Method and apparatus for improving signal quality in implantable hearing systems

• US 6,689,045 B2
• Filed: 12/12/2001
• Issued: 02/10/2004
• Est. Priority Date: 09/24/1998
• Status: Expired due to Term

• Current Assignee: Envoy Medical Corporation
• Original Assignee: St Croix Medical Incorporated
• Inventors: Kroll, Kai, Kennedy, Joel A.
• Primary Examiner(s): Lacyk, John P.
• Application Number:
  US10/015,735
• Publication Number:
  US 20020123662A1
• Time in Patent Office: 790 Days
• Field of Search: 600/25, 181/129-130, 181/132-137, 381/312-331
• US Class Current: 600/25
• CPC Class Codes: H04R 2225/49 Reducing the effects of electromagnetic noise on the functioning of hearing aids, by, e.g. shielding, signal processing adaptation, selective (de)activation of electronic parts in hearing aid
• 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 implantable hearing assistance system includes a sensor transducer and an electronics unit. The sensor transducer, such as a piezoelectric transducer, is operatively coupled to an auditory element of the middle ear (e.g., malleus), and electrically connected to the electronics unit. The transducer and the electronics unit are arranged together to minimize the driving impedance and lead capacitance therebetween, thereby minimizing susceptibility to electromagnetic interference and minimizing high audio frequency signal attenuation.

In one example, the transducer and the electronics unit are disposed immediately adjacent each other or physically joined together to virtually eliminate (or at least significantly shorten) the length of the electrical connection between the transducer and the electronics unit. In another example, the electronics unit is located remotely from the transducer, and a preamplifier (or other impedance transforming electronics) is placed in close physical proximity to the transducer in the middle ear between the transducer and the remaining electronics unit.

Claims

1. An implantable hearing assistance system capable of maximizing high frequency audio performance and minimizing electromagnetic interference and high frequency audio attenuation, comprising:

a high impedance sensor transducer;

an impedance transformation device located at a minimal distance from and electrically connected to the sensor transducer, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the impedance transformation device that is susceptible to electromagnetic interference and high frequency audio attenuation;

a high impedance electronics unit electrically connected to the impedance transformation device; and

a driver transducer electrically connected to the electronics unit.

2. The system of claim 1, wherein the sensor transducer is a piezoelectric transducer.

3. The system of claim 1, wherein the sensor transducer is an electromagnetic transducer.

4. The system of claim 1, wherein the impedance transformation device is located at a maximum distance from the sensor transducer equal to ½

of the total distance between the sensor transducer and the electronics unit.

5. The system of claim 1, wherein the sensor transducer and the electronics unit are electrically connected with at least one lead wire of a minimal length, the minimal length designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the impedance transformation device that is susceptible to electromagnetic interference and high frequency audio attenuation.

6. The system of claim 5, wherein the minimal length of the lead wire is a maximum of {fraction (1/20)}^th as long as the wavelength of the interfering signals impinging on the hearing assistance system.

7. The system of claim 5, wherein the minimal length of the lead wire is a maximum of ¾

centimeter for a 2 GHz input signal.

8. The system of claim 1, further comprising two lead wires electrically connecting the electronics unit to the impedance transformation device wherein the wires are adapted to provide a matched pair of differential input to the impedance transformation device.

9. The system of claim 1, further including an electrically conductive substrate configured for electrically connecting the impedance transformation device to the sensor transducer.

10. The system of claim 1, wherein the impedance transformation device is disposed adjacent to the sensor transducer.

11. The system of claim 1, wherein the impedance transformation device is physically connected to the sensor transducer.

12. The system of claim 1, wherein the impedance transformation device and the sensor transducer are housed as a single unit.

13. The system of claim 1, further comprising a support member for supporting the sensor transducer and impedance transformation device.

14. The system of claim 13, wherein the support member supports the impedance transformation device and at least an adjacent portion of the sensor transducer.

15. The system of claim 13, wherein the support member further includes an electrically conductive substrate electrically connecting the sensor transducer to the impedance transformation device.

16. The system of claim 1, wherein the impedance transformation device is a preamplifier.

17. The system of claim 1, wherein the impedance transformation device includes a JFET amplifier circuit.

18. An implantable hearing assistance system capable of maximizing high frequency audio performance and minimizing electromagnetic interference and high frequency audio attenuation, comprising:

a high impedance sensor transducer;

a high impedance electronics unit disposed at a minimal distance from and electrically connected to the sensor transducer, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the high impedance electronics unit that is susceptible to electromagnetic interference and high frequency audio attenuation.

19. The system of claim 18, further comprising a driver transducer electrically connected to the electronics unit.

20. The system of claim 18, wherein the sensor transducer is a piezoelectric transducer.

21. The system of claim 18, wherein the sensor transducer is an electromagnetic transducer.

22. The system of claim 18, wherein the minimal distance is a maximum of {fraction (1/20)}^th of the wavelength of interfering signals impinging upon the hearing assistance system.

23. The system of claim 18, wherein the minimal distance is a maximum of ½

centimeter for a 2 GHz input signal.

24. The system of claim 18, wherein the electronics unit is electrically connected directly to the sensor transducer through an electrically conductive substrate.

25. The system of claim 18, wherein the electronics unit is mechanically connected to the sensor transducer through a bracket adapted to support both the electronics unit and the sensor transducer, the bracket also adapted to be mounted to an auditory element of the middle ear.

26. The system of claim 18, wherein the electronics unit includes an amplifier.

27. The system of claim 18, wherein the electronics unit and sensor transducer are housed as a single unit.

28. The system of claim 18, further including a housing support for housing the electronics unit and at least an adjacent portion of the sensor transducer.

29. The system of claim 18, further comprising a support member for supporting the sensor transducer and impedance transformation device.

30. The system of claim 29, wherein the support member supports the impedance transformation device and at least an adjacent portion of the sensor transducer.

31. The system of claim 29, wherein the support member further includes an electrically conductive substrate electrically connecting the sensor transducer to the impedance transformation device.

32. An implantable hearing assistance system capable of maximizing high frequency audio performance and minimizing electromagnetic interference and high frequency audio attenuation, comprising:

an electronics unit housing one or more electronic components; and

a sensor transducer mechanically connected to the electronics unit and electrically connected to the electronic components by two or fewer lead wires having a minimal length and configured for eliminating the need to use a longer lead wire that is more susceptible to electromagnetic interference and high frequency audio attenuation.

33. The system of claim 32, wherein the sensor transducer is a piezoelectric transducer.

34. The system of claim 32, wherein the sensor transducer is an electromagnetic transducer.

35. The system of claim 32, further comprising a driver transducer electrically connected to the electronics module.

36. The system of claim 32, wherein one of the electronic components includes an amplifier.

37. The system of claim 32, wherein the electronics unit is electrically connected directly to the sensor transducer through electrically conductive substrate.

38. The system of claim 32, further including a mounting component adapted to mount the electronics unit and the sensor transducer at a minimal distance from each other, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the electronics unit that is susceptible to electromagnetic interference and high frequency audio attenuation.

39. The system of claim 38, wherein the mounting component comprises a bracket adapted to support the electronics unit and the sensor transducer and be mounted to an auditory element of the middle ear.

40. The system of claim 32, wherein the electronics unit and sensor transducer are housed as a single unit.

41. The system of claim 32, further comprising a support member for supporting the sensor transducer and the electronics unit.

42. The system of claim 41, wherein the support member supports the electronics unit and at least an adjacent portion of the sensor transducer.

43. The system of claim 41, wherein the support member further includes an electrically conductive substrate electrically connecting the sensor transducer to the electronics unit.

44. A mounting support for an implantable hearing system device for mounting components of the hearing system at a minimal distance from each other, thereby minimizing electromagnetic interference and high frequency audio attenuation, the mounting support comprising:

a bracket adapted to support a transducer and one or more auditory components of the implantable hearing assistance system directly adjacent from each other and be mounted to an auditory element of the middle ear.

45. The mounting support of claim 44, wherein the one or more auditory components include an impedance transformation device.

46. The mounting support of claim 44, wherein the one or more auditory components include an electronics unit.

47. The mounting support of claim 44, wherein the transducer is separated from the one or more auditory components at a minimal distance, the minimal distance being a maximum of {fraction (1/20)}^th as long as the wavelength of the interfering signals impinging on the hearing assistance system.

48. The mounting support of claim 44, wherein the transducer is separated from the one or more auditory components at a minimal distance, the minimal distance being a maximum of ¾

centimeter for a 2 GHz input signal.

49. A method of positioning an implantable hearing assistance system inside of an ear so as to maximize high frequency audio performance and minimize electromagnetic interference and high frequency audio attenuation, comprising the steps of:

positioning a high impedance sensor transducer in contact with an auditory element of the middle ear;

positioning an impedance transformation device at a minimal distance from the sensor transducer, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the impedance transformation device that is susceptible to electromagnetic interference and high frequency audio attenuation

providing a short length of electrical connection between the sensor transducer and the impedance transformation device.

50. The method of claim 49, wherein the step of positioning an impedance transformation device at a minimal distance from the sensor transducer includes the step of physically connecting the impedance transformation device to the sensor transducer.

51. The method of claim 49, wherein the step of positioning an impedance transformation device at a minimal distance from the sensor transducer is accomplished by housing the impedance transformation device and the sensor transducer in one unit.

52. The method of claim 49 wherein the step of positioning an impedance transformation device at a minimal distance from the sensor transducer includes the step of positioning the impedance transformation device adjacent to the sensor transducer.

53. The method of claim 49, wherein the step of positioning an impedance transformation device at a minimal distance from the sensor transducer includes the steps of mounting both the impedance transformation device and the sensor transducer on a single bracket assembly and mounting the bracket assembly to a bone.

54. The method of claim 53, wherein the bone is the mastoid bone.

55. The method of claim 49, wherein the minimal distance between the sensor transducer and the impedance transformation device is a maximum of {fraction (1/20)}^th as long as a wavelength of an interfering signal impinging on the components of the hearing system.

56. The method of claim 49, wherein the minimal distance between the sensor transducer and the impedance transformation device is a maximum of ¾

centimeter for a 2 GHz input signal.

57. The method of claim 49, wherein the step of providing a short length of electrical connection between the sensor transducer and the impedance transformation device includes using two or fewer lead wires having a minimal length and configured for eliminating the need to use a longer lead wire that is more susceptible to electromagnetic interference and high frequency audio attenuation.

58. The method of claim 49, wherein the step of providing a short length of electrical connection between the sensor transducer and the impedance transformation device is accomplished by connecting an electrically conductive substrate to electrically conductive surfaces of the sensor transducer and impedance transformation device.

59. The method of claim 49, wherein the impedance transformation device is a preamplifier.

60. The method of claim 49, further including the step of electrically connecting an electronics unit to the impedance transformation device.

61. The method of claim 60, further including the step of electrically connecting a driver transducer to the electronics unit.

62. A method of positioning an implantable hearing assistance system inside of an ear so as to maximize high frequency audio performance and minimize electromagnetic interference and high frequency audio attenuation, comprising the steps of:

positioning a high impedance sensor transducer in contact with an auditory element of the middle ear;

positioning a high impedance electronics unit at a minimal distance from the sensor transducer, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the impedance transformation device that is susceptible to electromagnetic interference and high frequency audio attenuation; and

providing a short length of electrical connection between the sensor transducer and the electronics unit.

63. The method of claim 62, wherein the step of positioning an electronics unit at a minimal distance from the sensor transducer includes physically connecting the electronics unit to the sensor transducer.

64. The method of claim 62, wherein the step of positioning an electronics unit at a minimal distance from the sensor transducer includes housing the electronics unit and the sensor transducer into one unit.

65. The method of claim 62, wherein the step of positioning an electronics unit at a minimal distance from the sensor transducer includes positioning the electronics unit adjacent to the sensor transducer.

66. The method of claim 62, wherein the step of positioning an electronics unit at a minimal distance from the sensor transducer includes mounting both the electronics unit and the sensor transducer on a single bracket assembly and mounting the bracket assembly to a bone.

67. The method of claim 66, wherein the bone is the mastoid bone.

68. The method of claim 62, wherein the minimal distance between the sensor transducer and the electronics unit is a maximum of {fraction (1/20)}^th as long as a wavelength of an interfering signal impinging on the sensor transducer and other components of the hearing system.

69. The method of claim 62, wherein the minimal distance between the sensor transducer and the electronics unit is a maximum of ¾

centimeter for a 2 GHz input signal.

70. The method of claim 62, wherein the step of providing a short length of electrical connection between the sensor transducer and the electronics unit includes using two or fewer lead wires having a minimal length and configured for eliminating the need to use a longer lead wire that is more susceptible to electromagnetic interference and high frequency audio attenuation.

71. The method of claim 62, wherein the step of providing a short length of electrical connection between the sensor transducer and the electronics unit includes connecting an electrically conductive substrate to electrically connect the sensor transducer to the electronics unit.

72. The method of claim 62, wherein the electronics unit further includes an amplifier.

73. The method of claim 62, further including the step of electrically connecting an driver transducer to the electronics unit.

74. A method of positioning an implantable hearing assistance system inside of an ear so as to maximize high frequency audio performance and minimize electromagnetic interference and high frequency audio attenuation, comprising the steps of:

mounting a high impedance sensor transducer on a bracket;

mounting one or more components of the hearing system on the bracket at a minimal distance from the sensor transducer, the minimal distance designed to eliminate the possibility of having a greater length of electrical connection between the sensor transducer and the one or more components of the hearing system that is susceptible to electromagnetic interference and high frequency audio attenuation;

mounting the bracket to an auditory element of the middle ear; and

electrically connecting the sensor transducer to the one or more components of the hearing system so that the length in electrical connection is minimal.

75. The method of claim 74, wherein the one or more components of the hearing system include an impedance transformation device.

76. The method of claim 75, wherein the impedance transformation device is a preamplifier.

77. The method of claim 74, wherein the one or more components of the hearing system include an electronics unit.

78. The method of claim 77, wherein the electronics unit further includes an amplifier.

79. The method of claim 74, wherein the minimal distance is a maximum of {fraction (1/20)}^th as long as a wavelength of interfering signals impinging on the sensor transducer and other components of the hearing system.

80. The method of claim 74, wherein the minimal distance is a maximum of ¾

centimeter for a 2 GHz input signal.

81. The method of claim 74, wherein the step of electrically connecting the sensor transducer to one or more components of the hearing system includes using one or more lead wires having a minimal length and configured for eliminating the need to use a longer lead wire that is more susceptible to electromagnetic interference and high frequency audio attenuation.

82. The method of claim 81, wherein the one or more minimal length lead wires has a maximum length of ¾

centimeter for a 2 GHz signal.

83. The method of claim 81, wherein the one or more minimal length lead wires has a maximum length of {fraction (1/20)}^th as long as a wavelength of an interfering signal impinging on the sensor transducer and other components of the hearing system.