Cochlear endosteal electrode carrier member

1. An elongate carrier member comprising:

a longitudinally-extending central region;

two side regions laterally extending from opposing sides of the central region such that the carrier member is substantially symmetrical about a longitudinal plane;

a lateral surface defined by the central and side regions together forming a convex circumferential surface defined by a single radius;

a medial surface defined by a convex surface of the central region and a concave surface for each of the side regions;

a plurality of longitudinally-spaced electrodes disposed on or in the convex surface of the central region of the medial surface; and

a support structure comprising a plurality of longitudinally extending wires each connected to one or more of the electrodes, wherein a subset of the plurality of wires is disposed in the central region and at least one of the plurality of wires is disposed in one of the side regions.

2. The carrier member of claim 1 , wherein the carrier member is resiliently flexible in the longitudinal plane.

3. The carrier member of claim 2 , wherein the carrier member is less resiliently flexible in a lateral plane than the longitudinal plane.

4. The carrier member of claim 2 , wherein the side regions are resiliently flexible in a lateral plane.

5. The carrier member of claim 4 , wherein the side regions are configured to flex when the carrier member is implanted in a crevice between the spiral ligament and the endosteum of the lateral wall of the cochlea.

6. The carrier member of claim 1 , wherein the side regions each have a smooth end edge that connects the lateral surface to the medial surface.

7. The carrier member of claim 1 , wherein the curvature of the lateral surface approximates the curvature of the endosteum along the basal turn of the cochlea.

8. The carrier member of claim 1 , further comprising a stop member at a proximal end of the carrier member.

9. The carrier member of claim 1 , further comprising a tip member at a distal end of the carrier member.

10. The carrier member of claim 9 , wherein the tip member comprises:

a first rounded surface extending from the medial surface to a front surface and having a first taper defined by a first radius; and

a second rounded surface extending from the lateral surface to the front surface and having a second taper defined by a second radius;

wherein the first radius and the second radius are different.

11. The carrier member of claim 9 , wherein, at the tip member, the medial surface curves towards the lateral surface; and

wherein the tip member comprises an extension that longitudinally extends beyond said curving medial surface to form a plateau and which has a blunt leading surface.

12. The carrier member of claim 1 , wherein at least one of the plurality of wires is disposed in a first one of the two side regions and at least one of the plurality of wires is disposed in a second one of the two side regions.

13. A hearing prostheses comprising:

an implantable stimulator; and

an electrode array connected to the stimulator, the array comprising:

an elongate carrier member having a contiguous smooth shape defined by a lateral convex surface having a substantially consistent radius of curvature and which curves at each end to meet a medial surface having two symmetrical concavities about a longitudinal plane that define a central region having a convex surface and two opposing side regions, wherein the thickest part of the carrier member is near the central region,

wherein the carrier member comprises a plurality of electrodes disposed on or in the convex surface of the central region of the medial surface; and

wherein the carrier member further comprises a support structure comprising a plurality of longitudinally extending wires each connected to one or more of the electrodes, wherein a subset of the plurality of wires is disposed in the central region and at least one of the plurality of wires is disposed in one of the side regions.

14. The prostheses of claim 13 , wherein the carrier member is resiliently flexible in the longitudinal plane.

15. The prostheses member of claim 14 , wherein the carrier member is less resiliently flexible in a lateral plane than the longitudinal plane.

16. The prostheses member of claim 14 , wherein the side regions are resiliently flexible in a lateral plane.

17. The prostheses of claim 16 , wherein the side regions are configured to flex when the carrier member is implanted in a crevice between the spiral ligament and the endosteum of the lateral wall of the cochlea.

18. The prostheses of claim 13 , wherein the side regions each have a smooth end edge that connects the lateral surface to the medial surface.

19. The prostheses of claim 13 , wherein the curvature of the lateral surface approximates the curvature of the endosteum along the basal turn of the cochlea.

20. The prostheses of claim 13 , further comprising a tip member at a distal end of the carrier member.

21. The prostheses of claim 20 , wherein the tip member comprises:

a first rounded surface extending from the medial surface to a front surface and having a first taper defined by a first radius; and

a second rounded surface extending from the lateral surface to the front surface and having a second taper defined by a second radius;

wherein the first radius and the second radius are different.

22. The prostheses of claim 20 , wherein, at the tip member, the medial surface curves towards the lateral surface; and

wherein the tip member comprises an extension that longitudinally extends beyond said curving medial surface to form a plateau and which has a blunt leading surface.

23. The prosthesis of claim 13 , wherein at least one of the plurality of wires is disposed in a first one of the two side regions and at least one of the plurality of wires is disposed in a second one of the two side regions.