{HEAD ~ A flow generator} coupled to a gas delivery system delivers {TAIL ~ breathable gas} to the patients airway 
delivers
{ HEAD ~ A flow generator } coupled to a gas delivery system delivers { TAIL ~ breathable gas } to the patients airway
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH