A Cost-Effective, Thermally Optimized Transradial Prosthesis using Nylon PA12: A Single-Subject Case Study on Mechanical and Functional Validation

Resumen

Upper limb amputation has a major impact on quality of life; however, the cost of traditional prostheses is often beyond the reach of users in developing economies. Though 3D printing has enhanced accessibility, the commonly used material, PLA, is prone to degradation and also generates heat within the socket. This paper describes a single-subject case study concerning the development of a low-cost, thermally optimized transradial prosthesis made from Nylon PA12. The device was designed using a User-Centered Design approach and customized through 3D scanning and validated via Finite Element Analysis (FEA). Most importantly, material properties used in the simulation were not generic but experimentally characterized according to ASTM D638, ASTM D790, and ISO 868 standards. The simulation gave an FOS value greater than 3.0 for the critical load of 300 N. Additionally, flammability testing (ISO 11925-2) and thermographic analysis proved that the Nylon PA12 socket can be considered as safe self-extinguishing thermal insulation. Functional field tests indicated that the participant was able to manipulate industrial tools with a weight of up to 5 kg successfully. These preliminary findings indicate that experimentally characterized Nylon PA12 can be considered as an alternative material for affordable rehabilitation concerning mechanical durability and thermal comfort in low-resource settings.