Ear implant electrode and method of manufacture

1. An ear implant electrode array for implantation along an inner diameter of a scala tympani of a recipient patient cochlea, the electrode array comprising:

a plurality of electrode wires for carrying electrical stimulation signals;

at a terminal end of each electrode wire, an electrode stimulation contact for applying the electrical stimulation signals to adjacent neural tissue;

an electrode carrier of resilient material encasing the electrode wires and having an outer surface with a plurality of contact openings exposing the stimulation contacts; and

a plurality of individual bend control elements distributed along the length of the electrode array to control bending flexibility of the electrode array as a function of a bend radius threshold to be greater for bending less than the bend radius threshold and lesser for bending greater than the bend radius threshold;

wherein the bend radius threshold is greater than half of the inner diameter of the scala tympani of the patient cochlea.

2. An ear implant electrode array according to claim 1 , wherein the bend control elements are made of a softer material than the electrode carrier material.

3. An ear implant electrode array according to claim 1 , wherein the bending flexibility is anisotropic to be greater in one direction than another.

4. An ear implant electrode array according to claim 1 , further comprising:

an electrode array core encased within the electrode carrier, said electrode array core being made of a flexible polymer material within which are embedded the electrode wires.

5. An ear implant electrode array according to claim 4 , wherein the array core includes an elongated helical portion having a plurality of helical turns.

6. An ear implant electrode array according to claim 5 , wherein the helical portion of the array core extends along substantially the entire length of the electrode carrier.

7. An ear implant electrode array according to claim 5 , wherein a second portion of the array core has a substantially planar shape.

8. An ear implant electrode array according to claim 5 , wherein a second portion of the array core has an elongated wavy shape having a plurality of recurring waves.

9. An ear implant electrode array according to claim 5 , wherein a stimulation contact is located at every helical turn of the array core.

10. An ear implant electrode array according to claim 5 , wherein a stimulation contact is not located at every helical turn of the array core.

11. An ear implant electrode array according to claim 10 , wherein a stimulation contact is located at every second helical turn of the array core.

12. An ear implant electrode array according to claim 5 , wherein the array core has a constant distance between helical turns.

13. An ear implant electrode array according to claim 5 , wherein the array core has a variable distance between helical turns.

14. An ear implant electrode array according to claim 5 , wherein the helical shape has a substantially constant diameter.

15. An ear implant electrode array according to claim 5 , wherein the helical shape has a diameter that decreases towards one end.

16. An ear implant electrode array according to claim 5 , wherein the array core is substantially hollow.

17. An ear implant electrode array according to claim 5 , wherein the array core contains a core material polymer that is harder than the carrier material.

18. An ear implant electrode array according to claim 17 , wherein the bend control elements extend above the outer surface of the electrode carrier.

19. An ear implant electrode array according to claim 1 , wherein each stimulation contact comprises a plurality of split contact sections electrically connected by a plurality of connecting sections.