Fig. 4From: Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilationBox plot of quartiles of respiratory effort and Flow Index. Scatter plot of Flow Index model prediction and measured pressure time product, pressure time product ratio and muscular pressure. Left column: box plot of Flow Index in quartiles of inspiratory effort as evaluated with PTPpt, breath, PTPratio,breath and Pmusc. Right column: scatter plot of Flow Index model prediction for PTPpt, breath, PTPratio,breath and Pmusc compared with measured PTPpt, breath, PTPratio,breath and Pmusc. Different PS levels are identified with different colors, as indicated above each panel. PTP = pressure time productBack to article page