Two U.S. patients paralyzed by stroke learned to make reach-and-grasp movements with a robotic arm, guided by their thoughts, researchers say.

The trial’s lead investigator, Dr. Leigh Hochberg -- an associate professor of engineering at Brown University in Providence, R.I., and a critical care neurologist at Massachusetts General Hospital/Harvard Medical School in Boston -- said the trial is evaluating an investigational device, the BrainGate neural interface system.

The system is a type of brain-computer interface intended to put robotics and other assistive technology under the brain’s control, Hochberg said.

The sensor is a baby aspirin-sized square of silicon containing 100 hair-thin electrodes that can record the activity of small groups of brain cells. It is implanted into the motor cortex, a part of the brain that directs movement, Hochberg said.

A report published in Nature highlighted the potential for long-term use and durability of the BrainGate system, part of which is implanted in the brain to capture the signals underlying intentional movement.

“For all of us involved, we were encouraged that the research is making the kind of progress that we had all hoped,” Hochberg said in a statement. “Years after the onset of paralysis, we found that it was still possible to record brain signals that carry multidimensional information about movement and that those signals could be used to move an external device.” (UPI)