title: Performance of the frequency domain indices with respect to sleep staging.
abstract: OBJECTIVE
  To compare computerized staging using spectral analyses of various electrophysiological signals with manual sleep staging.
  
  
  METHODS
  Sleep recordings from 21 normal subjects were scored by an experienced rater and by a dichotomous algorithm. The performance of the spectral indices was assessed by the largest kappa value (LKV).
  
  
  RESULTS
  Theta/beta power ratio of the electroencephalogram, high frequency power (8-58 Hz) of the electromyogram (PEMG), mean R-R interval, and total power (0-16 Hz) of the body acceleration (PACCE) had high (>0.5) LKVs when differentiating between waking and sleep. To differentiate sleep with (stage 2 and slow wave sleep) and without (rapid eye movement and stage 1 sleep) spindles, sigma/beta power ratio had high LKVs. PEMG had a medium (>0.25) LKV to separate rapid eye movement from stage 1 sleep whereas delta/beta power ratio had a high LKV to separate stage 2 and slow wave sleep.
  
  
  CONCLUSIONS
  The frequency components of electroencephalogram perform well in identifying sleep, sleep with spindles, and slow wave sleep. Electromyogram, heart rate, and body acceleration offer high agreement only when differentiating between wakefulness and sleep.
  
  
  CONCLUSIONS
  The human-machine agreement is acceptable with spectral parameters, but heart rate and body acceleration still cannot substitute for electroencephalogram.
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Terry B J
authors.initials: TB
authors.lastname: Kuo
authors.forename: C Y
authors.initials: CY
authors.lastname: Chen
authors.forename: Ya-Chuan
authors.initials: YC
authors.lastname: Hsu
authors.forename: Cheryl C H
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D001611:Beta Rhythm / Q000502:physiology; D004569:Electroencephalography; D004576:Electromyography; D055724:Electrophysiological Phenomena / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012890:Sleep / Q000502:physiology; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D013826:Theta Rhythm / Q000502:physiology; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult