A man paralysed from the shoulders down has managed to move his arm for the first time in years after scientists created an artificial connection to his brain.
Bill Kochevar, 56, who lost the use of almost his entire body when he was hurt in a cycling accident eight years ago, had electrodes fitted to the part of his brain that controls motor skills.
These were connected to a brain-computer interface, which can interpret his thoughts and send messages to other electrodes designed to stimulate the muscles in his right arm and hand.
The result is that Mr Kochevar, of Cleveland, Ohio, is now able to eat mashed potato with a fork or drink coffee simply by thinking about wanting to do it.
His movements are slow and awkward and his arm is in a sling, but the effect is dramatic.
“For somebody who’s been injured eight years and couldn’t move, being able to move just that little bit is awesome to me,” said Mr Kochevar, who first started using the system about two years ago.
“It’s better than I thought it would be.
“It’s probably a good thing that I’m making it move without having to really concentrate hard at it.
“I just think ‘out’ and it just goes.”
The scientists involved, who described the system in a paper in the journal The Lancet, said it was the first time someone with complete paralysis had been able to reach out and grasp something using a brain-controlled implant in this way.
Dr Bolu Ajiboye, of Case Western Reserve University in the US, said: “Our research is at an early stage, but we believe that this neuro-prosthesis could offer individuals with paralysis the possibility of regaining arm and hand functions to perform day-to-day activities, offering them greater independence.
“So far it has helped a man with tetraplegia to reach and grasp, meaning he could feed himself and drink.
“With further development, we believe the technology could give more accurate control, allowing a wider range of actions, which could begin to transform the lives of people living with paralysis.
“Although similar systems have been used before, none of them have been as easy to adopt for day-to-day use and they have not been able to restore both reaching and grasping actions.”
He said it should be possible to build a fully implanted and wireless brain-computer interface to control the movements.
“This could lead to enhanced performance of the neuro-prosthesis with better speed, precision and control,” Dr Ajiboye added.
The researchers cautioned that the movements made using the system were slower and less accurate than ones made using a virtual reality arm used during training.
Mr Kochevar also had to watch his arm, because he does not have an intuitive sense of where it is as a result of his paralysis.
Writing in a commentary in The Lancet, Dr Steve Perlmutter, of the University of Washington, said the treatment was “not nearly ready for use outside the lab” as the movements were “rough and slow and required continuous visual feedback”.
But the research was nonetheless “groundbreaking”, he added.
“The goal is futuristic: a paralysed individual thinks about moving her arm as if her brain and muscles were not disconnected, and implanted technology seamlessly executes the desired movement,” he wrote.
“The study is a proof-of-principle demonstration of what is possible, rather than a fundamental advance in neuro-prosthetic concepts or technology.
“But it is an exciting demonstration nonetheless, and the future of motor neuro-prosthetics to overcome paralysis is brighter.”