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INNOVATION FOR INDEPENDENCE
ISSUE 88 DECEMBER/JANUARY 2012/13 £6.95
Breakthrough could lead to better systems By Helen Williams RESEARCHERS from Stanford University in California have made a breakthrough in thought control of computers. They have developed an algorithm that translates neurological signals for movement with greater speed and accuracy. The system, which relies on a silicon chip implanted in the brain, has been used to allow monkeys to control computer cursors – but could one day control prosthetic limbs. Krishna Shenoy, who led the research team, said: “These findings could lead to greatly improved prosthetic system performance and robustness in paralysed people.” When a paralysed person imagines moving a limb, cells in the part of the brain that controls movement still activate as if trying to make the immobile limb work again. Even where a neurological injury or disease has severed the pathway between brain and muscle, the region where the signals originate often remains intact. Previous research has begun to develop brainimplantable sensors able to measure signals
from individual neurons, interpret them, and use them to control computer cursors with thoughts alone. But the new algorithm, known as ReFIT, vastly improves speed and accuracy of that control. And, more than four years after implantation, the new system is still going strong, while previous systems have steadily declined. The Stanford system records neural activity from an array of electrode sensors and sends data to a computer, providing key information about the direction and speed of the user’s intended movement. To test the new system, the team gave monkeys the task of mentally directing a cursor to a target – an onscreen dot – and holding the cursor there for half a second. ReFIT performed vastly better than previous systems. The path of the cursor from the starting point to the target was straighter and reached the target twice as quickly, achieving 75 to 85 per cent of the speed of real arms. Critical to ReFIT's improvement was its superior ability to stop and make adjustments ‘on the fly’ while guiding the cursor to a target.
A prosthetic hand from Touch Bionics features in a new music video with Britney Spears. The song, Scream and Shout, is the result of a collaboration between pop megastars Britney and Will.i.am. The i-limb ultra hand – said to be the world’s most advanced prosthetic hand – appears in the futuristic video, premiered on The X Factor USA television show.