Modular oro-nasal patient interface

A method of assembling a modular patient interface, the method comprising:

• providing a nasal patient interface comprising:
• a nasal plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH2O above ambient air pressure,
• a nasal seal forming structure configured to seal with a patient's nares,
• a vent structure including a vent body connected to the nasal plenum chamber and a vent wall connected to the vent body and movable between a closed position and an open position, and
• a first positioning and stabilising structure configured to provide a tensile force for holding the nasal seal forming structure in an operative position;
• providing an oral cushion comprising:
• an oral plenum chamber pressurisable to the therapeutic pressure of at least 4 cmH2O above ambient air pressure;
• an oral seal forming structure configured to seal with the patient's mouth,
• a receptacle disposed outside of the oral plenum chamber and spaced apart from the oral seal forming structure, the receptacle comprising,
• a receptacle opening providing fluid communication with the oral plenum chamber, and
• at least one prong disposed around at least a portion of the perimeter of the receptacle opening;
• a second positioning and stabilising structure configured to hold the nasal seal forming structure in the operative position;
• and
• positioning the nasal patient interface in the receptacle and aligning the vent structure with the receptacle opening;
• inserting the at least one prong into the nasal plenum chamber by moving the vent wall to the open position;
• connecting the nasal patient interface to the oral cushion so that the nasal plenum chamber and the oral plenum chamber are connected to one another in an air tight configuration;
• and
• connecting the first positioning and stabilising structure to the second positioning and stabilising structure.