Paralyzed People Using Computers, Amputees Controlling Bionic Limbs, With Microelectrodes On (Not In) Brain

Photo: Microwires emerging from the green and orange tubes connect to two arrays of 16 microelectrodes. Each array is embedded in a small mat of clear, rubbery silicone. The mats are barely visible in this image. These microelectrode arrays sit on the brain without penetrating it, a step toward longer-lived, less invasive versions of "neural interfaces" that in recent experiments elsewhere have allowed paralyzed people to control a computer cursor with their thoughts. The new microeletrode arrays were placed in two patients at the University of Utah who already were undergoing brain surgery for severe epilepsy. The larger, numbered, metallic electrodes are used to locate the source of epileptic seizures in the brain, so the patients allowed the micoelectrodes to be placed on their brains at the same time. (Credit: University of Utah Department of Neurosurgery)

From Science Daily:

ScienceDaily (July 6, 2009) — Experimental devices that read brain signals have helped paralyzed people use computers and may let amputees control bionic limbs. But existing devices use tiny electrodes that poke into the brain. Now, a University of Utah study shows that brain signals controlling arm movements can be detected accurately using new microelectrodes that sit on the brain but don't penetrate it.

"The unique thing about this technology is that it provides lots of information out of the brain without having to put the electrodes into the brain," says Bradley Greger, an assistant professor of bioengineering and coauthor of the study. "That lets neurosurgeons put this device under the skull but over brain areas where it would be risky to place penetrating electrodes: areas that control speech, memory and other cognitive functions."

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