Multivariate analyses and predictive equations
According to the above results, VT, f and oxygen flow rate affect FO2 insp. and FO2 pre-insp. measurements; thus, we aimed to approximate their relationship using a linear regression analysis. In normal lung conditions, both VT and oxygen flow rate have significant (p < 0.05) effects on FO2 insp. and FO2 pre-insp., but f only affects FO2pre-insp. (Table 2a). In addition, the restrictive (Table 2b) and obstructive (Table 2c) lung model display the same regression pattern. Finally, simple linear regression models using VT, f and oxygen flow rate as predictor variables were found to provide the equations that are presented in Table 3.