Design and Prototyping of Low Cost, 3D Printed Body Powered Hand Prosthesis for Transradial Amputees in Bolivia

Abstract

Hand prostheses are crucial in improving the quality of life for individuals with upper limb amputations, enabling them to regain functional capabilities and reintegrate into society. However, in countries like Bolivia, the elevated prices of commercial hand prostheses and their complex acquisition represent a major barrier for the 15.000 individuals in the country who need them. With the development of myoelectric prostheses, options for users are limited to more expensive models each time, thus body-powered prostheses have slowly stopped being developed despite their advantages concerning weight, force, and self-power. On the other hand, in the last few years, many prostheses have been developed taking advantage of the recent accessibility of 3D printers. In this work, we analyze the general problems of the distinct types of prostheses and define parameters of design, actuation, and material, finishing with a trans-radial hand prosthesis which is body-powered, hydraulic, printed in rigid and flexible filaments and contains a limited number of external elements to provide Bolivians a local, low-cost option with light and simple use, and accessible maintenance in the most remote areas in the country. The hand prosthesis, weighing 338 grams and 545 grams with the actuator, was evaluated with a portion of the SHAP (South Hampton Assessment Procedure) test with the help of a volunteer user who accomplished half of the tasks selected. The cost of the developed prosthesis is 33 USD.