Method and apparatus for inducing the perception of color in a visual prosthesis
The present invention is an improved method of electrically stimulating percepts in a patient with a visual prosthesis, to induce the perception of color. In particular, the present invention is a method of inducing the perception of color by determining experimentally which patterns induce which colors, storing that information and using the stored information to induce the perception of color according to video input data and the stored color information.
1. A method of inducing perception of color with a visual prosthesis, comprising:
a. testing a stimulation pattern on a subject on an electrode group or an individual electrode;
b. determining if a subject perceives a particular color in response to the first stimulation pattern;
c. altering at least one of frequency, pulse width, inter-pulse gap, and intra-pulse gap in the stimulation pattern based on the step of determining until a desired color perception is obtained;
d. repeating steps a-c for each electrode or electrode group in an array of electrodes;
e. storing relationships of each of said electrode groups or individual electrodes to stimulation patterns and colors; and
d. using the stored relationships to determine patterns used for later stimulation for that subject.
2. The method according to claim 1 , wherein the step of testing stimulation patterns includes testing variations in frequency.
3. The method according to claim 1 , wherein the step of testing stimulation patterns includes testing variations in pulse width.
4. The method according to claim 1 , wherein the step of testing stimulation patterns includes testing variations in inter-pulse gap.
5. The method according to claim 1 , wherein the step of testing stimulation patterns includes testing variations in intra-pulse gap.
6. The method according to claim 1 , wherein the step of storing relationships comprises storing relationships of stimulation patterns and colors in look-up tables.
7. The method according to claim 1 , wherein the step of testing stimulation patterns is performed using an array of electrodes, and wherein a stimulation amplitude of a stimulation signal to be applied to one electrode in the array of electrodes is based on values in the look-up tables.
8. The method according claim 1 , wherein the step of testing stimulation patterns is performed using an array of electrodes, and wherein at least one of frequency, pulse width, inter-pulse gap, and intra-pulse gap of a stimulation signal to be applied to one electrode in the array of electrodes is based on values in the look-up tables.
9. The method according to claim 6 , wherein each subject is associated with one or more look-up tables specific to each subject.
10. The method according to claim 6 , wherein each electrode in the array of electrodes for each subject is associated with one or more look-up tables specific to each subject.
11. A visual prosthesis, comprising:
a camera providing video data to a video processing unit;
the video processing unit including memory means for storing individual, color video configuration information including at least one of frequency, pulse width, inter-pulse gap, and intra-pulse gap derived from testing of individual electrodes or electrode groups separately for each of a plurality of electrode groups or individual electrodes, and processing means for altering the video data according to the stored color video configuration information; and
a neural stimulator receiving video data from the video processing unit and stimulating visual neurons according to video data altered according to the color video configuration information for that subject.
12. The visual prosthesis according to claim 11 , wherein the individual color video configuration information is stored in look-up tables.
13. The visual prosthesis according to claim 12 , further comprising an array of electrodes adapted to provide stimulation signals to a subject based on the altered video data, wherein a stimulation amplitude of a particular stimulation signal to be applied to one electrode in the array of electrodes is based on values in the look-up tables.
14. The visual prosthesis according to claim 12 , further comprising an array of electrodes adapted to provide stimulation signals to a subject based on the altered video data, wherein at least one of frequency, pulse width, inter-pulse gap, and intra-pulse gap of a particular stimulation signal to be applied to one electrode in the array of electrodes is based on values in the look-up tables.
15. The visual prosthesis according to claim 11 , further comprising an array of electrodes adapted to provide stimulation signals to a subject, wherein the individual color video configuration information is obtained by applying, for each electrode in the array of electrodes, a particular stimulation signal to one electrode in the array of electrodes and adjusting at least one of frequency, pulse width, inter-pulse gap, and intra-pulse gap of the particular stimulation signal based on feedback from the subject.