TECHNOLOGIES are often billed as transformative. For William Kochevar, the term is justified. Mr Kochevar is paralysed below the shoulders after a cycling accident, yet has managed to feed himself by his own hand. This remarkable feat is partly thanks to electrodes, implanted in his right arm, which stimulate muscles. But the real magic lies higher up. Mr Kochevar can control his arm using the power of thought. His intention to move is reflected in neural activity in his motor cortex; these signals are detected by implants in his brain and processed into commands to activate the electrodes in his arms.
IN THE gleaming facilities of the Wyss Centre for Bio and Neuroengineering in Geneva, a lab technician takes a well plate out of an incubator. Each well contains a tiny piece of brain tissue derived from human stem cells and sitting on top of an array of electrodes. A screen displays what the electrodes are picking up: the characteristic peak-and-trough wave forms of firing neurons. To see these signals emanating from disembodied tissue is weird. The firing of a neuron is the basic building block of intelligence.
William Kochevar of Cleveland can slowly move his right arm and hand. No big deal--except that the 56-year-old had been paralyzed from the shoulders down since a bicycling accident ten years ago. The setup that is allowing Kochevar to move his arm again is a "neuroprosthetic" involving two tiny recording chips implanted in his motor cortex and another 36 electrodes embedded in his right arm. Now, during visits he makes to an Ohio lab each week, signals collected in his brain are being captured and sent to his arm so he can make some simple voluntary movements. "I was completely amazed," says Kochevar.
A quadriplegic man in the US has been able to use his right arm and hand again after eight years of paralysis. Bill Kochevar, who was paralysed below his shoulders in a cycling accident, was able to do this thanks to a neuroprosthesis. Electrodes implanted under his skull record brain activity in his motor cortex region, sending signals to electrodes in his arm that tell them when to stimulate his muscles. The device has enabled him to raise a mug of water and drink from a straw, and scoop mashed potato from a bowl. "For somebody who's been injured eight years and couldn't move, being able to move just that little bit is awesome to me," says Kochevar.
PARIS – A decade after a bike crash left an American man paralyzed from the shoulders down, he can again feed himself thanks to a medical first, researchers reported Wednesday. The remarkable advance hinges on a prosthesis that circumvents rather than repairs his spinal injury, using wires, electrodes and computer software to reconnect the severed link between his brain and muscles. "To our knowledge, this is the first instance in the world of a person with severe and chronic paralysis directly using their own brain activity to move their own arm and hand to perform functional movements," said the study's lead author, Bolu Ajiboye of Case Western Reserve University in Cleveland. The study's only patient, 56-year-old Bill Kochevar, has two surgically implanted clusters of electrodes -- each no bigger than a baby aspirin -- in his head. They read his brain signals, which are interpreted by a computer.