Inertia is potentially important for the forward flow, especially in the atrioventricular valves. The regurgitant flow resistor is linear, but the forward flow resistor is not. Under normal circumstances, valvular resistance is negligible. The gas exchange simulator is described as a steady state solution of a 50 compartment ventilation-perfusion model. Several built-in processes are taken to alter gas exchange parameters.
Alveolar shunt arises in a fashion that depends directly on accumulated lung edema.
Hyperinflation is directly linked to dead space and is inversely related to the shunt fraction associated with lung edema. Peripheral Gas Exchange Peripheral gas exchange is handled by assuming delivery independent consumption above a critical point, and delivery dependent consumption below it. Demand varies with suppressible muscle activity. Lactate production occurs whenever oxygen delivery is too low to support full oxidative metabolism, and lactate absorption occurs when oxygen is in good supply. The former describes the passive mechanics of the chest wall and lung.