Implants link paralyzed man's arm to his brain to restore movement
A man paralyzed from the shoulders down in a bicycle accident eight years ago has regained movement in his arms and hands, thanks to a combination of cutting-edge technologies. By implanting electrodes under Bill Kochevar's skull and others into in his arm, the 56-year-old has reconnected his brain with his paralyzed muscles and can now perform certain everyday tasks like drinking water and eating food.
The system, dubbed BrainGate2, is the latest iteration of a technology that has been under development for decades. It involves planting two aspirin-sized 96-channel electrode arrays into the brain's motor cortex, where they monitor brain signals as the subject imagines making certain movements. Just last month, the system was used to help mobility impaired individuals move a cursor on a screen using only their brains to type out messages.
In this case, it was a matter of tracking Kochevar's brain activity as he thought about moving an arm and hand, and this was first done using a virtual reality version on a computer screen. This was mastered over a period of around four months, at which point scientists from Case Western Reserve University, who led the research, decided he was ready for the real thing.
The scientists then implanted a functional electrical stimulation (FES) system, which consists of 36 electrodes designed to animate the muscles in his upper and lower arm. This takes its commands from the brain implant, which decodes the electric signals and translates them into intended movements, with the FES delivering the electric pulses to the arm. These in turn trigger the muscles that control Kochevar's hand, wrist, arm, elbow and shoulder.
The process involved considerable rehabilitation of the muscles in Kochevar's arm, taking about a year. He can now make each joint in his right arm move individually using a mobile arm support (also brain-controlled) to overcome gravity. He is at the point where just by thinking about feeding himself or taking a drink, the muscles kick into gear and act in coordination, allowing him to eat spoonfuls of mashed potatoes, scratch his nose with a sponge and grab a mug of water.
"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 Kochevar. "It's better than I thought it would be."
The breakthrough calls to mind a success story from last year, where a paralyzed man named Ian Burkhart used a similar system called NeuroLife to bypass the injured spinal cord and regain the ability to handle everyday objects. He can now swipe credit cards, stir drinks and play a Guitar Hero-style video game.
Like NeuroLife, BrainGate2 is a an ongoing project and, buoyed by Kochevar's success, the scientists behind it now have high hopes for its future. This research project is part of a pilot clinical trial and the team says it represents early feasibility, with the advances needed to take the tech out of the lab not all that far from reality. It is currently working to make the brain implant wireless and continuing to improve the decoding and simulation patterns, which will allow for more precise movements.
"It's been so inspiring to watch Mr Kochevar move his own arm and hand just by thinking about it," said Leigh Hochberg, a neurologist and neuroengineer at Massachusetts General Hospital and co-author of the study. "As an extraordinary participant in this research, he's teaching us how to design a new generation of neurotechnologies that we all hope will one day restore mobility and independence for people with paralysis."
The research was published in the journal The Lancet, while you can hear from those involved in the project below.
Source: Case Western Reserve University