Paralysed man can now lift objects with his mind using thought-control technology
Thought-control technology has brought American Bill Kochevar's immovable right arm and hand back to life after eight years.
Mr Kochevar, who was paralysed below his shoulders in a bicycling accident, can now grasp and lift objects.
In one test, he slowly raised a mug of water to his lips and drank from a straw. Another saw him scoop forkfuls of mashed potato from a bowl.
He is believed to be the first person in the world with quadriplegia to have arm and hand movement restored by two kinds of implant.
Electrodes under his skull record the activity of brain neurons to generate signals that tell another device to stimulate muscles in the paralysed limb.
Mr Kochevar, 56, from Cleveland, Ohio, said: "For somebody who's been injured eight years and couldn't move, being able to move just that little bit is awesome to me.
"It's better than I thought it would be."
A report on his progress appears in the latest issue of The Lancet medical journal.
Principal investigator Dr Bob Kirsch, from Case Western Reserve University in the US, said: "He's really breaking ground for the spinal cord injury community.
"This is a major step toward restoring some independence."
Mr Kochevar is a participant in the on-going BrainGate2 trial looking at the safety and feasibility of using brain-computer interface systems to help people paralysed by spinal injuries.
Other BrainGate research has demonstrated the "mind control" of cursors on computer screens and robotic arms.
A team of surgeons implanted two pill-sized 96-channel electrode arrays on the surface of the motor cortex region of Mr Kochevar's brain.
The arrays record brain signals generated by imagined movements of the arm and hand.
Information about movements Mr Kochevar intends to make are filtered out of the signals and used to command the functional electrical stimulation (FES) muscle activation system.
In preparation, Mr Kochevar first learned how to use his brain signals to move a virtual-reality arm on a computer screen.
"He was able to do it within a few minutes," said Dr Kirsch said. "The code was still in his brain."
After four months of practice, it was time for him to take control of his own arm and hand.
At that stage the 36-electrodes of the FES device were implanted in Mr Kochevar's upper and lower right arm.
Pulses sent through the electrodes trigger muscles regulating movement of the hand, wrist, arm, elbow and shoulder.
To counterbalance the force of gravity, which would otherwise drag his arm down, Mr Kochever was fitted with a mobile support also under his brain's control.
Using the system, Mr Kochevar is able to activate his muscles in a co-ordinated fashion.
He told the researchers: "I'm making it move without having to really concentrate hard at it .. I just think 'out' .. and it goes."
BrainGate2 clinical principal investigator Dr Benjamin Walter, from Case Western Reserve School of Medicine, said: "Every day, most of us take for granted that when we will to move, we can move any part of our body with precision and control in multiple directions and those with traumatic spinal cord injury or any other form of paralysis cannot.
"The ultimate hope of any of these individuals is to restore this function.
"By restoring the communication of the will to move from the brain directly to the body, this work will hopefully begin to restore the hope of millions of paralysed individuals that someday they will be able to move freely again."