Fig. 3From: Overnight variation in tidal expiratory flow limitation in COPD patients and its correction: an observational studyPercentage of time during PSG that the screening EPAP was equivalent to (green), greater than (yellow) or less than (red) that needed to eliminate EFLT determined when supine awake Black circles and numbers represent the clinical EPAP screening value needed to abolish EFLT (represented on the right-hand Y-axis). Overnight EPAP data were not available for participant 15 due to a data acquisition failureBack to article page