Abstract: Ventilation masks are disclosed herein including a mask body and a gas manifold coupled to the mask body to form a gas channel for directing a gas through a gas port to create a curtain effect gas flow within the patient cavity and form a gas curtain within the patient cavity and adjacent to at least one vent opening formed through the mask body, and a sampling cover couplable with the mask body to form a sampling channel between a sampling portal of the sampling cover and a sensing port, where the sampling portal is formed by a protrusion of the sampling cover that extends into the vent opening and can extend toward a patient cavity formed by an inner surface of the mask body.

Abstract: An HME unit including a housing, an HM media, and a check valve assembly. The housing forms a first port, a second port, and an intermediate section defining first and second flow paths fluidly connecting the first and second ports. The HM media is maintained within the intermediate section along the second flow path. The check valve assembly includes an obstruction member movably positioned within the intermediate section to selectively provide opened and closed positions. In the opened position, the first flow path is open relative to the obstruction member. In the closed position, the obstruction member closes the first flow path. In one mode, the obstruction member transitions to the opened position in response to gas flow in a flow direction from the second port toward the first port, and transitions to the closed position in response to gas flow in an opposite flow direction.