Auditory midbrain implant

• US 20050004627A1
• Filed: 10/25/2002
• Published: 01/06/2005
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Gibson, Peter, Parker, John, Patrick, James Finlay, Mackiewicz, Miro, Lenarz, Minoo, Lenarz, Thomas
• Granted Patent: US 7,797,029 B2
• Time in Patent Office: Days
• US Class Current: 607/57
• CPC Class Codes: A61F 11/04 Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense, e.g. through the touch sense electronic stimulation of auditory nerves A61N1/36036
• CPC Class Codes: A61N 1/0529 Electrodes for brain stimulation
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

An electrode array (10) that is implantable within the inferior colliculus of the midbrain and/or other appropriate regions of the brain of an implantee and adapted to provide electrical stimulation thereto. The electrode array (10) an elongate member (11) having a plurality of electrodes (12) mounted thereon in a longitudinal array. A delivery cannula (30) for delivering the electrode array (10) comprised of two half-pipes (31) is also described.

Claims

1. A brain stimulating electrode array comprising an elongate member having a plurality of spaced electrodes thereon, the elongate member being insertable into an inferior colliculi of an implantee and wherein the electrodes are spaced along the member to apply preselected tissue stimulation to different frequency layers of the inferior colliculi.

2. The brain stimulating electrode array of claim 1 wherein the elongate member has between about 4 and 80 electrodes mounted thereon.

3. The brain stimulating electrode of claim 2 wherein the elongate member has about 20 electrodes mounted thereon.

4. The brain stimulating electrode array of claim 1 wherein the electrodes are disposed in a longitudinal array on the elongate member.

5. The brain stimulating electrode array of claim 4 wherein the electrodes are equally spaced along the elongate member.

6. The brain stimulating electrode array of claim 1 wherein each electrode comprises at least one single penetrating pin.

7. The brain stimulating electrode array of claim 1 wherein each electrode is selected from a group comprising a ring, a half ring, a flat pad, and a multiple number of pains or pads around the circumference of the elongate body.

8. The brain stimulating electrode array of claim 7 wherein each of the electrodes are identical in form.

9. The brain stimulating electrode array of claim 7 wherein at least one of the electrodes has a different form from at least one of the other electrodes.

10. The brain stimulating electrode array of claim 1 wherein each electrode has a width of between about 50 and about 2000 microns.

11. The brain stimulating electrode array of claim 10 wherein each electrode has a width of about 100 microns.

12. The brain stimulating electrode array of claim 1 wherein the spacing between the electrodes is between about 50 and about 2000 microns.

13. The brain stimulating electrode array of claim 12 wherein the spacing between the electrodes is about 100 microns.

14. The brain stimulating electrode array of claim 1 wherein the pitch of the electrodes is between about 50 microns and about 2000 microns.

15. The brain stimulating electrode array of claim 14 wherein the pitch of the electrodes is about 200 microns.

16. The brain stimulating electrode array of claim 1 wherein the array has a length of between about 2 mm and about 6 mm.

17. The brain stimulating electrode array of claim 16 wherein the array has a length of about 4 mm long.

18. The brain stimulating electrode array of claim 1 wherein the elongate member has a tip at a distal end that assists in passage of the member into the brain while causing relatively minimal trauma to the sensitive tissues of the brain.

19. The brain stimulating electrode array of claim 18 wherein the diameter of the elongate member begins to decrease proximate the distal end to the tip.

20. The brain stimulating electrode array of claim 19 wherein the tip is formed of a biocompatible material.

21. The brain stimulating electrode array of claim 1 wherein the elongate member has a body formed from a relatively stiff biocompatible material to allow the elongate member to penetrate the surface of the brain and be inserted at a desired depth therein.

22. The brain stimulating electrode array of claim 21 wherein the elongate body has a diameter of about 0.2 mm to about 2 mm.

23. The brain stimulating electrode array of claim 22 wherein the elongate body has a diameter of about 0.5 mm.

24. The brain stimulating electrode array of claim 18 wherein the elongate member has a cuff or skirt positioned about the body at a predetermined distance from the distal tip.

25. The brain stimulating electrode array of claim 24 wherein the skirt or cuff is adapted to collapse on insertion of the elongate member through a delivery cannula but expand on exiting a distal end of the cannula.

26. The brain stimulating electrode array of claim 25 wherein the skirt or cuff is spaced a distance of between about 6 and 6.5 mm from the distal tip and is adapted to stabilize the elongate member in a portion of the brain and ensure the elongate member does not migrate further into said portion following correct placement.

27. The brain stimulating electrode array of claim 26 wherein the skirt has a plurality of fold lines and/or ribs formed therein so as to allow the skirt to collapse on insertion through the delivery cannula.

28. The brain stimulating electrode array of claim 27 wherein the skirt is adapted to collapse and/or expand in a spiral fashion.

29. The brain stimulating electrode array of claim 1 wherein the elongate member has a stiffening element extending at least partially therethrough.

30. An implant system that provides a hearing sensation to an implantee, the system comprising an electrically stimulating electrode array as defined in claim 1.

31. The implant system of claim 30 wherein the system further comprises a stimulator that outputs stimulation signals to the electrodes of the electrode array.

32. The implant system of claim 31 wherein the stimulator is electrically connected to the elongate member by way of an electrical lead having one or more wires extending from each electrode of the array.

33. The implant system of claim 32 wherein the stimulator is positioned within a housing that is implantable within the head of the implantee.

34. The implant system of claim 33 wherein the housing further contains a receiver that receives signals from a controller mounted external to the body of the implantee such that the signals are transmitted transcutaneously between the controller and the receiver.

35. The implant system of claim 34 wherein the receiver includes a receiver coil adapted to receive radio frequency (RF) signals form a corresponding transmitter coil worn externally of the body.

36. The implant system of claim 35 wherein the external controller comprises a speech processor that receives signals output by a microphone, encodes the sound detected by the microphone into a sequence of electrical stimuli following given algorithms, and then transfers the encoded sequence to the implanted device using the transmitter and receiver coils.

37. The implant system of claim 36 wherein the external controller further comprises a power supply, with the transmitter and receiver coils providing power via transcutaneous induction to the implanted device and the electrode array.

38. The implant system of claim 32 wherein the elongate member has a stiffening element extending at least partially therethrough.

39. The implant system of claim 38 wherein the stiffening element comprises a removable stylet extending through a lumen formed in the elongate member and the lead.

40. The implant system of claim 38 wherein the stiffening element has a stepped outer surface with the element having a section of relatively narrower dimensions that is inserted into elongate member and a section of relatively wider dimensions that is normally positioned external of the array.

41. A stiffening element when used with a brain stimulating electrode array as defined in claim 1 wherein the stiffening element has a stepped outer surface with the element having a section of relatively narrower dimensions that is inserted into the electrode array and a section of relatively wider dimensions that is normally positioned external of the array.

42. A delivery cannula for delivering an electrode array as defined in claim 1.

43. The delivery cannula of claim 42 wherein the cannula is comprised of two or more longitudinal portions joined at respective longitudinal joins.

44. The delivery cannula of claim 43 wherein the two more longitudinal portions comprise two half-pipes, with the cannula when assembled being cylindrical in form.

45. The delivery cannula of claim 44 wherein the two half-pipes are held together by a holding device adapted to be positioned outside the skull during use of the cannula.

46. The delivery cannula of claim 45 wherein the holding device is a ring that removably surrounds the half-pipes.

47. A method of providing a hearing sensation to an implantee, the method comprising the steps of:

implanting at least one electrode array as defined in claim 1 within the inferior colliculus of the implantee; and

delivering electrical stimulation to the inferior colliculus.

48. The method of providing a hearing sensation to an implantee of claim 47 wherein step (i) of the method further comprises the steps of:

identifying the position of the inferior colliculus in the implantee;

mounting a sterotactic frame to the implantee'"'"'s head; and

inserting the electrode array into the inferior colliculus of the midbrain using the stereotaxis.

49. The method of providing a hearing sensation to an implantee of claim 48 wherein the position of the inferior colliculus is localized using magnetic resonance imaging (MRI) with exact intraoperative placement adjusted by direct electrical stimulation of the inferior colliculus and recording of electrically evoked auditory potentials.

50. The method of providing a hearing sensation to an implantee of claim 49 wherein the stereotactic implantation is performed through a burr hole, with a stimulator/receiver device placed subperiostally in a bony bed behind the pinna.

51. A brain stimulating electrode array comprising an elongate member having a plurality of spaced electrodes thereon, the member having a lumen extending at least partially therethrough for a length, and a stiffening element removably positionable in at least a portion of the lumen.

52-53. -53. (Cancelled)