A high-pressure alarm for the detection of obstruction of the fresh gas line in the T-piece circuit.

An electronic high-pressure alarm for detecting obstruction of the fresh gas flow line in T-piece type anaesthetic circuits is described. The system is small, battery operated, and unobtrusive on the anaesthetic machine. The alarm is designed to sound whenever an obstruction reduces fresh gas flow to the patient, resulting in undesired rebreathing of expired gases.