A Blog by Jonathan Low

 

May 17, 2012

Paralyzed Woman Uses Brain Waves to Move Robotic Arm

Technology and hope are wedded in the minds of most contemporary societies.

We expect minor miracles as a matter of course, to the point where we too often take them for granted.

Seeing the power of the brain harnessed to technology in ways that enable the extension of both is the stuff of science fiction. But even given the relative simplicity of moving a robotic arm so that coffee can be sipped, imagine what other wonders can be achieved when advances in both technology and neuroscience combine to solve other medical, scientific, creative and philosophical problems. JL

Dan Vergano reports in USA Today:
A fully paralyzed man and woman have demonstrated the ability to hold a ball or grab a cup of coffee using their brain signals to control a robotic arm, researchers report.

The demonstrations, reported in the journal Nature, mark yet another significant step in efforts by researchers to connect severely paralyzed patients to prosthetic devices that they can maneuver with their own thoughts.
The study team, headed by neuroscientist John Donoghue of Brown University and the Department of Veterans Affairs in Providence, R.I., made news in 2008, when one of the patients in the latest study, Cathy Hutchinson, 58, used brain implants to control computer cursors.

In the slowly progressing world of brain implant research, Hutchinson grabbing herself a cup of coffee for the first time in nearly 15 years , stands as the emotional highlight of the latest study, Donoghue says. "This is just a start at restoring independence to paralyzed patients."

In the study, Hutchinson and a paralyzed 66-year-old man, both stroke victims unable to speak, controlled a right-handed robotic arm by signals sent from brain implants. The brain implants, about the size of a baby aspirin, have 100 thin wires that slightly protrude into the covering of the patients' brains, centered over the regions connected to arm movements.

"We asked them to imagine moving their arms and the implant picks up the signal," in brain cells, Donoghue says. Essentially a computer weighed signals from brain cells firing beneath the implant to initiate movement from the patients. But instead of making those movements in discreet directions — up, down, backward, forward and sideways — the updated program allows the robotic arm to move in a smooth curving path to touch targets. Success rates varied from 46% to 62% in grasping foam balls, using a robot arm designed by "Segway" inventor Dean Kamen with Defense Advanced Research Projects Agency (DARPA) support.

Most notably, Hutchinson's implant has worked for six years, Donoghue says, despite fears that scarring would build up around the implants and stop their signals. "There has been some dropoff, but we think a lot of that is tied to the equipment, which was only designed to last a year," he says. ("The warranty is over," he jokes.)

"Immobilized patients should be encouraged by these capabilities," says neurobiologist Andrew Schwartz of the University of Pittsburgh, who was not part of the study team. "In the future we are going to be seeing even more improvements," says Schwartz, whose team has demonstrated similar robot arm and wrist control in monkeys . And on Monday, neurosurgeons from Washington University School of Medicine in St. Louis reported the partial restoration of finger and thumb control to a 71-year-old man paralyzed with a spinal cord injury, by rerouting an undamaged nerve in his neck to connect to arm muscles.

About 260,000 U.S. patients are living with spinal cord injuries, which combined with traumatic brain injuries and strokes cause roughly a million disability cases nationwide every year, according to American Heart Association committee estimates. Brain implants are now contemplated for only the most severely paralyzed, where patients are "locked-in" to their brain, without movement or speech.

"Encouraging progress is being made on all fronts," says neuroscientist Andrew Jackson of the United Kingdom's Newcastle University, in a commentary accompanying the report that suggests reconnecting patient's brain signals to their muscles using wireless devices should be a final goal of paralysis researchers. Ultimately, he cautions, "the greatest obstacle" may be economics because of the costs of human experiments on the brain interfaces.

0 comments:

Post a Comment