French researchers have developed a device they hope will end the isolation of quadriplegics who can't communicate: It allows them to literally write with their eyes.
As the patient looks at a special keyboard, a laser-guided camera records the gaze as the patient's eye moves from letter to letter. The camera feeds the selected letters into a computer, and the text appears instantaneously on a computer screen.Within a year, researchers expect the device will be fine-tuned to allow paralyzed people to turn on the TV, the radio or the lights, shut the door or even log on to the Internet. They'll do it all by simply gazing at a control panel.
"It was conceived for people who have nothing but their eyes left," said Thierry Saniez, head of the project that developed the device. "Such people live in enormous distress and isolation. For them, it's an extraordinary thing. It allows them to have an opening on a world that today is completely closed to them."
The result of five years of research, the device was first displayed this week at a Paris exhibition on language-learning techniques.
Saniez is co-manager of Association Delta 7, a humanitarian group that, among other things, focuses on alleviating the suffering of paralyzed people. The group coordinated and found funding for the project. The device was conceived by scientists at the National Health and Medical Research Institute in Lille.
Neurologist Robert Daroff, editor of the respected U.S. journal Neurology and chief of staff at University Hospitals of Cleveland, praised the new technique.
"Imagine being paralyzed, unable to communicate. You can't make your thoughts known. This would be terrific," Daroff said in a telephone interview Wednesday. "This would be the most sophisticated system developed for paralyzed persons to communicate."
However, he said, the system won't work for all quadriplegics.
"There's the presupposition that the eye movements are normal with people who can't move their limbs. People in that condition frequently have difficulty with eye movements, too," he said.
The Deltavision device is simple to use. A camera in the middle of a visual keyboard facing the patient focuses on the eye. A red beam reflects eye movement back to the machine. Users need only look at a key for less than a second for it to register, and can write about 50 characters per minute.
"The movements of your cornea are analyzed to determine exactly what part of the keyboard you're looking at," Saniez said. "But in passing from left to right, you don't register the letters you don't look at. Only the ones you stop on."
The technique has been successfully used by 100 quadriplegics in pilot projects at rehabilitation centers in Nantes, Le Mans and Bordeaux, he said.
The prototypes cost $20,000, but once the device is marketed, possibly next year, Association Delta 7 expects the price to go down because of larger-scale production.