An assembly for modifying airflow into a nasopharyngeal airway or trachea of a patient. A valve assembly is adapted to attach to an airflow generator. A linear actuator is signaled by the airflow. An inhalation valve is within the feed tube at the inlet. An exhalation valve is within the feed tube at the outlet, the exhalation valve adapted to slide axially within the feed tube and incrementally cover the outlet, moving in unison with the inhalation valve. A drive means operates the inhalation valve and the exhalation valve simultaneously such that upon sliding of the inhalation valve toward the mask side, the exhalation valve thereby slides towards the mask side, wherein upon activation of both the airflow generator and a controller circuit, pressurized air from the airflow generator continuously enters the feed tube but is converted to a single, repeatable burst.
