Facial Expression-Based Pain Analysis Using Deep Learning Models
Keywords:
RNN, MIntPAIN, BioVid, UNBC-McMaster, Deep LearningAbstract
Pain is a key physiological signal of potential harm or dysfunction. While many can describe their pain, others, such as infants, unconscious patients, or those with speech impairments, cannot. In these cases, automated pain assessment is essential. Facial expressions offer a reliable, objective, and noninvasive means for real-time pain analysis. In This paper reviews deep learning algorithms for facial expression-based pain detection, comparing models developed between 2017 and 2025. It examines performance across datasets such as UNBC-McMaster, BioVid, MIntPAIN, and paediatric pain datasets. Advanced architectures, including convolutional neural networks, recurrent neural networks, Vision Transformers, and hybrid ensembles, have achieved up to 98.7% accuracy. The paper concludes with an overview of current challenges and future directions for real-time clinical use.
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