Low voltage stimulation to elicit stochastic response patterns that enhance the effectiveness of a cochlear implant

• US 6,249,704 B1
• Filed: 08/10/1999
• Issued: 06/19/2001
• Est. Priority Date: 08/11/1998
• Status: Expired due to Term

• Current Assignee: Advanced Bionics AG (Sonova Holding AG)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Harrison, William Vanbrooks, Maltan, Albert A.
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US09/371,725
• Time in Patent Office: 679 Days
• Field of Search: 607/55-57, 607/137, 623/10, 600/25
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36038 Cochlear stimulation

Abstract

A cochlear stimulation system includes a speech processing strategy that applies non-auditory-informative stimuli as well as auditory-informative stimuli to the same or neighboring sets of electrodes. The non-auditory-informative stimuli are applied to the auditory neural system for the purpose of influencing the properties and response characteristics of the auditory system so that when the auditory-informative stimuli are applied, such stimuli are more effective at evoking a desired auditory response, i.e., are more effective at allowing the patient to perceive sound. The information-carrying stimuli may be applied to the auditory neural system at the same time as is the non-auditory-informative stimuli, or may be applied during time slots between application of the non-auditory-informative stimuli.

Claims

1. A cochlear stimulation implant device comprising:

an electrode array adapted for insertion into the cochlea;

a plurality of spaced-apart electrodes on the electrode array;

first means for generating auditory-informative stimuli and applying such stimuli to selected pairs of the electrodes;

second means for generating non-auditory-informative stimuli and applying the non-auditory-informative stimuli to selected pairs of the electrodes;

wherein the non-auditory-informative stimuli have a magnitude that is substantially no greater than an auditory perception threshold level, and further wherein the non-auditory-informative stimuli bias or precondition auditory neurons so that application of the auditory-informative stimuli to the auditory neurons is more effective.

2. The cochlear stimulation implant device of claim 1 wherein the non-auditory-informative stimuli and the auditory-informative stimuli are interspersed in a single stimulation channel.

3. The cochlear stimulation implant device of claim 1 wherein the non-auditory-informative stimuli and the auditory-informative stimuli are applied simultaneously to parallel stimulation channels.

4. The cochlear stimulation implant device of claim 1 wherein the non-auditory-informative stimuli comprise fast sequential stimuli that enhance stochastic response patterns and thereby enhance the effectiveness of the auditory-informative stimuli.

5. The cochlear stimulation implant device of claim 4 wherein the fast sequential stimuli used as the non-auditory-informative stimuli have a frequency above 5 kHz.

6. The cochlear stimulation implant device of claim 4 wherein the fast sequential stimuli used as the non-auditory-informative stimuli have a pulse width less than 100 microseconds.

7. A cochlear stimulation system comprising:

a plurality of spaced apart electrodes configured for insertion into the cochlea;

a stimulus pulse generator connected to the electrodes that generates auditory-informative stimuli and non-auditory-informative stimuli responsive to control signals;

a control circuit coupled to the stimulus pulse generator that generates the control signals which cause the stimulus pulse generator to apply both the auditory-informative stimuli and the non-auditory-informative stimuli to selected electrodes of the plurality of spaced-apart electrodes, and wherein the non-auditory-informative stimuli have a pulse width, pulse amplitude and repetition rate selected to condition tissue and nerves receiving such non-auditory-informative stimuli so that application of the auditory-informative stimuli to the same or adjacent tissue is more effective.

8. The cochlear stimulation system of claim 7 wherein the pulse width, pulse amplitude and repetition rate of the non-auditory-informative stimuli are selected, as a combination, to provide stimuli to a user of the cochlear stimulation system that is not noticeably perceptible.

9. The cochlear stimulation system of claim 8 wherein the pulse width of the non-auditory-informative stimuli is no greater than 100 microseconds and the repetition rate is at least 5 KHz.

10. The cochlear stimulation system of claim 7 wherein the stimulus pulse generator and control circuit are housed within hermetically sealed housings which are implantable.

11. A method of stimulating the auditory nerve from inside the cochlea, the auditory nerve having an auditory perception threshold, the method comprising:

(a) implanting a cochlear electrode array inside of the cochlea, the electrode array having a plurality of spaced-apart electrodes thereon;

(b) applying non-auditory-informative stimuli having pulse width, pulse amplitude and repetition rate characteristics having a magnitude that is substantially greater than the auditory perception threshold to selected electrodes of the electrode array; and

(c) applying auditory-informative stimuli to selected electrodes of the electrode array.

12. The method of claim 11 wherein steps (b) and (c) comprise applying the non-auditory-informative stimuli and the auditory-informative stimuli to the same electrodes by interspersing the non-auditory-informative stimuli with the auditory-informative stimuli.

13. The method of claim 11 wherein steps (b) and (c) comprise applying the non-auditory-informative stimuli to one set of electrodes within the electrode array simultaneously with applying the auditory-informative stimuli to another set of electrodes within the electrode array.

14. The method of claim 11 wherein the repetition rate, pulse width, and pulse amplitude of the non-auditory-informative stimuli are selected to enhance stochastic response patterns of auditory neurons for the purpose of enhancing the effectiveness of the auditory-informative stimuli applied in step (c).

15. The method of claim 14 wherein step (b) comprises applying non-auditory-informative stimuli having a frequency of at least 5 KHz.

16. The method of claim 14 wherein step (b) comprises applying non-auditory-informative stimuli having a pulse width of no more than 100 microseconds.