New Device Allows Paralyzed Man to Move His Arm With His Mind
The brain implant bypasses the patient’s injured spinal cord, allowing him to eat and drink on his own
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This week, researchers from Case Western Reserve University and the Cleveland Functional Electrical Stimulation Center revealed a brain implant system that allows a paralyzed man to move his arm and hand with just his thoughts, reports Julie Steenhuysen at Reuters.
This brain-computer interface allowed 56-year-old Bill Kochevar, who was paralyzed from his shoulders down in a bicycle accident, to move his own arm and even feed himself—something he has not been able to do for eight years.
“I thought about moving my arm and I could move it. I ate a pretzel, I drank water," Kochevar says in a video press release. “It’s pretty cool. You get to be the first one in the world to do it. Now we can tell the world, it’s possible to reconnect the brain and make the arm move again.”
As Jon Hamilton at NPR explains, a spinal cord injury often makes it impossible for signals from the brain to reach muscles in the body. The new system, called BrainGate2, works around that problem. The researchers published their results this week in The Lancet.
The researchers implanted two sensors on the surface of Kochevar's motor cortex, each about the size of a small pill containing 96 electrodes, reports Steenhuysen. Those sensors monitor neural activity in the brain, sending the signals to a computer. “We have an algorithm that sort of transforms those neural signals into the movements he intended to make," Robert Kirsch, a professor of biomedical engineering at Case Western and co-author of the paper, tells Hamilton.
Another 36 electrodes implanted in Kochevar’s muscles relay his thoughts to his arm. Hamilton reports that the system allows Kochevar to extend his arm and grab onto objects. He’s even figured out how to scratch his nose with the aid of a mind-controlled arm support.
But learning to use the device wasn't easy. According to a press release, the team worked with Kochevar for 45 weeks, using the electrodes to stimulate and strengthen his atrophied muscles. Kochevar also practiced his movements with the computer algorithm to help it learn his brainwave patterns.
The current version of the system is considered a proof of concept and won’t go beyond the research lab. “I think what we've done, though, is shown that we can put this all together and it's feasible," Kirsch tells Hamilton. “We can actually record signals from his brain, determine what he's trying to do and make that happen.”
But the researchers say in the press release that they hope the project will lead to a functional model in the near future. Improvements they hope to add include wireless brain implants and stimulation to add precision to the movements.
“We actually have a handle on everything that we need,” lead author Abidemi Bolu Ajiboye tells Susan Scutti at CNN. “There are no significant novel discoveries we need to make for the system.”
Not everyone is as optimistic that the system is ready for prime time. Associate professor at University of Washington in Seattle Steve I. Perlmutter wrote in a commentary alongside the study that although the work is "groundbreaking," it is "not nearly ready for use outside the lab.”
He tells Scutti that Kochevar’s movements were “slow and rough” and that direct stimulation of muscles is probably not the way to go. He believes that figuring out how to stimulate the spinal cord or nerves is preferable.
Even so, the work marks a major milestone in the development of prostheses that could one day give paralyzed people more control over their world.