Engineering students at Imperial College London developed a rotational adapter to allow people with transfemoral amputations to adjust their prostheses when they want to sit cross-legged, pray, or drive. The project was funded with a grant from the Institution of Mechanical Engineers (IMechE) for the International Committee of the Red Cross (ICRC).
The students found that existing adapters were incompatible with the polypropylene prosthetic system provided by the ICRC. The adapter needs to be designed with injection molding and comply with ISO 10328, a standard for the strength of lower-limb prostheses.
“When I first heard ‘rotational adapter,’ in my head it sounds like it just allows free rotation. That’s not the case,” Prithvi Philip, project lead for Imperial College’s Prosthetic Society, told IMechE. “You can press a button that allows you to rotate your leg when you need it to be rotated, such as when you sit cross-legged. And then once you’re done, you can rotate your leg back, then it locks in place.”
Through codesign with experienced researchers, the students prototyped several variants using a combination of 3D printing and CNC machining.
“Things as simple as tying a shoelace can be made a lot easier by the ability to access your foot,” Philip said. “There are some other considerations we want to take into account…, such as dust ingress and water ingress, which are important considerations in low-to-middle-income countries.”
“The [IMechE] funding has enabled us to prototype using materials that would normally be out of reach for student projects, producing a more accurate representation of the final product,” said team member Sara Galal. “In addition, it has enabled us to transition further along the development process through increased design iterations, ultimately leading to a more refined and stronger final outcome.”
Editor’s note: This story was adapted from materials provided by IMechE.
