The performance of a brain-machine interface designed to help paralyzed subjects move objects with their thoughts is improved with the addition of a robotic arm providing sensory feedback, a new study from the University of Chicago finds.
Devices that translate brain activity into the movement of a computer cursor or an external robotic arm have already proven successful in humans. But in these early systems, vision was the only tool a subject could use to help control the motion.
Adding a robot arm that provided kinesthetic information about movement and position in space improved the performance of monkeys using a brain-machine interface in a study published today in The Journal of Neuroscience. Incorporating this sense may improve the design of "wearable robots" to help patients with spinal cord injuries, researchers said.
"A lot of patients that are motor-disabled might have partial sensory feedback," said Nicholas Hatsopoulos, PhD, Associate Professor and Chair of Computational Neuroscience at the University of Chicago. "That got us thinking that maybe we could use this natural form of feedback with wearable robots to provide that kind of feedback."
In the experiments, monkeys controlled a cursor without actively moving their arm via a device that translated activity in the primary motor cortex of their brain into cursor motion. While wearing a sleeve-like robotic exoskeleton that moved their arm in tandem with the cursor, the monkey's control of the cursor improved, hitting targets faster and via straighter paths than without the exoskeleton.
"We saw a 40 percent improvement in cursor control when the robotic exoskeleton passively moved the monkeys' arm," Hatsopoulos said. "This could be quite significant for daily activities being performed by a paralyzed patient that was equipped with such a system."
When a person moves their arm or hand, they use sensory feedback called proprioception to con
|Contact: Robert Mitchum|
University of Chicago Medical Center