A rancher in Halfway, Oregon, Bob Goodman lost his arm below his elbow in a freak accident. Researchers at the University of Utah attached a myoelectric arm, which he controls by flexing the muscles in his arm that are still intact. Sensors on the inside of the prosthetic arm socket pick up the faint electrical signals from the muscles and amplify them to control the robot arm. In this way, Goodman can cook his dinner and do his chores, just as he did before the accident. From the book Robo sapiens: Evolution of a New Species, page 179 top.