Acoustic Modeling of Lung Dynamics Using Bond Graphs

Bond graphs are used to model the acoustic behavior of the respiratory system. The model includes the distributed dynamics of the upper airways while the lower passage generations are represented by “lumping” of resistance and compliance effects. The lower airway representation is terminated with ten lung segments. The model is accurate for frequencies as high as 8500 Hz. The model is currently capable of predicting system eigenvalues as a function of system parameters and geometry for a “nonbreathing” lung. Future plans include modifying the model to include lung segment expansion and contraction as well as turbulence generaton at airway bifurcations.