Patent ID: 8042540

Claim:
A mask for delivery of gas to a patient from a source of pressurized gas, comprising: a mask body configured to enclose the patient's nose and mouth having a rim configured for contacting the patient's face; a gas inlet opening into said mask body to admit a gas stream from said source into the interior of said mask body; an L-shaped gas supply connector engaged to said gas inlet; a fastener adapted to maintain contact between the patient's face and the rim; and a diffuser within the interior of the mask body adapted to be located at a position opposed to and directed towards the user's nose and mouth, said diffuser comprising an upper wall portion and a lower wall portion, wherein the end of the lower wall portion is continuously formed with the mask body, said diffuser further surrounding said inlet defining a partially enclosed space, and said diffuser further comprising a baffle located at least partially within said space in the path of said gas stream, said baffle comprising a post and an enlarged head having a lip wherein the head fills a portion of the enclosed space of the diffuser and the lip is configured to generate a turbulent plume when contacted by the stream of gas, said diffuser adapted to be opposed to the patient's face and positioned within the mask such that the direction of gas flow exiting the diffuser is configured towards the patient's face in a non-oblique direction; and wherein said mask body comprises a substantially open structure having openings which altogether comprise between 30 and 80% of the mask body.