For 1st Woman With Bionic Arm, a New Life Is Within Reach
Thursday, September 14, 2006
The first time Claudia Mitchell peeled a banana one-handed, she cried.
It was several months after she lost her left arm at the shoulder in a motorcycle accident. She used her feet to hold the banana and peeled it with her right hand. She felt like a monkey.
"It was not a good day," Mitchell, 26, recalled this week. "Although I accomplished the mission, emotionally it was something to be reckoned with."
Now, Mitchell can peel a banana in a less simian posture. All she has to do is place her prosthetic left arm next to the banana and think about grabbing it. The mechanical hand closes around the fruit and she's ready to peel.
Mitchell, who lives in Ellicott City, is the fourth person -- and first woman -- to receive a "bionic" arm, which allows her to control parts of the device by her thoughts alone. The device, designed by physicians and engineers at the Rehabilitation Institute of Chicago, works by detecting the movements of a chest muscle that has been rewired to the stumps of nerves that once went to her now-missing limb.
Mitchell and the first person to get a bionic arm -- a power-line technician who lost both arms to a severe electric shock -- will demonstrate their prostheses today at a news event in Washington. The Rehabilitation Institute of Chicago is part of a multi-lab effort, funded with nearly $50 million from the Defense Advanced Research Projects Agency (DARPA), to create more useful and natural artificial limbs for amputees.
As of July, 411 members of the military serving in Iraq, and 37 in Afghanistan, have suffered wounds requiring amputation of at least one limb. (How many involved losing arms could not be immediately learned.) Mitchell spent four years in the Marine Corps but did not lose her arm during military service.
Someday she hopes to upgrade to a prosthesis, still under development, that will allow her also to "feel" with an artificial hand. She is ready for it now.
Last summer, surgeons took the first step by rewiring the skin above her left breast so that when the area is stimulated by impulses from the bionic arm, the skin sends a message to the region of her brain that feels "hand."
Future arms will also be able to perform more complicated motions. She recently spent time at the Chicago hospital trying out a prototype with six motors, not just the three of her current prosthesis. It will theoretically allow her to reach for things over her head.
But even the first-generation device "has changed my life dramatically," she said. "I use it to help with cooking, for holding a laundry basket, for folding clothes -- all kinds of daily tasks."
For Todd A. Kuiken, 46, a physician and biomedical engineer, this is the latest step in his 20-year effort to make a better artificial arm. Over that time, his laboratory has spent about $3 million on research and development, with more than $2 million provided by the National Institutes of Health.