For the first time ever, a quadriplegic patient has had arm and hand function restored via electrodes implanted into the brain.
Bill Kochevar, paralyzed from the neck down due to a bicycle accident eight years ago, can now feed himself, scratch an itch, and gesture to friends simply by thinking about the movements. It’s a breakthrough for the high-injury level population that has historically lacked the technological options available to those with less extensive forms of paralysis.
Two arrays of 96 recording electrodes each were implanted near the top of Kochevar’s skull at the primary motor cortex, the area related to arm and hand function. The arrays themselves are quite small — four millimeters by four millimeters — with the electrodes themselves each about 1.5 millimeters long. Wires connect them to a functional electrical stimulation (FES) system that re-links his brain to the muscles in his arm and hand from which they’d previously been cut off. A paper detailing the research was published Tuesday in the journal The Lancet.
“We’ve shown it’s actually feasible to do this,” Bob Kirsch, lead author of the paper, tells Inverse. “We can record somebody’s intentions, decode those intentions, and then apply stimulation to the right muscles in the right patterns so when they think about a movement, it actually happens.”
Kochevar was chosen because of the extent of his injuries; Kirsch has been studying quadriplegia for the past 15 years. The combination meant that the research could help benefit patients who, like Kochevar, don’t have the alternative options for controlling stimuli that could help patients paralyzed from the waist down, in comparison.
There’s been other research into harnessing brain waves that could benefit severely paralyzed individuals, but much of it is a ways off. And while we have robots that can help disabled individuals stick to their daily routines and ones that can mimic human movement, this development cuts out the concept of an external party, allowing a quadriplegic like Kochevar to directly control his arm with his own brain.
Perhaps one day the technique could be modified to help individuals with quadriplegia walk again, but that goal is easier to accomplish for those with paraplegia, who still retain the ability to balance themselves with their upper body. For now, the focus is on hands and arms. After the success is replicated with other patients physically similar to Kochevar, the next step is to eliminate the physical connectors to the head and the rack of equipment that accompanies it.
“So this would be basically a wireless device that’s implanted and streams data out wirelessly to the system,” Kirsch says. “It’s not too far [off] — probably two or three years.”
People with chronic tetraplegia, due to high-cervical spinal cord injury, can regain limb movements through coordinated electrical stimulation of peripheral muscles and nerves, known as functional electrical stimulation (FES). Users typically command FES systems through other preserved, but unrelated and limited in number, volitional movements (eg, facial muscle activity, head movements, shoulder shrugs). We report the findings of an individual with traumatic high-cervical spinal cord injury who coordinated reaching and grasping movements using his own paralysed arm and hand, reanimated through implanted FES, and commanded using his own cortical signals through an intracortical brain–computer interface (iBCI).