FIG. 26:  This Figure is a summary of how the automatic EPAP works and resolves upper airway flow limitation.  The ASV algorithm detects obstructed airway apnea or hypopnea.  All three ASV devices detect flow limitation and vibratory snoring.  With analysis of the response to backup breaths, they can distinguish between closed and open airway apneas.  Finally, with flow analysis, which is both qualitative and quantitative, the consequence is adjustment of EPAP pressure within the pressure range given by the clinician in order to resolve upper airway flow limitation.