Methods and systems for fitting a cochlear implant to a patient

• US 20050137650A1
• Filed: 11/16/2004
• Published: 06/23/2005
• Est. Priority Date: 11/21/2003
• Status: Active Grant

• Current Assignee: Advanced Bionics AG (Sonova Holding AG)
• Original Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Inventors: Litvak, Leonid M., Mishra, Lakshmi N.
• Granted Patent: US 7,292,892 B2
• Time in Patent Office: Days
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36039 fitting procedures
• CPC Class Codes: H04R 2225/67 Implantable hearing aids or parts thereof not covered by H04R25/606

Abstract

An exemplary method of fitting a cochlear implant system to a patient includes establishing an implant fitting line having a slope and a position. The implant fitting line represents a relationship between a number of stimulation sites within a cochlea of the patient and a number of corresponding audio frequencies. That is, the implant fitting line defines which locations along the length of the cochlea, when stimulated, are perceived by the patient as specific tones or frequencies. The method further includes presenting a first audio signal having a number of audio frequencies to the patient and applying a stimulus current to one or more stimulation sites corresponding to the number of audio frequencies of the first audio signal. The method further includes adjusting the slope of the fitting line based on a response of the patient to the stimulus current. An exemplary system for fitting a cochlear implant to a patient includes an implantable cochlear stimulator with a number of stimulus channels configured to apply stimulus current to a number of stimulation sites within a cochlea of the patient. The system further includes a speech processor having a number of analysis channels configured to divide an input audio signal into a number of signals having distinct frequencies and mapping circuitry configured to map the number of signals generated by the analysis channels to the stimulus channels according to a mapping scheme. The mapping scheme is adjusted based on a change in a slope of a fitting line, the fitting line representing a relationship between the number of stimulation sites and a number of corresponding audio frequencies.

Claims

1. A method of fitting a cochlear implant system to a patient, said method comprising:

establishing an implant fitting line having a slope and a position, said fitting line representing a relationship between a number of stimulation sites within a cochlea of said patient and a number of corresponding audio frequencies;

presenting a first audio signal to said patient, said first audio signal comprising a number of audio frequencies;

applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said first audio signal; and

adjusting said slope of said fitting line based on a response of said patient to said stimulus current.

2. The method of claim 1, further comprising:

presenting a second audio signal to said patient, said second audio signal comprising a number of audio frequencies;

applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said second audio signal; and

adjusting said position of said fitting line based on a response of said patient to said stimulus current corresponding to said number of audio frequencies of said second audio signal.

3. The method of claim 2, wherein said second audio signal comprises human speech.

4. The method of claim 2, wherein said step of adjusting said position of said fitting line comprises adjusting a horizontal axis intercept of said fitting line.

5. The method of claim 2, wherein said step of adjusting said position of said fitting line comprises horizontally shifting said position of said fitting line in a first direction if an overall pitch of said second audio signal is perceived by said patient as being too high.

6. The method of claim 5, wherein said step of adjusting said position of said fitting line further comprises horizontally shifting said position of said fitting line in a second direction if an overall pitch of said second audio signal is perceived by said patient as being too low.

7. The method of claim 2, wherein said second audio signal is identical to said first audio signal.

8. The method of claim 1, wherein said first audio signal comprises a musical tune.

9. The method of claim 1, wherein said step of adjusting said slope of said fitting line comprises increasing said slope of said fitting line if said patient perceives said first audio signal as being harmonically out of tune.

10. The method of claim 1, wherein said step of adjusting said slope of said fitting line comprises decreasing said slope of said fitting line if said patient perceives said first audio signal as being harmonically out of tune.

11. The method of claim 1, wherein said step of applying said stimulus current to said one or more stimulation sites comprises presenting weighted stimulus currents simultaneously at two physical electrodes.

12. The method of claim 1, wherein said step of applying said stimulus current to said one or more stimulation sites comprises presenting stimulus currents at two physical electrodes in a time-multiplexed manner.

14. The method of claim 1, further comprising:

presenting a second audio signal to said patient, said second audio signal comprising a number of audio frequencies;

applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said second audio signal; and

adjusting said slope of said fitting line based on a response of said patient to said stimulus current corresponding to said number of audio frequencies of second audio signal.

13. A method of fitting a cochlear implant system to a patient, said method comprising:

establishing an implant fitting line having a slope and a position, said fitting line representing a relationship between a number of stimulation sites within a cochlea of said patient and a number of corresponding audio frequencies;

presenting a first audio signal to said patient, said first audio signal comprising a number of audio frequencies;

applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said first audio signal; and

adjusting said position of said fitting line based on a response of said patient to said stimulus current.

15. A system for fitting a cochlear implant to a patient, said system comprising:

an implantable cochlear stimulator with a number of stimulus channels configured to apply stimulus current to a number of stimulation sites within a cochlea of said patient;

a speech processor having a number of analysis channels configured to divide an input audio signal into a number of signals having distinct frequencies; and

mapping circuitry configured to map said number of signals generated by said analysis channels to said stimulus channels according to a mapping scheme;

wherein said mapping scheme is adjusted based on a change in a slope of a fitting line, said fitting line representing a relationship between said number of stimulation sites and a number of corresponding audio frequencies.

16. The system of claim 15, wherein said mapping scheme is further adjusted based on a change in a position of said fitting line.

17. The system of claim 16, wherein said change in said position of said fitting line comprises a change in a horizontal axis intercept of said fitting line.

18. The system of claim 16, wherein said position of said fitting line is changed if an overall pitch of said input audio signal is perceived by said patient as being too high.

19. The system of claim 16, wherein said position of said fitting line is changed if an overall pitch of said input audio signal is perceived by said patient as being too low.

20. The system of claim 16, further comprising a control interface configured to allow a user to selectively change said slope of said fitting line and change said position of said fitting line.

21. The system of claim 20, wherein said control interface comprises a graphical user interface, a remote control, or an analog tuning mechanism.

22. The system of claim 15, wherein said input audio signal is a musical tune or human speech.

23. The system of claim 15, wherein said slope of said fitting line is change if said patient perceives said input audio signal as being harmonically out of tune.

24. A system for fitting a cochlear implant system to a patient, said system comprising:

means for establishing an implant fitting line having a slope and a position, said fitting line representing a relationship between a number of stimulation sites within a cochlea of said patient and a number of corresponding audio frequencies;

means for presenting a first audio signal to said patient, said first audio signal comprising a number of audio frequencies;

means for applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said first audio signal; and

means for adjusting said slope of said fitting line based on a response of said patient to said stimulus current.

25. The system of claim 24, further comprising:

means for presenting a second audio signal to said patient, said second audio signal comprising a number of audio frequencies;

means for applying a stimulus current to one or more stimulation sites corresponding to said number of audio frequencies of said second audio signal; and

means for adjusting said position of said fitting line based on a response of said patient to said stimulus current corresponding to said number of audio frequencies of said second audio signal.

26. The system of claim 25, wherein said means for adjusting said position of said fitting line comprises means for horizontally shifting said position of said fitting line in a first direction if an overall pitch of said second audio signal is perceived by said patient as being too high.

27. The system of claim 26, wherein said means for adjusting said position of said fitting line comprises means for horizontally shifting said position of said fitting line in a second direction if an overall pitch of said second audio signal is perceived by said patient as being too low.

28. The system of claim 24, wherein said means for adjusting said slope of said fitting line comprises means for increasing said slope of said fitting line if said patient perceives said first audio signal as being harmonically out of tune.

29. The system of claim 24, wherein said means for adjusting said slope of said fitting line comprises means for decreasing said slope of said fitting line if said patient perceives said first audio signal as being harmonically out of tune.

30. The system of claim 24, wherein said means for applying said stimulus current to said one or more stimulation sites comprises means for presenting weighted stimulus currents simultaneously at two physical electrodes.

31. The system of claim 24, wherein said means for applying said stimulus current to said one or more stimulation sites comprises means for presenting stimulus currents at two physical electrodes in a time-multiplexed manner.