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Photo: Joseph Xu/Michigan Engineering
Details on the design and clinical tests of an open-source bionic leg are now freely available online, so that researchers can hopefully create and test safe and useful new prosthetics.
Bionic knees, ankles and legs under development worldwide to help patients walk are equipped with electric motors.
Getting the most from such powered prosthetics requires safe and reliable control systems that can account for many different types of motion: for example, shifting from striding on level ground to walking up or down ramps or stairs.
However, developing such control systems has proven difficult. “The challenge stems from the fact that these limbs support a person's body weight,” says Elliott Rouse, a biomedical engineer and director of the neurobionics lab at the University of Michigan, Ann Arbor.
“If it makes a mistake, a person can fall and get seriously injured. That's a really high burden on a control system, in addition to trying to have it help people with activities in their daily life.”
Part of the problem with designing these control systems is the fact that many research groups don't have access to prosthetic legs for testing purposes.
As such, they have to either build their own, which is expensive and time-consuming, or rely on virtual testing, which may not adequately emulate real-life situations.
To solve this problem, Rouse and his colleagues have developed the Open Source Leg.
The scientists detailed their research findings online today in the journal Nature Biomedical Engineering.
Accompanying the artificial limb are free-to-copy step-by-step guides meant to assist researchers looking to assemble it or order parts for it.
The Michigan group has also produced videos illustrating how to build and test the hardware, and has developed code for programming the prosthetic to walk using a preliminary control system.
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Tracking Respiratory Droplets on The Fly
A new technique in fiber printing generates tiny 3D sensors that can sense breath escaping from masks
by Emily Waltz
Image: University of Cambridge
Covid-19 spreads via droplets expelled from an infected person’s lungs, so determining how the release of moisture is affected by different masks is an important step towards better protective gear.
Now, using a new technique in 3D printing, University of Cambridge researchers have created tiny, freestanding, conducting fibers they claim can detect respiratory moisture more effectively than anything currently on the market.
The researchers demonstrated the fiber sensors by testing the amount of breath moisture that leaks through face coverings.
They attached their fiber array to the outside of the mask, wired it to a computer, and found that it outperformed conventional planer chip-based commercial sensors, particularly when monitoring rapid breathing. (A paper describing the invention was published today in the journal Science Advances.)
Dubbed “inflight fiber printing,” the technique enables the researchers to print the fibers and hook them into a monitoring circuit, all in one step.
“Previously you could have very small conducting fiber production but it could not be incorporated directly into a circuit,” says Shery Huang, a lecturer in bioengineering at the University of Cambridge who led the research.
“The main innovation here is we can directly incorporate these small conducting fibers onto the circuit with designable fiber pattern structures,” she says.