Researchers have created a soft, lightweight bionic walking aid that straps to the leg and can be worn anywhere to help people recovering from a stroke walk faster, farther, and more safely.
The medical exosuit has breathable wraps made from proprietary materials, thin cables, and a series of small motors that help it mimic human muscles and tendons.
The technology has already been licensed and a suit could be commercially available for use in clinics within the next few years. That would be life changing for thousands. Researchers detail its medical benefits in the journal Science Translational Medicine.
Every year, 795,000 Americans have a stroke, which stops blood flow to parts of the brain and can leave survivors with chronic weakness or paralysis, turning walking into a frustrating—even dangerous—chore. For 15 to 35 percent of survivors, learning to walk independently can take more than six months.
Many of those who do learn to walk again will not regain their former speed or stability; according to Stroke Connection magazine, about 40 percent of all survivors have a serious fall within a year of their stroke.
More sports brace than cyborg
For a robot, the exosuit is understated, more high-tech sports brace than sci-fi cyborg; it weighs only about 10 pounds. A matchbox-sized sensor attaches to the outside collar of the shoe close to the ankle, while two black wraps cover most of the lower leg and the waist. Cables, similar to those used to control bicycle brakes, run from inside the wearer’s shoe to their calf and from the shoe’s tongue to their shin. Motors—worn around the waist and regulated by a computer unit loaded with algorithms—apply forces through the cables to help the wearer walk
“People who have had a stroke have trouble with dorsiflexion, or foot clearance,” says Terry Ellis, a physical therapy professor at the Boston University College of Health & Rehabilitation Sciences: Sargent College; they have a reduced ability to bend their ankle and lift their foot. When they try to plant their heel on the ground to walk, they instead “drag their toes and their foot gets caught.”
The exosuit counteracts that issue by retracting the cable attached to the shoe’s tongue, applying a small amount of force to bring the toes up. When the wearer needs to take a step forward, the rear cable contracts to ensure their foot pushes off the ground, a movement called plantar flexion.
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