A helping hand for prosthetic accessibility
Prostheses for digit amputees are expensive and often inaccessible, which has spurred the creation of a 3D-printed finger prosthetic that is both inexpensive and robust.
David Edquilang, a recent University of Houston graduate (TX, USA), has developed a 3D-printable prosthesis for finger amputees that restores functionality. The open-source, freely available design hinges on simplicity to deliver a sturdy, functional and accessible product, for which it was awarded the prestigious 2023 Red Dot: Luminary Award.
Current prostheses for digits are complex and expensive, often requiring metal fasteners, special adhesives and tools to assemble. This complexity and cost combine with their perceived level of importance, which medical insurance companies place below arm or leg prostheses, often meaning that they are not available on insurance.
“The problem with higher mechanical complexity is that these designs are less durable,” Edquilang stated. “The more parts you have, the more points of failure. You need to make prosthetic fingers robust and as strong as possible, so it doesn’t break under normal use, yet you want the design to be simple.
To address this inaccessibility, Edquilang created a prosthesis composed of common 3D-printed plastics: polylactic acid and thermoplastic polyurethane. In comparison to other finger prostheses, Edquilang’s prosthetic fingers are made up of only 4 parts and are held together with simple, plastic pins. The motion of the prosthesis is modeled on arcs and circular orbits, giving rise to its name “Lunet”.
Lunet’s low number of components reduces the likelihood of mechanical failure, making it more durable and robust for patient’s everyday use.
Optimizing the human–machine interface of prostheses
An interdisciplinary team of researchers has developed a human–machine interface that improves the prosthetic connection to the residual limb, making it more comfortable and reliably effective.
Another important consideration of Lunet is that it expands the amputee’s accessibility to prostheses. Lunet provides a low-cost solution to standard prosthetics which can cost thousands of dollars and which are often not considered vital enough to warrant medical insurance coverage. In addition, Edquilang has made the design open access, enabling the prosthesis to be produced by any capable 3D printer without the need to pay for a license, cementing its accessibility.
“Not every good idea needs to be turned into a business. Sometimes, the best ideas just need to be put out there. Making Lunet available online for free will allow it to help the greatest number of people,” commented Edquilang.
The prosthesis was awarded the Red Dot 2023 Luminary Award, the highest level of recognition accorded at the international design competition, and could prove life-changing for many finger amputees who could not previously afford a prosthetic.