{HEAD ~ The system} further provides for detecting {TAIL ~ changes} in air pressure in the air flow supplied to a mask adapted to supply positive airway pressure to a patient undergoing treatment for a sleep disorder 
{ HEAD ~ The system } further provides for detecting { TAIL ~ changes } in air pressure in the air flow supplied to a mask adapted to supply positive airway pressure to a patient undergoing treatment for a sleep disorder
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL 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