A man who was paralyzed from the shoulders down has learned to feed himself and drink, thanks to a robotic arm he controls with his brain.
The 53-year-old man had been completely paralyzed due to a traumatic neck injury eight years before. He agreed to undergo surgery to have an experimental “neuro-prosthesis” fitted.
The surgery involved placing sensors in the area of his brain responsible for arm movement, called the motor cortex. He then had another surgery to place 36 muscle-stimulating electrodes under the skin of his upper and lower right arm.
At first, only the arm and hand electrodes were switched on to begin began stimulating the man’s muscles for a few hours a day to build up his strength and movement.
Researchers from Case Western Reserve University in Ohio then connected the arm electrodes and the brain sensors together and began using a decoder to translate his brain signals into commands for the electrodes in his arm. The electrodes stimulated the muscles to contract, helping the man to learn to complete the movements he was thinking of.
After a full year of practising with the neuro-prosthesis, he began to try everyday tasks.
First, he watched closely while his arm was placed under computer control to do such things as grabbing a cup of coffee. As he did, he thought about making the same movement. Then he tried the movements himself.
First, he attempted to grab a cup of coffee and bring it to his mouth. He moved slowly, taking 20 to 40 seconds to complete the task, but was successful in getting a drink from the cup in 11 out of the 12 attempts.
He then attempted to feed himself and was able to successfully scoop several forkfuls of food and navigate them to his mouth.
The researchers say while they have tested their system in only one participant, they believe the work is a major advance in helping someone with paralysis circumvent their injuries through technology.
The full report on the project appears in The Lancet.
The authors admit the technology isn’t perfect and the man’s movements were slow and not always accurate. The man also needed to concentrate hard and watch his arm the whole time since he no longer had an intuitive sense of the position of his limbs because of the paralysis. But they hope to continue to improve the system.
“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,” lead author Bolu Ajiboye said in a statement.
Steve Perlmutter, who works in computational neuroscience at the University of Washington, says while the technology the Case Western team developed is still clunky, their research is a good “proof-of-principle demonstration of what is possible,” adding “the future of motor neuro-prosthetics to overcome paralysis is brighter.”
