Fig. 5

Scatter plots of %FEV₁ and bilateral LMV in tidal respiratory phase with approximate line. LMV in the tidal inspiration phase versus %FEV₁ in the right lung (a) and in the left lung (b). LMV in the tidal expiration phase versus %FEV₁ in the right lung (c) and in the left lung (d). In each phase, the statistically significant correlation between %FEV₁ and LMV in tidal inspiration in both lungs as well as those between %FEV₁ and LMV in tidal expiration in the right lung was indicated by the Spearman rank correlation coefficient. COPD Chronic obstructive pulmonary disease, %FEV₁ Percent predicted forced expiratory volume in one second, LMV Lung motion velocity, r_s Spearman’s rank correlation coefficient