Estimating sleep time from non-EEG-based PSG signals in the diagnosis of sleep-disordered breathing.
OBJECTIVE
The purpose of this study was to use non-EEG PSG signals to estimate TST in order to diagnose SDB with a greater sensitivity than type 3 device methodology that relies on TRT.


METHODS
Movement patterns were obtained from the thoracoabdominal signals of adult PSG recordings (n = 60) in the laboratory and the home. Parameters obtained allowed, with 95% certainty, identification of sleep and wake based on the duration of movements and quiescent time (Qd). Snoring, apneas, and hypopneas indicated sleep with 100% certainty. The method was tested in a different set of PSG recordings (n = 80).


RESULTS
Subjects lay awake and immobile for longer in the laboratory (QdLAB= 27.4 (12.1, 62.0), QdHOME= 16.0 s (8.0, 36.0); p < 0.0001) but asleep and immobile for longer at home (QdLAB= 65.2 (23.0, 121.4), QdHOME= 95.0 s (44.5, 247.5); 0.005). Only 5% of wake Qd periods were >173 s in the laboratory and >105 s at home. In both locations, 95% of movements during sleep were <10 s. Experimental TST values were 21 min shorter than EEG-defined TST and, combined with fewer scored respiratory events, produced AHI values that were 1.6 events/h lower than the reference. The experimental TST increased the sensitivity of SDB diagnosis from 73 to 97%.


CONCLUSIONS
In the sleep laboratory, subjects are immobile for longer periods when awake and for shorter periods when asleep. The experimental TST was similar to EEG-defined TST and could be used to diagnose SDB with a much higher sensitivity than the type 3 method.
David Read Laboratory, University of Sydney, Room 450 Blackburn Building D06, Camperdown, NSW, 2006, Australia. mark.norman@sydney.edu.au.
M B
MB
Norman
David Read Laboratory, University of Sydney, Room 450 Blackburn Building D06, Camperdown, NSW, 2006, Australia.
C E
CE
Sullivan
D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012890:Sleep; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology*; D013997:Time Factors
Ambulatory; Home recording; Movement; Type 3 device