Subthreshold stimulation of a cochlea

• US 20050033377A1
• Filed: 11/11/2002
• Published: 02/10/2005
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Milojevic, Dusan, Parker, John
• Granted Patent: US 8,538,541 B2
• Time in Patent Office: Days
• US Class Current: 607/45
• CPC Class Codes: A61M 2205/05 combined with other kinds of therapy
• CPC Class Codes: A61M 2210/0662 Ears
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/00 Electrotherapy; Circuits therefor A61N2/00 takes precedence; irradiation apparatus A61N5/00
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Abstract

An implantable apparatus, such as a cochlear implant, for delivering electrical plasticity informative stimuli to a neural network of an implantee. The apparatus comprises a stimulator device (40) that generates stimulation signals, and an electrode array (20) that receives the stimulation signals and delivers the stimuli to the neural network of the implantee in response to the signals. The stimuli delivered to the implantee facilitates and/or controls the production and/or release of naturally occurring agents into the neural network to influence the functionality thereof.

Claims

1. An implantable apparatus for delivering electrical stimuli to a neural network of an implantee, the apparatus comprising:

a stimulator that generates stimulation signals; and

at least one electrode member for receiving the stimulation signals and for delivering the stimuli to the neural network in response to said signals;

wherein the stimuli includes plasticity informative stimuli having a magnitude below a perception threshold of the implantee, the plasticity informative stimuli facilitating the production and/or release of naturally occurring agents into the neural network to influence the functionality thereof.

2. An implantable apparatus of claim 1 wherein the stimuli modifies the functionality of the neural network in a predetermined desired manner.

3. An implantable apparatus of claim 1 wherein the apparatus delivers stimuli to the auditory system of the implantee.

4. An implantable apparatus of claim 1 wherein the stimuli is delivered to the cochlea, inferior colliculus, the Subthalamic Nucleus (STN), the Globus Pallidus (GPi), and/or the Thalamus of the implantee.

5. An implantable apparatus of claim 3 wherein the perception threshold is an auditory perception threshold of the implantee.

6. An implantable apparatus of claim 5 wherein the apparatus is a component of a hearing prosthesis that is also adapted to deliver auditory informative stimuli having a magnitude that is about at or above the auditory perception threshold of the implantee to the auditory system of the implantee.

7. An implantable apparatus of claim 6 wherein the hearing prosthesis is a cochlear implant.

8. An implantable apparatus of claim 6 wherein the hearing prosthesis is a hearing aid.

9. An implantable apparatus of claim 6 wherein the prosthesis includes an electrode array that is implantable in the cochlea of the implantee and is adapted to deliver both plasticity informative stimuli and auditory informative stimuli to the cochlea of the implantee.

10. An implantable apparatus of claim 6 wherein the prosthesis comprises a first electrode array for delivering plasticity informative stimuli and a second electrode array for delivering auditory informative stimuli to the auditory system of the implantee.

11. An implantable apparatus of claim 10 wherein the first electrode array is insertable into the neural network at a location different from that of the second electrode array.

12. An implantable apparatus of claim 10 wherein both said first and said second electrode arrays comprise an elongate carrier member having a plurality of electrodes mounted thereon.

13. An implantable apparatus of claim 12 wherein the stimulator is electrically connected to each of the elongate carrier members by way of an electrical lead, the lead including one or more wires extending from each electrode of each elongate member.

14. An implantable apparatus of claim 6 wherein the hearing prosthesis includes an external component that works in conjunction with the implantable apparatus, the external component comprising:

a microphone that detects sounds and outputs acoustic signals representative of said detected sounds;

a processor that receives said acoustic signals from the microphone and converts the signals into stimulation signals representative of the detected sounds that are then delivered transcutaneously to the stimulator.

15. An implantable apparatus of claim 14 wherein the external component comprises a controller that controls the output of the stimulator.

16. An implantable apparatus of claim 14 wherein the external component further comprises a power source.

17. An implantable apparatus of claim 5 wherein the apparatus delivers plasticity informative stimuli to the cochlea of an implantee and works in conjunction with a cochlear implant device adapted to deliver auditory informative stimuli to the same cochlea of the implantee.

18. An implantable apparatus of claim 5 wherein the apparatus works in conjunction with an external component, the external component comprising a controller that controls the output of the plasticity informative stimuli from the stimulator.

19. An implantable apparatus of claim 18 wherein the external component further comprises a power source.

20. An implantable apparatus of claim 5 wherein the stimulator is housed in a housing that is totally implantable within the implantee.

21. An implantable apparatus of claim 20 wherein the housing further houses a power source that provides the apparatus with at least sufficient power to deliver plasticity informative stimuli.

22. An implantable apparatus of claim 3 wherein said at least one electrode member is part of an electrode array that is implantable in the auditory system of the implantee.

23. An implantable apparatus of claim 22 wherein said electrode array comprises an elongate electrode carrier member having a plurality of electrodes mounted thereon.

24. An implantable apparatus of claim 23 wherein the stimulator is electrically connected to the elongate member by way of an electrical lead, the lead including one or more wires extending from each electrode of the array mounted on the elongate member.

59. An implantable apparatus of claim 5 wherein the plasticity informative stimuli is delivered in a duty cycle comprising a period of time (t1) of active stimulus and a period of time (t2) of no stimulus.

60. An implantable apparatus of claim 59 wherein the period of time of active stimulus (t1) is a relatively short period of time compared to the period of time of no stimulus (t2).

61. An implantable apparatus of claim 60 wherein t1:

t2 is about 0.1;

2 or less.

62. An implantable apparatus of claim 61 wherein t1 is in the range of about 0.001 seconds to about 100 seconds.

63. An implantable apparatus of claim 59 wherein the period of active stimulus comprises a series of individual stimuli.

64. An implantable apparatus of claim 59 wherein the apparatus has at least two electrode members and the plasticity informative stimuli is delivered simultaneously or sequentially by said at least two electrode members.

65. An implantable apparatus of claim 59 wherein the apparatus has at least two electrode members and wherein the active part of the duty cycle for each active electrode occurs simultaneously.

66. An implantable apparatus of claim 59 wherein the apparatus has at least two electrode members and wherein at any given time only one stimulating electrode is active.

67. An implantable apparatus of claim 66 wherein the active part of each duty cycle is delivered sequentially by said at least two electrode members.

68. An implantable apparatus of claim 64 wherein the beginning of the active part of the duty cycle for an electrode member occurs with a delay with respect to the commencement of the duty cycle of at least one adjacent electrode member, but before the active part of the duty cycle of said at least one adjacent electrode member is finished.

69. An implantable apparatus of claim 60 wherein the apparatus measures the activity of one or more of the electrode members delivering auditory informative stimuli over a period of time of use.

70. An implantable apparatus of claim 69 wherein the plasticity informative stimuli delivered by each electrode member is varied depending on the measure of activity determined for that electrode over said period of time.

71. An implantable apparatus of claim 70 wherein the delivery of the plasticity informative stimuli is varied such that the overall delivered stimulation from any particular electrode member over a predetermined period of time is substantially equal or the same as received from other electrode members.

72. An implantable apparatus of claim 1 wherein the stimulator comprises a processor that processes a set of instructions stored on the processor in the form of software.

73. An implantable apparatus of claim 1 wherein said naturally occurring agents comprise one or more neurotrophic factors or neurotrophins selected from the group comprising Brain Derived Neurotrophic Factor (BDNF), NGF, NT-3, NT-4/5, NT-6, LIF, GDNF, CNTF, and IGF-1.

74. An implantable apparatus of claim 1 wherein said naturally occurring agents comprise neurotrophic factors that increase the survival of spiral ganglion cells.

75. An implantable apparatus of claim 1 wherein said stimuli elicits outgrowth of spiral ganglion cells towards said at least one electrode member.

76. An implantable apparatus of claim 1 wherein said stimuli is delivered at a frequency less than 5 kHz, more preferably at about 50 Hz.

77. An implantable apparatus of claim 5 wherein the apparatus delivers plasticity informative stimuli at times when the apparatus is not delivering auditory informative stimuli.

25. An implantable apparatus for delivering electrical plasticity informative stimuli and auditory informative stimuli to the auditory system of an implantee, comprising:

(i) a power source that provides power for the implant;

(ii) a stimulator that outputs stimulation signals; and

(iii) at least one electrode member that receives the stimulation signals and delivers said stimuli to the auditory system of the implantee in response to said signals;

wherein the stimuli facilitates and/or controls the production and/or release of naturally occurring agents into the auditory system of the implantee to influence the functionality thereof.

26. An implantable apparatus of claim 25 wherein the stimuli modifies the functionality of the auditory system in a predetermined desired manner.

27. An implantable apparatus of claim 25 wherein the stimuli is delivered to the cochlea, inferior colliculus, the Subthalamic Nucleus (STN), the Globus Pallidus (GPi), and/or the Thalamus of the implantee.

28. An implantable apparatus of claim 25 wherein the implant is adapted to monitor when said at least one electrode member is not delivering auditory informative stimuli.

29. An implantable apparatus of claim 28 wherein on monitoring that no auditory informative stimuli is being delivered by said at least one electrode member, the apparatus commences delivery of plasticity informative stimuli.

30. An implantable apparatus of claim 29 wherein the apparatus delays commencement of delivery of plasticity informative stimuli until a predetermined time period has elapsed since delivery of the last auditory informative stimulus.

31. An implantable apparatus of claim 28 wherein the apparatus ceases delivery of plasticity informative stimuli on commencing delivery of auditory informative stimuli to the implantee'"'"'s auditory system.

32. An implantable apparatus of claim 25 wherein the apparatus further comprises an array of electrode members, said array comprising an elongate electrode carrier member having said electrode members mounted thereon.

33. An implantable apparatus of claim 32 wherein the carrier member on implantation into the auditory system has a coating containing neurotrophic factors.

34. An implantable apparatus of claim 28 wherein the plasticity informative stimuli is delivered in a duty cycle comprising a period of time (t1) of active stimulus and a period of time (t2) of no stimulus.

35. An implantable apparatus of claim 34 wherein the period of time of active stimulus (t1) is a relatively short period of time compared to the period of time of no stimulus (t2).

36. An implantable apparatus of claim 35 wherein t1:

t2 is about 0.1;

2 or less.

37. An implantable apparatus of claim 36 wherein t1 is in the range of about 0.001 seconds to about 100 seconds.

38. An implantable apparatus of claim 34 wherein the period of active stimulus comprises a series of individual stimuli.

39. An implantable apparatus of claim 34 wherein the apparatus has at least two electrode members and the plasticity informative stimuli is delivered simultaneously or sequentially by said at least two electrode members.

40. An implantable apparatus of claim 34 wherein the apparatus has at least two electrode members and wherein the active part of the duty cycle for each active electrode occurs simultaneously.

41. An implantable apparatus of claim 34 wherein the apparatus has at least two electrode members and wherein at any given time only one stimulating electrode is active.

42. An implantable apparatus of claim 41 wherein the active part of each duty cycle is delivered sequentially by said at least two electrode members.

43. An implantable apparatus of claim 39 wherein the beginning of the active part of the duty cycle for an electrode member occurs with a delay with respect to the commencement of the duty cycle of at least one adjacent electrode member, but before the active part of the duty cycle of said at least one adjacent electrode member is finished.

44. An implantable apparatus of claim 35 wherein the apparatus measures the activity of one or more of the electrode members delivering auditory informative stimuli over a period of time of use.

45. An implantable apparatus of claim 44 wherein the plasticity informative stimuli delivered by each electrode member is varied depending on the measure of activity determined for that electrode over said period of time.

46. An implantable apparatus of claim 45 wherein the delivery of the plasticity informative stimuli is varied such that the overall delivered stimulation from any particular electrode member over a predetermined period of time is substantially equal or the same as received from other electrode members.

47. An implantable apparatus of claim 25 wherein the stimulator comprises a processor that processes a set of instructions stored on the processor in the form of software.

48. An implantable apparatus of claim 25 wherein said naturally occurring agents comprise one or more neurotrophic factors or neurotrophins selected from the group comprising Brain Derived Neurotrophic Factor (BDNF), NGF, NT-3, NT-4/5, NT-6, LIF, GDNF, CNTF, and IGF-1.

49. An implantable apparatus of claim 25 wherein said naturally occurring agents comprise neurotrophic factors that increase the survival of spiral ganglion cells.

50. An implantable apparatus of claim 25 wherein said stimuli elicits outgrowth of spiral ganglion cells towards said at least one electrode member.

52. An implantable apparatus of claim 29 wherein the apparatus delivers plasticity informative stimuli at times when the apparatus is not delivering auditory informative stimuli.

51. An implantable apparatus of claim 125 wherein said stimuli is delivered at a frequency less than 5 kHz, more preferably at about 50 Hz.

53. A method of delivering stimuli to a neural network of an implantee comprising the steps of:

(i) positioning at least one electrode member in a position suitable to deliver said stimuli to said implantee;

(ii) generating stimulation signals;

(iii) transmitting said signals to said at least one electrode member; and

(iv) delivering said stimuli in response to said signals;

wherein the stimuli includes plasticity informative stimuli having a magnitude below a perception threshold of the implantee, the plasticity informative stimuli facilitating the production and/or release of naturally occurring agents into the neural network to influence the functionality thereof.

54. A method of delivering stimuli to a neural network of claim 53 wherein the stimuli modifies the functionality of the neural network in a predetermined desired manner.

55. A method of delivering stimuli to a neural network of claim 53 wherein the stimuli is delivered to the auditory system of the implantee.

56. A method of delivering stimuli to a neural network of claim 53 wherein in step (i) said at least one electrode member is positioned in a cochlea of an implantee.

57. A method of delivering stimuli to a neural network of claim 53 wherein said at least one electrode is adapted to deliver plasticity informative stimuli and auditory informative stimuli to the cochlea of the implantee.

58. (Cancelled)