Technology brings thought to invention — "Brain drives arm" by Fiona MacCrae The Courier-Mail 16-17/9/2006
WHEN Claudia Mitchell lost her left arm, the simplest of tasks became nigh on impossible.
But having been equipped with the world's most advanced bionic arm, tasks such as peeling a banana have become possible.
Ms Mitchell, a 26-year-old former US marine, can bend her wrist back, move her thumb and clench her fingers. What makes it special is that the $5 million bionic arm is controlled by thought alone. This week, she was even able to exchange "high fives" with Jesse Sullivan, the first person to be given a bionic arm.
While Mr Sullivan's arm was a breakthrough, Ms Mitchell, who lost her left arm at the shoulder in a motorcycle accident two years ago, has the most advanced in the world.
"I can flex my elbow, extend my elbow, open and close my hand with the mere thought of doing it," she said. "I can carry a tray, I can open a jar. I can hold fruit and vegetables while I cut them up. I can peel a banana. Small things like that might seem trivial to a two-armed person, but it is very exciting to me."
The bionic arm was created at the US's Rehabilitation Institute of Chicago. Doctors capitalised on the brain's determination to try to send signals to a limb, even if only a stump remains.
Chicago plastic surgeon Gregory Dumanian moved the five nerves that once controlled her arm and placed the ends of the nerves in her chest, where they re-grew close to the skin.
When Ms Mitchell decides to move her arm, the nerves fire as if they are still leading to her arm. But they make the chest muscles twitch and electrodes on the chest surface detect this and transmit signals to a computer in the artificial arm.