Surface electromyography using dry polymeric electrodes

Abstract

Conventional wet Ag/AgCl electrodes are widely used in electrocardiography, electromyography (EMG), and electroencephalography (EEG) and are considered the gold standard for biopotential measurements. However, these electrodes require substantial skin preparation, are single use, and cannot be used for continuous monitoring (>24 h). For these reasons, dry electrodes are preferable during surface electromyography (sEMG) due to their convenience, durability, and longevity. Dry conductive elastomers (CEs) combine conductivity, flexibility, and stretchability. In this study, CEs combining poly(3,4-ehtylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) in polyurethane are explored as dry, skin contacting EMG electrodes. This study compares these CE electrodes to commercial wet Ag/AgCl electrodes in five subjects, classifying four movements: open hand, fist, wrist extension, and wrist flexion. Classification accuracy is tested using a backpropagation artificial neural network. The control Ag/AgCl electrodes have a 98.7% classification accuracy, while the dry conductive elastomer electrodes have a classification accuracy of 99.5%. As a conclusion, PEDOT based dry CEs were shown to successfully function as on-skin electrodes for EMG recording, matching the performance of Ag/AgCl electrodes, while addressing the need for minimal skin prep, no gel, and wearable technology.

Flexible PDMS Composite Electrodes with Boronic Acid-Modified Carbon Dots for Surface Electrophysiological Signal Recording

“…Wet Ag/AgCl electrodes utilize an electrolyte gel between the electrode and the surface of the skin, hence increasing the conductivity and reducing the contact impedance and motion artifacts. This, in turn, minimizes the unwanted noise extracted with the collected signal thereby achieving a higher signal-to-noise ratio (SNR) . Generally, wet electrodes offer advantages such as their low cost, low impedance at skin-electrode interface, and ease of operation .…”

“…This, in turn, minimizes the unwanted noise extracted with the collected signal thereby achieving a higher signal-tonoise ratio (SNR). 4 Generally, wet electrodes offer advantages such as their low cost, low impedance at skin-electrode interface, and ease of operation. 1 However, wet electrodes come with some long-term disadvantages including electrode gel drying and irritation of skin.…”

Highly Stretchable Self-Adhesive PEDOT:PSS Dry Electrodes for Biopotential Monitoring

“…The human epidermal biopotentials such as electromyography (EMG) − and electrocardiogram (ECG) are of great significance for the therapy and diagnosis of muscle and heart-related diseases . As these biopotentials can be electrically connected to the human body by skin electrodes, it is essential for efficient wearable electrodes to accurately record physiological signals.…”