Which of the following is a controlled delivery device which is used to deliver a fixed concentration of oxygen?

Venturi mask is a type of HAFOEmask (High Air Flow Oxygen Enrichment Devices). It is used to deliver a controlled oxygen concentration to a patient. The patient breathes a fixed concentration of oxygen enriched air because the gas flow is greater than the peak inspiratory flow rate of the patient. Thus there is minimal dilution from atmospheric air. The high gas flow flushes expired gas from the mask preventing rebreathing. Nasal cannula isused when a low-flow of oxygen is indicated. These do not increase dead space. Inspiratory oxygen concentration depends on the flow rate. No rebreathing occurs. Non-rebreathing mask has a one way valve prevents the exhaled air from entering the reservoir bag. It provides the patient with enriched oxygen during inhalations. Nasal masks are effective interfaces for non invasive positive pressure ventilation (NIPPV) in most pediatric patients. It allows better removal of CO2.