Method and apparatus for reduced feedback in implantable hearing assistance systems

• US 20020032363A1
• Filed: 07/05/2001
• Published: 03/14/2002
• Est. Priority Date: 06/05/1998
• Status: Active Grant

• Current Assignee: Envoy Medical Corporation
• Original Assignee: St Croix Medical Incorporated
• Inventors: Kroll, Kai, Meyerson, Scott C., Urbanski, Paul J., Bushek, Donald J.
• Granted Patent: US 6,540,662 B2
• Time in Patent Office: Days
• US Class Current: 600/25
• CPC Class Codes: A61F 2002/183 Ear parts
• CPC Class Codes: H04R 25/456 mechanically
• 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

A method and apparatus assists a hearing impaired person by introducing and maintaining a mechanical feedback barrier between a microphone and a transducer of an implantable hearing assistance system. In this method, mechanical sound vibrations impinging on the person'"'"'s body habitus are received with an electromechanical device (e.g. microphone) disposed at a body habitus sound reception site. The body habitus sound reception site can be located within the external auditory canal, or external of the external auditory canal either subdermally or external of the scalp. The mechanical sound vibrations are converted with the electromechanical device to an amplified electrical signal. Next, the amplified electrical signal is delivered to the inner ear with a transducer operatively coupled between the electromechanical device and the middle ear or the inner ear. Finally, a mechanical feedback barrier is introduced and maintained between the sound reception site and the transducer to minimize acoustic feedback therebetween. Preferably, this feedback barrier is established by removing, separating, or fixing, or combinations thereof, a portion of the hearing impaired person'"'"'s ossicular chain (e.g malleus, incus, or stapes).

Claims

1. A method for assisting hearing for a sensorineurally hearing impaired person comprising:

receiving sound vibrations impinging on the person'"'"'s body habitus with an electromechanical device disposed at a body habitus sound reception site and converting the sound vibration with the electromechanical device to an amplified electrical signal;

delivering the amplified electrical signal to the inner ear with transducer means operatively coupled between the electromechanical device and the inner ear;

maintaining a mechanical feedback barrier between the sound reception site and the inner ear to minimize feedback therebetween during the receiving and delivering steps.

2. The method of claim 1, wherein the maintaining step further comprises:

interrupting the ossicular chain.

3. The method of claim 2, wherein the interrupting step further comprises:

cutting a portion of the incus to separate the incus into two separate portions that do not contact each other.

4. The method of claim 3, wherein the cutting step is performed with a laser.

5. The method of claim 3, wherein the cutting step is applied to the long process of the incus.

6. The method of claim 3, wherein the cutting step further comprises:

selecting the cutting location on the incus to maintain intact the incudostapedial joint.

7. The method of claim 1, wherein the maintaining step further comprises:

separating a portion of the ossicular chain into separate first and second portions and mounting the transducer on the first portion and maintaining a separation distance between the transducer and the second portion to prevent tissue reconnection between the second portion and at least one of the transducer and the first portion.

8. The method of claim 2, wherein the interrupting step further comprises:

removing only the incus to maintain intact the malleus.

9. The method of claim 1, wherein the receiving step further comprising:

locating the sound reception site of the electromechanical device externally of the skull.

10. The method of claim 1, wherein the receiving step further comprising:

locating the sound reception site of the electromechanical device within the external auditory canal.

11. The method of claim 1, wherein the receiving step further comprising:

locating the sound reception site of the electromechanical device subdermally adjacent the ear.

12. The method of claim 1, wherein the delivering step further comprises:

operatively coupling the electromechanical device to the transducer means with an electromechanical linkage.

13. The method of claim 12, wherein the operative coupling step further comprises:

arranging a connection assembly within the middle ear to secure the electromechanical device and the transducer relative to the cranium and a portion of the ossicular chain.

14. The method of claim 13, wherein the connection assembly further comprises a bracket.

15. The method of claim 13, wherein the connection assembly further comprises a hanger.

16. The method of claim 9, wherein the connection assembly further comprises a combination mounting bracket and removable portion.

17. The method of claim 1, wherein the delivering step further comprises:

operatively connecting the transducer to at least one of a stapes and an incus of the middle ear.

18. The method of claim 1, wherein the transducer comprises a piezoelectric transducer.

19. The method of claim 1, wherein the transducer comprises an electromagnetic transducer.

20. The method of claim 1, wherein the electromechanical device comprises a microphone.

21. The method of claim 1, wherein the electromechanical device comprises a second transducer.

22. The method of claim 1, wherein the electromechanical device further comprises a directional microphone for enhancing sound reception of sound energy traveling into the external auditory canal toward the tympanic membrane and for excluding sound energy traveling outwardly away from the tympanic membrane.

23. The method of claim 1, wherein the electromechanical device and the transducer are arranged into a single unit sound energy processor.

24. The method of claim 23, wherein the receiving step further comprises:

locating the sound reception site subdermally.

25. The method of claim 23, wherein the receiving step further comprises:

locating the sound reception site in the external auditory canal.

26. The method of claim 23, wherein the receiving step further comprises:

locating the sound reception site externally from the scalp.

28. The apparatus of claim 27, wherein the artificial sensing transducer is configured and arranged for disposition external of the subject'"'"'s external auditory canal.

29. The apparatus of claim 27, wherein the artificial sensing transducer is configured and arranged for disposition within the subject s auditory canal.

30. The apparatus of claim 27, wherein the transducer is a piezoelectric transducer.

31. The apparatus of claim 27, wherein the transducer is an electromagnetic transducer.

32. The apparatus of claim 27, wherein the electromechanical linkage means further comprises:

a connection assembly adapted to be secured to a portion of the subject'"'"'s ossicular chain.

33. The apparatus of claim 32, wherein the connection assembly further comprises a bracket.

34. The apparatus of claim 32, wherein the connection assembly further comprises a hanger.

35. The apparatus of claim 32, wherein the connection assembly further comprises a combination mounting bracket and removable portion.

36. The apparatus of claim 27, and further comprising:

means for separating a portion of the ossicular chain to prevent mechanical feedback.

38. The method of claim 37, wherein the maintaining step further comprises:

stabilizing the ossicular chain with a mechanical fixator to prevent transmission of sound energy along the ossicular chain.

39. The method of claim 38, wherein the stabilizing step further comprises:

stabilizing an incus of the ossicular chain with the mechanical fixator.

40. The method of claim 37, wherein the maintaining step further comprises:

separating an incus from a stapes of the ossicular chain at the incudostapedial joint and positioning a long process of the incus to prevent unintended reconnection of the incus with the stapes.

41. The method of claim 40, wherein the positioning of incus further comprises:

restraining a portion of the incus apart from the stapes to maintain separation at the incudostapedial joint.

42. The method of claim 41, wherein the restraining step further comprises:

preserving the incus by performing the separating step without cutting the incus.

43. The method of claim 41, wherein the restraining step further comprises:

securing a portion of the incus against a bracket mounted within a middle ear cavity.

44. The method of claim 38, wherein the stabilizing step is performed without separating the ossicular chain.

45. The method of claim 37, wherein the receiving step further comprises:

locating the sound reception site of the electromechanical device externally of the skull.

46. The method of claim 37, wherein the receiving step further comprises:

locating the sound reception site of the electromechanical device within the external auditory canal.

47. The method of claim 37, wherein the receiving step further comprises:

locating the sound reception site of the electromechanical device subdermally adjacent the ear.

48. The method of claim 37, wherein the maintaining step further comprises:

prior to fixing a portion of the incus, cutting the incus to separate the incus into two separate portions that do not contact each other.

49. The method of claim 48, wherein the cutting step is performed with a laser.

50. The method of claim 48, wherein the cutting step is applied to the long process of the incus.

51. The method of claim 50 wherein the cutting step further comprises:

selecting the cutting location on the incus to maintain intact the incudostapedial joint.

52. The method of claim 48 wherein the maintaining step further comprises:

mounting the transducer on the first portion and maintaining a separation distance between the transducer and the second portion to prevent tissue reconnection between the second portion and at least one of the transducer and the first portion.

27. A partially implantable apparatus for improving the hearing of a sensorineural hearing impaired subject without causing feedback through the ossicular chain of the subject, comprising:

an artificial sensing transducer for sensing air conducted signals external to the middle ear;

input and output transducer means adapted for cranial location for mediating mechanical and electrical signals having controlled amplification characteristics, the input and output transducer means having electromechanical linkage means for operatively communicatively coupling the artificial sensing transducer to the inner ear of the subject to transmit signals therebetween without feedback of mechanical sound energy from the inner ear to the artificial sensing transducer through the ossicular chain and the external auditory canal.

37. A method for assisting hearing for a sensorineurally hearing impaired person comprising:

receiving sound vibrations impinging on a person'"'"'s body habitus with an electromechanical device disposed at a body habitus sound reception site and converting the sound vibration with the electromechanical device to an amplified electrical signal;

delivering the amplified electrical signal to the inner ear with transducer means operatively coupled between the electromechanical device and the inner ear;

maintaining a portion of the ossicular chain in a fixed position to maintain a mechanical feedback barrier preventing transmission of sound energy along the ossicular chain to minimize sound energy feedback between the inner ear and the sound reception site during the receiving and delivering steps.

53. A partially implantable apparatus for improving the hearing of a sensorineural hearing impaired subject without causing feedback through the ossicular chain of the subject, comprising:

an artificial sensing transducer for sensing air conducted signals external to the middle ear;

input and output transducer means adapted for cranial location for mediating mechanical and electrical signals having controlled amplification characteristics, the input and output transducer means having electromechanical linkage means for operatively communicatively coupling the artificial sensing transducer to the inner ear of the subject to transmit signals therebetween; and

means for maintaining a portion of the ossicular chain in a fixed position to prevent transmission of feedback sound energy from the inner ear to the artificial sensing transducer through the ossicular chain and the external auditory canal.

54. The apparatus of claim 53 wherein the artificial sensing transducer is configured and arranged for disposition external of the subject'"'"'s external auditory canal.

55. The apparatus of claim 53 wherein the artificial sensing transducer is configured and arranged for disposition within the subject'"'"'s auditory canal.

56. The apparatus of claim 53 wherein the transducer is a piezoelectric transducer.

57. The apparatus of claim 53 wherein the transducer is an electromagnetic transducer.

58. The apparatus of claim 53 wherein the electromechanical linkage means further comprises:

a connection assembly adapted to be secured to a portion of the subject'"'"'s ossicular chain.

59. The apparatus of claim 58 wherein the connection assembly further comprises a bracket.

60. The apparatus of claim 58 wherein the connection assembly further comprises a hanger.

61. The apparatus of claim 58 wherein the connection assembly further comprises a combination mounting bracket and removable portion.

62. The apparatus of claim 53 wherein the fixation means further comprises:

means for maintaining a separation between a first portion of the ossicular chain and a second portion of the ossicular chain to prevent transmission of sound energy from the first portion to the second portion.

63. The apparatus of claim 53 wherein the separation means further includes:

means for restraining one of the first and second portions at a distance from the other of the first and second portions.

64. A method for assisting hearing for a sensorineurally hearing impaired person comprising:

receiving sound vibrations impinging on the person'"'"'s body habitus with an electromechanical device disposed at a body habitus sound reception site and converting the sound vibration with the electromechanical device to an amplified electrical signal;

delivering the amplified electrical signal to the inner ear with transducer means operatively coupled between the electromechanical device and the inner ear;

prior to the receiving and the delivering steps, inserting at least one of the electromechanical device and the transducer through the tympanic membrane for implantation in the middle ear.

65. The method of claim 64, wherein the maintaining step further comprises:

maintaining a mechanical feedback barrier between the sound reception site and the inner ear to minimize feedback therebetween during the receiving and delivering steps.

66. The method of claim 64, wherein the electromechanical device is a microphone located subdermally along and in contact with the external auditory canal.

67. The method of claim 64, wherein the electromechanical device is a microphone affixed to the malleus within the middle ear adjacent to the tympanic membrane.

68. The method of claim 64, wherein the inserting step further comprises:

prior to insertion in the middle ear, affixing at least one of the electromechanical device and the transducer to a mounting bracket.

69. The method of claim 68, wherein the inserting step further comprises:

prior to insertion in the middle ear, manipulating a first and a second portion of the mounting bracket to be aligned in an elongate configuration generally parallel along a single axis.

70. The method of claim 69, wherein the mounting bracket includes a universal joint for adjustably mounting the electromechanical device and the transducer in contact with an auditory element of the ossicular chain.

71. The method of claim 70, wherein the manipulating step further comprises:

arranging the first and second portion of the mounting bracket alongside each other.

72. The method of claim 70, wherein the manipulating step further comprises:

arranging the first and second portion of the mounting bracket in an end-to-end relationship.

73. A partially implantable apparatus for improving the hearing of a hearing impaired subject without causing feedback through the ossicular chain of the subject, comprising:

an artificial sensing transducer for sensing air conducted signals external to the middle ear, the transducer configured and arranged for disposition subdermally along and in contact with the external auditory canal;

input and output transducer means adapted for cranial location for mediating mechanical and electrical signals having controlled amplification characteristics, the input and output transducer means having electromechanical linkage means for operatively communicatively coupling the artificial sensing transducer to the inner ear of the subject to transmit signals therebetween without feedback of mechanical sound energy from the inner ear to the artificial sensing transducer through the ossicular chain and the external auditory canal; and

means for maintaining the malleus of the middle ear in a fixed position to prevent transmission of sound energy along the ossicular chain.

74. The apparatus of claim 73, wherein the maintaining means further comprises:

a bracket for securing the malleus against the mastoid bone.

75. The apparatus of claim 73, wherein the maintaining means further comprises:

a suture for securing the malleus against the mastoid bone.

76. The apparatus of claim 73, wherein the transducer is a piezoelectric transducer.

77. The apparatus of claim 73, wherein the transducer is an electromagnetic transducer.

78. The apparatus of claim 73, wherein the electromechanical linkage means further comprises:

a connection assembly adapted to be secured to a portion of the subjects ossicular chain.

79. The method of claim 78, wherein the connection assembly further comprises a bracket.

80. The method of claim 78, wherein the connection assembly further comprises a hanger.

81. The method of claim 78, wherein the connection assembly further comprises a combination mounting bracket and removable portion.

82. A method for assisting hearing for a sensorineurally hearing impaired person comprising:

receiving sound vibrations impinging on the persons body habitus with an electromechanical device disposed subdermally in contact with a wall defining the external auditory canal and converting the sound vibration with the electromechanical device to an amplified electrical signal;

delivering the amplified electrical signal to the inner ear with a transducer operatively coupled between the electromechanical device and the inner ear;

maintaining a mechanical feedback barrier between the sound reception site and the inner ear to minimize feedback therebetween during the receiving and delivering steps.

83. The method of claim 82, wherein the delivering step further comprises:

locating the transducer within the middle ear in contact with at least one of an incus and a stapes of the middle ear.