A University of Texas at Dallas professor applied robot control theory to enable powered prosthetics to dynamically respond to the wearer’s environment and help amputees walk.
In research available online and in an upcoming print issue of IEEE Transactions on Robotics, wearers of the robotic leg could walk on a moving treadmill almost as fast as an able-bodied person.
“We borrowed from robot control theory to create a simple, effective new way to analyze the human gait cycle,” said Dr. Robert Gregg, a faculty member in the Erik Jonsson School of Engineering and Computer Science and lead author of the paper. “Our approach resulted in a method for controlling powered prostheses for amputees to help them move in a more stable, natural way than current prostheses.”
Humanoid robots can walk, run, jump and climb stairs autonomously, but modern prosthetics limit similar actions in humans. While prosthetics have been made lighter and more flexible, they fail to mimic the power generated from human muscles in able-bodied individuals. Powered prostheses, or robotic legs, have motors to generate force, but lack the intelligence to stably respond to disturbances or changing terrain.
Control engineers view the human gait cycle through the lens of time — the interval at which each movement in the walking cycle needs to occur. Gregg, an assistant professor of bioengineering and mechanical engineering, proposed a new way to view and study the process of human walking: measuring a single variable that represents the motion of the body. In this study, that variable was the center of pressure on the foot, which moves from heel to toe through the gait cycle.
“The gait cycle is a complicated phenomenon with lots of joints and muscles working together,” Gregg said. “We used advanced mathematical theorems to simplify the entire gait cycle down to one variable. If you measure that variable, you know exactly where you are in the gait cycle and exactly what you should be doing.”
Gregg first tested his theory on computer models, and then with three above-knee amputee participants at the Rehabilitation Institute of Chicago, an affiliate of Northwestern University. He implemented his algorithms with sensors measuring the center of pressure on a powered prosthesis. Inputted with only the user’s height, weight and dimension of the residual thigh into his algorithm, the prosthesis was configured for each subject in about 15 minutes. Subjects then walked on the ground and on a treadmill moving at increasing speeds.
“We did not tell the prosthesis that the treadmill speed was increasing. The prosthesis responded naturally just as the biological leg would do,” Gregg said.
The participants were able to move at speeds of more than 1 meter per second; the typical walking speed of fully able-bodied people is about 1.3 meters per second, Gregg said. The participants also reported exerting less energy than with their traditional prostheses.
The Latest on: Prosthetic legs
via Google News
The Latest on: Prosthetic legs
- Goose receives artificial legs after being rescued from ice-covered pondon March 3, 2021 at 3:00 pm
A goose was recently rescued from a pond at the Harbour Club Apartments in Centerville after becoming stuck in the ice. According to a Facebook post that was sent to News Center 7, a maintenance tech ...
- New Type of Amputation Surgery May Enable Better Control of Prosthetic Limbson February 26, 2021 at 6:22 am
Reconnecting muscle pairs during amputation gives patients more sensory feedback from the limb. MIT researchers have invented a new type of amputation surgery that can help amputees to better control ...
- He’s a good boy: Two-legged dog fitted with prosthetic leg [photos]on February 25, 2021 at 5:47 am
Meet Eddie, a two-legged dog that had overcome a terrible start to life. He was fitted with a prostethic leg on Valentine's Day.
- Prosthetic limbs give Lebanese new hopeon February 22, 2021 at 8:36 pm
BEIRUT, Lebanon－Nihad Abou Dargham is a 60-year-old Lebanese who never imagined he would return to work at his farm after his leg was amputated three years ago when a cluster bomb exploded in a field ...
- SEE IT: Koala with prosthetic foot gets new lease on lifeon February 22, 2021 at 7:08 pm
A koala in Australia is bear-y happy after being fitted with a prosthetic limb. A dentist recently crafted a prosthetic foot for the marsupial named Triumph, who was born with three feet, according to ...
- Lebanese association launches initiative to provide free prosthetic limbs for cluster bombs' victimson February 22, 2021 at 6:22 pm
A technician installs an artificial leg for a victim of cluster bombs at a center launched by the Vision Association for Development Rehabilitation and Care in the Bekaa town of Lebanon, on Feb. 20, ...
- Prosthetic foot a triumph for three-legged koalaon February 22, 2021 at 3:00 pm
SYDNEY • Triumph, a male koala born without a foot, has been climbing and running since he was fitted with a prosthetic one made by a neighbourhood dentist, an Australian wildlife carer said yesterday ...
- Cancer survivor to be the youngest American in space, first with prosthetic body parton February 22, 2021 at 1:05 pm
A former patient at St. Jude Children's Research Hospital who survived bone cancer will become the youngest American to travel to space and the first to do so with a prosthetic limb when she joins a ...
- Triumph the koala climbs and runs with prosthetic foot made by Australian dentiston February 22, 2021 at 8:08 am
Triumph, a male koala born without a foot, has been climbing and running since he was fitted with a prosthetic one made by a neighborhood dentist, an Australian wildlife carer said ...
- Australian dentist gifts koala new prosthetic footon February 22, 2021 at 5:05 am
Triumph the koala was rescued with only three legs. Now, he climbs and runs with his new prosthetic foot and is "exhausted" from all the attention it is bringing him.
via Bing News