Figure 4.

(A) Optimal inlet flow rates at the trachea minimizing capture at each generation of the human airway geometry using a 3-dimensional airway tree for several particles sizes. The first generation is the trachea and since it is orientated vertically the flow that minimizes deposition is low. As generation number increases the risk of deposition due to inertial impaction for a given particle decreases and hence optimal flow increases. (B) Optimal flows as a function of time. Note that the time of the flow only represents a window during inspiration (see text for further explanation).