Development of a Low-Cost and Multi-Size Foot Prosthesis for Humanitarian Applications uri icon

Abstract

  • © 2018 IEEE. Many different technology improvements in the area of prosthetics have contributed to the enhancement of healthcare and mobility for individuals living with an amputation. Although there are many lower-limb prosthetic products on the market, very few of them fulfill the accessibility and functionality requirements for humanitarian applications. Furthermore, passive (non-powered), yet dynamic foot prostheses must be custom-made for each amputee depending on body weight (BW), foot size and amputation laterality. Motivated by this unmet need in the market for low-cost prostheses, variations of the Tec-LIMBS prosthetic foot have been engineered for four different ranges of BWs while preserving a uniform shoe size and laterality. The method developed for engineering the composite material for each of the body weights was guided by a previously developed finite element (FE) model of the prosthetic foot. Using this FE model, the layup of a glass fiber multilayer composite has been engineered to produce the desired load-displacement response during the forefoot toe-off and heel-strike phases of gait. After multiple virtual iterations of layups for the keel and heel components, each of the four designed layups is prototyped and tested in a laboratory setting. Vacuum Assisted Resin Transfer Molding (VARTM) is utilized for fabricating the prototypes. The combined set of four different foot prosthesis layups have been designed to cover a total range of BWs from 55 kg to 110 kg. Further, the loading conditions for these BWs are defined based on the AOPA standard. The results of the quasi-static laboratory tests carried out on the prototyped foot prostheses confirm the effectiveness of the method based on results from the FE model to scale the BW capacity, thereby tailoring the prosthesis design to the end-user. This work, along with prior work [15] [16], will enable personalizing prostheses for performance in the manufacturing environment of local clinics in developing regions. Furthermore, a small investment in the molds is the only requirement for producing the TEC-LIMBS foot locally, thereby improving functionality and usability of this foot prosthesis in humanitarian conditions as well as ensuring economic accessibility.

Publication date

  • January 3, 2019