US Patent 10272223 Respiratory valve apparatus

The invention relates to a pressure responsive respiratory valve apparatus for enabling positive pressure from a source of pressure to be applied to a user's airway, and allowing ingress of a breathable gas from an inlet port into a user's airway during inhalation and egress of expired tidal volume of air from the user's respiratory system to an exhalation port during exhalation. The invention minimizes rebreathing of expired gas and optimizes delivery of pressurized breathable gas by venting gas only during exhalation, as well as addressing important user considerations including minimizing noise, pressure swing, and size.