Prosthetic limbs that users control with their minds aren’t yet widely available, but several have been shown to work. Soldiers returning from the wars in Iraq and Afghanistan have made amputeeism a much more prevalent disability, and one with enough funding to drive innovative solutions.
Those who are paralyzed have remained more difficult to help because human nerves and muscles require more intricate forms of control than the simplified prosthetic devices.
But BrainGate, a program that pools research from several universities, is moving ever closer to giving paralyzed patients use of their limbs by using the same technology developed to drive computerized prosthetics to drive the paralyzed limbs.
BrainGate is developing a system in which a patient’s mental signal to move an arm is recorded, filtered through a computer and sent as a command to an electric stimulation device that activates the patient’s muscles.
An implanted 16-channel sensor records the patient’s brain signals looking for those related to limb movement and sends it wirelessly to a computer. There, an algorithm designed to recognize motion-related signals translates the information into a command for an electrical stimulation device that prods the muscles used in the motion the patient envisioned. The stimulator can spur as many as 18 hand and arm muscles into action.
“The patient thinks ‘up and to the right,’ and we have a controller that actually figures out the correct muscle activations to move in that direction,” Robert Kirsch, a project collaborator, chair of biomedical engineering at Case Western and executive director of the Department of Veterans Affairs Functional Electrical Stimulation Center, told the MIT Technology Review.