Optically Coupled Cochlear Implant Systems and Methods

• US 20110144719A1
• Filed: 06/18/2010
• Published: 06/16/2011
• Est. Priority Date: 06/18/2009
• Status: Active Application

• Current Assignee: EarLens Corporation
• Original Assignee: SoundBeam, LLC
• Inventors: Rucker, Paul C., Perkins, Rodney C., Puria, Sunil
• Granted Patent: US 10,286,215 B2
• Time in Patent Office: Days
• US Class Current: 607/57
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: H04B 10/1141 One-way transmission
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window

Abstract

An output assembly is sized for placement in the middle and inner ear, such that removal of bone can be decreased. The output assembly may comprise at least one photo detector, a demultiplexer and an electrode array sized to pass through an incision in the eardrum. An input transducer assembly is configured to transmit a multiplexed optical signal to the output assembly. The input assembly can be configured to transmit the multiplexed optical signal through the eardrum, such that tissue removal can be decreased and the device can be placed without removal of bone, for example. The multiplexed optical signal may comprise a pulse width modulated signal so as to decrease the effect of non-linearities of the light source and light detector and provide quality sound to the user.

Claims

1. A method of stimulating tissue, the method comprising:

transmitting a multiplexed optical signal to stimulate the tissue.

2. A method of transmitting a sound to a cochlea of a user, the user having a tissue, the method comprising:

transmitting a multiplexed optical signal through the tissue of the user such that the user hears the sound in response to the multiplexed optical signal transmitted through the tissue.

3. The method of claim 2 wherein the tissue comprises tissue of an eardrum.

4. The method of claim 2 wherein the multiplexed optical signal is transmitted to an optical structure supported with the middle ear, the optical structure configured to separate wavelengths of the multiplexed signal to stimulate the cochlea.

5. The method of claim 4 wherein the said optical structure is affixed to the middle ear.

6. The method of claim 4 wherein the said optical structure is sized to pass through an incision in the eardrum for placement in the middle ear cavity.

7. The method of claim 4 wherein the optical structure comprises at least one of an optical filter, an optical fiber, a grating, an etalon, a plurality of optical fibers, a waveguide, a plurality of waveguides, a mirror or a prism.

8. The method of claim 4 wherein the multiplexed optical signal comprises a plurality of channels, each channel of the plurality corresponding to at least one frequency of the sound.

9. The method of claim 8 wherein the plurality of channels corresponds to at least about sixteen channels and said at least one frequency corresponds to at least about sixteen frequencies.

10. The method of claim 8 wherein the multiplexed optical signal is transmitted through the eardrum with a plurality of light sources, each light source configured to transmit a light signal corresponding to said channel of the plurality such that said light source corresponds to said at least one frequency of sound.

11. The method of claim 10 wherein the plurality of light sources comprises at least three light sources and wherein each of the at least three light sources is configured to emit separate wavelengths of light.

12. The method of claim 8 wherein each of the plurality of channels corresponds to a pair of electrodes and wherein a first current travels between said pair of electrodes in response to a first width modulated light pulse and a second current travels between said pair of electrodes in response to a second width modulated light pulse, the first current opposite the second current, the first current opposite the second current, the first current having a first amount corresponding to a first width of the first pulse and the second current having a second amount corresponding to a second width the second pulse, and wherein the width of the first pulse corresponds to the width of the second pulse so as to inhibit rectification and balance charge transfer between the first electrode and the second electrode.

13. The method of claim 12 wherein the first light pulse comprises a first wavelength of light coupled to a first detector and wherein the second light pulse comprises a second wavelength of light coupled to a second detector.

14. The method of claim 2 wherein the multiplexed optical signal is transmitted through the eardrum of the user to at least one photodetector, the at least one photodetector affixed to the middle ear and coupled to an electrode array positioned at least partially within the cochlea.

15. The method of claim 14 wherein the at least one photodetector and at least one electrode array are sized to pass through an incision in the eardrum.

16. The method of claim 14 wherein the multiplexed optical signal comprises a wavelength multiplexed optical signal, the wavelength multiplexed optical signal comprising a plurality of wavelengths such that each wavelength corresponds to an electrode of the array.

17. The method of claim 16 wherein each wavelength of the plurality corresponds to an electrode of the array.

18. The method of claim 16 wherein the at least one photodetector comprises a plurality of photodetectors, each photodetector of the plurality coupled to a corresponding electrode of the array and a corresponding wavelength of the plurality such that the tissue stimulating current is passed through the electrode in response to the tissue stimulating wavelength.

19. The method of claim 18 wherein further comprising an optical structure positioned in the middle ear of the user to separate the wavelengths to correspond with each detector, and such that each separated wavelength corresponding to each detector is transmitted to said each detector based on the wavelength.

20. The method of claim 18 further comprising a plurality of optical filters positioned in the middle ear of the user and wherein the wavelengths are separated with the optical filters, each optical filter positioned over one detector and configured to pass the wavelengths corresponding to the electrode coupled to said one detector.

21. The method of claim 18 wherein further comprising a grating configured to select the wavelengths of each detector to corresponding to each electrode.

22. The method of claim 14 wherein the multiplexed optical signal comprises a time division multiplexed signal.

23. The method of claim 22 wherein the time division multiplexed signal comprises the plurality of time-slots, each time slot of the plurality corresponding to an electrode of the array.

24. The method of claim 23 wherein the time division multiplexed signal comprises the plurality of time slots and a clock signal and wherein circuitry is coupled to the at least one photodetector and the electrode array to receive the clock signal and divide the time division multiplexed signal among the electrodes of the array such that each time slot corresponds to the electrode of the array.

25. The method of claim 24 wherein each time slot corresponds to at least one frequency of the sound such that current is passed through each electrode in response to a portion of the multiplexed signal corresponding to the time slot.

26. The method of claim 25 the time division multiplexed signal is pulse width modulated such that each timeslot of the plurality comprises a pulse of light having a duration that corresponds to current through the electrode corresponding to said timeslot.

27. The method of claim 2 wherein the multiplexed optical signal is transmitted to at least one optical fiber extending into the cochlea.

28. The method of claim 27 wherein the at least one optical fiber is sized to pass through an incision in the middle ear.

29. The method of claim 27 wherein the at least one optical fiber comprises a plurality of optical fibers extending into the cochlea, each fiber corresponding to at least one frequency of the sound.

30. The method of claim 27 wherein each fiber is configured to stimulate the cochlea at a predetermined location of the cochlea corresponding to a corresponding range of frequencies in response to the at least one frequency of the sound.

31. The method of claim 2 wherein the multiplexed optical signal is transmitted through at least one of an opening or a window in the eardrum.

32. The method of claim 2 wherein the electrode array, the at least one photodetector, and the demultiplexer comprise substantially non-magnetic materials configured for MRI imaging when implanted in the user.

33. The method of claim 2 wherein the sound comprises a phase and wherein the optical signal comprises width modulated light pulses transmitted with a frequency of at least about 10 kHz and wherein each light pulse generates an electrical current within the cochlea such that the cochlea demodulates the light pulses and the phase of the sound is maintained.

34. The method of claim 33 wherein the width modulated light pulses comprises a series of width modulated pulses for each channel and wherein the series of width modulated pulses of said each channel comprises a frequency of at least about 10 kHz to maintain the phase of the sound when the user hears the sound.

35. The method of claim 34 wherein the frequency of said each series comprises at least about 20 kHz to maintain the phase of the sound when the user hears the sound.

36. The method of claim 35 wherein the plurality of channels comprises at least about eight channels and the frequency of the width modulated light pulses comprises at least about 160 kHz.

37. The method of claim 34 wherein the pulses of the series of width modulated pulses of each channel are combined to form a sequence of packet of pulses, each packet comprising one pulse from each series.

38. The method of claim 2 wherein the at least one photodetector is positioned in the middle ear cavity so as to receive the multiplexed optical signal through a posterior portion of the eardrum.

39. A system to stimulate tissue, the system comprising:

a plurality of electrodes configured for placement at least partially within the tissue;

circuitry configured to receive a signal from a source;

at least one light source coupled to the circuitry and configured to emit a multiplexed optical signal comprising a plurality of light pulses;

at least one photo detector configured to receive the multiplexed optical and pass current through the electrodes in response to the light pulses to stimulate the tissue.

40. A system to transmit an audio signal to a user, the system comprising:

an electrode array comprising a plurality of electrodes configured for placement at least partially within a cochlea of the user;

circuitry configured to receive the audio signal from a sound source;

at least one light source coupled to the circuitry and configured to emit a multiplexed optical signal comprising a plurality of light pulses;

at least one detector configured to receive the multiplexed optical and pass current through the electrodes in response to the light pulses.

41. The system of claim 40 the circuitry is configured to determine widths of a plurality of light pulses and wherein each light pulse corresponds to an electrode of the array and a width of said each light pulse corresponds to an amount of current through said corresponding electrode of the array.

42. The system of claim 40 wherein the circuitry is configured to determine frequencies of the audio signal and wherein the frequencies correspond to electrodes of the array and wherein the circuitry is configured to determine a width of each pulse in response to one or more of the frequencies.

43. The system of claim 40 wherein the at least one light source comprises a plurality of light sources and wherein each light source corresponds to one electrode of the array.

44. The system of claim 43 each of the plurality of light sources is configured to emit light comprising wavelengths substantially separated from wavelengths of other light sources of the plurality.

45. The system of claim 43 wherein the plurality of light sources comprises at least three light sources and the electrode array comprises at least three electrodes and wherein each of the at least three light sources corresponds to one electrode of the at least three electrodes of the array.

46. The system of claim 45 each of the at least three light sources is configured to emit light comprising wavelengths substantially separated from others of the at least three light sources and wherein the wavelengths of each source correspond to one electrode of the at least three.

47. The system of claim 40 wherein the at least one detector comprises a plurality of detectors and wherein each detector of the plurality corresponds to one electrode of the array.

48. The system of claim 47 wherein the plurality of light detectors comprises at least three light detectors and the electrode array comprises at least three electrodes and wherein each of the at least three light detectors corresponds to one electrode of the at least three electrodes of the array.

49. The system of claim 40 further comprising an optical structure configured to receive the multiplexed optical signal, the optical structure configured for placement in the middle, the optical structure configured to select wavelengths of the multiplexed signal.

50. The system of claim 49 wherein the said optical structure is sized to pass through an incision in the eardrum for placement in the middle ear and wherein the electrode array is sized for placement at least partially inside the cochlea through a round window of the cochlea.

51. The system of claim 49 wherein the optical structure comprises at least one of an optical filter, a grating, an etalon, a plurality of optical fibers, or a prism.

52. The system of claim 49 wherein the multiplexed optical signal comprises a plurality of optical channels, each optical channel of the plurality corresponding to at least one frequency of the sound.

53. The system of claim 52 wherein the plurality of optical channels corresponds to at least about sixteen channels and said at least one frequency corresponds to at least about sixteen frequencies.

54. The system of claim 52 further comprising an elongate optical transmission structure configured for placement at least partially within the ear canal of the user and wherein the elongate optical transmission structure is configured to transmit multiplexed optical signal through the eardrum.

55. The system of claim 40 wherein the multiplexed optical signal is transmitted through the eardrum of the user to at least one photodetector, the at least one photodetector affixed to the middle ear and coupled to an electrode array positioned at least partially within the cochlea.

56. The system of claim 55 wherein the at least one photodetector and the electrode array are sized to pass through an incision in the eardrum.

57. The system of claim 55 wherein the multiplexed optical signal comprises a wavelength multiplexed optical signal, the wavelength multiplexed optical signal comprising a plurality of wavelengths such that each wavelength corresponds to an electrode of the array.

58. The system of claim 57 wherein each wavelength of the plurality corresponds to an electrode of the array.

59. The system of claim 57 wherein the plurality of wavelengths comprises at least three wavelengths and wherein the plurality of electrodes comprises at least three electrodes and wherein each wavelength of the plurality corresponds to one electrode of the at least three electrodes.

60. The system of claim 40 wherein the circuitry is configured to transmit a series of the light pulses to correspond to electrodes of the array.

61. The system of claim 60 wherein the series comprises a plurality of pulses and wherein each pulse of the plurality corresponds to one electrode of the plurality.

62. The system of claim 61 wherein the plurality of electrodes comprises at least three electrodes and wherein the series comprises at least three pulses and wherein each pulse of the at least three pulses corresponds to one electrode of the at least three electrodes.

63. The system of claim 60 wherein the series comprises a timing pulse.

64. The system of claim 63 wherein the timing pulse comprises a substantially fixed width and wherein the timing pulse comprises energy to power circuitry coupled to the plurality of electrodes.

65. The system of claim 63 further comprising switching circuitry coupled to the at least one detector to couple sequentially each electrode of the plurality to the at least one detector in response to the timing pulse such that each pulse of the series corresponds to one electrode of the plurality.

66. The system of claim 65 wherein the series of pulses comprises a pre-determined order and timing of the pulses and wherein the switching circuitry comprises a timer coupled to switches to open the switches and close the to correspond with pulses of the series.

67. The system of claim 65 wherein the series comprises at least three pulses and wherein the switching circuitry is configured to coupled at least one detector sequentially to each electrode of the at least three such that each pulse of the series corresponds to one electrode of the plurality.

68. The system of claim 40 wherein the electrode array, the at least one photodetector, and the demultiplexer comprise substantially non-magnetic materials configured for MRI imaging when implanted in the user.

69. The system of claim 40 wherein the sound comprises a phase and wherein the optical signal comprises width modulated light pulses transmitted with a frequency of at least about 10 kHz and wherein each light pulse generates an electrical current within the cochlea such that the cochlea demodulates the light pulses and the phase of the sound is maintained.

70. The system of claim 69 wherein the width modulated light pulses comprises a series of width modulated pulses for each channel and wherein the series of width modulated pulses of said each channel comprises a frequency of at least about 10 kHz to maintain the phase of the sound when the user hears the sound.

71. The system of claim 70 wherein the frequency of said each series comprises at least about 20 kHz to maintain the phase of the sound when the user hears the sound.

72. The system of claim 71 wherein the plurality of channels comprises at least about eight channels and the frequency of the width modulated light pulses comprises at least about 160 kHz.

73. The system of claim 70 wherein the pulses of the series of width modulated pulses of each channel are combined to form a sequence of packet of pulses, each packet comprising one pulse from each series.

74. The method of claim 73 wherein each of the plurality of channels corresponds to a pair of electrodes and wherein a first current travels between said pair of electrodes in response to a first width modulated light pulse and a second current travels between said pair of electrodes in response to a second width modulated light pulse, the first current opposite the second current, the first current opposite the second current, the first current having a first amount corresponding to a first width of the first pulse and the second current having a second amount corresponding to a second width the second pulse, and wherein the width of the first pulse corresponds to the width of the second pulse so as to inhibit rectification and balance charge transfer between the first electrode and the second electrode.

75. The method of claim 74 wherein the first light pulse comprises a first wavelength of light coupled to a first detector coupled to said pair of electrodes and wherein the second light pulse comprises a second wavelength of light coupled to a second detector coupled to said pair of electrodes and wherein the first detector is coupled to the pair opposite the second detector.

76. A method of providing a hearing prosthesis for a user, the method comprising:

making an incision in an eardrum of the user, the eardrum comprising an annuls; and

passing an electrode array, at least one photodetector, and a demultiplexer through the incision.

77. The method of claim 76 wherein the incision extends at least partially through the annulus.

78. The method of claim 76 wherein the eardrum is positioned to a side of an ear canal to pass the electrode array, the demultiplexer and the at least one photodetector through the incision.

79. The method of claim 80 wherein the at least one detector and the demultiplexer are affixed to the middle ear of the user.

80. The method of claim 76 wherein the electrode array is positioned at least partially through a round window and wherein the at least one detector and the demultiplexer are positioned in a middle ear of the user.

81. The method of claim 80 wherein the at least one detector and the demultiplexer are affixed to the middle ear of the user.

82. The method of claim 76 wherein the at least one photo detector comprises at least three photodetectors.

83. The method of claim 82 wherein the demultiplexer comprises an optical demultiplexer.

84. The method of claim 83 wherein the optical demultiplexer comprises at least three filters to separate at least three wavelengths of light.

85. The method of claim 76 wherein the demultiplexer comprises switching circuitry and a timer.

86. The method of claim 76 wherein the electrode array, the at least one photodetector, and the demultiplexer passed through the incision comprise substantially non-magnetic materials configured for MRI imaging.

87. The method of claim 76 wherein the at least one photodetector is positioned in the middle ear cavity to receive light energy transmitted through the posterior portion of the eardrum.

88. A device to stimulate tissue, the device comprising:

means for generating a multiplexed optical signal; and

means for stimulating tissue in response to the optical signal.