1. Association of airway obstruction, sleep, and phasic abdominal muscle activity after upper abdominal surgery† 
M.Q. Rahman, R.N. Kingshott, P. Wraith, W.H. Adams, G.B. Drummond 
British Journal of Anaesthesia 
Volume 87, Issue 2, Pages (August 2001)
DOI: /bja/
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Part of polysomnogram tracing from a typical patient with awake and sleep pattern. EOG: electrooculogram; CzPz and bib4: EEG traces. The awake trace shows low voltage high frequency activity and the sleep trace shows K complexes and sleep spindles.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Abdominal EMG patterns. (a) Tonic, (b) phasic. Vertical lines indicate 5 s.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
Examples of nasal flow pattern during (a) normal breathing and (b) obstructed inspiration showing absence of expiratory flow and flow limitation during inspiration. Vertical lines indicate 5 s.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Median proportion of time spent in each condition by the patients studied. P indicates time when phasic EMG was present. The greater proportion of phasic activity during obstructed breathing, particularly during wakefulness, can be seen.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

6. Fig 4
Median proportion of time spent in each condition by the patients studied. P indicates time when phasic EMG was present. The greater proportion of phasic activity during obstructed breathing, particularly during wakefulness, can be seen.
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions