A Mathematical Physiological Model of the Dynamics of Pulmonary Ventilation

The effect of arteriolar resistance on perfusion distribution in a model of the pulmonary perfusion

“…In order to simulate a subject under mechanical ventilation a previous ventilation model is used (Mogensen et al (2010b), Steimle et al 2010)). This model uses the pressure exerted by the ventilator as input to calculate densities and thicknesses of the different layers.…”

“…It is assumed that all layers contain the same number of alveoli and the same number of arterioles and capillaries surrounding an alveolus regardless of layer height. The chest wall pressure determined using the ventilation model (Mogensen et al (2010b), Steimle et al (2010)) and the hydrostatic pressure due to the lung tissue add up to the extraalveolar pressure outside the arterioles and capillaries, P EA , as stated in (1):…”

“…In addition assumptions were made about the pressure profile at the proximal end of the lung capillaries. The distribution of lung tissue densities were taken from a model of pulmonary ventilation (Steimle et al (2010), Mogensen et al (2010b)). Although the model by Mogensen et al (2010a) produced distributions of perfusion similar to that previously measured in healthy human subjects, the model overestimated the ratio, Q Ratio , between the perfusion at the bottom of the lungs (dependent part) and the top (non-dependent part).…”