Patent ID: 11969552
Assignee: RESMED PTY LTD
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 25:
26. A mask system for delivering breathable gas at positive pressure to a patient for treatment of sleep disordered breathing, comprising:
a frame having an opening formed therein and arranged to receive the breathable gas in use;
an axis extending through the opening in the frame;
a cushion connected to the frame, the cushion comprising silicone and configured to, in use, form a seal with the patient's face to deliver the breathable gas to an airway of the patient, an inner edge of the cushion defining an aperture through which the breathable gas is delivered to the patient, the axis extending through the aperture;
the frame being formed of a material having increased rigidity as compared to the silicone material of the cushion;
an air delivery tube configured to convey the breathable gas from a source of pressurized breathable gas along a gas passageway of the air delivery tube towards the cushion;
a hollow vent structure disposed between the frame and the air delivery tube, the hollow vent structure including a plurality of vent holes formed therein for washout of exhaust gases, the plurality of vent holes being disposed in a spaced-apart arrangement forming an arc around the axis of the opening in the frame;
a shroud connected to the hollow vent structure; and
a pair of elongate arms connected from the shroud and configured to, in use, extend upwardly and posteriorly along respective sides of the patient's face, each elongate arms having a slot formed therein to receive an end portion of the headgear strap,
wherein the plurality of vent holes formed in the hollow vent structure consists only of a single row of vent holes,
wherein the plurality of vent holes includes a first vent hole, a second vent hole, a third vent hole, a fourth vent hole and a fifth vent hole arranged in series, the first vent hole, the second vent hole, the third vent hole, the fourth vent hole and the fifth vent hole all being disposed along a section of the hollow vent structure that extends only half-way around a perimeter of the hollow vent structure, and
wherein the mask system does not include a forehead support configured to engage the patient's forehead in use.