PRE-CURVED COCHLEAR IMPLANT ELECTRODE ARRAY

• US 20090043370A1
• Filed: 10/13/2008
• Published: 02/12/2009
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Gibson, Peter, Treaba, Claudiu, Parker, John, Dadd, Fysh
• Granted Patent: US 7,974,712 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
• CPC Class Codes: B28B 5/00 Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in or on conveyors irrespective of the manner of shaping

Abstract

An implantable electrode array (30) that can adopt a first configuration selected to allow the array (30) to be inserted into a cochlea (12) of an implantee and at least a second configuration in which the array can apply tissue stimulation. The array (30) comprises an elongate carrier (31) having a proximal end (37), a distal end (34), and an inner surface (35) conformable with the inner wall of the implantee'"'"'s cochlea (12). A plurality of electrodes (36) are supported within the carrier (31) at respective spaced locations thereon in a region between the proximal end (37) and the distal end (34) with at least one of the electrodes having a surface that is at least adjacent the inner surface (35) of the carrier (31). The carrier (31) is formed in the second configuration from a first layer (32) and at least a second layer (32) of resiliently flexible material. A method of forming an array (30) is also described.

Claims

1. An implantable electrode array comprising a carrier that is insertable into a cochlea of an implantee, the carrier having a proximal end and a distal end and comprising:

a first layer of a resiliently flexible material and having an inner surface and an outer surface;

at least a second layer of a resiliently flexible material and which at least partially overlies the outer surface of the first layer; and

a plurality of electrodes supported within the carrier at respective spaced locations in a region between the proximal end and the distal end of the carrier, at least one of the electrodes having a surface that is at least adjacent the inner surface of the first layer;

wherein the carrier is formed in a second configuration in which the array can apply tissue stimulation to the cochlea and is manipulable to a first configuration that allows the carrier to be insertable into the cochlea of an implantee.

2. An implantable electrode array of claim 1 wherein each of the electrodes in the carrier have a surface that is at least adjacent the inner surface of the first layer.

3. An implantable electrode array of claim 2 wherein the surfaces of the electrodes being at least adjacent the inner surface of the first layer are aligned with the inner surface of the first layer of the carrier.

4. An implantable electrode array of claim 3 wherein the first layer overlies each of the electrodes except their said respective surfaces at least adjacent the inner surface of the first layer of the carrier.

5. An implantable electrode array of claim 1 wherein the first layer extends from the proximal end of the distal end of the carrier.

6. An implantable electrode array of claim 5 wherein the second layer extends from the proximal end to the distal end of the carrier and overlies the entire outer surface of the first layer.

7. An implantable electrode array of claim 1 wherein the first layer and second layer are formed from different materials.

8. An implantable electrode array of claim 1 wherein the first and second layers are formed from the same material.

9. An implantable electrode array of claim 8 wherein the first and second layers are each formed from a biocompatible silicone rubber.

10. An implantable electrode array of claim 5 wherein the thickness of the first layer between its inner surface and outer surface is substantially constant for at least a majority of the length of the carrier from the proximal end to the distal end.

11. An implantable electrode array of claim 5 wherein the thickness of the first layer decreases from the proximal end to the distal end of the carrier.

12. An implantable electrode array of claim 11 wherein the thickness of the second layer decreases from the proximal end to the distal end of the carrier.

13. An implantable electrode array of claim 1 wherein the preferential second configuration comprises a spiral configuration.

14. An implantable electrode array of claim 1 wherein the carrier further comprises:

a lumen extending for a length from an opening at the proximal end towards the distal end of the carrier; and

a stiffening element that is positioned in the lumen and biases the carrier into the first configuration in which the carrier is insertable into the cochlea of the implantee.

15. An implantable electrode array of claim 14 wherein the first configuration is straight or substantially straight.

16. An implantable electrode array of claim 1 wherein at least a portion of an outer surface of the carrier has a coating of a material that becomes lubricious on being brought into contact with a fluid, said material being selected from the group consisting of polyacrylic acid (PAA), polyvinyl alcohol (PVA), polylactic acid (PLA) and polyglycolic acid (PGA).

17. An implantable electrode array including a carrier having a first layer and at least a second layer and formed using a method comprising:

moulding the first layer of the carrier in a first spiral-shaped mould having a first degree of curvature from a first resiliently flexible material about a series of electrodes such that at least one of the electrodes has a surface that is at least adjacent an inner surface of the first layer;

removing the first layer from the first mould, once the first layer is at least partially cured and placing the first layer in a second spiral-shaped mould having a second degree of curvature different from the first degree of curvature; and

moulding the second layer of the carrier from a second resiliently flexible material over at least a portion of the surface of the spiral-shaped first layer other than its inner surface.

18. The implantable electrode array of claim 17, wherein the series of electrodes is formed by positioning a series of platinum rings on or about a removable longitudinal support.

19. The implantable electrode array of claim 18, wherein the support comprises a wire coated with a relatively low-friction material.

20. The implantable electrode array of claim 19, further comprising at least one electrically conducting wire welded to each of the electrodes.

21. The implantable electrode array of claim 19, wherein the first spiral-shaped mould subtends an arc of greater than about 720°

.

22. The implantable electrode array of claim 19, wherein the second degree of curvature of the second spiral-shaped mould is less than the first degree of curvature, said second mould comprising a spiral-shaped cavity having at least an inner surface which subtends an arc less than that of the first mould.

23. The implantable electrode array of claim 22, wherein the second mould subtends a spiral arc of about 180°

less than the spiral arc subtended by the first mould.

24. The implantable electrode array of claim 23, wherein the inner-surface of the first layer abuts with the inner surface of the second mould when the first layer in the second mould.

25. The implantable electrode array of claim 19, further comprising a lumen within the carrier formed by removing the wire from within the carrier.

26. An implantable electrode array including a carrier having a first layer and at least a second layer and formed using a method comprising:

moulding the first layer of the carrier in a first spiral-shaped mould having a first degree of curvature from a first resiliently flexible material about a series of electrodes such that at least one of the electrodes has a surface that is at least adjacent an inner surface of the first layer;

removing the first layer from the first mould, once the first layer is at least partially cured and placing the first layer in a second spiral-shaped mould having a second degree of curvature different from the first degree of curvature; and

moulding the second layer of the carrier from a second resiliently flexible material over at least a portion of the surface of the spiral-shaped first layer other than its inner surface, wherein once the second layer is at least partially cured, the carrier is removed from the second mould and placed in a straightening jig.

27. An implantable electrode array comprising a carrier that is insertable into a cochlea of an implantee, the carrier having a proximal end and a distal end and comprising:

a first layer of a resiliently flexible material moulded in a curved configuration and having a first degree of curvature; and

at least one second layer of a resiliently flexible material moulded in a curved configuration and having a second degree of curvature;

wherein the layers are moulded together and in combination form an electrode carrier having a degree of curvature dependent on the respective degrees of curvature of the first layer and the at least second layer.

28. An implantable electrode array of claim 27 wherein the first layer has a greater degree of curvature than said at least one second layer.

29. An implantable electrode array comprising a carrier that is insertable into a cochlea of an implantee, the carrier having a proximal end and a distal end and comprising:

a first layer of a resiliently flexible material and having an inner surface and an outer surface, the first layer having a first degree of a curvature;

a second layer of a second resiliently flexible material and partially overlay the outer surface of the first layer, said second layer having a second degree of curvature different from the first degree of curvature; and

a plurality of electrodes supported within the carrier at respective locations in a region between the proximal end and the distal end of the carrier, at least one of the electrodes having a surface that is adjacent the inner surface of the first layer;

wherein the carrier is formed in a spiral-shaped configuration in which the array can apply tissue stimulation to the cochlea and is configurable to a first non-spiral shaped configuration that allows the carrier to be insertable into the cochlea of the implantee.