A brain implant the size of a baby aspirin may soon change the lives of people with quadriplegia. The device, a four–millimeter square array of microelectrodes, sits inside the brain, where it records imagined arm and hand movements and transmits those neural signals to an external computer bank. The computers then translate the cortical imaginings into directions that guide a cursor on a computer screen.
Dubbed BrainGate, the prototype device has logged more than a thousand days of continuous performance in the brain of a paralyzed woman. The patient has maneuvered a cursor on a computer screen to perform point–and–click tasks with 90–percent accuracy and to hit targets the size of a typical computer menu icon.
This is a welcome milestone, says Leigh Hochberg, one of BrainGate’s principal investigators and an HMS visiting associate professor of neurology at Massachusetts General Hospital.“While there is still a lot of research to do, long–held hopes for chronic intracortical recording technologies are becoming a reality. This research is providing a glimpse into what might be possible.”
The research team has already demonstrated simple robotic limb, prosthetic hand, and wheelchair control through BrainGate2. Hochberg is now directing a feasibility study of the technology. The ongoing clinical trial, which will enroll up to 15 patients, is testing safety and examining whether patients might use the device for more complex tasks, such as operating an email program.