cause it to move from the outer expanded position where a maximum amount of air is contained within the vacuum chamber 36 defined within the interior of the bellows 33 to an inwardly directed collapsed position wherein a minimal amount of air is contained within the vacuum chamber 36 preferably this collapsed position is achieved before the assembly 10 is sealed against the user 39 s face when however the vacuum chamber 36 is positioned in its collapsed position and once the seal 20 is in sealing engagement about the nose and nostrils of the user 100 the patient facilitates isolation of the lower esophagus 32 by swallowing swallowing causes the rearward rotation in accordance with the directional arrow 24 of the end of the soft palate 25 into engagement with the nasopharynx 27 indeed once sealed against a user so as to enclose the nose there is a low pressure state inside the nasal cavity and nasopharynx and there is insufficient air movement to move liquids into the assembly 10 as the bellows moves to the expanded position shown in fig1 and 3 a flow of air which was under negative tension will be caused to travel from the interior of the nasal cavity 28 into the hollow interior 16 of the body portion 14 and eventually into the interior of.