Bionic implant

‘Bionic’ devices that produce functional hand and arm movement through electrical stimulation have been fitted to the arm of a stroke patient at the University of Southampton.

Similar devices have been implanted in patients’ arms or shoulders in the US, Canada and Japan, but this is the first time that the operation has taken place in the UK to achieve a coordinated hand and arm movement.

The fitting of the device is the latest stage in a long-term experimental research study by the University of Southampton in partnership with the Alfred Mann Foundation (AMF), a non-profit medical research organisation in the US.

The study is exploring the feasibility of using radio frequency microstimulator (AMF RF microstimulator) electrical stimulation devices to improve motor recovery and re-learning of arm and hand function following stroke.

The cylindrical microstimulators measure 1.7 centimetres long and 2.4 millimetres in diameter. They can be injected into the body through a small incision and are implanted next to a nerve or adjacent to a muscle at the motor point near to where the nerve attaches. Once implanted, the microstimulators receive power and stimulation commands via a link from a radio frequency coil fitted to the arm, which is in turn connected to a control unit.

When the AMF RF microstimulators are implanted into a patient’s arm, they provide electrical stimulation to both control and re-educate weak or paralysed muscles. The effect is to produce functional arm and hand movements in patients who have suffered damage to the central nervous system following a stroke.

At the end of April, five such AMF RF microstimulators were implanted close to the nerves supplying muscles in a female patient’s arm under local anaesthetic at Southampton General Hospital. Then, last week, she was fitted with a cuff which sends signals to the AMF RF microstimulators. The system will then be programmed to produce functional patterns of movement.