DEVELOPMENT OF AN ON-LINE NON-CONTACTING METHOD FOR ANALYSIS OF TORSIONAL EYE-MOVEMENTS

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Authors
  1. Eizenman, M.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN);Toronto Univ, Toronto ONT (CAN) Inst of Biomedical Engineering
Abstract
Measurement of ocular torsion (OT) can be used for vestibular research, clinical diagnosis and in studies of spatial orientation. In this report we described a video-based system that estimates ocular torsion by analysing rotation of the iris structures. In our video system, the subject's eye is illuminated by infra-ed light and images of the eye are captured by a head-mounted video-camera. Each image is anlayzed, and spatial sequences of the iris structure are extracted. The extracted sequences are cross-correlated, in real-time, with a reference sequence to obtain (from the position of the peak of the cross-correlation) an estimate of ocular torsion. During the development of the OT estimation algorithms, we have optimized parameters such as the length of the extracted sequence and the distance of the extracted sequence from the edge of the pupil and developed filters for optimal processing. The system that we have developed is non-invasive and allows free head-movements. The subject's eyes are allowed to move in horizontally and vertically over a range of -20 degrees to +20 degrees. The performance of the system was evaluated by comparing video-based OT measurements to OT measurements obtained by a scleral coil system (the "gold-standard"). TRUNCATED
Date of publication
01 Mar 1995
Number of Pages
150
DSTKIM No
97-02145
CANDIS No
502302
Format(s):
Hardcopy;Document Image stored on Optical Disk

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