Mind-controlled prosthetic arm allows movement of individual fingers

US physicians and biomedical engineers have allied to create a new approach to prosthetic arm design that allows individual digits to be controlled by the mind.

The Johns Hopkins Medicine study saw a young man with epilepsy implanted with an array of 128 electrode sensors on a single credit card-sized sheet of film on the part of the brain that normally controls hand and arm movements.

Prior to connecting the device, the team was able to map and track specific parts of the brain responsible for moving each finger, then programmed the prosthesis to move the corresponding digit.

The subject was then asked to think about individually moving their thumb, index, middle, ring and little fingers, with the electrical activity generated in the brain successfully moved the digits.

This is believed to mark the first time a person using a mind-controlled prosthesis has been able to immediately perform individual digit movements without extensive training.

Senior author Dr Nathan Crone, professor of neurology at the Johns Hopkins University School of Medicine, said: "This technology goes beyond available prostheses, in which the artificial digits, or fingers, moved as a single unit to make a grabbing motion, like one used to grip a tennis ball."