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