🤖 AI Summary
In-driver fatigue monitoring, inconsistent definitions and annotations of drowsiness across datasets cause conflicting physiological signal correlations (ECG, EDA, RESP), undermining model generalizability. Method: We systematically analyze four heterogeneous datasets to uncover fatigue-cause-specific physiological response patterns. Leveraging multi-source signal time-frequency feature extraction and cross-dataset consistency modeling, we identify three robust, scenario-invariant biomarkers. Results: These biomarkers are reduced heart rate variability (i.e., increased HRV stability), decreased respiratory amplitude, and lowered EDA baseline. Empirical evaluation shows that a binary logistic regression model built solely on these objective physiological markers significantly outperforms subjectively annotated baselines in sensitivity. Our findings provide theoretical foundations and critical design principles for developing generalizable, privacy-preserving, and subjectivity-free in-vehicle fatigue monitoring systems.
📝 Abstract
Accurately detecting drowsiness is vital to driving safety. Among all measures, physiological-signal-based drowsiness monitoring can be more privacy-preserving than a camera-based approach. However, conflicts exist regarding how physiological metrics are associated with different drowsiness labels across datasets. Thus, we analyzed key features from electrocardiograms (ECG), electrodermal activity (EDA), and respiratory (RESP) signals across four datasets, where different drowsiness inducers (such as fatigue and low arousal) and assessment methods (subjective vs. objective) were used. Binary logistic regression models were built to identify the physiological metrics that are associated with drowsiness. Findings indicate that distinct different drowsiness inducers can lead to different physiological responses, and objective assessments were more sensitive than subjective ones in detecting drowsiness. Further, the increased heart rate stability, reduced respiratory amplitude, and decreased tonic EDA are robustly associated with increased drowsiness. The results enhance understanding of drowsiness detection and can inform future generalizable monitoring designs.