Reliability-enhanced apparatus operation for re-breathing and methods of effecting same

摘要

Apparatus for affording a re-breathing capability to a breathing circuit (500), comprising: a device (550) for altering operation of the breathing circuit (500) from a first mode permitting air flow through a first path in the breathing circuit (500) to a second mode providing a re-breathing capability to the breathing circuit (500); a CO 2 sensor (560) located to detect CO 2 in the breathing circuit (500) between the device (550) and a patient; an air flow sensor (560) located to detect a rate of air flow in the breathing circuit (500) between the device (550) and the patient; and a processor (522) for computing a parameter comprising at least one of: end-tidal CO 2 concentration responsive to signals from the CO 2 sensor (560); end-inspired CO 2 . concentration responsive to signals from the CO 2 sensor (560); or inspired CO 2 volume responsive to signals from the air flow sensor (560) and the CO 2 sensor (560); and configured for triggering an alarm (116) responsive to deviation of the computed parameter from a selected magnitude or range of magnitudes for the parameter.