Bionic Leg Controlled By Brain Power
So important I had to share this. Video at link of Vawter walking with this amazing prosthetic.
Two articles included. LA Times and Reuters
Bionic leg is controlled by brain power
By Melissa Healy
September 25, 2013, 5:45 p.m.
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Before Vawter could strap on the bionic lower limb, engineers in Chicago had to "teach" the prosthetic how to read his motor intentions from tiny muscle contractions in his right thigh.
At the institute's Center for Bionic Medicine, Vawter spent countless hours with his thigh wired up with electrodes, imagining making certain movements on command with his missing knee, ankle and foot.
Using pattern-recognition software, engineers discerned, distilled and digitized those recorded electrical signals to catalog an entire repertoire of movements. The prosthetic could thus be programmed to recognize the subtlest contraction of a muscle in Vawter's thigh as a specific motor command.
Given surgical practices still in wide use, the prospects for such a connection between a patient's prosthetic and his or her peripheral nerves are generally dim. In most amputations, the nerves in the thigh are left to languish or die.
Dr. Todd Kuiken, a neurosurgeon at the rehabilitation institute, pioneered a practice called "reinervation" of nerves severed by amputation, and Vawter's orthopedic surgeon at the University of Washington Medical Center was trained to conduct the delicate operation. Dr. Douglas Smith rewired the severed nerves to control some of the muscles in Vawter's thigh that would be used less frequently in the absence of his lower leg.
Within a few months of the amputation, those nerves had recovered from the shock of the injury and begun to regenerate and carry electrical impulses. When Vawter thought about flexing his right foot in a particular way, the rerouted nerve endings would consistently cause a distinctive contraction in his hamstring. When he pondered how he would position his foot on a stair step and ready it for the weight of his body, the muscle contraction would be elsewhere — but equally consistent.
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http://www.latimes.com/science/la-sci-robotic-leg-20130926,0,7310017.story
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The robotic leg is being developed with an $8 million grant from the U.S. Army. There are more than one million lower leg amputees in the U.S.
Troy Turner, a member of the scientific advisory panel of The Amputee Coalition in Manassas, Virginia, said the project "represents the first true effort at letting someone control their prosthetic leg in a way that's very similar to biologic control."
Turner, who is a rehabilitation and human performance portfolio manager with the U.S. Army's Medical Research and Materiel Command in Fort Detrick, Maryland, estimated that only about four to six groups are researching the problem on this high level.
"I think this will be the first real successful effort in making it commercializable. It also lays the groundwork for a lot of continued efforts in taking this concept much further," he said.
A similar system has been used in robotic arms for years. But the challenge is greater in developing a robotic leg, according to Hargrove, because users of a robotic arm don't face a serious risk of falling if the signals are misread.
http://www.reuters.com/article/2013/09/25/us-robotic-leg-idUSBRE98O16L20130925