The technology is being tested on patients in Plymouth

British scientists are developing a microchip which gives people with prosthetic arms greater control over these limbs.

The technology works by turning thought processes in the brain into actual physical movements.

Many people who have lost their arms still have some movement in the surrounding muscles.

Brain signals

They can flex these muscles as if they were trying to move their arms.

Many people already have high-tech prosthetic arms which can read this flexing, enabling them to open or close their hand.

Our ultimate goal is to have a full multi-functional hand Professor Roland Burns

But scientists at Advanced Control Research in Plymouth have developed a new microchip which can read more of these signals and enable users to move their artificial arms much more freely.

The microchip, which is placed inside the prosthesis, can read up to four different signals at any one time.

This enables users to not only open or close their hand but also to move their wrist and elbow.

Preliminary trials on patients at Plymouth and Derriford Hospital have shown that the technology is effective and easy to use.

Scientists are now planning to carry out further trials over the coming months, with a view to making the technology more widely available.

Greater movement

Professor Roland Burns, a director at Advanced Control Research, said the technology would have major benefits for people who use artificial arms.

"It will give them a greater range of movements," he told BBC News Online.

The technology is much more advanced than anything currently available to most people using artificial arms.

"With existing hardware on the market, we can utilise existing open and closing of the hand and combine it with our elbow and wrist movements," Professor Burns said.

"What we can do is look at the signal and the information contained in that signal and through a pattern recognition system, which is related to what the amputee is thinking, we can use this to command the wrist to rotate or the index finger to move."

Professor Burns said advances in technology could one day give people with artificial arms full control over their limbs.

"Our ultimate goal is to have a full multi-functional hand but that is a little way from the market place at the moment," he said.

The scientists have received £65,000 from the National Endowment for Science, Technology & the Arts (Nesta) to help them develop the technology.

Its chief executive Jeremy Newton said: "ACR is a wonderful example of the type of innovation that can go unseen in the UK, the type of new idea, method or product that Nesta is here to support.