A former US marine who lost her left
arm in a motorcycle accident has been fitted with a prosthetic limb
that operates much like a natural arm.
Claudia Mitchell received a "Bionic Arm" at the Rehabilitation Institute of Chicago, where
the prosthesis was developed by a team working under Professor Todd
Kuiken.
Mitchell’s new arm is neuro-controlled – operated by thought, in
other words. Nerves in her shoulder that
formerly threaded into her arm were rerouted to her chest, where they connected to skin and muscle tissue. Touching
that area of Mitchell’s chest produces a sense of being touched on her remembered hand. A signal from the brain to move her former hand contracts the muscle tissue and a myoelectric signal is sent from that muscle to her prosthetic hand. She thinks "clench," the chest muscle contracts, and her steel and silicone hand squeezes a ball.
It’s not perfect — sensory feedback, displaced into the skin of her chest, is a bit loopy, and some fine movements are difficult — but money is being pumped into research and development, and improvements, such as touch sensitive finger pads, may come rapidly.
Mitchell was a passenger on a motorcycle that crashed in a curve in May 2004. She hit a guardrail that severed her arm. She is the first woman fitted with
the Bionic Arm. After reading an article about former power lineman Jesse Sullivan (pictured with her), who lost both arms after touching a live wire and subsequently received the first such transplant, she found her way into the program and since has “returned to
a life that is more rewarding and active than I ever could have
imagined,” she says.
Here’s a video of Mitchell
demonstrating the arm: www.youtube.com, and here’s a New Yorker magazine article about the technology.
