Fig. 2.

Data acquisition and periods of interest. Example of data recorded during a simulated episode of obstructive apnea. The periods of interest were the 30 s preceding the event (A: pre-event period), 15–20 s of event duration (B: event period), and 30 s following the event (C: post-event period). $\dot{V}$_aw = respiratory flow; $P$_aw = airway pressure.