Automatic Oxford-Medilog 9200 sleep staging scoring: comparison with visual analysis.
We report the results of a comparison study between automatic sleep staging using the ambulatory Oxford-Medilog 9200 system and visual analysis in a group of 30 subjects. Sleep analysis was performed during the second nighttime period of each 48-h polygraphic monitoring. The automatic analysis determined a significant underestimation of total sleep time and stage 2 non-rapid eye movement (NREM) sleep and an overestimation of stage 1. No significant differences were found between the two analyses regarding slow-wave sleep and REM sleep. The differences between automatic and visual analysis of stage 2 were correlated positively with the amplitude and duration of K-complexes and negatively with the amplitude and frequency of spindles. Differences in electroencephalographic characteristics of these sleep figures were correlated negatively with age. Our results showed that (a) the Oxford-Medilog 9200 sleep staging system did not improve the scoring of stages 1 and 2 NREM sleep and (b) the degree of differences between visual and automatic analysis are related to the amplitude and frequency of sleep figures, i.e., spindles and K-complexes, used in the scoring of stage 2.
Sforza
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Institute of Neurology, University of Bologna, Italy.
Vandi
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D000293:Adolescent; D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000503:physiopathology; D004867:Equipment Design; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000175:diagnosis / Q000503:physiopathology; D017286:Polysomnography / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology