TrustEMG-Net: Using Representation-Masking Transformer with U-Net for Surface Electromyography Enhancement

TL;DR

TrustEMG-Net is a novel neural network combining U-Net and Transformer for robust, generalized surface electromyography denoising, outperforming existing methods across various noise types and SNR conditions.

Contribution

It introduces TrustEMG-Net, a new neural network architecture that effectively denoises sEMG signals using a representation-masking transformer with U-Net, enhancing robustness and generalization.

Findings

Achieves at least 20% improvement over existing methods.

Performs consistently across five contaminant types and SNRs from -14 to 2 dB.

Proves the effectiveness of the representation-masking approach.

Abstract

Surface electromyography (sEMG) is a widely employed bio-signal that captures human muscle activity via electrodes placed on the skin. Several studies have proposed methods to remove sEMG contaminants, as non-invasive measurements render sEMG susceptible to various contaminants. However, these approaches often rely on heuristic-based optimization and are sensitive to the contaminant type. A more potent, robust, and generalized sEMG denoising approach should be developed for various healthcare and human-computer interaction applications. This paper proposes a novel neural network (NN)-based sEMG denoising method called TrustEMG-Net. It leverages the potent nonlinear mapping capability and data-driven nature of NNs. TrustEMG-Net adopts a denoising autoencoder structure by combining U-Net with a Transformer encoder using a representation-masking approach. The proposed approach is evaluated using the Ninapro sEMG database with five common contamination types and signal-to-noise ratio (SNR) conditions. Compared with existing sEMG denoising methods, TrustEMG-Net achieves exceptional performance across the five evaluation metrics, exhibiting a minimum improvement of 20%. Its superiority is consistent under various conditions, including SNRs ranging from -14 to 2 dB and five contaminant types. An ablation study further proves that the design of TrustEMG-Net contributes to its optimality, providing high-quality sEMG and serving as an effective, robust, and generalized denoising solution for sEMG applications.