Pulse wave sensor for non-intrusive driver´s drowsiness detection

This research proposes a PVDF film pulse wave sensor for use in driver´s drowsiness detection. The sensor non-intrusively measures heart pulse wave from driver´s palm and an adaptive filter is employed to cancel the measurement noise aroused by the changing of gripping force. Experimental results show clear pulse wave signals can be obtained. Two-hour driving simulation is performed for drowsiness detection tests. The low frequency to high frequency (LF/HF ratio) is calculated from power spectrum density (PSD) of subjects´ heart rate time series. The LF/HF ratio shows decreasing trends as subjects go from awake to drowsy.