Diseño y construcción de una prótesis de mano con sistema de agarre basado en un mecanismo tipo pinza de dos grados de libertad

Abstract

The technical project arises from the need to increase interest in hand prosthesis technology, especially those adaptable to various ages. Given the limited availability of this type of technology in the country, the aim is to improve the quality of life of disabled people. The main objective is to design and build a hand prosthesis based on a clamp-type mechanism with two degrees of freedom, controlled by myoelectric signals, to achieve a shape as similar as possible to the position of a human clamp. Considering the functional importance of the index, middle, and thumb fingers in daily life, a QFD analysis was carried out to identify challenges and chart a safe path toward the goal. An analysis of different mechanisms was initiated to determine the modules of the prosthesis, selecting them using weighted criteria. Simultaneously, the biomechanics of the hand and its anthropometry were studied to obtain measurements adaptable to an adult hand. Using SolidWorks, the elements of the prosthesis were modeled according to the selected measurements and mechanisms. Considering the programs mentioned in the methodology, materials and manufacturing processes were determined through CAE analysis. Finally, the control of the electronic system was carried out through programming on the Arduino platform, ensuring the necessary security with appropriate components. This methodology allowed us to obtain critical characteristics of the prosthesis, including the overall safety factor, control through myoelectric signals, and, crucially, a compliance level of 73% in the desired hand positions during the tests. In context, the selection of mechanisms, measurements, control system components, and other variables, as well as the manufacturing process, met the requirements, overcoming the challenges and achieving the project's general objective.