Abstract
We made a two-dimensional-flow model composed of two bands in parallel, the roof of which was made up with the condome rubber collapsible and segmented into five parts to keep interdependence in movement of each segment and the bottom with the plastic plate. In this model, pressure flow relationships demonstrated the flow to reach its maximum at a certain driving pressure, and the lower the compliance of the elastic roof, the higher the maximum flow rate established. Displacement of the collapsible roof toward the bottom occurred just at a very limited segment near the outlet of the airway. Combining the theoretical analysis with our experimental findings on dogs, it is concluded that the maximum flow has an inverse relation with both compliance and resistance of the bronchi. The fact that displacement of the collapsible roof toward the bottom appears at very limited segment, means stress on the membrane to focus into much narrower segment and might indicate “expiratory check valve” to occur also at a very limited segment of bronchi.
