VORRICHTUNG ZUR BESTIMMUNG DES GASVOLUMENS SOWIE VOLUMENÄNDERUNGEN IN EINEM NARKOSESYSTEM

摘要

A detector for determining the volume and volumetric changes of respiratory gases in a closed circuit anaesthesia circuit having a bellows ventilator. The device includes a first sensor positioned with respect to the bellows for detecting and indicating when the bellows assumes a given expanded position in a bellows housing indicative of the given volume of respiratory gas in the circuit. A second sensor detects and indicates when the bellows assumes an expanded position indicative of the greater amount of expansion than that corresponding to the given expanded position. During respiratory cycles of the patient, indications from the first sensor in the absence of indications from the second sensor indicates that the volume of gas in the closed circuit anaesthesia circuit is not changing, but is remaining at that corresponding to the given expanded position of the bellows. Indications from both the first sensor and the second sensor indicates that the degree of expansion of the bellows is greater than that corresponding to the given expanded position and hence the volume of gas in the closed circuit anaesthesia circuit has increased. The absence of indications from both the first and second sensors indicates that the degree of expansion of the bellows is less than that corresponding to the given expanded position and that the volume of gas in the closed circuit anaesthesia circuit has decreased.