Divided Attention Steering Simulator Alertness Test

Overview

Driving simulator programmes are used under a wide range of conditions, and a correlation of driving performance and real accident risks in patients with obstructive sleep apnoea syndrome(OSAS)could be shown. The most frequently used driving simulator is the Divided Attention Steering Simulator (DASS) of Stowood Scientific Instruments Ltd. (SSI). Until today there are no reference levels with regards to sex and age in existence. To define the boundaries of normality age and sex reference values are to be generated and compared to values of patients with OSAS. 50 male and 50 female healthy subjects (10 of each age decade between 20 and 70 years) will perform the DASS for 30 minutes. In the other arm 100 OSAS Patients will perform the test as well. A better differentiation of pathologic driving performance and response times of OSAS patients should be possible with new reference levels.

The DASS programme records several data, including mean and absloute errors and standard deviations from centre and curve. Additionally the response time to a randomly appearing target number is recorded (divided attention). The standard deviation (curve) is the difference between the steering angle and the road angle. Standard deviation (centre) is the standard deviation of the centre of the car from the centre of the road. Steering performance is quantified as the standard deviation of the error from a theoretical perfect path. The secondary task of the divided attention test is to respond to a randomly appearing target number at the sides of the monitor while trying to keep the car in the centre of the road. Average Reaction time is the average time (in seconds) it takes the subject to respond to the target numbers.

Conditions