Artificial Eye Gives Vision to Blind Man
- By Malcolm Ritter
- Jan. 22 2000 00:00
NEW YORK -- A blind man can read large letters and navigate around big objects by using a tiny camera wired directly to his brain, the first artificial eye to provide useful vision, a researcher reports.
The 62-year-old man doesn't see an image. He perceives up to 100 specks of light that appear and disappear, like stars that come and go behind passing clouds, as his field of vision shifts.
But as he showed a reporter last week, that's enough to let him find a mannequin in a room, walk to a black stocking cap hanging on a white wall, and then return to the mannequin to plop the cap on its head. He also can recognize a 5-centimeter-tall letter from 1.5 meters away, researcher William Dobelle said.
"He can do remarkably well" with the limited visual signal, said Dobelle, who is developing the artificial vision system.
The man, who asked to be identified only as Jerry, has been blind since the age of 36. He volunteered for the study and got the brain implant in 1978; scientists have been working since then to improve the software.
Dobelle is chairman of the Dobelle Institute, a medical device company in New York. He describes the device and its performance in this month's issue of the ASAIO Journal, a publication of the American Society of Artificial Internal Organs.
Richard Normann, who studies artificial vision at the University of Utah, said he's encouraged by how much Jerry can do. He said Dobelle's report suggests that, someday, even limited signals to the brain will let blind people do relatively complicated visual tasks.
It's the first demonstration of useful artificial vision, he said, but he stressed the device is "a very limited navigational aid, and it's a far cry from the visual experience that normal people enjoy."
Still, an implant that helps blind people navigate would be a major step forward, said Dr. Bill Heetderks, who directs a National Institute of Health program to develop electronic implants that work with the brain.
"When Dr. Dobelle provides additional details on his methodology that establishes this result, we may be there," Heetderks said after reading Dobelle's report.
While Dobelle's device uses a brain implant, some other scientists are studying implants in the retina, the light-sensing tissue at the back of the eye. The retina strategy made news recently when blind musician Stevie Wonder expressed interest.
To use the device, Jerry wears sunglasses with a tiny pinhole camera mounted on one lens and an ultrasonic range finder on the other. Both devices communicate with a small computer carried on his hip, which highlights the edges between light and dark areas in the camera image. It then tells an adjacent computer to send appropriate signals to an array of small electrodes on the surface of Jerry's brain, through wires entering his skull behind his right ear.
The electrodes stimulate certain brain cells, making Jerry perceive the specks of light. The shifting patterns as Jerry scans across a scene tells him where light areas meet dark ones, letting him find the black cap on the white wall, for example.
The device provides a sort of tunnel vision, reading an area about the size of a card 5 centimeters wide and 20 centimeters tall, held at arm's length.
Jerry uses the device only two or three days a week at Dobelle's lab, as researchers tinker with it. Dobelle said an improved version of the device should go on sale, in limited numbers, later this year.