Man With Quadriplegia Controls Prosthetic Arms With His Mind

Megan Brooks

December 09, 2020

Patient "Buz" Chmielewski is able to control his prosthetic arms using only his thoughts.

A man with quadriplegia has been able to simultaneously control a pair of prosthetic arms with only his thoughts by virtue of electrodes implanted in both sides of his brain and a brain-computer interface.

Until now, brain-computer interface research for quadriplegia has largely focused on only one arm that was controlled from only one side of the brain, Gabriela Cantarero, PhD, assistant professor of physical medicine and rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, told Medscape Medical News.

"We're using two sides of the brain to control two limbs at the same time," Cantarero said.

The patient, Robert "Buz" Chmielewski, age 49, has been paralyzed with only minimal movement in his arms and hands since a surfing accident when he was a teenager.

In January 2019, surgeons implanted electrodes into the primary motor cortex and the primary somatosensory cortex in the right and left hemispheres of the brain in a 10-hour operation.

The goal was to improve sensation in his hands and enable the patient to mentally operate two arm prostheses.

Now, almost 2 years later, and with lots of practice, Chmielewski has reached an important milestone, the Johns Hopkins team reports. He can now use both of his robotic appendages to perform simple tasks such as feeding himself.

"A Clear Step Forward"

"Being able to control two robotic arms performing a basic activity of daily living ― in this case, cutting a pastry and bringing it to the mouth using signals detected from both sides of the brain via implanted electrodes ― is a clear step forward to achieve more complex task control directly fed from the brain," Pablo Celnik, MD, professor and director of physical medicine and rehabilitation at the Johns Hopkins University School of Medicine, said in a news release.

The team has released a video showing Chmielewski cutting food with his left hand and feeding himself with the right, at times simultaneously controlling both robotic arms.

The technology uses a system of devices that automates a portion of the robotic control with artificial intelligence.

"Our goal is to make activities such as eating easy to accomplish by having the robot do one part of the work and leaving the user in charge of the details: which food to eat, where to cut, how big the cut piece should be, and so on," said David Handelman, PhD, a senior roboticist at Johns Hopkins University's Applied Physics Laboratory, in the release.

"By combining brain-computer interface signals with robotics and artificial intelligence, we allow the user to focus on the parts of the task that matter most," he added.

The research team says next steps include expanding the number and types of activities of daily living that can be performed using this human-machine interface. Another is to provide the user with additional sensory feedback as tasks are conducted.

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