FOUR people have learned to move a prosthetic limb using their thoughts.
Electrodes that pick up the electrical activity in the brain have already helped people control computer programs and allowed monkeys to feed themselves with a robot arm 鈥� all just by thinking.
Takufumi Yanagisawa of Osaka University Medical School in Japan and his colleagues focused on electrocorticography (ECoG), in which electrodes are placed directly on the surface of the brain during surgery. ECoG is typically used to find the focal point of epilepsy, but it has been used to connect people鈥檚 brains to machines.
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Yanagisawa鈥檚 team recruited five people with epilepsy but no paralysis, four with weakness in their arms following strokes, and three with damage to the motor nerves of the shoulder, arm and hand. After placing electrodes on the volunteers鈥� brains, the team studied activity in the sensorimotor cortex, a band of brain tissue that controls voluntary movement. The electrodes recorded neural activity as the participants performed actions such as grasping and flexing their elbows, to the best of their ability.
Once the researchers had characterised a unique pattern of brain activity for each movement, the team designed a computer program to match the different ECoG patterns with the corresponding hand or arm movements. When the program recognised a particular pattern of activity recorded by the electrodes, it instructed a nearby prosthetic arm to complete the relevant motion.
The prosthetic arm successfully parroted the movements of one person who had experienced a stroke and three with no paralysis ().
鈥淭hey have shown some promising results,鈥� says of the New York State Department of 午夜福利1000集合 in Albany. Schalk has previously used ECoG to distinguish individual finger movements. 鈥淭o my knowledge it is the first attempt to use ECoG to control a robotic hand in people that have neuromuscular disorders.鈥�
It is unlikely to be the last. at Washington University in St Louis, Missouri, is researching ECoG for neuroprosthetics, and researchers at the University of Pittsburgh in Pennsylvania are for a clinical trial of ECoG in people with upper limb paralysis.