Myoelectric Thumb Prosthesis for Fine Motor Tasks in a Transmetacarpal Amputation Case: Interdisciplinary Approach of Health and Biomechanical Engineering

Gómez A.P.Q.; Quispe A.M.C.; Tacza Y.V.; Mamani J.M.Z.; Rios R.J.C.; Vela-Anton P.; Shah D.; Ganga T.A.; Kunkel M.E. · IFMBE Proceedings (2025) · DOI: 10.1007/978-3-031-93646-3_18

Resumen

The thumb is vital for manual dexterity and precision movements. Thumb amputation significantly impairs hand function by 60% and grip strength by 20%. This study presents a customized mechanical thumb prosthesis with a myoelectric system. Developed at the Prototyping Laboratory of the Universidad Peruana Cayetano Heredia (UPCH), the prosthesis replicates thumb opposition through activation by superficial flexor muscle contraction. Manufacturing utilized advanced CAD/CAE/CAM tools, considering anatomical and biomechanical characteristics. Additive manufacturing using poly lactic acid (PLA) and Thermoplastic Polyurethane (TPU) materials was employed. Integrated hardware includes a 180° rotation servomotor for distal (49.7°) and proximal (41.7°) phalanges movement, triggered by myoelectric signals. Prosthesis software aligns with biomechanical analysis, for precise pinching movements. Results confirm functionality in generating thumb opposition and pinching movements for fine motor tasks. This interdisciplinary approach shows promise in prosthesis development, particularly for transmetacarpal amputation. © Brazilian Society of Biomedical Engineering 2025.

Instituciones: Universidad Peruana Cayetano Heredia