Movement Lost and Found
Eight years ago, Bill Kochevar was paralyzed in a cycling accident. Since then, he hasn't been able to move anything below his shoulders — until now.
As part of a trial at Case Western Reserve University, two tiny, 96-channel electrodes were implanted in the motor cortex of Kochevar's brain. Essentially, the electrodes register the actions of his neurons and respond by signaling a device that stimulates his arm muscles. The system has given him the ability to grasp and lift things the same way he used to, by simply “thinking” the command to his body. He can now drink through a straw after raising a mug of water to his mouth and eat mashed potatoes with a fork.
Kochevar prepared for the trials by learning how to move a virtual reality (VR) arm on a computer using his mind. He practiced this for four months, after which 36 electrodes were surgically implanted into his right arm. The electrodes were strategically placed to control the movement of his upper and lower arm, elbow, hand, shoulder, and wrist.
Now, when Kochevar thinks about moving his arm, the brain signals travel to the brain-computer interface (BCI), which decodes and translates them into commands for intended movements. Those commands are then converted again into patterns of electrical pulses by the Functional Electrical Stimulation (FES) system in his arm. The pulses stimulate the electrodes, which move the muscles.
Will to Move
The research team says that advances needed to use the technology outside of a lab setting are not far from reality.
The brain implant would need to be wireless, but work on that is already underway. The movements themselves would also need to be more precise. That will be achieved once the investigators improve the stimulation and decoding patterns. FES systems that are entirely implantable are already being tested in other clinical research, as well.
“Every day, most of us take for granted that when we will to move, we can move any part of our body with precision and control in multiple directions, and those with traumatic spinal cord injury or any other form of paralysis cannot,” Case Western Reserve School of Medicine associate professor of neurology Benjamin Walter told The Daily Case. “By restoring the communication of the will to move from the brain directly to the body, this work will hopefully begin to restore the hope of millions of paralyzed individuals that someday they will be able to move freely again.”
“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.”