with a constant supply of the test liquids into the model tube ( 0.5 ml/min ) , the liquid layer transport speed ( llts ) as well as the mean liquid layer thickness at steady-state condition ( hs ) was measured in conjunction with various airflow patterns of different expiratory and inspiratory flow rate , breathing frequency ( f ) , and tidal volume ( vt ) .
C0231800
expiratory
C0035203
breathing