During the inhalation by the patient, the entrainment flow through the entrainment passage may substantially prevent the control gas from flowing across the entrainment passage so as to interrupt {HEAD ~ the delivery} of the control gas to {TAIL ~ the fluid conduit} 
to
During the inhalation by the patient , the entrainment flow through the entrainment passage may substantially prevent the control gas from flowing across the entrainment passage so as to interrupt { HEAD ~ the delivery } of the control gas to { TAIL ~ the fluid conduit }
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 HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL