08.05.17 - The EPFL and International Committee of the Red Cross launched the research and development phase of its joint project in early 2017. The project, in the form of a CTI (Commission for Technology and IInnovation) project, will last until the end of 2018. The first stage, which consisted of evaluating the performances of different types of prosthetic feet, has just been completed.

A prosthetic foot with advanced design features for Global South countries

Agilis is working to develop a prosthetic foot designed for use by amputees with high mobility needs, in the hopes of improving their capacity for socio-economic integration. Much of the technology currently available in developed countries is often out of reach in South countries due to cost. Moreover, these technologies are generally not adapted for use in these countries (durability, aesthetic aspect, etc.). The project aims to meet this growing worldwide need through targeted technology.

The CODEV’s EssentialTech program, the project’s leader, along with the Laboratory of Movement Analysis and Measurement (LMAM), the Laboratory of Applied Mechanics and Reliability Analysis (LMAF) and the Laboratory for Processing of Advanced Composites (LPAC) together form the EPFL’s "taskforce." The International Committee of the Red Cross and CR Equipements SA, an orthopedic components manufacturer, complete the alliance, bringing with them knowledge of the field and industrial craftsmanship.

Understanding the biomechanical functions of prosthetic limbs

There are currently a multitude of prosthetic feet are available on the market. These products offer a variety of features ranging from walking in a confined context to outdoor sports. The design and materials used determine the prosthesis’s performance and manufacturing cost.

To better understand the option the different designs offer, a comparative study of the prostheses currently available on the market was done. The decision was made not to call on amputees initially, but instead to modify the ankle immobilization splints in order to affix the prostheses to them (see photo). This device proved very effective when tested by several able-bodied volunteers on the prostheses models selected.

After an ICRC orthoprosthetist aligned and adjusted each subject’s prosthesis, the LMAM laboratory analyzed and broke down the walking cycle, the ground impact and the prostheses’ deformation during various tests.

The results were then compared with the static machine tests carried out in the LMAF laboratory to make the link between design, rigidity and dynamic performance.

Next step: designing a new prosthesis

The yearlong design phase is now underway at the LMAF laboratory. The goal is to propose an innovative, efficient design that gives the prosthesis advanced biomechanical performance functions, thus allowing the user to walk as naturally as possible.

As the prosthesis is designed for humanitarian needs, limiting manufacturing costs is key for promoting the widest possible access to the new product. The “cost modeling” approach developed by the LPAC laboratory helped identify potential materials and processes while controlling costs linked to their use at the design stage.

The EssentialTech program's approach aims to improve the impact on the target market through tailored technologies and a business model that takes into account contextual specificities—an approach that will be applied throughout the development process to ensure the project’s success.

Author:Grégory HuotSource:Cooperation