In a remarkable advance, a paralyzed man - Tim Hemmes - has managed to move a robot hand attached to his wheelchair only with the use of his mind. He was left paralyzed after a motorcycle accident. Moving a robot hand towards his girlfriend was a success for both the man and for the team of scientists at the University of Pittsburgh, who led and monitored the experiment.
Hemmes had met with his accident seven years ago which left him quadriplegic. Since that time, his ultimate goal is to get back the use of his hands. “I always tell people your legs are great ... but they just get you from here to there”, Tim says, but “the arms and fingers and hands do everything else”.
His great luck was the possibility of joining the volunteers testing the 100 million dollar project for DARPA, the research agency of the Pentagon. The project revolved around constructing a robot arm that moves on the command of the human mind. For this, Hemmes, who is 30 years old, underwent a brain surgery, where electrodes were implanted in his brain, to record the electrical signals. Those signals are then sent through connecting wires to the hand. Hemmes’s electrodes were implanted on the surface of his motor cortex and the intervention lasted about two hours.
Initially after the operation, Hemmes was assigned to simply get used to the robotic arm. He had no significant tasks. But within a week, he had to command the hand to reach to a ball and grasp it. The experiment turned into frustration for the man, as his hand would to the exact opposite of what he wanted. After several attempts, he managed to complete the task. “There's no owner's manual, I'm training my brain to figure how to do all this”, he said.
On Monday, Tim managed to reach out and touch with his new hand the hand of his girlfriend, Katie Schaffer. It was the first time he has ever reached to her, as they met after his accident. It was a highly emotional moment for both of them. “I believe this is the future,” Hemmes says thrilled about the new perspectives opening up in front of him. “Just let people know there's hope.”
The research is years away from commercial use, but numerous teams are investigating different methods. At Pittsburgh, monkeys learned to reward themselves with marshmallows by thinking a robot arm into motion. At Duke University, monkeys used their thoughts to move virtual arms on a computer and got feedback that let them distinguish the texture of what they “touched.”
Through a project known as BrainGate and other research, a few paralyzed people outfitted with brain electrodes have used their minds to use computers and make simple movements with prosthetic arms.
“We really are at a tipping point now with this technology,” says Michael McLoughlin of the Johns Hopkins University Applied Physics Laboratory, which developed the humanlike arm in a $100-million project for DARPA, the Pentagon's research agency. Pittsburgh is helping to lead a series of government-funded studies over the next two years to try to find out.
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