Fig. 3.
Correlation between collapsibility index of inferior vena cava diameter (cIVC) and right diaphragmatic motions at the three levels of inspiratory effort (n = 50). For the graph, cIVC has been normalized with an arcsine square root transformation. F0 = low inspiratory effort; F5 = intermediate inspiratory effort = −5 cm H2O; F10 = maximal inspiratory effort = −10 cm H2O; E-right = maximal excursion of the right diaphragm during a single respiratory cycle; r = Spearman correlation coefficient (r estimate).