Natural breathing full face mask

A patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to a patient's airways including at least an entrance of a patient's nares, wherein the patient interface is configured to maintain a therapy pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout a patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing;

• said patient interface comprising:
• a cushion comprising,
• a nasal portion comprising:
• a nasal plenum chamber at least partially forming a nasal cavity pressurisable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure, the nasal plenum chamber including at least one plenum chamber inlet port configured to convey the flow of air into the nasal plenum chamber;
• a nasal seal-forming structure constructed and arranged to form a seal with a region of the patient's face surrounding an entrance to the patient's nares, said nasal seal-forming structure having a hole therein such that the flow of air at said therapeutic pressure is delivered to at least the entrance to the patient's nares, the nasal seal-forming structure constructed and arranged to maintain said therapeutic pressure in the nasal plenum chamber throughout the patient's respiratory cycle in use;
• and
• a nasal vent structure connected to the nasal plenum chamber and configured to allow gases to flow from an interior of the nasal plenum chamber to ambient, said nasal vent structure being sized and shaped to maintain the therapeutic pressure in the nasal plenum chamber in use;
• an oral portion comprising:
• an oral plenum chamber at least partially forming an oral cavity pressurisable above ambient air pressure;
• and
• an oral seal-forming structure constructed and arranged to form a seal with a region of the patient's face surrounding an entrance to the patient's mouth, said oral seal-forming structure having a hole therein such that air in the oral cavity is delivered to at least the entrance to the patient's mouth, the oral seal-forming structure constructed and arranged to maintain a pressure above ambient pressure in the oral plenum chamber throughout the patient's respiratory cycle in use;
• a passage formed between the nasal plenum chamber and the oral plenum chamber, wherein the passage is configured to allow airflow to pass between the nasal plenum chamber and the oral plenum chamber;
• a valve including valve body and an adjustment structure being positioned between the nasal plenum chamber and the oral plenum chamber and being movable relative to the valve body, the adjustment structure movable between an open position configured to allow airflow between the nasal plenum chamber and the oral plenum chamber, and a closed position configured to limit airflow between the nasal plenum chamber and the oral plenum chamber;
• and
• a positioning and stabilising structure to provide a force to hold the nasal seal-forming structure and the oral seal-forming structure in a therapeutically effective position on the patient's head;
• and
• wherein the adjustment structure is configured to allow airflow through the nasal vent in the closed position and is configured to limit airflow through the nasal vent in the open position.