| 1. |
- Anund, Anna, et al.
(författare)
-
Driver impairment at night and its relation to physiological sleepiness.
- 2008
-
Ingår i: Scand J Work Environ Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 34:2, s. 142-50
-
Tidskriftsartikel (refereegranskat)abstract
- Driver impairment at night and its relation to physiological sleepiness.Anund A, Kecklund G, Peters B, Forsman A, Lowden A, Akerstedt T.VTI, S-581 95 Linköping, Sweden. anna.anund@vti.se.OBJECTIVES: Studies of devices detecting sleepiness need reference points of physiological sleepiness. The present study sought to validate the Karolinska drowsiness score (KDS) as an indicator of physiological sleepiness against driving impairment and eye blink duration during a 45-minute drive in an advanced moving-base driving simulator. METHODS: Data from 19 persons were used in the analysis. Electrooculography, electroencephalography, and electromyography were administered continuously. Physiological sleepiness was quantified by scoring the percentage (0-100%) of the scoring epoch with alpha and theta activity and slow eye movements (KDS). Lateral position and speed were used as measures of driving behavior. Lane departure was defined as two wheels touching the lane markers. Blink duration was used as a secondary indicator of sleepiness. RESULTS: The results showed that, for young drivers, sleepiness increased with time in the task with higher levels. The variability of the lateral position and the mean and variability of the blink duration significantly changed when sleepiness increased to KDS >/=20%. Furthermore, there was an increase in the risk of lane departure for KDS >/=30%. CONCLUSIONS: The results suggest that KDS scoring is a reasonable procedure for estimating physiological sleepiness under conditions of driving. The results also indicate that a younger age is associated with greater sensitivity to sleepiness at the wheel.
|
|
| 2. |
- Lowden, Arne, et al.
(författare)
-
Wakefulness in young and elderly subjects driving at night in a car simulator.
- 2009
-
Ingår i: Accident; analysis and prevention. - : Elsevier BV. - 1879-2057 .- 0001-4575. ; 41:5, s. 1001-7
-
Tidskriftsartikel (refereegranskat)abstract
- Young drivers are over-represented in nighttime traffic accidents and several studies have suggested that many accidents are associated with elevated sleepiness levels. It has been suggested that there may be a connection between lowered wake capacity and functional sensory motor skills on the one hand and sleep deprivation at the circadian low in young drivers on the other. Performance during a 45/min evening and night drive among young (n=10, age range 18-24 years) and elderly (n=10, age range 55-64 years) subjects was studied using a moving base driving simulator. EEG was measured continuously. Every 5 min, subjects were rated on the Karolinska Sleepiness Scale (KSS). Saliva cortisol was assessed before and after each drive. The results showed that sleepiness increased across each drive and was higher among young drivers at night. Relative EEG power increased among older drivers for frequencies of 10-16Hz. The sigma 1 frequency band (12-14Hz) proved particularly sensitive to sustained driving, and was elevated among subjects in the elderly group. Cortisol levels before and after the evening and night drive showed higher mean levels for elderly subjects. The present study has demonstrated that young drivers were more sleepy while driving at night. The effects could represent a mobilization of effort and a reorganization of brain firing pattern among older subjects, possibly reflecting better ability and effort to resist sleepiness.
|
|
