"The results," said senior author of the paper, John Donoghue, professor and director of the brain science program at Brown University and chief scientific officer of Cyberkinetics, "hold promise to one day be able to activate limb muscles with these brain signals, effectively restoring brain-to-muscle control via a physical nervous system."
"Our researchers initiated the clinical trial with the hope of being able to develop a non-obtrusive system that would one day provide more freedom to those with severe paralysis," said Timothy Surgenor, president and CEO for Cyberkinetics. "We are eager to expand on this initial proof-of-concept toward one day providing improved independence and overall quality of life."
The BrainGate System consists of a 4x4 millimeter sensor, about the size of a baby aspirin, with 100 tiny electrodes, each thinner than a human hair. The sensor is implanted on the surface of the area of the brain responsible for voluntary movement, the motor cortex. The electrodes penetrate about 1 mm into the surface of the brain where they pick up electrical signals -- known as neural spiking, the language of the brain -- from nearby neurons and transmit them through thin gold wires to a titanium pedestal that protrudes about an inch above the patient's scalp. An external cable connects the pedestal to computers, signal processors and monitors.
Converting digitized intentions into meaningful action, however, is not simple. Active neurons fire between 20 and 200 times a second and they work in teams.
Although scientists have long been able to eavesdrop on individual nerve cells, before 1996 no one had developed a reliable system for directly collecting precise data from large groups of brain cells. That year, Donohue and his
Source:University of Chicago Medical Center