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This Prosthetic Arm Can Be Controlled With the Mind

Johns Hopkins University
Johns Hopkins University | Johns Hopkins University

A new kind of prosthetic limb is revolutionizing the way amputees can move. Researchers at Johns Hopkins University’s Applied Physics Laboratory and the Canadian robotics company ThalmicLabs have developed a non-invasive arm prosthetic that can be controlled with the mind. 

The Modular Prosthetic Arm works in conjunction with two Myo armbands—a $200 wearable tech originally designed for gesture-based computer and video game control. The wireless bands record electric activity in the muscles of the arm so the user can move the prosthetic naturally, picking up objects or moving his fingers just as he would a real limb. The electromyography signals from the muscles are sent wirelessly to a computer, where they’re processed and then sent back to the prosthetic to tell it what joints to operate. 

In spring 2015, California researchers were able to program a robotic arm so that a paralyzed man could control it with his mind, allowing him to drink a beer unaided. However, that process required implanting electrodes in the patient’s brain. A Myo-controlled prosthetic doesn’t require anything more than strapping on an armband. 

The patient in the video above, Johnny Matheny, does have his prosthetic surgically attached to his upper arm. Attached to the bone in his arm, this implanted socket eliminates some of the discomfort of wearing a fake limb (like sweating and chafing) and gives him a much wider range of motion, allowing him to reach above his head and behind his back. With this Myo-enabled prosthetic, he’s able to control individual fingers, grasp objects, and move his wrist, simply by moving the muscles in the remaining part of his arm.

"The APL arm is the most unique arm I've ever worn," Matheny says in the video. "It has the ability to do anything that your natural hand, wrist, elbow, shoulder can do."

The system isn’t quite ready for everyday use—Matheny only uses it in the lab right now—but the researchers hope to make it more broadly available at some point in the future.