Researchers design cheap prosthetic knee that mimics normal walking motion
In the last two decades, prosthetic limb technology has grown by leaps and bounds. Today, the most advanced prostheses incorporate microprocessors that work with onboard gyroscopes, accelerometers, and hydraulics to enable a person to walk with a normal gait. Such top-of-the-line prosthetics can cost more than $50,000.
Amos Winter is aiming to develop a passive, low-tech prosthetic knee that performs nearly as well as high-end prosthetics, at a fraction of the cost.
“We’re going after this disruptive opportunity,” says Winter, an assistant professor of mechanical engineering at MIT. “If we can make a knee that delivers similar performance to a $50,000 knee for a few hundred dollars, that’s a game-changer.”
Now Winter and his colleagues have taken a significant step toward that goal. In a paper published in IEEE Transactions on Neural Systems and Rehabilitation Engineering, the team reports that it has calculated the ideal torque that a prosthetic knee should produce, given the mass of the leg segments, in order to induce able-bodied kinematics, or normal walking.
Using the paper’s results, the group has built a prototype of a prosthetic knee that generates a torque profile similar to that of able-bodied knees, using only simple mechanical elements like springs and dampers. The team is testing the prototype in India, where about 230,000 above-knee amputees currently live.
“In places like India, there’s still stigma associated with this disability,” Winter says. “They may be less likely to get a job or get married. People want to be incognito if they can.”
The paper’s co-authors include graduate student Murthy Arlekatti and Yashraj Narang, a PhD student at Harvard University.
Most amputees in developing countries wear passive prostheses — simple, cheap designs with no moving parts. “When you see people walk in them, they have a pretty distinctive limp,” Winter says. In part, that’s because passive prostheses do not adjust the amount of torque exerted as a person walks. For instance, in normal walking, the knee flexes slightly, just before the foot pushes off the ground — a shift in torque that keeps a person’s center of mass steady. In contrast, a stiff, unbending prosthetic knee would cause a person to bob up and down with each step.
Winter reasoned that in order to produce a passive prosthetic knee that mimics normal walking, he would have to also mimic the changing forces, or torque profile, during normal walking. He and his team looked through the scientific literature for data on normal walking, and found a complete dataset that represented one person’s gait, including the angle of their joints, the weight of each leg segment, and the ground reaction force — the force between the ground and the foot — during a single step, or gait cycle.
The researchers used the measurements to calculate a torque profile — the amount of torque generated by the knee during normal walking. As prostheses are generally one-third to one-half as heavy as human legs and feet, the researchers adjusted the torque profile to apply to lighter leg segments.
“If you applied healthy levels of torque to a much lighter limb, your kinematics would get all screwed up,” Winter says. “Robotic limbs are designed to dial that torque back. Our challenge was, how do you tune the torque profile to get able-bodied motion, with a passive prosthetic knee?”
The researchers then looked at whether they could build a prosthetic knee to replicate the adjusted torque profile, using simple mechanical elements. Currently, the group has engineered a simple prototype that includes a spring and two dampers that act as brake pads. The spring allows the knee to bend just before the foot pushes off the ground. At the same time, the first damper engages to prevent the leg from swinging back. The second damper engages as the leg swings forward, in order to slow it down just before the heel strikes the ground.
Winter’s team is now testing the design with volunteers in India.
Read more: A cheaper, high-performance prosthetic knee
The Latest on: High-performance prosthetic knee
via Google News
The Latest on: High-performance prosthetic knee
- Global Digital Interface Design Market Analysis by 2020-2025on November 22, 2020 at 6:31 pm
Global Info Research offers a latest published report on Digital Interface Design Analysis and Forecast 2019-2025 delivering key insights and providing a competitive advantage to clients through a ...
- Innovation Celebrationon November 21, 2020 at 4:00 pm
Plié microprocessor-controlled knee, manufactured and submitted by Freedom Innovations ... The Amaris excimer laser is a high-performance medical laser used in corneal refractive surgery for permanent ...
- Forensic science internationalon November 12, 2020 at 4:00 pm
The case of a prosthetic limb used to cause lethal ... methyl]ethanamine] in fluids and tissues determined by high performance liquid chromatography with tandem mass spectrometry from a traumatic ...
- How medical innovations are making life-changing differenceson November 4, 2020 at 4:00 pm
His work on high-performance prosthetics has led him to open his own manufacturing company, BioDapt, which markets the Moto Knee and Versa Foot. The business has already support hundreds of users.
- Pythia’s Halloween Wicked Witch Tutorial and Product Must-Haveson October 29, 2020 at 12:41 pm
Prosthetics: Build the Foundation clownantics.com Build out those wicked witch features using these prosthetics. Witch Nose and Chin The post Pythia’s Halloween Wicked Witch Tutorial and ...
- Hit by a boat in the ocean, he watched his arm fall off. Now Carter Viss tells his tale of survivalon October 19, 2020 at 5:40 am
More than 10 months later, after seven surgeries and 68 days in the hospital, Viss is getting used to his prosthetic arm ... Verado outboard engines with high-performance lower units and five ...
- Proteor to Expand Lower Limb Prosthetics Portfolio Through Its Acquisition of Freedom Innovations Assetson October 9, 2020 at 12:00 pm
Proteor USA, LLC, a wholly owned subsidiary of the France based, Proteor Group, has signed an agreement with Ottobock to acquire a significant portion of the lower limb prosthetics portfolio ... by ...
- Executive 360on August 14, 2020 at 2:36 pm
Executive 360 is a comprehensive health evaluation designed for high-performance individuals. When it comes to health, peace of mind comes from thoroughness and precision. Executive 360 is a ...
- The IOC Centres of Excellence bring prevention to Sports Medicineon July 29, 2018 at 12:24 pm
In recent years, these actions within high-performance sport have been undertaken as collaborations ... and the Canadian Institutes of Health Research funded programme ‘Consequences of knee joint ...
- Unity Knee Fifth Generation Knee System from Corinon August 7, 2017 at 8:44 am
The Unity Knee has been designed as a high performance, knee platform. Combining innovative implant design concepts, advanced manufacturing technology and state of the art Unity ...
via Bing News