Modeling the Pressure-Flow Relation of Bifurcating Networks

Abstract

Despite a considerable number of measurements of the variation of pressure drop with flow rate through the bronchial tree (or physical models of it), reducing the data to a single relation is difficult. Much of the difficulty arises because of differences in geometry and experimental method. Integration of data obtained in vivo or in excised lungs depends strongly on controlling the experiment under isodimensional conditions. For example, during graded expirations the increasing pressure gradient with flow and the resulting decrease in bronchial caliber suggest that isovolume conditions may not be isodimensional. Consequently, experiments investigating pressure gradient in rigid models may be helpful in modeling the more complex situation in vivo.