New Mind-Controlled Bionic Limb to Debut With a 103-Story Stair-Climb
Posted November 04, 2012 1:12 PM
Zac Vawter thinks big. A
software engineer and former competitive long-distance runner, Vawter's
blog is a list of his not-so-modest aspirations, things like winning a
marathon or writing a new large-scale search engine. After the
motorcycle accident that took his right leg, Vawter kept running and
quickly volunteered as a test subject for experimental new therapies.
Now the Rehabilitation Institute of Chicago is using that tenacity to
help debut its new, thought-controlled prosthetic leg in a grueling
103-floor stair-climb of Chicago's Willis Tower. And Vawter is
determined to do it in under an hour.
Unlike many other
thought-controlled prosthetics, Vawter's experimental leg requires no
electrodes be implanted in or on the brain, and instead takes its cues
entirely from the nerves and muscles in Vawter's upper leg. Researchers
used a procedure called "targeted muscle reinnervation" to re-wire
nerves previously bound for below the knee to the remaining hamstring
muscle. Years of careful study then allowed them to read and interpret
the signals meant for Vawter's lost lower leg.
Levi Hargrove told the Chicago Tribune that Vawter "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." Vawter himself calls previous leg replacements his
"dumb" legs, since they are incapable of responding to his unconscious
impulses. The 31-year-old will have to return the leg after the climb,
however, and get by on the simple limbs until the technology is approved
for commercial sale.