Thanks to an electrical implant in his brain, a paralyzed man was able to successfully move his arm and hand using his own brain signals. The Case Western Reserve University scientists behind the test say it marks the first time that signals originating in the brain have been redirected to electrodes in someone’s arm to restore movement.
The project started nine months ago, when surgeons inserted two bunches of silicon electrodes called Utah arrays (pictured above) into the volunteer’s motor cortex. The wires were threaded through metal ports attached to the skull and hooked up to computers that could interpret his brain signals. These signals were then directed to the volunteer’s right arm and hand where doctors had implanted electrodes that responded to his impulses by causing certain muscles to contract. This is known as functional electrical stimulation, or FES, and it allowed the volunteer to move his shoulder, elbow, and wrist despite being paralyzed.
Similar brain-implant studies have been done in the past, including ones that have allowed subjects to control computer cursors and robotic arms. Last year, a man with a partially paralyzed arm was able to successfully open and close his hand using electrodes placed on the outside of his limb. The latest test took this idea to the next level by using surgically implanted electrodes to help restore movement in a fully paralyzed arm.
Though the results represent a huge breakthrough for people with paralysis, the technology still has a long way to go. The volunteer’s arm muscles had atrophied from being paralyzed for so long, causing his movements to be rough and awkward. But when he used the brain implants to control a simulation of his arm on a screen, scientists say his virtual performance was pretty much perfect. The project is a vital step towards technology that can transmit signals from brain implants to internal electrodes wirelessly. Though it's a far way off, the ultimate goal is a system that grants full mobility to paralyzed individuals.
[h/t: MIT Technology Review]