The respiratory conduit includes {TAIL ~ at least two air flow control devices}, wherein {HEAD ~ the at least one airflow control device} is configured to withdraw air from at least one location within the respiratory conduit 
The respiratory conduit includes { TAIL ~ at least two air flow control devices } , wherein { HEAD ~ the at least one airflow control device } is configured to withdraw air from at least one location within the respiratory conduit
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH