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Paralyzed Individuals Use Thought-Controlled Robotic Arm

In an ongoing clinical trial, a paralyzed woman was able to reach for and sip from a drink on her own—for the first time in nearly 15 years—by using her thoughts to direct a robotic arm. The trial, funded in part by the National Institutes of Health (NIH), is evaluating the safety and feasibility of an investigational device called the BrainGate neural interface system. This is a type of brain/computer interface intended to put robotics and other assistive technology under the brain’s control.

A report published in Nature describes how two individuals, both paralyzed by stroke, learned to use the BrainGate system to make reach-and-grasp movements with a robotic arm as part of the BrainGate2 clinical trial. The report highlights 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. It also describes the most complex functions to date that anyone has been able to perform using a brain/computer interface.

For the woman, it was the first time since her stroke that she was able to sip a drink without help from a caregiver.

“The smile on her face was a remarkable thing to see. For all of us involved, we were encouraged that the research is making the kind of progress that we had all hoped,” says the trial’s lead investigator Leigh Hochberg, MD, PhD, who is an associate professor of engineering at Brown University in Providence, RI, and a critical care neurologist at Massachusetts General Hospital/Harvard Medical School in Boston.

He notes that the technology is years away from practical use and that the trial participants used the BrainGate system under controlled conditions in their homes with a technician present to calibrate it.

The BrainGate neural interface system consists of a sensor to monitor brain signals and computer software and hardware that turns these signals into digital commands for external devices. 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.

In the trial, both participants learned to perform complex tasks with a robotic arm by imagining the movements of their own arms and hands.

Roderic Pettigrew, MD, PhD, director of NIH’s National Institute of Biomedical Imaging and Bioengineering, which supports the research, indicates that the technology is promising but at present is still undergoing development and evaluation. “The researchers have begun the long, difficult process of testing and refining the system with feedback from patients, and they’ve found that it is possible for a person to mentally control a robotic limb in three-dimensional space. This represents a remarkable advance,” he says.

— Source: National Institutes of Health