부산대학교 도서관

Lumped models are frequently used to provide a satisfactory descriptionof the hemodynamic properties of the pulmonary vasculature. The purpose ofthis study is to describe a method to identify simultaneously the parametersvalues of windkessel models components. The following equation was used toobtain R[sub 1] (characteristic resistance), R[sub 2] (peripheralresistance), C (total compliance) and L (inertance): For formulae see full text. where k[sub i] are the following functions of L, R[sub 1] , R[sub 2] and C: For formulae see full text. To assess the accuracy of the method, estimates of R[sub 1] , R[sub 2] , and C were compared to characteristic impedance R[sub c] , vascularresistance PVR and pulmonary arterial compliance C[sub d] respectivelycomputed from referenced methods. Comparison between R[sub 1] and R[sub c] , PVR and R[sub 1] + R[sub 2] , C and C[sub d] were obtainedin 5 anaesthetised pigs during basal conditions and after endotoxin-shock. The results indicate that in both conditions, comparisons evidenced highlysignificant correlations between values computed by the different approaches(p < 0.0001). Although our method yielded to consistently lower valuesthan values provided by referenced methods, the results were concordant withrespect to the expected response of pulmonary vasculature to endotoxin insult.We conclude that our method of identification is suitable for the assessmentof lumped parameters windkessel model estimates. The main interest is thatactual resistance and compliance values can be obtained easily and simultaneouslyby a global method approach. [ABSTRACT FROM AUTHOR]