Figure 1From: Noninvasive assessment of asthma severity using pulse oximeter plethysmograph estimate of pulsus paradoxus physiology Plethysmograph Estimate of Pulsus Paradoxus Calculation. 1) AUC is calculated for each cardiac cycle from plethysmograph waveform. 2) ΔAUC is calculated for each successive 3-sec interval. 3) PEP is 180-sec moving average of ΔAUC.Back to article page