Systems and methods for determining a threshold current level required to evoke a stapedial muscle reflex

1. A cochlear implant system comprising:

an implantable cochlear stimulator configured to be implanted within a patient and generate a stimulation current having an adjustable current level;

one or more electrodes communicatively coupled to said stimulator and configured to apply said stimulation current to one or more locations within an ear of said patient; and

a probe configured to acquire sound data used to derive an acoustic reflectance of said ear, said probe comprising

a speaker configured to apply one or more probe signals within an ear canal of said patient; and

a microphone configured to detect said sound data;

wherein said sound data represents at least a portion of said probe signals that reflect off of a tympanic membrane of said patient, and

wherein said implantable cochlear stimulator is further configured to adjust said current level of said stimulation current until a change in said acoustic reflectance above a threshold is detected.

2. The system of claim 1 , further comprising a fitting station communicatively coupled to said probe, wherein said fitting station is configured to:

process said sound data to derive said acoustic reflectance;

transmit data representative of a command to adjust said current level to said stimulator in accordance with said acoustic reflectance; and

detect said change in said acoustic reflectance.

3. The system of claim 2 , wherein said fitting station is configured to detect said change in said acoustic reflectance by:

deriving a baseline acoustic reflectance while said implantable cochlear stimulator is not generating said stimulation current;

deriving an acoustic reflectance while said implantable stimulator is generating said stimulation current; and

comparing said acoustic reflectance derived while said implantable stimulator is generating said stimulation current to said baseline acoustic reflectance.

4. The system of claim 1 , further comprising a sound processor communicatively coupled to said probe, wherein said sound processor is configured to:

process said sound data to derive said acoustic reflectance;

transmit data representative of a command to adjust said current level to said stimulator in accordance with said acoustic reflectance; and

detect said change in said acoustic reflectance.

5. The system of claim 4 , wherein said sound processor is configured to detect said change in said acoustic reflectance by:

deriving a baseline acoustic reflectance while said implantable cochlear stimulator is not generating said stimulation current;

deriving an acoustic reflectance while said implantable stimulator is generating said stimulation current; and

comparing said acoustic reflectance derived while said implantable stimulator is generating said stimulation current to said baseline acoustic reflectance.

6. The system of claim 1 , further comprising a probe tip configured to seal said speaker and said microphone within said ear canal.

7. The system of claim 1 , wherein said one or more probe signals comprise at least one of a chirp signal and a noise signal.

8. The system of claim 1 , wherein said change in said acoustic reflectance indicates a presence of a stapedial muscle reflex.

9. The system of claim 1 , wherein said implantable cochlear stimulator is configured to set said current level of said stimulation current that results in said change in said acoustic reflectance as a threshold current level corresponding to a most comfortable current level of said patient.

10. A system comprising:

an implantable cochlear stimulator configured to be implanted within a patient and generate a stimulation current having an adjustable current level;

one or more electrodes communicatively coupled to said stimulator and configured to apply said stimulation current to one or more locations within an ear of said patient;

a sound processor communicatively coupled to said stimulator and configured to control said stimulator in accordance with one or more stimulation parameters;

a fitting station separate from and communicatively coupled to said sound processor; and

a probe communicatively coupled directly to said fitting station and configured to acquire sound data, said probe comprising

a speaker configured to apply one or more probe signals within an ear canal of said patient; and

a microphone configured to detect said sound data;

wherein said sound data represents at least a portion of said one or more probe signals that reflect off of a tympanic membrane of said patient;

wherein said fitting station is configured to derive an acoustic reflectance of said ear in accordance with said sound data; and

wherein said stimulator is configured to adjust said current level of said stimulation current until a change in said acoustic reflectance above a threshold is detected by said fitting station.

11. The system of claim 10 , wherein said fitting station is configured to detect said change in said acoustic reflectance by:

deriving a baseline acoustic reflectance while said implantable cochlear stimulator is not generating said stimulation current;

deriving an acoustic reflectance while said implantable stimulator is generating said stimulation current; and

comparing said acoustic reflectance derived while said implantable stimulator is generating said stimulation current to said baseline acoustic reflectance.

12. The system of claim 10 , further comprising a probe tip configured to seal said speaker and said microphone within said ear canal.

13. The system of claim 10 , wherein said one or more probe signals comprise at least one of a chirp signal and a noise signal.

14. The system of claim 10 , wherein said change in said acoustic reflectance indicates a presence of a stapedial muscle reflex.

15. The system of claim 10 , wherein said implantable cochlear stimulator is configured to set said current level of said stimulation current that results in said change in said acoustic reflectance as a threshold current level corresponding to a most comfortable current level of said patient.

16. A method of determining a threshold current level required to evoke a stapedial muscle reflex within a patient, said method comprising:

applying a stimulation current having an adjustable current level to one or more locations within an ear of a patient;

measuring with a fitting station an acoustic reflectance of said ear during said application of said stimulation current by

applying one or more probe signals with a speaker to an ear canal of said patient; and

detecting sound data representing at least a portion of said probe signals that reflect off of a tympanic membrane of said patient with a microphone;

adjusting said current level of said stimulation current until a change in said acoustic reflectance above a threshold is detected; and

setting said threshold current level to a value related to said current level of said stimulation current that causes said change in said acoustic reflectance.

17. The method of claim 16 , wherein said change in said acoustic reflectance indicates a presence of a stapedial muscle reflex.

18. The system of claim 2 , wherein the fitting station comprises a clinician's programming unit.

19. The system of claim 10 , wherein the fitting station comprises a clinician's programming unit.

20. The method of claim 16 , wherein the fitting station comprises a clinician's programming unit.