Researchers at the University of Utah built an exoskeleton that can ease walking for people with above-knee amputations. The new system, which uses an electromechanical actuator attached to the thigh and AI to adapt to each person’s walking style, significantly reduces energy consumption for users.
Above-knee amputations are particularly challenging in terms of walking. Many of the leg muscles are removed, meaning that the remaining muscles, both residual and intact, have a lot of work to do. Conventional prosthetic legs do not provide any assistance while walking, so users have to exert significant amounts of energy to swing them into place with each step.
“The consequence of this, even though you have the ability to move your hip, is your abilities in walking are quite impaired,” said Tommaso Lenzi, a researcher involved in the study. “There is a lack of strength and range of motion.”
The new exoskeleton is intended to address this problem. It wraps around the affected leg and the waist, and uses an actuator to provide assistance to the affected leg. An artificial intelligence component helps to customize the activity of the exoskeleton for each user and the actuator can be swapped to either leg, depending on which side the amputation is.
The device is intended to act as an assist, and reduce the energy required for walking. So far, the researchers have tested it in a group of six people with above-knee amputations, who wore the exoskeleton while their metabolic rate was measured. This involved them walking on a treadmill while the researchers measured carbon dioxide levels and oxygen intake. Strikingly, the exoskeleton reduced the energy consumed by an average of 15.6%.
“It’s equivalent to taking off a 26-pound backpack. That is a really big improvement,” said Lenzi. “We’re very close to what an average person would expend at the same speed. The metabolic consumption is almost indistinguishable from that of an able-bodied person, depending on the fitness level.”
Check out this video introducing the new exoskeleton:
Study in Nature Medicine: Powered hip exoskeleton improves walking economy in individuals with above-knee amputation
Via: University of Utah