{TAIL ~ A counter} counts a first time duration commencing from the last transition to {HEAD ~ inspiration} and whereby if the first time duration elapses before a transition to expiration is detected, the controller initiates the supply of a given expiratory pressure 
{ TAIL ~ A counter } counts a first time duration commencing from the last transition to { HEAD ~ inspiration } and whereby if the first time duration elapses before a transition to expiration is detected , the controller initiates the supply of a given expiratory pressure
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD 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