.

30. The lead of claim 22, further comprising a stylet insertion channel.