An EMG-Based Deep Learning Approach for Multi-DOF Wrist Movement Decoding

In robotics, decoding complex human movements of multiple degrees of freedom from surface electromyography (sEMG) remains challenging. Recently, the rapid development of artificial intelligence (AI) technology provides a new solution to this problem. In this article, we propose an AI-based framework that consists of a series of deep learning approaches for achieving a precise and robust decoding on three-dimensional (3-D) wrist movements. A previously developed device (wrist movement detector) was utilized to tag the myoelectric signals with 3-D kinematic labels. A public dataset (HIT-SimCo) was established, wherein the sEMG signals were collected from diverse wrist movements and multiple subjects. A lightweight convolutional neural network was constructed, which can extract the motion-related features directly from raw sEMG, and make motion predictions in an end-to-end manner. In addition, several data augmentation strategies were explored to improve the robustness of the model against environmental variations; and a fine-tuning policy was proposed to further improve the subject-specific accuracy. The decoding model was finally tested in three scenarios: a robotic arm/hand system performing daily-living tasks (pouring, screwing, etc.), a supernumerary robotic hand playing blocks-building, and a virtual prosthesis conducting motor rehabilitation training.