March 2000, Vol. 17, No. 3 Dobelle Institute's artificial vision system Device stimulates visual cortex of the totally blind On January 18, 2000, a biomedical engineering team announced the development of an artificial vision system providing independent mobility to blind people. The system reflects more than 30 years in development work by the Dobelle Institute (New York; www.dobelle.com) and its affiliates in Long Island and Switzerland. It enables a totally blind person to achieve visual acuity of about 20/400, in a narrow visual "tunnel." The "Dobelle Eye," as described in a recent issue of the ASAIO (American Society of Artificial Internal Organs) Journal, consists of a sub-miniature television camera and an ultrasonic distance sensor, both of which are mounted on a pair of eyeglasses. The sensors connect through a cable to a miniature computer, which is worn in a pack on a person's belt. After processing the video and distance signals, the computer uses computer-imaging technology, including edge-detection algorithms to simplify the image by eliminating "noise." The computer then triggers a second microcomputer that transmits pulses to an array of 68 platinum electrodes implanted on the surface of the brain's visual cortex. When stimulated, each electrode produces one to four closely spaced phosphenes, which have been described as resembling "stars in the sky." This white phosphene on a black background "map" is roughly eight inches by two inches at arms length. The patient in the study, a 62-year-old male, was totally blinded by trauma when he was 36 years old. After learning to use the system and "read" the display, the patient is now able to read two inch tall letters at a distance of five feet, representing a visual acuity of about 20/400. Although the relatively small electrode array produces tunnel vision, the patient is also able to navigate unfamiliar environments like the New York City subway system. By replacing the sub-miniature television camera with an electronic interface, the patient is also learning to "watch" television, use a computer and access the Internet. William Dobelle, who led the research team from the Dobelle Institute and the Columbia-Presbyterian Medical Center (New York; cpmcnet.columbia.edu), said that the new artificial vision systems are expected to be made available, on a limited commercial basis, starting later this year. Table of Contents Web Site © Copyright 2000 by Lionheart Publishing, Inc. All rights reserved. Lionheart Publishing, Inc. 2555 Cumberland Parkway, Suite 299, Atlanta, GA 30339 USA Phone: 770-431-0867 | Fax: 770-432-6969 E-mail: lpi@lionhrtpub.com Web: www.lionheartpub.com