Question of the study Drowsy driving is believed to be a major factor in road crashes, but currently cannot be assessed accurately. A new system of infrared (IR) reflectance oculography is described that uses transducers attached to a glasses frame to measure drivers' drowsiness continuously on a new scale (JDS). Driving in a car simulator was investigated in relation to JDS scores per minute. Methods Fifty volunteers had their eye and eyelid movements monitored while performing RT-tests when alert and when drowsy. Multiple regression analysis of ocular variables, measured every minute in alert and drowsy conditions, was used to establish the drowsiness scale (JDS). Driving off the road in the driving simulator was the criterion for dangerous driving by 8 sleep-deprived drivers. Results The regression predicting conditions was highly significant (R=0.70, p<0.0001). Mean JDS scores and mean RTs in all test conditions were highly correlated (r=0.70, n=88, p<0.001). There were 62 'off-road' events in 8 drowsy drivers, and 61 of them were preceded by JDS scores > 5. Conclusions It is possible to measure drivers’ drowsiness continuously by IR oculography using the new JDS scale which does not require adjustment for individuals or the attachment of electrodes. (Author/publisher)
Samenvatting