Abstract: A humidifier (10) is disclosed which is adapted to be used in conjunction with a patient gas delivery system. The humidifier includes a housing (15) and two masses of hydrophilic polymer material (16) and (17) within the housing (15). The housing is configured to be isolated from an external liquid source during operation of the humidifier. The housing (15) also includes an inlet end (19) and an outlet end (20) through which a gas stream is pumped. As the gas stream passes through the saturated hydrophilic material, the gas stream becomes saturated with the fluid, thereby humidifying the gas stream.

Abstract: An oxygen mask assembly including an oxygen dilutor assembly with air inlet apertures located in a top wall thereof for diluting the oxygen flowing therethrough. In one embodiment, the mask assembly additionally includes an air reservoir bag assembly, a one-way inhalation valve for maintaining continuous positive airway pressure in the mask and a pressure valve on the mask for adjusting the air pressure in the mask.