| 主权项 |
1. A patient interface for delivery of a flow of breathable gas at a continuously positive treatment pressure with respect to ambient air pressure to an entrance to a patient's airways, while the patient is sleeping, to ameliorate sleep disordered breathing, said patient interface comprising:
a patient contacting portion to seal against an area surrounding the entrance to the patient's airways for the flow of breathable gas; a frame defining a cavity pressurised at the treatment pressure; and a gas washout vent configured to allow a flow of patient exhaled CO2 to an exterior of the patient interface to minimise rebreathing of exhaled CO2 by the patient, the gas washout vent comprising an orifice, a first vent, and a second vent, the gas washout vent having a first position wherein the orifice is in pneumatic communication with the first vent, and the gas washout vent having a second position wherein the orifice is in pneumatic communication with the second vent, wherein a first visual indicator is associated with said first position and a second visual indicator is associated with said second position. |
