Design and Fabrication of a Low-Cost Prosthetic Hand with Electromyographic Signal Control for Upper-Limb Amputees in Katsina State

Upper-limb amputation resulting from trauma, diabetes, and other medical conditions affects a significant number of individuals in Katsina State, North West Nigeria, yet access to functional and affordable prosthetic hands remains extremely limited. This project presents the design and fabrication of a low-cost myoelectric prosthetic hand that uses electromyographic signals from residual limb muscles to control finger movements. Surface EMG electrodes detect muscle electrical activity from the forearm stump, and the signals are amplified, filtered, and fed into an Arduino Nano microcontroller. A trained threshold-based classifier distinguishes between open-hand and close-hand gesture intentions, driving five servo motors arranged within a 3D-printed hand scaffold to execute corresponding movements. The 3D printing was executed using polylactic acid filament, resulting in a total device weight of 340 grams. Clinical testing was conducted with eight volunteer amputees recruited through Katsina General Hospital, each undergoing a two-week adaptation and training protocol. By the end of the training period, six of the eight participants successfully performed basic grasp tasks including holding a cup, gripping a pen, and picking up a smartphone. Total fabrication cost per unit was approximately 45,000 Naira, representing a fraction of the cost of imported commercial myoelectric prosthetics. The study discusses signal reliability challenges under physical exertion and recommends machine learning classification for improved grip pattern recognition in future iterations. Keywords: myoelectric prosthetic, EMG signal, 3D printing, upper limb amputee, Katsina State