A nitrous oxide and oxygen supply, {TAIL ~ vacuum source}, a breather bag, and {HEAD ~ a nasal delivery interface system} are fluidly connected to the fluid control system and a patient 
A nitrous oxide and oxygen supply , { TAIL ~ vacuum source } , a breather bag , and { HEAD ~ a nasal delivery interface system } are fluidly connected to the fluid control system and a patient
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH