CHICAGO (AP)
-- The metal on Zac Vawter's bionic leg gleamed as he climbed the 103
floors of Chicago's iconic Willis Tower, becoming the first person ever
to complete the task wearing a mind-controlled prosthetic limb.
Vawter,
who lost his right leg in a motorcycle accident, put the smart limb on
public display for the first time during an annual stair-climbing
charity event called "SkyRise Chicago" hosted by the Rehabilitation
Institute of Chicago, where he is receiving treatment.
"Everything went great," said Vawter at the event's end. "The prosthetic leg did its part, and I did my part."
The
leg is designed to respond to electrical impulses from muscles in his
hamstring. When Vawter thought about climbing the stairs, the motors,
belts and chains in his leg synchronized the movements of its ankle and
knee.
The computerized prosthetic limb, like something from a sci-fi film, weighs about 10 pounds and holds two motors.
Bionic
- or thought-controlled - prosthetic arms have been available for a few
years, thanks to pioneering work done at the Rehabilitation Institute.
Knowing leg amputees outnumber people who have lost arms and hands, the
Chicago researchers are focusing more on lower limbs. If a bionic hand
fails, a person drops a glass of water. If a bionic leg fails, a person
falls down stairs.
This event was a research project for us, said Joanne Smith, the Rehabilitation Institute's CEO.
"We
were testing the leg under extreme conditions. Very few patients who
will use the leg in the future will be using it for this purpose. From
that perspective, its performance was beyond measure," Smith added.
To
prepare for his pioneering climb, Vawter said, he practiced on a small
escalator at a gym, while researchers spent months adjusting the
technical aspects of the leg to ensure that it would respond to his
thoughts.
When Vawter goes home to Yelm,
Wash., where he lives with his wife and two children, the experimental
leg will stay behind in Chicago. Researchers will continue to refine its
steering. Taking it to the market is still years away.
"We've
come a long way, but we have a long way to go," said lead researcher
Levi Hargrove of the institute's Center for Bionic Medicine. "We need to
make rock solid devices, more than a research prototype."
The
$8 million project is funded by the U.S. Department of Defense and
involves Vanderbilt University, the Massachusetts Institute of
Technology, the University of Rhode Island and the University of New
Brunswick.
"A lot of people say that losing a
leg is like losing a loved one," said Vawter. "You go through a grieving
process. You establish a new normal in your life and move on. Today was
a big event. It's just neat to be a part of the research and be a part
of RIC."
Nearly, 3,000 climbers participated
in the annual charity event. Participants climbed about 2,100 steps to
the Willis Tower's SkyDeck level to raise money for the institute's
rehabilitation care and research.
Copyright 2012 by The Associated Press. All rights reserved.
