The respiratory conduit includes at least two volumes, wherein one volume is positioned between a first air flow control device and a second air flow control device and {HEAD ~ another volume} is positioned between a second air flow control device and {TAIL ~ a third air flow control device} 
The respiratory conduit includes at least two volumes , wherein one volume is positioned between a first air flow control device and a second air flow control device and { HEAD ~ another volume } is positioned between a second air flow control device and { TAIL ~ a third air flow control device }
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 OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL