Text reading and translation in a visual prosthesis
The present invention is a visual prosthesis which restores partial vision to patients blinded by outer retinal degeneration. While visual prosthesis users have achieved remarkable visual improvement to the point of reading letters and short sentences, the reading process is still fairly cumbersome. In the present invention the visual prosthesis is adapted to stimulate visual braille as a sensory substitution for reading written letters and words. The visual prosthesis system, used in the present invention, includes a 10×6 electrode array implanted epiretinally, a tiny video camera mounted on a pair of glasses, and a wearable computer that processes the video and determines the stimulation current of each electrode in real time.
1. A method of processing written words in a visual prosthesis comprising:
providing a visual prosthesis including a camera, video processor, and implantable stimulation system configured to stimulate visual neurons;
recording a visual scene with the camera and transferring data representing the visual scene to the video processor;
converting the data to visual stimulation patterns;
presenting the visual stimulation patterns including the visual scene to a user through the implantable stimulation system;
scanning the data for patterns representing written characters;
switching to a reading mode upon recognition by the video processer of patterns representing written characters, wherein said reading mode includes:
converting the written characters to Braille characters;
encoding the Braille characters into the visual stimulation patterns, creating altered stimulation patterns; and
presenting the altered visual stimulation patterns including the Braille characters to a user through the implantable stimulation system;
switching back to presenting the visual stimulation patterns including the visual scene through the implantable stimulation system, after presenting the altered visual stimulation patterns including the Braille characters.
2. The method according to claim 1 , wherein the step of presenting the Braille characters includes presenting only Braille characters without the visual scene.
3. The method according to claim 2 , wherein the Braille characters are presented sequentially.
4. The method according to claim 3 , wherein the Braille characters are presented for less than one second per letter.
5. The method according to claim 4 , wherein the Braille characters are present for about 500 milliseconds.
6. The method according to claim 4 , wherein the Braille characters are presented for about 250 milliseconds.
7. The method according to claim 3 , wherein a first gap between characters is different than a second gap between words.
8. The method according to claim 3 , wherein a gap between characters is less than one second.
9. The method according to claim 1 , wherein the step of presenting the Braille characters is presenting a visual scene with Braille characters overlaid over the written characters in the visual scene.