Cardell MAX-12 HD - Veterinary Instrumentation

Cardell® MAX-12HD User’s ManualSECTION 12CO2 MONITORING12.1 General InformationThe Cardell MAX-12 monitor uses Microstream non-dispersive infrared(NDIR) spectroscopy to continuously measure the amount of CO2 duringevery breath, the amount of CO2 present at the end of exhalation (EtCO2) andduring inhalation (FiCO2), and the Respiratory Rate. Infrared spectroscopy isused to measure the concentration of molecules that absorb infrared light.Because the absorption is proportional to the concentration of the absorbingmolecule, the concentration can be determined by comparing its absorption tothat of a known standard.The Microstream EtCO2 sample tube delivers a sample of the inhaled andexhaled gases from the ventilator circuit or directly from the patient into themonitor for CO2 measurement. Moisture and patient secretions are extractedfrom the sample while maintaining the shape of the CO2 waveform.The 50 ml/min. sampling flow rate reduces liquid and secretionaccumulation, decreasing the risk of obstruction in the sample pathway inhumid ICU environmentsOnce inside the Microstream CO2 sensor, the gas sample goes through amicrosample cell (15 microliters). This extremely small volume is quicklyflushed, allowing for fast rise time and accurate CO2 readings, even at highrespiration rates. The Microbeam IR source illuminates the microsample celland the reference channel. This proprietary IR light source generates only thespecific wavelengths characteristic of the CO2 absorption spectrum.Therefore, no compensations are required when different concentrations ofN20, O2, anesthetic agents, and water vapor are present in the inhaled andexhaled breath.The IR that passes through the microsample cell and the IR that passesthrough the reference channel are measured by the IR detectors.The microcomputer in the monitor calculates the CO2 concentration by90 M1.0 5-15-09