An Ultra-Low-Cost, Pressure Sensing and Haptic Feedback-Enabled Transradial Prosthesis

Abstract

Transradial prostheses frequently lack intuitivity and responsiveness, constraining their suitability for everyday use. The high prevalence of below-the-elbow amputations in low- and middle-income countries underscores the need for affordable and functional prostheses. This study presents WeArm, a low-cost prosthesis that is lightweight, flexible, and provides haptic and pressure feedback. Our innovative design merges soft and articulated robotics, incorporating a 3D-printed, five-finger polyarticulated joint system made of rigid and flexible resin. Thin-film pressure sensors regulate soft inflatable haptic actuators, relaying a sense of touch to the amputee. We developed a gradient convolution kernel compensation algorithm (gCKC) for detecting and decoding amputee motor units. The gCKC, coupled with a convolutional neural network demonstrated an ROC of 90.38 ± 0.05%, a sensitivity of 0.83 (IQR 0.16), and a specificity of 0.89 (IQR 0.18) in decoding sEMG signals and accurately actuating the prosthetic arm, determined using sixfold cross-validation. The complete system cost $379.89 to produce. WeArm introduces a novel, cost-effective, and efficient prosthetic solution with the potential to enhance amputees’ quality of life and mobility.