Insertion tool for a cochlear implant electrode array

• US 20030093139A1
• Filed: 11/18/2002
• Published: 05/15/2003
• Est. Priority Date: 10/17/2000
• 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 7,894,916 B2
• Time in Patent Office: Days
• US Class Current: 607/137
• 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), and a shape element (15) formed of a memory material, such as Nitinol. The elongate member (11) is made of a resiliently flexible first material and has a length and a plurality of electrodes (12) mounted thereon adapted to apply a preselected tissue stimulation. The elongate member (11) has a pre-formed curved orientation that at least substantially matches an inside surface of a cochlea, an implantable orientation different to said pre-formed orientation that allows said member to be inserted into an implantee'"'"'s cochlea, and an at least one intermediate orientation between said implantable orientation and said pre-formed orientation. The shape element (15) is removably positioned within the elongate member (11) and extends along at least a portion of the length thereof. The shape element (15) has a first shape selected for biasing the elongate member (11) into the implantable orientation when the shape element is at a first temperature, and at least a second shape that allows the elongate member (11) to adopt said at least one intermediate orientation when the shape element (15) is exposed to a temperature of the cochlea (30) being different than the first temperature.

Claims

1. An implantable tissue-stimulating device comprising:

a stimulating means;

an elongate member coupled to said stimulating means made of a resiliently flexible first material and having a length and a plurality of electrodes mounted thereon adapted to apply a preselected tissue stimulation, the elongate member having a pre-formed orientation, an implantable orientation different to said pre-formed orientation that allows said member to be inserted into an implantee'"'"'s body, and an at least one intermediate orientation between said implantable and said pre-formed orientation; and

a shape element removably positioned within the elongate member and extending along at least a portion of the length thereof, said element having;

a first shape selected for biasing said elongate member into said implantable orientation when the shape element is at a first temperature; and

at least a second shape that allows the elongate member to adopt said at least one intermediate orientation when the shape element is exposed to a pre-determined temperature different than said first temperature.

3. A device of claim 1 wherein the pre-formed orientation of the elongate member is curved.

4. A device of claim 3 wherein the elongate member adopts a spiral curvature when in the pre-formed orientation.

5. A device of claim 1 or claim 2 wherein the shape element is formed from a shape memory material that is relatively stiffer than the first material.

6. A device of claim 5 wherein the shape memory material is a metal or metal alloy, and the shape element biases the elongate member of the electrode array in at least a substantially straight orientation while the array is at a temperature different to human body temperature.

7. A device of claim 5 wherein the shape memory material is a plastics material.

8. A device of claim 6 wherein the shape memory material is Nitinol™

.

9. A device of claim 6 wherein on insertion into the body and exposure to body temperature, the shape element adopts at least the second shape.

10. A device of claim 9 wherein upon removal of the shape element the elongate member of the electrode array adopts the implantable orientation.

11. A device of claim 10 wherein upon removal of the shape element the elongate electrode carrier member adopts its pre-formed curved orientation that at least substantially matches an inside surface of a cochlea.

18. A device of claim 1 or claim 2 wherein the elongate member has an outer layer that acts as a stiffening sheath for the elongate member.

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

20. A device of claim 19 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).

21. A device of claim 18 wherein the device has an additional layer surrounding the stiffening sheath, the additional layer having a first rate of fluid ingress therethrough and having 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 comprise 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 can has a coating of a lubricious material.

24. 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).

2. A cochlear implant electrode assembly device comprising:

an elongate electrode carrier member made of a resiliently flexible first material and having a length and a plurality of electrodes mounted thereon adapted to apply a preselected tissue stimulation, the elongate member having a pre-formed curved orientation that at least substantially matches an inside surface of a cochlea, an implantable orientation different to said pre-formed orientation that allows said member to be inserted into an implantee'"'"'s cochlea, and an at least one intermediate orientation between said implantable orientation and said pre-formed orientation; and

a shape element removably positioned within the elongate member and extending along at least a portion of the length thereof, said element having;

a first shape selected for biasing said elongate member into said implantable orientation when the shape element is at a first temperature; and

at least a second shape that allows the elongate member to adopt said at least one intermediate orientation when the shape element is exposed to a temperature of the cochlea being different than said first temperature.

12. A device of claim 2 wherein the elongate member is preformed from a biocompatible plastics material and has a first end that is firstly insertable into the implantee.

13. A device of claim 12 wherein the elongate member is formed from a biocompatible material selected from the group comprising a silicone, and a polyurethane.

14. A device of claim 12 wherein the shape element is removably positionable within a lumen extending through the elongate member for at least a portion of its length.

15. A device of claim 14 wherein the lumen extends through the elongate member for a substantial portion of its length from an opening distal the first end to or adjacent the first end.

16. A device of claim 15 wherein the shape element extends out of the opening allowing the element to be manipulated and removed from the lumen during insertion of the device.

17. A device of claim 2 wherein the plurality of electrodes are mounted along a surface of the elongated member that at least substantially conforms to the inside surface of the cochlea.

25. A device of claim 12 wherein a resiliently flexible tip member extends forwardly from the first end of the elongate member.

26. A device of claim 25 wherein the tip member has a plurality of metallic particles dispersed therethrough.