An infrared system for determining ocular position

Bioengineering research in the Electronics Division of the Denver Research Institute has centered around the development of an ocular controlled communications device for the severely handicapped. The means for accurate determination of eye position for use in communication/control applications have been investigated by various groups for at least ten years. A highly satisfactory device for eye tracking has been developed in our laboratories and is currently undergoing clinical evaluation as part of a communications system. An infrared LED is mounted on the nose pad of an ordinary pair of eyeglass frames. This LED floods the cornea with light after reflection from the inside surface of an unground eyeglass lens in the frames. The cornea acts as a convex mirror and reflects the light (via the inside surface of the eyeglass (lens) into an image transducer mounted on the bow of the frames. The image transducer is a 32 x 32 cell (1k) dynamic RAM. Utilizing TTL scanning circuitry, the position of the eye can be determined from the address of the illuminated cell of the RAM.