A pneumatic system for delivering oxygen to a subject, including an oxygen supply channel having an inlet, a patient delivery outlet and an exhaust and a flow control element configured to control the flow from the oxygen inlet to the patient delivery outlet, or to the exhaust wherein inhalation by the patient causes the flow control element to assume a first position, allowing oxygen to flow from the oxygen inlet to the patient delivery outlet and wherein exhalation by the patient causes the flow control element to assume a second position, directing oxygen flow from the oxygen inlet to the exhaust.
