Venturi

a type of disposable face mask used to deliver a controlled oxygen concentration to a patient. (See also oxygen therapy.) The flow of 100 per cent oxygen through the mask draws in a controlled amount of room air (21 per cent oxygen). Commonly available masks deliver 24, 28, 31, 35, or 40 per cent oxygen. At concentrations above 24 per cent, humidification may be required. Called also venturi.