Automated Neuromuscular Assessment: Machine-Learning-Based Facial Palsy Classification Using Surface
Ibrahim Manzoor1, Aryana Popescu1, Sarah Ricchizzi1
1Department of Neurosurgery and Neurotechnology, Eberhard Karls University, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany.
Sensors (Basel, Switzerland)
|January 10, 2026
Summary
Facial palsy (FP) severity can be predicted using facial surface electromyography (EMG) and machine learning models. This automated approach offers a reliable alternative to subjective clinical assessments for diagnosing facial nerve function.
Area of Science:
- Biomedical Engineering
- Neurology
- Machine Learning Applications
Background:
- Facial palsy (FP) significantly impacts facial muscle control, leading to asymmetry and emotional expression difficulties.
- Current assessment methods like the House-Brackmann (HB) score are subjective and examiner-dependent.
- Objective and consistent FP assessment is crucial for effective diagnosis and management.
Purpose of the Study:
- To develop and evaluate an automated system for predicting facial palsy severity using facial surface electromyography (EMG).
- To compare the performance of various machine learning models in classifying FP grades based on EMG data.
- To establish a non-invasive, objective alternative to traditional clinical scoring methods for FP.
Main Methods:
- Facial surface EMG data were collected from 58 subjects during specific facial movements (smile, eye closure, forehead raising).
- Time-domain EMG features were extracted and analyzed using nine different machine learning models.
- Model performance was assessed using accuracy, precision, recall, and F1-score metrics.
Main Results:
- Ensemble-based machine learning models, specifically random forest and decision tree ensembles, demonstrated the highest effectiveness.
- Classification accuracies for these models ranged from 81.7% to 84.8%, depending on the facial movement analyzed.
- The models reliably distinguished between different grades of facial palsy using non-invasive EMG signals.
Conclusions:
- Ensemble-based machine learning models provide a robust and reliable method for automated facial palsy grading using EMG.
- This approach offers an objective alternative to subjective clinical assessments, enhancing diagnostic consistency.
- The proposed method has the potential to improve longitudinal monitoring in both clinical and research settings for facial palsy.


