FIG. 2.
(A) Valved holding chamber (VHC) coupled to the pneumotachograph handle. The connector simulated the flow resistance of the Respimat SMI air vents and the handle was equipped with a release button which had to be pressed for simulating the release of a dose. (The Respimat SMI was not included in this setting). (B) Use of VHC with Respimat.