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