Problems in automatic sleep scoring applied to sleep apnea

Automatic sleep analysis is used in the daily work of sleep centers working with digital polysomnography. Automatic sleep analysis has a limited accuracy in the sleep of healthy volunteers with approximately 80% conformance depending on definition. The problem of limited accuracy is even more severe in sleep disorders. Sleep apnea is a sleep disorder with a high prevalence which requires polysomnography for diagnosis and starting therapy. About 70% of all sleep studies in Germany are related to this disorder. The problems which occur with automatic sleep staging in sleep apnea are related to a large number of movement artifacts, repetitive arousal, severe sleep fragmentation with rapid changes of sleep stages, distorted slow wave sleep and distorted rapid-eye-movement (REM) sleep. These problems are discussed and the limitations of current visual analysis and automatic analysis are pointed out.