A system that provides a flow of gas to an airway of a user that includes a source of gas, a conduit that carries the flow of gas to the airway of a patient, a first valve that controls a pressure, flow, or volume, of the flow of gas, a pressure sensor coupled to the conduit between the valve and the patient that monitors a pressure of the gas in the conduit, and a controller that controls the valve based on an output of the pressure sensor. A restrictor is provided in the conduit between the pressure sensor and the patient that divides the fluid delivery system with a first smaller volume in the conduit between the valve and the restrictor and a second larger volume between the patient and the restrictor. The system controls the pressure, flow, or volume relative to the first volume.
