Pulse Medical Instruments

Marc D Rafal

Tom N Cornsweet

Michael Rothberg

Eric Starin

Jeff L Krichmar

A pupil detection system projects two small infrared (IR) spots separated by approximately 0.5 mm. Each spot is turned on at different times (or alternatively, they can be modulated at different frequencies). The error signal produced by each spot is compared. If the errors are similar, a pupil is present. If the errors are different, no pupil is present (i.e., a blink or lost tracking). The sequencing of the IR spots and the reading of the detector data occur at the higher rates needed for accurate eye tracking.

Pupil detection system

A fitness impairment tester implements a self-administered screening test to determine whether a subject is physically impaired. The tester is fully automated to respond to the entering of a subject's personal identification on a keypad. By superposing two different colored lights as viewed through an eyepiece, the subject aligns his or her pupil on the optical axis of pupil imaging optics which focuses an image of the subject's pupil on an image plane. The tester automatically recognizes this condition and audibly signals the subject that the test is about to begin. Light stimuli are provided to cause the pupil to change size and the eye to move. Pupil diameter measurements are made of the image of the subject's pupil in response to on axis light stimuli. Eye tracking of the subject's eye in response to moving light stimuli provide a measure of eye movements. The data acquired by measuring pupil diameter and saccadic movements of the subject's eye as a function of time are compared with baseline data for the subject stored in a database, and an output indicative of a deviation of said current measurements from said baseline data is provided.

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Montgomery County, MD, United States of America

Marc D Rafal