Patient interface

A patient interface for delivering breathable gas to a patient, the patient interface comprising:

• a substantially rigid frame, the rigid frame comprising,
• a main body including an opening configured to receive a flow of pressurized gas, and
• a projection extending from the main body and forming a closed shape, the projection having an inner surface configured to direct the flow of pressurized gas, and an external surface including a lip and a groove, wherein the lip is disposed at a free end of the projection, and wherein the groove is disposed between the lip and the main body;
• a nasal seal assembly comprising,
• a first end having a pair of nasal prongs structured to sealingly communicate with nasal passages of the patient's nose in use,
• a second end opposite the first end, the second end having an opening with a closed shape corresponding to the closed shape of the projection, wherein an interior surface of the second end includes a frame contacting portion configured to be removably receivable within the groove and removably engage the frame, wherein the frame contacting portion includes an inner surface configured to engage the lip in use;
• and
• a positioning and stabilising structure connected to the frame at two discrete points, the positioning and stabilising structure comprising,
• a pair of rigidizers each having a first end connected to the frame and configured to extend at least partially along the patient's cheeks and a second end including a slot, and
• a headgear strap receivable through the slots and configured to contact the patient's head and maintain the pair of nasal prongs in a sealing position on the patient's head.

A patient interface for delivering breathable gas to a patient, the patient interface comprising:

• a substantially rigid frame, the rigid frame comprising,
• a main body including an opening configured to receive a flow of pressurized gas, and
• a projection extending from the main body and forming a closed shape, the projection having an inner surface configured to direct the flow of pressurized gas;
• a nasal seal assembly comprising,
• a first end having a pair of nasal prongs structured to sealingly communicate with nasal passages of the patient's nose in use,
• a second end opposite the first end, the second end having an opening with a closed shape corresponding to the closed shape of the projection, wherein an interior surface of the second end is configured to removably engage an external surface of the projection;
• and
• a positioning and stabilising structure connected to the frame at two discrete points, the positioning and stabilising structure comprising,
• a pair of rigidizers each having a first end connected to the frame and configured to have an inner surface extend at least partially along the patient's cheeks and a second end opposite to the first end, wherein the inner surface of each rigidizer includes a compound curvature having a first curvature proximate to the first end and a second curvature transitioning from the first curvature toward the second end, wherein the first curvature and the second curvature are in opposite directions, and wherein the first curvature is configured to form a convex shape with respect to the patient in use and the second curvature is configured to form a concave shape with respect to the patient in use, and
• a headgear strap connectable to the pair of rigidizers and configured to contact the patient's head and maintain the pair of nasal prongs in a sealing position on the patient's head.