A study published in the online edition of The Lancet medical journal describes the creation of a brain-computer interface (BCI) and a set of training programs which allowed Ms Sheuermann, a quadriplegic from Pittburgh, to move an robotic arm, turn and bend the wrist, and close the fingers of the hand. Ms Sheuermann promptly fulfilled a promise she made when she first embarked on the study – by feeding herself a bar of chocolate.
Previous BCI technology has allowed patients to control a pointer on a computer screen and make limited movements of a robotic arm, but this latest study is a big step forward for the technology.
“This is a spectacular leap toward greater function and independence for people who are unable to move their own arms,” said senior investigator Andrew B. Schwartz, Ph.D., professor, Department of Neurobiology, Pitt School of Medicine. “This technology, which interprets brain signals to guide a robot arm, has enormous potential that we are continuing to explore. Our study has shown us that it is technically feasible to restore ability; the participants have told us that BCI gives them hope for the future.”
Two quarter inch electrode grids, each one containing 96 tiny contact points, were implanted in the regions of Ms Sheuermann’s brain which would usually control right arm and hand movement. These grids were then able to communicate with a computer to allow the patient to control a robotic arm.
Within a week of the operation Ms Sheuermann could move the arm in and out, left and right, up and down. “What we did in the first week they thought we’d be stuck on for a month,” she said. Within three months she had complete control of the arm, allowing her to enjoy a bar of chocolate without assistance.
The next step for this exciting technology will be the development of two-way electrode systems which not only capture the intention to move, but also generate sensation by stimulating the brain, allowing users to experience sensory information.
“We’re hoping this can become a fully implanted, wireless system that people can actually use in their homes without our supervision,” said Dr. Collinger. “It might even be possible to combine brain control with a device that directly stimulates muscles to restore movement of the individual’s own limb.”