Combination stylet and straightening coating for a cochlear implant electrode array

• US 20030181967A1
• Filed: 05/29/2003
• Published: 09/25/2003
• Est. Priority Date: 10/04/2000
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Gibson, Peter, Treaba, Claudiu, Darley, Ian, Parker, John, Dadd, Fysh
• Granted Patent: US 7,146,227 B2
• Time in Patent Office: Days
• US Class Current: 607/122
• CPC Class Codes: A61F 11/20 Ear surgery
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

A cochlear implant electrode assembly device (10) comprising an elongate electrode carrier member (11), a stiffening element (15), and a stiffening sheath (16) that at least partially envelops the elongate member (11). The member (11) is made of a resiliently flexible first material and has a plurality of electrodes (12) mounted thereon. The member (11) has a first configuration that allows it to be inserted into an implantee'"'"'s cochlea (30). The member (11) also has a second configuration wherein the member is curved to match an inside surface of the cochlea (30), and at least one intermediate configuration between the first and second configurations. Both the stiffening element (15) and sheath (16) are made of a material that is relatively stiffer than the member (11). The stiffening element (15) and the stiffening sheath (16) in combination bias the elongate member (11) into the first configuration. If either the stiffening element (15) or the stiffening sheath (16) is removed or deactivated, the elongate member (11) adopts an intermediate configuration.

Claims

1. An implantable tissue-stimulating device comprising:

an elongate member having a plurality of electrodes mounted thereon and having a first configuration that allows said member to be inserted into an implantee'"'"'s body, a second configuration wherein said elongate member is adapted to apply a preselected tissue stimulation with the electrodes, and at least one intermediate configuration between said first and second configurations, said elongate member being made of a resiliently flexible first material;

a stiffening element made of a material relatively stiffer than said first material; and

a stiffening sheath at least partially enveloping said elongate member and made of a material relatively stiffer than said first material;

wherein said stiffening element and said stiffening sheath in combination bias said elongate member into said first configuration and further wherein if either the stiffening element or the stiffening sheath is removed or deactivated, the elongate member adopts said at least one intermediate configuration.

3. A device of claim 1 or claim 2 wherein the second configuration of the elongate member is curved.

4. A device of claim 3 wherein the elongate member adopts a spiral configuration when in the second configuration.

5. A device of claim 1 or claim 2 wherein the elongate member is preformed from a plastics material with memory and is preformed to the second or intermediate configuration.

6. A device of claim 1 or claim 2 wherein the elongate member has a first end that is firstly inserted into the implantee.

7. A device of claim 1 or claim 2 wherein the first configuration is at least substantially straight.

8. A device of claim 1 or claim 2 wherein the elongate member is formed from a biocompatible material.

9. A device of claim 8 wherein the biocompatible material is selected from the group comprising a silicone and a polyurethane.

10. A device of claim 1 or claim 2 wherein the stiffening element is formed of a bioresorbable material which softens or dissolves on exposure to a fluid.

11. A device of claim 10 wherein the stiffening element softens or dissolves on exposure to a saline solution or a body fluid of the implantee.

12. A device of claim 11 wherein the bioresorbable material of the stiffening element is selected from the group comprising polyacrylic acid (PAA), polyvinyl alcohol (PVA), polylactic acid (PLA) and polyglycolic acid (PGA).

13. A device of claim 1 or claim 2 wherein the stiffening element is formed from a non-bioresorbable material.

14. A device of claim 13 wherein the stiffening element is a stylet extending through a lumen in the elongate member.

15. A device of claim 14 wherein the stylet is formed from a biocompatible material selected from the group comprising a metal, a metallic alloy and a stiff plastic.

16. A device of claim 15 wherein the stylet is formed from platinum.

17. A device of claim 1 or claim 2 wherein the stiffening element is formed from a shape memory material.

18. A device of claim 1 or claim 2 wherein the stiffening sheath is formed of a bioresorbable material which dissolves or softens on exposure to a fluid.

19. A device of claim 18 wherein the bioresorbable material of the stiffening sheath is selected from the group comprising polyacrylic acid (PAA), polyvinyl alcohol (PVA), polylactic acid (PLA) and polyglycolic acid (PGA).

20. A device of claim 19 wherein an additional layer surrounds the stiffening sheath.

21. A device of claim 20 wherein the additional layer has a first rate of fluid ingress therethrough and at least one fluid ingress means formed therein, the rate of fluid ingress through the fluid ingress means being greater than the first rate of fluid ingress through the additional layer.

22. A device of claim 21 wherein the fluid ingress means comprises one or more openings in the additional layer.

23. A device of claim 1 or claim 2 wherein at least a portion of an outer surface of the elongate member has a coating of a lubricious material.

24. A device of claim 23 wherein a substantial portion or the entire outer surface of the elongate member has a coating of the lubricious material.

25. A device of claim 23 wherein the lubricious material is selected from the group comprising polyacrylic acid (PAA), polyvinyl alcohol (PVA), polylactic acid (PLA) and polyglycolic acid (PGA).

26. A device of claim 6 wherein a resiliently flexible tip member extends forwardly from the first end of the elongate member.

27. A device of claim 26 wherein the tip member has a plurality of metallic particles dispersed therethrough.

2. A cochlear implant electrode assembly device comprising:

an elongate electrode carrier member having a plurality of electrodes mounted thereon and having a first configuration that allows said member to be inserted into an implantee'"'"'s cochlea, a second configuration wherein said elongate member is curved to match an inside surface of said cochlea, and at least one intermediate configuration between said first and second configurations, said elongate member being made of a resiliently flexible first material;

a stiffening element made of a material relatively stiffer than said first material; and

a stiffening sheath at least partially enveloping said elongate member and made of a material relatively stiffer than said first material;

wherein said stiffening element and said stiffening sheath in combination bias said elongate member into said first configuration and further wherein if either the stiffening element or the stiffening sheath is removed or deactivated, the elongate member adopts said at least one intermediate configuration.