A patient ventilation apparatus is disclosed. The apparatus includes an inlet port connectible to an oxygen source with pressurized oxygen enriched gas. An outlet port is connectible over a gas delivery conduit to a patient interface configured for fitment on a patient respiratory passageway. A valve is in pneumatic communication with the inlet port and with the outlet port. A first pressure sensor measures a patient interface pressure, which is connectible to the first pressure sensor over a pressure sensor line. A second pressure sensor measures a valve output pressure. A controller is in communication with the first pressure sensor, the second pressure sensor, and the flow sensor, to detect a patient inspiratory phase and a patient expiratory phase based upon a combination of measurements of the first pressure sensor and the second pressure sensor and to regulate the valve to selectively deliver pressurized oxygen enriched gas to the patient interface.
