{TAIL ~ An air flow sensor} and pressure sensor is positioned to monitor {HEAD ~ air flow} channeled to the mask 
{ TAIL ~ An air flow sensor } and pressure sensor is positioned to monitor { HEAD ~ air flow } channeled to the mask
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH