September 21, 2002.
By KURT LOFT,
The Associated Press State & Local Wire.
Will science one day find a cure for blindness?
Can those who live in darkness ever discover the gift of sight?
Researchers on two independent projects hope to shed light on such a noble goal by helping the blind, in some ways, "see" the world around them. A University of Florida team in Gainesville has designed a wearable navigation system, while a national consortium of engineers is creating an optical implant and transmitter to stimulate electrical impulses within the eye.
The Florida researchers named their invention Drishti, after the Sanskrit word for vision. It combines speech-recognition software, wearable computers and a Global Positioning System to create a navigational aid. The waist-worn computer and headset are connected to a data base blueprint of a home, mall, campus, office or city park - wherever the person frequently travels. The device won't restore a blind person's sight, but it can assist him or her in getting around in restricted areas, says Steve Moore, a UF computer scientist who helped build the system.
"If you're out there all alone with only a cane, you can make a little turn here and there, and first thing you know you have no idea which way is west," he said. "But if you get directions from the voice telling you what direction you're going, how far off course you are, or if you are leaving the middle of the sidewalk, you feel much more comfortable."
Here's how Drishti works: A schematic of a city block, for example, is downloaded into the system. The wearer speaks into a microphone, and tells the computer where he or she wants to go, such as the corner drugstore. The computer keeps track of the person's location, and gives verbal directions on how to get there and when to avoid something.
The system responds with directions based on a starting point. It will tell the person to turn this way or that way, or how long to walk in one direction. If the person veers off course, the computer responds with a verbal correction. Any obstructions - say, a picnic table - are noted if their locations have been downloaded into the system.
"It can be fine-tuned," Moore said. "So if you wanted to be reminded of something, you could put it in there yourself. They're doing similar things with cars right now."
Scientists at Sandia National Laboratory in New Mexico have embarked on a more ambitious challenge - using nanotechnology to restore sight to people suffering from such eye diseases as macular degeneration and retinitis pigmentosa. These diseases damage rods and cones in the eye that normally convert light to electrical impulses, but leave intact the neural paths to the brain that transport signals.
These signals are the key, and so the team has designed an array packed with a thousand tiny electrodes. These arrays would be surgically implanted on a person's retinas, resting against nerve structures. If successful, the implants could restore a good part, but not all, of a person's vision.
"The aim is to bring a blind person to the point where he or she can read, move around objects in the house, and do basic household chores," said Sandia project leader Kurt Wessendorf. "The images will come a little slowly and appear yellow. But people who are blind will see."
The system includes a tiny camera and radio-frequency transmitter fixed on the frame of a pair of eyeglasses. The implants receive the signals and send them to the brain as electrical impulses. The idea is to directly stimulate some of the nerve endings within the retina, hopefully creating distinct images.
"Compared to the elegance of the original biological design, what we're doing is extremely crude," Wessendorf said. "We are trying to build electrode arrays that sit on the retina and stimulate the nerves that the eye's rods and cones formerly served."
The Sandia team is working with other researchers around the country to perfect the system. However, scientists don't yet know if the body will reject the arrays or how long the devices might work inside a human eye.
The project is funded by a $9 million, three-year grant from the Department of Energy's Office of Biological and Environmental Research.
Go to ...
Top of Page.
List of Categories.
Blind World Website
Designed and Maintained by:
All Rights Reserved.