A bionic leg that connects with an amputee’s brain to control it with natural motion: not a science-fiction device, but a within-reach reality for another Brigham and Women’s Hospital patient.
The patient, 22-year-old Morgan Stickney, underwent what’s known as a Ewing amputation, so named for Jim Ewing, the first person to undergo the procedure in 2016, after falling 40 feet on a rock climbing trip. Based on a method known as agonist-antagonist myoneural interface (AMI), invented at MIT, it replicates natural muscle pairings that facilitate movements. It’s a novel approach compared with a standard amputation, which severs muscle-brain connections. With those connections intact, the brain still thinks the limb is present.
“And the idea is that once they've healed, when they fire off those muscles and think about moving their ankle, their body basically thinks it's moving a biological ankle still,” notes Matthew Carty, MD, Brigham reconstructive plastic surgeon, who performed the surgery.
Dr. Carty is collaborating with the Biomechanatronics Group at the MIT Media Lab, to develop a “bionic” robotic leg that will respond to those preserved brain signals. Once generally available, the leg will be a game changer for patients like Stickney, a former competitive swimmer who was sidelined by a rare vascular condition and resulting injury. Finally pain-free thanks to the Ewing amputation, she hopes to return to competitive swimming following her rehabilitation treatment at Spaulding Rehabilitation Hospital.
“Nothing will stop me from getting in the pool,” Stickney says. “My goal is to go to the 2024 Paralympic Games. I'll be in a different classification this time, but that doesn't change anything. Whether I'm going to be working just as hard in the pool, if not harder.”
With three grants from the Department of Defense, the Brigham will continue to expand research around the Ewing amputation, and will soon offer it to patients in need of upper limb amputations.
Read more at WGBH.
Header image via The New York Times