Nerve-Connected Prosthetic Leg Responds To Wearer’s Thoughts

By Brent McKnight | Published

This article is more than 2 years old

A medical breakthrough, years in the making, is now one step closer to coming to fruition, in the form of bionic prosthetics that wearers can control with their thoughts.

Zac Vawter tests his bionic leg.

Thirty-one-year-old Zac Vawter, a software engineer from Yelm, Washington, lost his leg in a 2009 motorcycle accident. In the wake of his injury, researchers at the Rehabilitation Institute of Chicago equipped him with a state-of-the-art prosthetic that responds to the electrical impulses from the nerves and muscles of Vawter’s upper thigh. This control allows him an increased range of movement, including the ability to climb stairs.

Vawter said, “The first time that we went up and down stairs was a little clunky and not particularly smooth…Now I’m comfortable taking a hand off of the railing.”

This past weekend, he set out to participate in the “SkyRise Chicago” challenge, where contestants climb the 2,700 stairs of the Willis Tower to raise money or charity, the RHC in this instance.

A procedure called “targeted muscle reinnervation” was used to allow Levi Hargrove, lead researcher on the project, and his team “to tap into the preserved neural signals to control the prosthetic limb.”

Hargrove said:

He [Vawter] just thinks about moving his ankle…He thinks about doing those movements and the signals travel down the nerves and are redirected onto hamstring muscle. The body doesn’t know that the ankle is not contracting. It is very intuitive for him.

Bionic arms similar to these have been on the market for a while, but the counterparts for the lower portion of the body won’t be readily available for at least a few years. This climb, however, is a huge step forward to this device being marketed commercially.

The Department of Defense has taken an interest in this project, funding the five-year mission with an eye on future applications for wounded veterans. Technology like this could benefit countless individuals.