Paralysed man able to control robotic arm by thought

A MAN paralysed from the neck down has shown he can open email, control a TV and move objects with a robotic arm by thought alone.

The 25-year-old American Matthew Nagle had a computer-linked implant placed in his brain that enabled him to operate devices just by thinking about it.

Brain-computer interfaces have been demonstrated before in humans and animals. But this is the biggest step taken so far towards developing “bionic” systems that can restore motor function in people who have lost control of their limbs.

In the 1970s TV series The Six Million Dollar Man, scientists rebuilt the body of crash victim Steve Austin with bionic prosthetics controlled by his mind.

At the time the concept was pure fantasy, but in future thought-controlled replacement limbs could be made real.

The results described in the journal Nature represent the culmination of decades of work.

However, the scientists involved in the research stress that the technology is still in its infancy.

Mr Nagle, from Massachusetts, whose spinal cord was severed in 2001, received his implant at Rhode Island Hospital in 2004.

Known as the BrainGate Neural Interface System, it consists of an array of electrodes that record neural activity from the motor cortex of the brain.

Signals from the implant are decoded and processed by a computer, allowing them to be translated into movement commands.

First, Mr Nagle learned to move a computer cursor by focusing his thoughts on the task. Later, during 57 trial sessions at the New England Sinai Hospital and Rehabilitation Centre in Massachusetts, he greatly expanded his repertoire of thought control.

He was able to open simulated email, draw circular shapes on the computer screen, play a simple video game, and change the channel and adjust the volume on a television.