Cambridge Newspapers Ltd ©2005

Professor Stephen Hawking is using a new gadget to communicate by blinking - due to his deteriorating health.

The world famous physicist, 63, who is Britain's longest surviving sufferer of the debilitating motor neurone disease, has for years used one hand to control the computer system which operates his voice.

But his hand is getting weaker and he is now using a new high-tech gadget, which allows him to control the computer simply by blinking his eye.

David Pond, Prof Hawking's graduate assistant at Cambridge University, said: "His hand has been slowing down.

"He wants to fight all the way but he recognises he needs a better way to communicate. He started using the switch two months ago. It's very simple to use and it's going really well."

The Infrared/Sound/Touch (IST) switch, developed by the American company Words+, emits a very low-powered infrared beam. The reflection of the beam changes when the eye is closed and the cheek muscle moves and so controlling the computer is as simple as blinking.

It is attached to Professor Hawking's glasses an inch from his cheek to detect the moving muscle.

Experts at the Electronics Department at Cambridge University are now working on making the gadget smaller and more user friendly.

Design engineer Richard Taylor said: "It's quite a large challenge in terms of making something that's more reliable. That will be the most difficult part. In terms of making it less obtrusive that should be much easier.

"We are currently at the research stage so it's difficult at the moment to know how much work this will require."

Last year Professor Hawking spent a month at the specialist sleep disorder unit at Papworth Hospital but returned to work full time at Cambridge University's Department of Applied Mathematics and Theoretical Physics.

He had previously spent several weeks at Addenbrooke's Hospital in Cambridge after contracting pneumonia.

He lives with his second wife Elaine in the Newnham area of the city and has round-the-clock medical attention from a team of nurses.