Blink Duration as an Indicator of Driver Sleepiness in Professional Bus Drivers

Abstract

This study focused on eyeblink duration as a measure of sleepiness in on-road driving and on the driving performance of professional bus drivers with polysomnographically confirmed mild obstructive Sleep Apnea Syndrome (OSAS). Ten bus drivers with OSAS and their matched controls participated in the study. The Maintenance of Wakefulness Test (MWT) and a monotonous on-road driving task were completed. Eyeblink duration and frequency and speed control were measured while driving. Lane-keeping was evaluated by the supervisor in the car. Subsequent to these tasks, drivers with OSAS received continuous positive airway pressure treatment (nasal CPAP). After nine weeks of treatment, the tasks were repeated. Prior to treatment the average blink duration in the driving task was significantly longer and sleep latency in the MWT was significantly shorter for bus drivers with OSAS than for controls (mean blink duration 82.3 ms; 51.9 ms and mean sleep latency 23.2 min; 35.4 min), indicating increased daytime sleepiness. Subsequent to treatment both measures in drivers with OSAS decreased to the level of the controls. Treatment effects in MWT and blink duration in on-road driving also correlated significantly. No significant differences between the groups appeared in average blink frequency or driving performance in terms of maintenance of speed. No significant lane drifting appeared either. These results support earlier findings on blink duration as an indicator of increased sleepiness and have important implications for those involved in the transport technological industry. The findings also suggest that nasal CPAP treatment is effective in reducing excessive daytime sleepiness.

Ocular Measures of Sleepiness Are Increased in Night Shift Workers Undergoing a Simulated Night Shift Near the Peak Time of the 6-Sulfatoxymelatonin Rhythm

“…However, none of the participants in our study required prescription lenses. The system provides 13 ocular measures sampled each minute, of which the following were selected based on previous work [21][22][23][24][25][26][27] (detailed description of each measure provided in Table 1): positive and negative amplitude/velocity ratio of each blink (PosAVR, NegAVR), Johns Drowsiness Scale (JDS) score, the percentage of time with eyes closed (%TEC), and mean blink total durations (BTD). For all measures, higher values indicate higher levels of sleepiness.…”

Predicting Driver’s Work Performance in Driving Simulator Based on Physiological Indices

“…The studies mentioned in Kramer's review all found shorter blink durations for increasing task demands (both mental and visual) [32]. Some studies show that blink duration is a sensitive and reliable indicator of driver visual workload [8,33]. Eye fixation duration is also extensively used measures and is believed to increase with increasing mental task demands [34].…”

Intelligent Human Computer Interaction

“…Tu et al [30] compared flicking to radial scrolling and found that radial scrolling led to shorter movement time than flicking for larger target distance. However, it was not clear if using the thumb is efficient since Wobbrock et al [33] has reported that the index finger is generally faster. This menu design was motivated by the second design goal which is minimize travel distance but focused on the interaction with the narrowed down list.…”

“…The studies mentioned in Kramer's review all found shorter blink durations for increasing task demands (both mental and visual) [32]. Some studies show that blink duration is a sensitive and reliable indicator of driver visual workload [8,33]. Eye fixation duration is also extensively used measures and is believed to increase with increasing mental task demands [34].…”