Researchers Create First Mind-controlled Bionic Leg

Researchers have developed the world's first mind-controlled bionic leg -- an innovation that could mean significant improvements in the lives of the estimated 1 million Americans with leg amputations. Previously, only thought-controlled bionic arms were available to amputees.

The new system, developed by scientists at the Rehabilitation Institute of Chicago (RIC), uses neural signals and a specially designed computer program to safely control the limb.

The case study regarding the invention focuses on Zac Vawter, an amputee who underwent a surgery pioneered by RIC and Northwestern University in 2009 designed to redirect nerves from damaged muscle in the patient's amputated limb to muscle located above the knee.

Called muscle reinnervation surgery, the procedure made it so whenever the redirected nerves instruct the muscles to contract, this message is received in the form of tiny electrical signals by a sensor on Vawter's leg. These signals are then decoded and sent in the form of a command to the robotic leg.

"This new bionic leg features incredibly intelligent engineering," Levi Hargrove, the lead scientist behind the research, said in a statement. "It learns and performs activities unprecedented for any leg amputee, including seamless transitions between sitting, walking, ascending and descending stairs and ramps and repositioning the leg while seated."

Vawter calls the innovation a "big improvement" in comparison to his prosthetic leg, which he has worn for years.

"The bionic leg responds quickly and more appropriately, allowing me to interact with my environment in a way that is similar to how I moved before my amputation," he said, adding that it "allows me to seamlessly walk up and down stairs and even reposition the prosthetic by thinking about the movement I want to perform. This is a huge milestone for me and for all leg amputees."

For video of Vawter using the bionic leg, click here.