Figure 2
From: Predictors of expiratory flow limitation measured by forced oscillation technique in COPD
Colored 3-dimensional images of Rrs and Xrs in each representative patient with high or low EFL index. Respiratory cycle dependence (Rrs was higher and Xrs shifted more negative in the expiratory phases than in the inspiratory phases) and frequency dependence (Rrs increased at lower frequencies and fell with increasing frequencies) were marked in patients with high EFL index. In contrast, Rrs was moderate over the entire frequency and respiratory cycle, and Xrs shifted slightly negative in patients with low EFL index. Abbreviations: EFL, expiratory flow limitation; Rrs, respiratory system resistance; Xrs, respiratory system reactance.