Method and ultrasonic air-in-line detector for detecting entrained air in a medication infusion system

摘要

An ultrasonic air-in-line detection system for use in detecting entrained air bubbles in the fluid line (306) of a disposable cassette mounted on a main pump unit which can accurately detect air bubbles in any type of fluid, whether clear or opaque. The system uses multiple windowing and air volume number weighting to determine when a threshold count of air in a predetermined number of windows of material pumped occurs, with the alarm being sounded only when this threshold count of air bubbles in present in the window volume. The system of the present invention will thus detect entrained air but avoids so-called nuisance alarms due to the presence of small isolated air bubbles. IMAGE