Robot arm boosts brain-controlled device’s performance

WASHINGTON - A new University of Chicago study has found that the performance of a brain-machine interface designed to help paralysed people move objects with their thoughts just got better with the addition of a robotic arm providing sensory feedback.

The study found that adding a robot arm that provided kinesthetic information about movement and position in space improved the performance of monkeys using a brain-machine interface.

Incorporating this sense may improve the design of ‘wearable robots’ to help patients with spinal cord injuries, said researchers.

“A lot of patients that are motor-disabled might have partial sensory feedback. That got us thinking that maybe we could use this natural form of feedback with wearable robots to provide that kind of feedback,” said Nicholas Hatsopoulos, of the University of Chicago.

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. This could be quite significant for daily activities being performed by a paralyzed patient that was equipped with such a system,” said Hatsopoulos.

The researchers also observed changes in the brain activity recorded from the monkeys when sensory feedback was added to the set-up.

The improvement seen from adding proprioception feedback may inform the next generation of brain-machine interface devices, said Hatsopoulos.

The findings were published in the Journal of Neuroscience. (ANI)