Woman receives 'bionic arm'

A young woman who lost her arm in a motorbike accident has undergone a pioneering surgical technique involving the rerouting of nerves which allows her to feel she is moving her artificial limb with merely the power of thought. Claudia Mitchell is one of only four people in the United States to have undergone the procedure, but the results will give hope to many who have lost a limb. "I just think about moving my hand and elbow and they move," she told her doctors.Not only can she move her arm and wrist spontaneously, but the transfer of sensory nerves into a patch of skin on her chest allows her to experience the feeling of somebody touching her missing hand. In a paper in the Lancet medical journal, published today, her doctors describe what they call the exciting implications of their surgery. It has the potential to give the patient back their sense of touch, the feeling of greater or lesser pressure on the fingers, the sensation of heat and cold and even an awareness of texture. Artificial arms are usually slow and cumbersome to use. They are controlled by electrical sensors on the skin that detect the movement of the muscle that remains at the point of amputation. But a turn of a hand or wrist is not easily controlled by a muscle in the shoulder, a bicep or a tricep and only movement in one direction at a time is possible.

Many people wear their prosthesis for only short periods or give up on it altogether. The case of Ms Mitchell, formerly in the US marine corps, will bring hope to many. Surgeons at the Neural Engineering Centre for Artificial Limbs at the Rehabilitation Institute of Chicago have devised a way of redirecting the severed nerves that would have sent messages from the brain to the arm and the hand. In a process they call targeted muscle reinnervation, they remove the nerves from certain muscles in the chest and transfer into them instead the remnants of nerves that would have run down the arm.

View: Full Article | Source: Guardian Unlimited