By Carla K. Johnson, AP Medical Writer
CHICAGO (AP) -- Zac Vawter lost his right leg in a motorcycle accident. Now the 31-year-old software engineer is a research subject, helping test a trailblazing prosthetic leg that's controlled by his thoughts.
He will put this "bionic" leg to the test Sunday when he attempts to climb 103 flights of stairs to the top of Chicago's Willis Tower, one of the world's tallest skyscrapers.
If all goes well, he'll make history with the bionic leg's public debut. A team of researchers from the Rehabilitation Institute of Chicago will be cheering him on and noting the leg's performance.
Lead researcher Levi Hargrove says the climb will be the bionic leg's first test in the public eye. "SkyRise Chicago" is a fundraiser for the institute with about 2,700 people climbing the Willis Tower stairs.