Automatic fitting for a visual prosthesis
The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual patient. By recording neural response to a predetermined input stimulus, one can alter that input stimulus to the needs of an individual patient. A minimum input stimulus is applied to a patient, followed by recording neural response in the vicinity of the input stimulus. By alternating stimulation and recording at gradually increasing levels, one can determine the minimum input that creates a neural response, thereby identifying the threshold stimulation level. One can further determine a maximum level by increasing stimulus until a predetermined maximum neural response is obtained.
1. A neural stimulation device comprising:
a neural stimulation driver;
a stimulating electrode electrically connected to the neural stimulation driver emitting a stimulation signal;
a neural recorder creating recordings;
a recording electrode separate from the stimulating electrode and electrically connected to the neural recorder;
a digital separator separating the recordings to remove the stimulation signal and producing separated recordings;
a fitting circuit automatically adjusting the neural stimulation driver based on the separated recordings from the neural recorder.
2. The neural stimulation device according to claim 1 , wherein the recording electrode is adapted to be located adjacent the stimulating electrode.
3. The neural stimulation device according to claim 1 , wherein the recording electrode is adapted to be located in a cortex.
4. The neural stimulation device according to claim 1 , wherein the recording electrode is adapted to be located on a scalp.
5. The neural stimulation device according to claim 1 , wherein the neural recorder is adapted to record simultaneous with activation of the neural stimulation driver.
6. The neural stimulation device according to claim 1 , wherein the neural recorder is adapted to record after activation of the neural stimulation driver.
7. The neural stimulation device according to claim 1 , wherein the fitting circuit includes memory for storing stimulation and recording levels.
8. The neural stimulation device according to claim 1 , wherein the stimulation and recording levels include threshold and maximum levels.
9. A visual prosthesis comprising:
a neural stimulation driver;
a stimulating electrode electrically connected to the neural stimulation driver emitting a stimulation signal;
a neural recorder creating recordings;
a recording electrode separate from the stimulating electrode and electrically connected to the neural recorder;
a digital separator separating the recordings to remove the stimulation signal and producing separated recordings;
a fitting circuit automatically adjusting the neural stimulation driver based on the separated recordings from the neural recorder.
10. The visual prosthesis according to claim 9 , wherein the recording electrode is adapted to be located adjacent the stimulating electrode on an epiretinal surface.
11. The visual prosthesis according to claim 9 , wherein the recording electrode is adapted to be located in a visual cortex.
12. The visual prosthesis according to claim 9 , wherein the recording electrode is adapted to be located on a scalp near the visual cortex.
13. The visual prosthesis according to claim 9 , wherein the recording electrode is adapted to be located in an iris.
14. The visual prosthesis according to claim 9 , wherein the recording electrode is adapted to be located external to a body near an iris.
15. The visual prosthesis according to claim 9 , wherein the neural recorder is adapted to record simultaneous with activation of the neural stimulation driver.
16. The visual prosthesis according to claim 9 , wherein the neural recorder is adapted to record after activation of the neural stimulation driver.
17. The visual prosthesis according to claim 9 , wherein the fitting circuit includes memory for storing stimulation and recording levels.
18. The visual prosthesis according to claim 9 , wherein the stimulation and recording levels include threshold and maximum levels.