Oxygen Cannula has an oxygen inlet flowably connectable to an oxygen supply, two neck tubes and oxygen delivery tubes. Oxygen cannulas are designed to deliver oxygen from an oxygen source to the nostrils at the prescribed rate determined by the healthcare giver.

An Oxygen Filter System is for preventing the transmission of a disease from a patient to medical personnel. The oxygen mask filter system includes a face mask having an interior surface and an exterior surface, a plurality of vent apertures, a disk member movably attached to the exterior surface of the face mask about the vent apertures and a filter member attached to the interior surface of the face mask for filtering gases prior to expulsion from the interior of the face mask to the exterior through the vent apertures.

An Oxygen Flowmeter System provides a flow of oxygen to the patient undergoing anesthesia in the event of a detected fault in the overall supply and mixing system of the anesthesia system. The normal design of such supply and mixing systems for an anesthesia system provides oxygen and at least one other gas that are mixed together in a desired proportion to be provided to a vaporizer and then to the anesthesia system as fresh gas. In the present system, a processor continuously monitors the output flows from those proportioning mixing valves. When the processor determines that those flows from the proportioning valves are off by a predetermined amount, indicative of a fault in the system, the processor immediately shuts off the supply of any gases other than oxygen and also provides a flow of oxygen to a bypass line that bypasses the oxygen proportioning valve, thus assuring a supply of oxygen to the patient despite the fault. A manual valve may be included in the bypass line so that the clinician can control the flow of oxygen and a flowmeter is provided so the clinician can visually note the flow and control that flow accordingly.