I thought Anthony Lloyd was wearing a black eyepatch when I met him. Except it was in the middle of his forehead, and both his eyes seemed fine. Then I noticed another eyepatch, this one on his wrist, attached by some wires to a small pack on his waist. Plugged into a nearby PC was what looked like a small radio.
The two "eyepatches", he explained, are the components of the hands-free mouse, whose signals are picked up by the radio. And to prove it he started playing "Quake", a computer game in which you use your mouse to manoeuvre up and down and around corridors, and click its buttons to fire a gun. Except that Mr Lloyd was just tilting his head slightly, and pulling an imaginary trigger. It looked even more realistic when he projected the screen image on to a wall.
"When I demonstrated this at a computer show recently, I ... had hundreds of kids who wanted to try it. They wouldn't stop asking. I left with a list a yard long of children who wanted one," said Mr Lloyd head of sales for BioControl Systems, of Palo Alto, California, which is marketing the device.
"The mouse has been around 20 years and it hasn't changed. But when you change the interface, you change the medium. That's happening already: people are increasingly talking about wearable computers. This is a 21st- century technology," he said.
The hands-free mouse works by detecting the tiny electrical currents on the surface of the skin created by the action of muscles by the nerves - rather like the heart or brain monitors used in hospitals.
Using software, those currents can be converted into instructions to move the mouse up and down and from side to side. The other "patch" on the arm can activate a mouse "click" if the forearm is tensed.
It should be on sale in the US for about $250 (pounds 150) next spring, and available in Britain from the summer.Reuse content