New Uses for Eye Tracking in a Visual Prosthesis

Patent metadata

Field	Value
Publication number	US-2017239477-A1
Application number	US-201715439746-A
Country	US
Kind code	A1
Filing date	Feb 22, 2017
Priority date	Feb 22, 2016
Publication date	Aug 24, 2017
Grant date	—

Abstract

The present invention is an improved system for use of eye tracking including spatial mapping percepts in a visual prosthesis by presenting an electrically induced precept through a visual prosthesis, requesting a subject look to the direction of the percept and tracking their eye movement. Eye movement is both faster and more accurate than asking a visual prosthesis user to point to the location of a percept. This method can be beneficial in a retinal prosthesis, but is particularly useful in a cortical visual prosthesis where visual cortex does not match the retinotopic map. Methods are presented for calibrating an eye tracker. Eye tracking hardware may also be used for blanking video information base on the subject's natural blink reflex.

First claim

What is claimed is:

1 . A method fitting a visual prosthesis comprising:
stimulating percepts in a subject with a test group of visual prosthesis electrodes at an actual location; asking the subject to look in the direction the subject perceives the percept, at a perceived location; recording the perceived location with an eye tracking sensor; calculating a difference between the actual location and the perceived location in a computer; and adjusting the visual prosthesis based on the difference.

2 . The method according to claim 1 , wherein the step of recording a perceived location is recording a location after stimulation relative to a starting location before stimulation.

3 . The method according to claim 1 , wherein the step of recording a perceived location is recording an absolute location after stimulation.

4 . The method according to claim 1 , wherein the eye tracking sensor is a camera.

5 . The method according to claim 1 , wherein the eye tracking sensor blocks a user's natural field of view.

6 . A method for calibration of an eye tracker in a visual prosthesis comprising:
providing an eye tracking sensor to determine a pupil location or estimated gaze; providing a forward facing camera; time synchronizing the eye tracking camera, forward facing camera, and visual prosthesis; stimulating a precept with the visual prosthesis in an actual location; asking the subject to place a trackable marker in the perceived location of stimulation; repeating the steps of stimulating and asking in multiple locations; and applying a formula to the actual location and perceived location to minimize the spread of the precieved locations based on the pupil location or estimated gaze.

7 . The method according to claim 6 , wherein the eye tracking sensor and forward facing camera are synchronized using a timestamp.

8 . The method according to claim 6 , wherein the step of applying a formula is applying a formula to find the parameters that will minimize the spread of pattern location for each group of electrodes.

9 . The method according to claim 6 , wherein the step of applying a formula is applying a formula to align the gaze and location of stimulation.

10 . The method according to claim 6 , wherein the eye tracking sensor is a camera.

11 . A method of stimulating visual neuron with a visual prosthesis comprising:
providing a visual prosthesis including a detector; stimulating visual percepts according to camera data; interrupting stimulation when the detector detects a physiological change; and stimulating visual percepts according to camera data when the detector detects the end of the physiological change.

12 . The method according to claim 11 , wherein the detector is a blink detector and the physiological change is a blink.

13 . The method according to claim 12 , wherein the blink detector is an eye tracking camera.

14 . The method according to claim 11 , wherein the detector is a saccade detector.

15 . The method according to claim 14 , wherein the saccade detector is an eye tracking camera and lack of a saccade is a consistent position for more than 50 milliseconds.

Assignees

• Second Sight Medical Products Inc

Inventors

• Caspi Avraham I
• Dorn Jessy D
• Roy Arup
• Greenberg Robert J

Classifications

• A61N1/0543

  Retinal electrodes · CPC title

• A61N1/36046 Primary

  of the eye · CPC title