If {HEAD ~ an alternative mask} is utilized, having {TAIL ~ a mask exhaust valve} 62 , the stimulus is directed to the patient will provide a reminder for the patient to check whether the exhaust valve 62 is blocked against a pillow or clothing 
having
If { HEAD ~ an alternative mask } is utilized , having { TAIL ~ a mask exhaust valve } 62 , the stimulus is directed to the patient will provide a reminder for the patient to check whether the exhaust valve 62 is blocked against a pillow or clothing
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH