OPTIMIZED STIMULATION RATE OF AN OPTICALLY STIMULATING COCHLEAR IMPLANT

• US 20130023965A1
• Filed: 07/21/2012
• Published: 01/24/2013
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Nurotone Medical Ltd.
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Stafford, Ryan C., Wells, Jonathon D., Stafford, James W., Norton, Bryan J.
• Granted Patent: US 8,998,914 B2
• Time in Patent Office: Days
• US Class Current: 607/88
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/36039 fitting procedures
• CPC Class Codes: A61N 2005/0605 Ear
• CPC Class Codes: A61N 2005/0626 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 2005/0659 infrared
• CPC Class Codes: A61N 5/0622 Optical stimulation for exciting neural tissue
• CPC Class Codes: A61N 5/067 using laser light
• CPC Class Codes: F04C 2270/0421 Controlled or regulated

Abstract

Method and apparatus for optically stimulating neurons of a plurality of auditory nerve pathways of a person to provide auditory sensations for the person including generating a plurality of pulsed light signals having one or more successive pulses; delivering the plurality of pulsed light signals to one or more auditory nerve pathways of the cochlea of the person; selectively controlling the plurality of light signals to optically stimulate and trigger nerve action potentials (NAPs) in the one or more auditory nerve pathways. In some embodiments, the stimulation rate (i.e., pulse-repetition rate) is optimized for the patient based on comfort levels, speech-recognition scores, and temperature feedback from monitors in the cochlea. In some embodiments, the methods of the present invention find practical lower and upper limits to the rate of stimulation to increase the speech-recognition scores while implementing safety limits to preventing overheating.

Claims

1. A method for optically stimulating neurons of a plurality of auditory nerve pathways of a person including a first auditory nerve pathway and a second auditory nerve pathway, to provide auditory sensations for the person, the method comprising:

generating a plurality of pulsed light signals having one or more successive pulses that, when applied to a neuron of a person, will each stimulate a nerve action potential (NAP) in the neuron, wherein the plurality of light signals includes a first light signal and a second light signal;

delivering the first light signal to one or more neurons of the first auditory nerve pathway of the person;

delivering the second light signal to one or more neurons of the second auditory nerve pathway of the person; and

selectively controlling the plurality of light signals to optically stimulate and trigger NAPs in the one or more neurons in the first auditory nerve pathway independently from NAPs in the one or more neurons in the second auditory nerve pathway, wherein the selectively controlling includes empirically testing the delivering of the plurality of light signals and determining which pulse-repetition rates of a plurality of pulse-repetition rates used for the plurality of light signals during the testing are most effective for optically stimulating the neurons of the plurality of auditory nerve pathways of the person, and using results of the testing such that the delivering includes delivering the plurality of light signals at the pulse-repetition rates that were determined to be most effective for optically stimulating.

2. The method of claim 1, wherein the determining of the most effective pulse-repetition rates includes eliciting and receiving feedback from the person as to a comfort level of the person at each repetition rate of the plurality of repetition rates used during the testing.

3. The method of claim 1, wherein the determining of the most effective pulse-repetition rates includes eliciting and receiving feedback from the person and, based on the feedback, determining a speech-recognition score for each pulse-repetition rate of the plurality of pulse-repetition rates used during the testing.

4. The method of claim 1, wherein the plurality of pulse-repetition rates are organized in a plurality of optical-stimulation channels, and wherein the determining of the most effective pulse-repetition rates includes determining the most effective pulse-repetition rates per optical-stimulation channel for the optically stimulating.

5. The method of claim 1, wherein the determining of the most effective pulse-repetition rates includes obtaining a temperature value of tissue of the person at each pulse-repetition rate of the plurality of pulse-repetition rates used during the testing, wherein the tissue includes the one or more neurons of the first auditory nerve pathway.

6. The method of claim 1, wherein the selectively controlling further includes modifying a pulse width of the plurality of light signals based on the received temperature value.

7. An apparatus for optical stimulation of neurons of a plurality of auditory nerve pathways of a person, including a first auditory nerve pathway and a second auditory nerve pathway, to provide auditory sensations for the person, the apparatus comprising:

a plurality of independently controllable light sources that are configured to generate a plurality of pulsed light signals that have one or more successive pulses and that, when applied to a neuron of the person, will each stimulate a nerve action potential (NAP) in the neuron, wherein the plurality of light signals includes a first light signal and a second light signal; and

a controller operatively coupled to the plurality of light sources to selectively control the plurality of light signals such that the first light signal is delivered to one or more neurons of the first auditory nerve pathway of the person in order to provide controlled optical stimulation to trigger nerve action potentials (NAPs) in the one or more neurons of the first auditory nerve pathway but not in the second auditory nerve pathway of the person, and such that the second light signal is delivered to one or more neurons of the second auditory nerve pathway of the person in order to provide controlled optical stimulation to trigger nerve action potentials (NAPs) in the one or more neurons of the second auditory nerve pathway but not in the first auditory nerve pathway of the person, wherein the controller is configured to empirically test the apparatus to determine which pulse-repetition rates of a plurality of pulse-repetition rates used for the plurality of light signals during the test are most effective for optical stimulation of the neurons of the plurality of auditory nerve pathways of the person, and wherein the controller is configured to use results of the test such that the plurality of light signals is delivered at the pulse-repetition rates that were determined to be most effective for optical stimulation.

8. The apparatus of claim 7, further comprising a user interface configured to elicit and receive feedback during the test of the apparatus, wherein the feedback includes a comfort level of the person at each repetition rate of the plurality of repetition rates used during the test of the apparatus, and wherein the most effective pulse-repetition rate is determined based at least in part on the received comfort-level feedback.

9. The apparatus of claim 7, further comprising a user interface configured to elicit and receive feedback during the test of the apparatus, wherein the feedback is used to determine a speech-recognition score for each repetition rate of the plurality of repetition rates used during the test of the apparatus, and wherein the most effective pulse-repetition rate is determined based at least in part on the received speech-recognition score.

10. The apparatus of claim 7, wherein the plurality of pulse-repetition rates are organized in a plurality of optical-stimulation channels, and wherein the controller is configured to test the apparatus to determine a most-effective total number of optical-stimulation channels to use simultaneously for optical stimulation.

11. The apparatus of claim 7, wherein the plurality of pulse-repetition rates are organized in a plurality of optical-stimulation channels, and wherein the controller is configured to test the apparatus to determine the most effective pulse-repetition rates per optical-stimulation channel for the optical stimulation.

12. The apparatus of claim 7, wherein the most effective pulse-repetition rate is at least 150 Hertz (Hz).

13. The apparatus of claim 7, wherein the plurality of light signals is configured to be delivered inside a cochlea of the person, the apparatus further comprising:

one or more temperature sensors located in the cochlea;

wherein the controller is configured to;

elicit and receive a temperature value of the cochlea from the one or more temperature sensors during the delivery of the first light signal and the second light signal, and

stop the generation of the plurality of light signals if the received temperature value is higher than a pre-determined overheat temperature value.

14. An apparatus for optically stimulating neurons of a plurality of auditory nerve pathways of a person including a first auditory nerve pathway and a second auditory nerve pathway, to provide auditory sensations for the person, the apparatus comprising:

means for generating a plurality of pulsed light signals having one or more successive pulses that, when applied to a neuron of a person, will each stimulate a nerve action potential (NAP) in the neuron, wherein the plurality of light signals includes a first light signal and a second light signal;

means for delivering the first light signal to one or more neurons of the first auditory nerve pathway of the person;

means for delivering the second light signal to one or more neurons of the second auditory nerve pathway of the person; and

means for selectively controlling the plurality of light signals to optically stimulate and trigger NAPs in the one or more neurons in the first auditory nerve pathway independently from NAPs in the one or more neurons in the second auditory nerve pathway, wherein the means for selectively controlling includes means for empirically testing the delivery of the plurality of light signals and means for determining which pulse-repetition rates of a plurality of pulse-repetition rates used for the plurality of light signals during each test are most effective for optically stimulating the neurons of the plurality of auditory nerve pathways of the person, and means for using results of the test such that the means for delivering the first light signal and the means for delivering the second light signal each includes means for delivering the plurality of light signals at the pulse-repetition rates that were determined to be most effective for optically stimulating.

15. The apparatus of claim 14, wherein the means for delivering the first light signal delivers the first light signal inside a cochlea of the person and the means for delivering the second light signal delivers the second light signal inside the cochlea of the person.

16. The apparatus of claim 14, wherein the means for determining the most effective pulse-repetition rates includes means for delivering eliciting and receiving feedback from the person as to a comfort level of the person at each repetition rate of the plurality of repetition rates used during the test.

17. The apparatus of claim 14, wherein the means for determining the most effective pulse-repetition rates includes eliciting and receiving a speech-recognition score for each pulse-repetition rate of the plurality of pulse-repetition rates used during the test.

18. The apparatus of claim 14, wherein the plurality of pulse-repetition rates are organized in a plurality of optical-stimulation channels, and wherein the means for determining of the most effective pulse-repetition rates includes means for determining a total number of optical-stimulation channels to use simultaneously for the optically stimulating.

19. The apparatus of claim 14, wherein the plurality of pulse-repetition rates are organized in a plurality of optical-stimulation channels, and wherein the means for determining of the most effective pulse-repetition rates includes means for determining the most effective pulse-repetition rates per optical-stimulation channel for the optical stimulation.

20. The apparatus of claim 14, wherein the means for delivering the first light signal delivers the first light signal inside a cochlea of the person and the means for delivering the second light signal delivers the second light signal inside the cochlea of the person, the apparatus further comprising:

one or more temperature sensors in the cochlea, wherein the means for selectively controlling includes means for receiving a temperature value of the cochlea from the one or more temperature sensors during the delivering of the first light signal and the second light signal, and means for stopping the generating of the plurality of light signals if the received temperature value is higher than a pre-determined overheat temperature value.