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Drowsiness Detection System Based on PERCLOS and Facial Physiological Signal
Robert Chen-Hao Chang1,2, Chia-Yu Wang1, Wei-Ting Chen1
1Department of Electrical Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
Sensors (Basel, Switzerland)
|July 27, 2022
Summary
This study introduces a novel drowsiness detection system combining heart rate variability and eyelid closure for safer driving. The non-contact system accurately identifies driver fatigue, enhancing road safety.
Area of Science:
- Biomedical Engineering
- Transportation Safety
- Human-Computer Interaction
Background:
- Fatigue-related accidents are a significant public safety concern.
- Current driver monitoring systems often rely on intrusive methods or lack robustness.
- Assessing driver alertness through physiological signals and eye-tracking is crucial for accident prevention.
Purpose of the Study:
- To develop an accurate and robust non-contact drowsiness detection system for drivers.
- To integrate heart rate variability (HRV) analysis with eyelid closure monitoring (PERCLOS) for improved fatigue assessment.
- To validate the system's performance against electroencephalography (EEG) signals.
Main Methods:
- Utilized photoplethysmographic imaging (PPGI) to derive the LF/HF ratio from HRV, indicating sympathetic/parasympathetic nervous system balance.
- Employed a near-infrared webcam for non-contact, low-light facial image acquisition to calculate PERCLOS.
- Developed an algorithm integrating HRV and PERCLOS for comprehensive drowsiness judgment.
Main Results:
- The system achieved high accuracy (92.5%) with a sensitivity of 88.9% and specificity of 93.5%.
- Non-contact measurement using a near-infrared webcam proved effective even in dark environments.
- The combined approach demonstrated improved robustness compared to individual methods, validated by EEG comparison.
Conclusions:
- The proposed integrated system offers a reliable and non-intrusive method for detecting driver drowsiness.
- This technology has the potential to significantly reduce fatigue-related road accidents.
- Further research can explore real-world implementation and integration into vehicle safety systems.

