title: Automated frequency analysis of synchronous and diffuse sleep spindles.
abstract: BACKGROUND
  Sleep spindles have different properties in different localizations in the cortex.
  
  
  OBJECTIVE
  First main objective was to develop an amplitude-independent multi-channel spindle detection method. Secondly the method was applied to study the anteroposterior frequency differences of pure synchronous (visible bilaterally, either frontopolarly or centrally) and diffuse (visible bilaterally both frontopolarly and centrally) sleep spindles.
  
  
  METHODS
  A previously presented spindle detector based on the fuzzy reasoning principle and a level detector were combined to form a multi-channel spindle detector.
  
  
  RESULTS
  The spindle detector had a 76.17% true positive rate and 0.93% false-positive rate. Pure central spindles were faster and pure frontal spindles were slower than diffuse spindles measured simultaneously from both locations.
  
  
  CONCLUSIONS
  The study of frequency relations of spindles might give new information about thalamocortical sleep spindle generating mechanisms.
authors.affiliation: Signal Processing Laboratory, Tampere University of Technology, Korkeakoulunkatu 1, FIN-33101 Tampere, Finland. eero.huupponen@tut.fi
authors.forename: Eero
authors.initials: E
authors.lastname: Huupponen
authors.forename: Antti
authors.initials: A
authors.lastname: Saastamoinen
authors.forename: Jukka
authors.initials: J
authors.lastname: Niemi
authors.forename: Jussi
authors.initials: J
authors.lastname: Virkkala
authors.forename: Joel
authors.initials: J
authors.lastname: Hasan
authors.forename: Alpo
authors.initials: A
authors.lastname: Värri
authors.forename: Sari-Leena
authors.initials: SL
authors.lastname: Himanen
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D003344:Cortical Synchronization / Q000379:methods*; D001330:Electronic Data Processing / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D017143:Fuzzy Logic; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D012372:ROC Curve; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors