Cushion and mask therefor

A mask for connection to a wearer' s face comprising:

• a mask body for connection with a supply of breathable gas;
• a cushion, the body and cushion defining a nose-receiving cavity;
• at least one securing strap to secure the mask body and cushion to the wearer's head;
• wherein the cushion includes:
• a frame of resilient material having a rim to surround at least a portion of the wearer's nose;
• a membrane also of resilient material, said membrane being thinner than and relatively more flexible than said frame, the membrane being fixed to and extending away from said frame so as to be spaced from said rim by a gap, said membrane having an outer surface forming a face contacting seal portion that is pre-shaped to generally match the contours of the wearer's face, wherein the face contacting seal portion is structured such that it is not required to turn in on itself to conform with the wearer's face, in use;
• wherein:
• the rim and frame are structured to resist deformation so as to form a support structure for the membrane,
• said rim and frame are not in contact with the wearer's face in use, and
• said seal portion is resiliently deformable towards said gap to abut said rim in use of said mask, depending on the facial contours of the wearer and/or strap tension applied the at least one securing strap.

A mask cushion to sealingly connect a mask to a wearer's face, the cushion comprising:

• a frame of resilient material having a rim shaped to generally match facial contours at least in the region of facial tissue around the sides of the nose, and between the base of the nose and the top lip;
• a membrane also of resilient material, the membrane being thinner than and relatively more flexible than the frame, said membrane being fixed to and extending away from the frame so as to be spaced from the rim by a gap, said membrane having an outer surface forming a face contacting seal portion that is pre-shaped to generally match the contours of the wearer's face, the membrane including a pre-formed notch to accommodate the wearer's nose bridge, wherein the face contacting seal portion is structured such that it is not required to turn in on itself to conform with the wearer's face, in use;
• and
• a strap structured to secure the cushion to the wearer's face, wherein, before application of strap tension, the seal portion is spaced from the rim of the cushion by the gap, and as a result of application of strap tension and/or to accommodate the wearer's facial contours, the seal portion is resiliently deformable into said gap to abut against the rim, said membrane resiliently returning to its original position, spaced from said rim by said gap, when the mask cushion is not in use,
• wherein:
• the rim is structured to resist deformation so as to form a support structure for the membrane, and
• said rim and frame are not in contact with the wearer's face in use.

A mask cushion for sealingly connecting a mask to a patient's face during the administration of positive airway pressure, the cushion including:

• a frame of resilient material, said frame having a rim to surround at least a portion of the patient's face;
• a membrane of resilient material and fixed to and extending away from the frame so as to be spaced from the rim, in at least one region of the frame, so as to include a gas-filled gap between the membrane and the rim before the cushion is in use, said membrane fully covering or overlying the rim as seen in cross section, wherein each of the rim and the membrane includes a distal end that is unsupported, the distal ends terminating in a substantially common orientation,
• a seal forming portion on an outer surface of said membrane, said seal forming portion being provided only on said membrane such that only the membrane forms a seal with the patient's face in use, said seal forming portion presenting a convex sealing surface to the patient's face;
• the membrane being pre-shaped to generally match the contours of the patient's face including a preformed contoured notch to accommodate the bridge of the patient's nose,
• wherein the seal forming portion is structured such that it is not required to turn in on itself to conform with the patient's face.