#$%^&*AU2016202268B220170921.pdf#####- 28 ABSTRACT A user interface comprising a non-sealing nasal cannula and a mask arranged about the nasal cannula, the mask including a seal configured to seal with a user's face to allow the interface to be pressurised, the cannula configured to deliver breathing gases to the nares of a user at a flow rate 5 exceeding the intended user's peak inspiratory flow requirements so that the mask and the user's pharynx are flushed continuously with fresh breathing gases to reduce dead space.lctr) ........ 00Q