Ian Burkhart is a 24 year-old quadriplegic who broke his neck in a swimming accident in the Outer Banks of North Carolina. He has rebounded to coach lacrosse and study for a business degree. But Burkhart is much, much more than a successful lacrosse coach. That’s because with help of a research team of physicians, surgeons and engineers, Burkhart became the first person to use brain implant technology to regain memory of paralyzed muscles.
In a paper released this week by the journal Nature, researchers from The Ohio State University Neurological Institute and Battelle Memorial Institute describe their experience with Burkhart. The research team is on the cusp of a new frontier for paralyzed people. In the past, researchers have created robotic limbs, computers and other mechanical devices that paralyzed people could control with other muscles they could still move.
What makes Burkhart different is that he is using his own muscles to perform tasks like strumming a guitar, picking up a bottle and pouring it and swiping a credit card through a card reader. This is part of a stunning development in medical research that uses brain implants to stimulate an actually frozen muscle. Right now Burkhart can only perform these tasks in a lab a few times a week, when he is connected to an experimental device which is able to interpret his brain signals and then stimulate his muscle with electrodes. The hundreds of electrodes are hooked to Burkhart’s forearm.
The research team hope that as the device improves, it can eventually be added to the list of devices that paralyzed people can take home to use in their every day lives. Burkhart was a college freshman when had his swimming accident six years ago, slamming his head into a sandbar. He is paralyze from mid-chest down and has no use of his arms below the elbows.
In 2014, surgeons put a small device inside Burkhart’s brain stem. It includes 96 electrodes that penetrate just below the surface of his head. The device is able to monitor a small population of brain cells in the region of the brain that controls movement of Burkhart’s right hand. This device samples the activity an amazing 3 million times a second.
“We’re really just eavesdropping on a few conversations between those neurons and we’re trying to figure out what they’re talking about,” said Chad Bouton, one of the authors of the Nature paper who worked on the project.
During Burkhart’s time in the lab, he is connected to a cable from a small port in his skull, which in turn carries signals from the sensor to a computer. The computer’s job is to interpret the movement that Burkhart is telling his brain to accomplish. Once the computer interprets the signals, it sends commands to an array of up to 160 electrodes which are strapped to Burkhart’s forearm. The electrical stimulation from those electrodes are able to activate the hand and finger muscles.
Dr. Ali Rezai, one of the study’s authors and a neurosurgeon at Ohio State, said the technology is essentially “taking one’s thoughts and, within milliseconds, linking it to concrete movements.”
For Burkhart, the stimulation is taxing. During the first months of the studies he was mentally exhausted from concentrating on which muscles he needed to move. However, now he describes it is much easier. The stimulation feels like a slight tingle or buzz, according to Burkhart, who confirms that he has a small amount of sensation in his arm. He can also feel his arm getting tired.
Dr. Rezai said the computer system learning from Burkhart and vice versa, which is helping Burkhart to become more fluid in his movements as well as gaining speed in his abilities.
As for what could be done to improve the technology, researchers sad replacing the forearm electrodes with implanted ones, placing electrodes on or just under the scalp instead of in the brain, and making all connections wireless would help make the technology home-based.