At least partially implantable system for rehabilitation of hearing disorder

• US 6,565,503 B2
• Filed: 04/13/2001
• Issued: 05/20/2003
• Est. Priority Date: 04/13/2000
• Status: Expired due to Fees

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Zenner, Hans Peter, Leysieffer, Hans, Baumann, Joachim W.
• Primary Examiner(s): Scherbel, David A.
• Assistant Examiner(s): Nicolas, Frederick C.
• Application Number:
  US09/833,643
• Publication Number:
  US 20010049466A1
• Time in Patent Office: 767 Days
• Field of Search: 600/25, 600/379, 607/55, 607/56, 607/57
• US Class Current: 600/25
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/36039 fitting procedures

Abstract

An at least partially implantable system for rehabilitation of a hearing disorder with at least one acoustic sensor (microphone) for picking up an acoustic sensor signal and converting the acoustic sensor signal into corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit which supplies individual components of the system with energy, and an output-side actuator stimulation arrangement, the actuator stimulation arrangement has a dual intracochlear arrangement in combination with a stimulator arrangement with at least one stimulator element for at least indirect mechanical stimulation of a damaged inner ear and one electrically acting stimulation electrode arrangement with at least one cochlear implant electrode for electrical stimulation of the inner ear.

Claims

1. An at least partially implantable system for rehabilitation of a hearing disorder comprising:

at least one acoustic sensor for picking up an acoustic sensor signal and converting the acoustic sensor signal into corresponding electrical signals,

an electronic signal processing unit for audio signal processing and amplification,

an electrical power supply unit which supplies individual components of the system with energy, and

an output-side actuator stimulation arrangement,

wherein the actuator stimulation arrangement comprises a dual intracochlear, stimulator arrangement with at least one intracochlear stimulator element for at least indirect electromechanical stimulation of a damaged inner ear and at least one intracochlear electrically acting stimulation electrode arrangement with at least one cochlear implant electrode for electrical stimulation of the damaged inner ear.

2. The system as claimed in claim 1, wherein the stimulator arrangement has at least one intracochlear electromechanical converter for direct mechanical stimulation of the inner ear.

3. The system as claimed in claim 1, wherein the stimulator arrangement has at least one intracochlear hair cell stimulating electrode for indirect mechanical stimulation of the inner ear by electrical stimulation of outer hair cells.

4. The system as claimed in claim 1, wherein the actuator stimulation arrangement comprises an intracochlear array with several stimulator elements for mechanical stimulation of the inner ear.

5. The system as claimed in claim 3, wherein the at least one hair cell stimulation electrode is adapted to rest in an immediate vicinity of the outer hair cells for indirect mechanical stimulation of the inner ear, in an implanted state.

6. The system as claimed in claim 1, wherein the at least one cochlear implant electrode is attached to a carrier is adapted to be in direct galvanic contact with one of a lymphatic fluid of the inner ear and a neural structure to be stimulated for electrical stimulation of the inner ear, in an implanted state.

7. The system as claimed in claim 2, wherein a common carrier is provided for the at least one cochlear implant electrode and the at least one electromechanical converter.

8. The system as claimed in claim 7, wherein the at least one electromechanical converter and the at least one cochlear implant electrode comprise a plurality of electromechanical converters and cochlear implant electrodes arranged in an alternating sequence along the carrier.

9. The system as claimed in claim 2, wherein a first carrier is provided for the at least one cochlear implant electrode and a second carrier is provided for the at least one electromechanical converter.

10. The system as claimed in claim 9, wherein the first carrier for the at least one cochlear implant electrode is adapted to be closer to the neural structures of the cochlea than the second carrier in an implanted state.

11. The system as claimed in claim 7, wherein the total diameter of the dual intracochlear arrangement is in the range from 0.4 mm to 2.0 mm.

12. The system as claimed in claim 7, wherein the total length of the dual intracochlear arrangement is between 5 mm and 50 mm.

13. The system as claimed in claim 7, wherein the carrier comprises a biocompatible material which is bio-stable in the inner ear.

14. The system as claimed in claim 13, wherein the biocompatible material is a polymer.

15. The system as claimed in claim 13, wherein the biocompatible material is a silicone.

16. The system as claimed in claim 7, wherein the at least one electromechanical converter is embedded in the carrier such that the at least one electromechanical converter is completely surrounded by a thin layer of a carrier material.

17. The system as claimed in claim 7, wherein the at least one electromechanical converter comprises a plurality of electromechanical converters;

and wherein mechanical attenuation elements are embedded in the carrier between the electromechanical converters for minimizing mechanical wave propagation within the carrier between adjacent electromechanical converters.

18. The system as claimed in claim 17, wherein an attenuation element material of the attenuation elements has a first cross sectional geometry similar to a second cross sectional geometry of the carrier and the attenuation element material has a high mechanical impedance difference as compared to that of the carrier material in order to achieve high attenuation values.

19. The system as claimed in claim 18, wherein the attenuation elements are formed by cochlear implant electrodes.

20. The system as claimed in claim 2, wherein the at least one electromechanical converter adapted to operate according to one of electromagnetic, electrodynamic, piezoelectric, magnetostrictive and capacitive principles.

21. The system as claimed in claim 20, wherein the at least one electromechanical converter is a piezoelectric converter made of one of lead zirconate titanate and polyvinylidene fluoride.

22. The system as claimed in claim 2, wherein the at least one electromechanical converter is made with passive material partners adapted to operate on a geometrical shape transformation principle which produces maximum deflection with minimum electric power consumption at converter voltage.

23. The system as claimed in claim 22, wherein the geometrical shape transformation principle is one of the bimorph principle, the unimorph principle and the heteromorph principle.

24. The system as claimed in claim 4, wherein the several stimulator elements are adapted distributed equidistantly along a basilar membrane of the inner ear in an implanted state for mechanical stimulation of the inner ear.

25. The system as claimed in claim 4, wherein the several stimulator elements are adapted to be distributed at logarithmic distances according to a tonotopic frequency-location assignment along a basilar membrane of the inner ear in an implanted state for mechanical stimulation of the inner ear.

26. The system as claimed in claim 24, wherein 20 to 24 stimulator elements are provided according to psychoacoustic critical bands in a tonotopic arrangement of stimulator elements for mechanical stimulation of the inner ear.

27. The system as claimed in claim 26, wherein the stimulator elements are arranged in groups of stimulator elements.

28. The system as claimed in claim 2, wherein the at least one electromechanical converter has a transmission range from about 100 Hz to about 10 kHz.

29. The system as claimed in claim 2, wherein the at least one electromechanical converter is tuned to have a first mechanical resonant frequency at an upper end of a desired transmission frequency range.

30. The system as claimed in claim 29, wherein the desired transmission frequency range is about 8 kHz to about 10 kHz.

31. The system as claimed in claim 2, wherein the at least one electromechanical converter is hermetically sealed.

32. The system as claimed in claim 1, wherein the at least one cochlear implant electrode is produced from a material selected from the group consisting of platinum, platinum-iridium alloy, gold, gold alloy, tantalum, tantalum alloy, niobium, niobium alloy, and high quality steel.

33. The system as claimed in claim 32, wherein the platinum-iridium alloy is about 90% platinum and about 10% iridium.

34. The system as claimed in claim 5, wherein the at least one hair stimulation electrode is produced from a material selected from the group consisting of platinum, platinum-iridium alloy, gold, gold alloy, tantalum, tantalum alloy, niobium, niobium alloy, and high quality steel.

35. The system as claimed in claim 34, wherein the platinum-iridium alloy is about 90% platinum and about 10% iridium.

36. The system as claimed in claim 1, wherein the electronic signal processing unit has a preprocessing arrangement for at least one of pre-amplification and filtering, and for analog-digital conversion of the acoustic sensor signal.

37. The system as claimed in claim 36, wherein the preprocessing arrangement comprises anti-aliasing filters.

38. The system as claimed in claim 1, wherein a plurality of acoustic sensors are provided and each of the plurality of acoustic sensors is upstream of an analog-digital converter.

39. The system as claimed in claim 1, wherein the electronic signal processing unit contains software modules which enable masking of tinnitus parallel to operation of the hearing aid.

40. The system as claimed in claim 1, wherein the electronic signal processing unit has a digital signal processor for processing analog-digital-converted acoustic sensor signals, and the analog-digital-converted acoustic sensor signals;

and wherein a preprocessing arrangement is provided for preprocessing the analog-digital-converted acoustic sensor signals for generation of digital signals for tinnitus masking.

41. The system as claimed in claim 1, wherein at least one digital-analog converter is connected upstream of the actuator stimulation arrangement.

42. The system as claimed in claim 41, wherein a digital-analog converter is provided upstream of the at least one stimulator element for mechanical stimulation of the inner ear and the at least one cochlear implant electrode for electrical stimulation of the inner ear.

43. The system as claimed in claim 1, wherein the electronic signal processing unit contains software modules which trigger the at least one stimulator element for mechanical stimulation of the inner ear by electrical signals having at least one of spectral, time, amplitude-referenced and phase-referenced properties for producing a traveling wave on a basilar membrane of a damaged inner ear in an implanted state which is as near as possible to that of healthy hearing.

44. The system as claimed in claim 43, wherein the electronic signal processing unit has a digital signal processor, and wherein the software modules are static being unchangeable once filed in a program storage of the digital signal processor.

45. The system as claimed in claim 1, wherein a PC-based wireless telemetry means for transmission of data between an implanted part of the system and an external unit is provided.

46. The system as claimed in claim 45, wherein the external unit is an external programming system.

47. The system as claimed in claim 43, wherein the software modules are dynamic.

48. The system as claimed in claim 47, wherein the software modules are adaptive, parameter matching in an implanted state by at least one of training conducted by an implant wearer and modification by an external aid.

49. The system as claimed in claim 1, wherein the electronic signal processing unit contains a software module for optimal simulation of a healthy cochlear amplifier based on an adaptive neural network.

50. The system as claimed in claim 49, wherein the adaptive neural network is adaptive by at least one of training conducted by an implant wearer and modification by an external aid.

51. The system as claimed in claim 49, wherein the electronic signal processing unit is adapted to produce a time-reversed acoustics principle triggering, of the stimulator elements for mechanical stimulation of the inner car such that locally limited areas of the cochlea are mechanically stimulated, in an implanted state in the adaptive neural network for simulation of a healthy cochlear amplifier.

52. The system as claimed in claim 45, wherein the electronic signal processing unit has a digital signal processor and wherein a rewritable implantable storage arrangement is assigned to the digital signal processor for accommodating and reproducing an operating program in a manner enabling at least parts of the operating program to be replaced or changed by data transmitted from the external unit via the telemetry means.

53. The system as claimed in claim 52, wherein a buffer storage arrangement is provided in which data transmitted from the external unit via the telemetry means can be buffered before the data are relayed to the digital signal processor.

54. The system as claimed in claim 53, wherein a checking logic is providing for checking the data stored in the buffer storage arrangement before the data are relayed to the digital signal processor.

55. The system as claimed in claim 40, wherein a microprocessor module is provided for control of one of an analog-digital converter, a digital-analog converter, and the digital signal processor via a data bus within the implant.

56. The system as claimed in claim 55, wherein the microprocessor module is a microcontroller.

57. The system as claimed in claim 54, wherein the checking logic and the buffer storage arrangement are implemented in a microprocessor module.

58. The system as claimed in claim 55, wherein at least a part of a software module can be transferred between an external unit, the microprocessor module, and the digital signal processor via the data bus and a PC-based wireless telemetry means.

59. The system as claimed in claim 55, wherein an implantable storage arrangement for storing a working program for the microprocessor module is assigned to the microprocessor module, and at least a part of a working program for the microprocessor module can be changed or replaced by data transferred from an external unit via a PC-based wireless telemetry means.

60. The system as claimed in claim 52, wherein at least two storage areas are provided for holding and reproducing at least the operating program of the digital signal processor.

61. The system as claimed in claim 54, wherein the buffer storage arrangement has at least two storage areas for holding and reproducing data transferred from an external unit via the telemetry means.

62. The system as claimed in claim 40, wherein a preprogrammed read-only memory area is assigned to the digital signal processor.

63. The system as claimed in claim 40, wherein a PC-based telemetry means is provided for transmission of operating parameters between an implanted part of the system and an external unit.

64. The system as claimed in claim 1, wherein the system is an implantable system having an implantable unit that comprises the at least one acoustic sensor, and a rechargeable electrical storage element of the electric power supply unit;

and wherein a wireless, transcutaneous charging device is provided for charging of the storage element.

65. The system as claimed in claim 64, wherein a wireless remote control is provided for enabling controlling of implant functions by an implant wearer.

66. The system as claimed in claim 1, wherein the system is a partially implantable system comprising a modulator/transmitter unit contained in an external module which is externally wearable on a body of an implant wearer;

wherein an implantable part of the partially implantable system is passive in terms of energy; and

wherein the implantable part of the partially implantable system receives operating energy and control data for mechanical and electrical inner ear stimulation via the modulator/transmitter unit in the external module.

67. The system as claimed in claim 1, wherein the system is a binaural system having two system units for rehabilitation of a hearing disorder of both ears, a respective system unit being provided for each of the ears of a user.

68. The system as claimed in claim 67, wherein the two system units are essentially identical to one another.

69. The system as claimed in claim 67, wherein one of the two system units is a master unit and another of the system units is a slave unit which is controlled by the master unit.

70. The system as claimed in claim 67, wherein a wired implantable line connection is provided for enabling one of the electronic signal processing unit of one of the system units to communicate with the electronic signal processing units of the other system unit to optimize binaural signal processing and converter array triggering.

71. The system as claimed in claim 67, wherein a wireless connection is provided for enabling communication between the electronic signal processing units of the two system units to optimize binaural signal processing and converter array triggering.

72. The system as claimed in claim 71, wherein the wireless connection is a bidirectional high frequency section.

73. The system as claimed in claim 67, wherein ultrasonic couplers are provided for enabling the electronic signal processing units of the two system units to communicate with one another via a solid borne sound-coupled ultrasonic section to optimize binaural signal processing and converter array triggering.

74. The system as claimed in claim 67, wherein the electronic signal processing units are connected to implantable electrodes and the implantable electrodes, in an implanted state are adapted to enable data transmission through body tissue of an implant wearer for communication of the electronic signal processing units of the two system units.

75. The system as claimed in claim 1, wherein the at least one stimulator element for mechanical stimulation of the inner ear and the at least one stimulation electrode for electrical stimulation of the inner car are selectively operable.

76. The system as claimed in claim 1, wherein the at least one stimulator element for mechanical stimulation of the inner ear and the at least one stimulation electrode for electrical stimulation of the inner ear are simultaneously operable.