a new exoskeleton has been introduced that powers the prosthetic leg, allowing them to walk less forcefully and naturally.
Tommaso Lenzi, assistant professor of mechanical engineering at the University of Utah, USA, announced in the 11th journal Nature Medicine that six people whose knees had their upper ear amputated were equipped with a new self-powered hip exoskeleton to improve their walking economy by 12.7 to 18.5 percent.
the exoskeleton, which wraps around the wearer’s waist and thighs, uses a battery-powered electric motor and a built-in microprocessor to allow leg-cutting patients to walk with much less effort.
Not when cut, the quality of life greatly degrades
millions of patients are known to have suffered knee-cutting accidents worldwide. not only do these patients have great difficulty moving because most of their leg muscles are lost but their quality of life itself is severely degraded.
“even if you have the ability to move your hips in such an accident, your ability to walk is greatly less,” renzi explained, “because you lack the power to move your prosthetic leg and the range of operation is small.”
the standard prosthetic leg for the severed person is difficult to fully replicate the biodynamic function of the original human leg. as a result, patients with above-the-knee amputations must move hard with excessive use of the above and intact one leg of the amputated leg to compensate for the lack of energy of the prosthetic (prosthetic) worn.
in this exoskeleton development, professor renzi aimed to provide additional energy to the prosthesis so that walking felt natural again. to do this, a lightweight and efficient electromagnetic actuator was connected to the wearer’s thigh.
belts mounted on the waist are equipped with a slimmed-down electronic system, microcontrollers, and sensors that run advanced control algorithms.
“Artificial intelligence in exoskeletons understands how humans move and helps them move,” said researcher Dante A. Archangeli, co-author of the paper. The actuator of the device can be mounted on both left and right sides of the waist belt for application to any left or right leg.
power-bonding when pedaling is similar to an electric bike
the exoskeleton developed by professor renzi is a little different from the power suit of iron man, the movie’s protagonist, or any other exoskeleton suit that helps the operator lift heavy loads. it only provides enough additional force for the wearer to walk.
professor renzi likened the device to an electric bike that powers bike riders as they pedal uphill.
the research team tested the exoskeleton developed by recording metabolic rates of six patients with above-the-knee amputations. the oxygen inhalation and carbon dioxide levels represented by walking on the treadmill when the patients wore the exoskeleton and when they were not wearing it were measured.
tests showed that all test subjects had improved metabolic rates, resulting in an average 15.6% reduction in energy consumption while wearing an exoskeleton.
“This is like taking off a 26-pound (11.8 kg) backpack, which is actually a big step forward,” renzi said, “and although the average person is close to the energy they spend walking at the same speed, and depends on their fitness level, the metabolic consumption is indistinguishable from normal.”
another advantage, the research team said, is that the device is very light. the frame is made of carbon fiber, and other components are made of synthetic plastic and aluminum, and the entire exoskeleton weighs only 5.4 pounds (2.45 kg).
“you can walk a se km”
Stan Schaar, 74, who participated in the test, said, “When I used the exoskeleton, it was almost like a human leg.”
“When I first used it, my exoskeleton and my muscles were fully fused to help me move faster,” Shar said, adding, “My legs helped me relax, move forward, and walk, and I felt like I could walk even a few Km because my exoskeleton helped me move my muscles.”
professor renzi believes that this exoskeleton can be commercialized in a few years as soon as 100.30 years. the u.s. department of defense provided $985,000 for the development of this new exoskeleton for veterans with disabilities, and earlier this year received $584,000 in research from the national science foundation.
professor renzi expressed his expectation that “national science foundation grants will allow us to continue our development work to create better devices so that more people can walk well.”
