Indirect airflow measurement through breath-operated device is accomplished
by incorporating an airflow sensor into the inhaler device along a low resistance
channel disposed away from the exhaust chamber of the device and having an input
port in airflow communication with a low resistance channel and output input port
and low resistance channel are formed in the main housing body of the device, and
further incorporating an output port formed near the exhaust changer near the mouthpiece
assembly, the output port also in airflow communication with the low resistance
channel. A method of measuring airflow in an inhalation device is also described
that measures air flowing through the low resistance channel. Another aspect of
the invention provides a method that allows for the closure of the devices' airflow
ports, by allowing for the rotation of the mouthpiece assembly from open to closed
positions relative to the inhaling device's main housing body and towards handle assembly.
