A double amputee from Colorado became the first man to wear two robotic arms developed by Johns Hopkins University and control them with nothing but his mind during an experiment earlier this summer.
As part of the experiment, Les Baugh — a bilateral shoulder-level amputee who lost his arms 40 years ago in an electrical accident — was fitted for two Modular Prosthetics Limbs (MPLs) developed by the university’s Applied Physics Laboratory (APL) and underwent a painful process known as “re-enverating,” in which surgeons woke up and reassigned nerves in his chest needed to control the MPLs.
“It’s a relatively new surgical procedure that reassigns nerves that once controlled the arm and the hand,” Johns Hopkins trauma surgeon Albert Chi, M.D., said in a statement released by the University this week. “By reassigning existing nerves, we can make it possible for people who have had upper-arm amputations to control their prosthetic devices by merely thinking about the action they want to perform.”
Baugh wears and controls the MPLs via a custom-fitted harness equipped with pattern-recognition technology that observers Baugh’s muscle activity — controlled by the altered nerves — and translates them into 30 degrees of motion in both of the MPLs.
Baugh learned how to control the MPLs with his mind by practicing with virtual reality arms before trying on the real thing in June. After only 10 days of training, Baugh was able to execute a range of everyday tasks including picking up a cup from a shelf and placing it on a higher shelf.
“We expected him to exceed performance compared to what he might achieve with conventional systems, but the speed with which he learned motions and the number of motions he was able to control in such a short period of time was far beyond expectation,” APL prosthetist Courtney Moran said in the statement. “What really was amazing, and was another major milestone with MPL control, was his ability to control a combination of motions across both arms at the same time. This was a first for simultaneous bimanual control.”
The next step in the experiment will be sending Baugh home with a pair of MPLs — something he’s looking forward to.
“Maybe for once I’ll be able to put change in the pop machine and get pop out of it,” Baugh said. “The simple things that most people don’t think of.”