The Bigger the Better? Towards EMG-Based Single-Trial Action Unit Recognition of Subtle Expressions

Dennis Küster, Rathi Adarshi Rammohan, Hui Liu, Tanja Schultz, Rainer Koschke

2025

Abstract

Facial expressions are at the heart of everyday social interaction and communication. Their absence, such as in Virtual Reality settings, or due to conditions like Parkinson’s disease, can significantly impact communication. Electromyography (EMG)-based facial action unit recognition (AUR) offers a sensitive and privacy-preserving alternative to video-based methods. However, while prior research has focused on peak intensity action units (AUs), there has been a lack of research on EMG-based AURs for lightweight recording of subtle expressions at multiple muscle sites. This study evaluates EMG-based AUR for both low- and high-intensity expressions across eight AUs using two types of mobile electrodes connected to the Biosignal Plux system. The results of four subjects indicate that even limited data may be sufficient to train reasonably accurate AUR models. Larger snap-on electrodes performed better for peak-intensity AUs, but smaller electrodes resulted in higher performance for low-intensity expressions. These findings suggest that EMG-based AUR is viable for subtle expressions from short data segments and that smaller electrodes hold promise for future applications.

Paper Citation

in Harvard Style

Küster D., Rammohan R., Liu H., Schultz T. and Koschke R. (2025). The Bigger the Better? Towards EMG-Based Single-Trial Action Unit Recognition of Subtle Expressions. In Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIODEVICES; ISBN 978-989-758-731-3, SciTePress, pages 100-110. DOI: 10.5220/0013389300003911

in Bibtex Style

@conference{biodevices25,
author={Dennis Küster and Rathi Rammohan and Hui Liu and Tanja Schultz and Rainer Koschke},
title={The Bigger the Better? Towards EMG-Based Single-Trial Action Unit Recognition of Subtle Expressions},
booktitle={Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIODEVICES},
year={2025},
pages={100-110},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0013389300003911},
isbn={978-989-758-731-3},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 18th International Joint Conference on Biomedical Engineering Systems and Technologies - Volume 1: BIODEVICES
TI - The Bigger the Better? Towards EMG-Based Single-Trial Action Unit Recognition of Subtle Expressions
SN - 978-989-758-731-3
AU - Küster D.
AU - Rammohan R.
AU - Liu H.
AU - Schultz T.
AU - Koschke R.
PY - 2025
SP - 100
EP - 110
DO - 10.5220/0013389300003911
PB - SciTePress