we measured forced expiratory volume in one second ( fev1 ) , forced vital capacity ( fvc ) , fev1/fvc % , the maximal mid-expiratory flow rate ( fef25-75 ) , the flow at 50 % ( vmax50 ) and 25 % ( vmax25 ) of a maximal expiratory flow-volume maneuver , the percent increase in the maximal expiratory flow at 50 % fvc breathing a mixture of 80 % helium-20 % oxygen as compared with air ( delta vmax50 ) , and the slope of phase iii of the single breath nitrogen test ( delta n2/l ) .
C0231800
expiratory
C0035203
breathing