Biolight Meditech S12 Vet - Chapter 15 Carbon Dioxide (CO 2 ); Introduction; Safety Information

S12 Vet Monitor User’s Manual
15-1
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Chapter 15 Carbon Dioxide (CO
2
)
15.1. Introduction
The monitor adopts infrared absorption technology to measure the carbon dioxide
(CO
2
) concentration in the breathing airway of patient. Because CO
2
molecule can absorb
infrared light of special wavelength, and the amount of absorbed infrared light directly
relates to the concentration of CO
2
, therefore while the infrared light radiated from the
infrared light source passing through the gas sample containing CO
2
, part of energy will
be absorbed by CO
2
in the gas. At another side of infrared light source, a photodetector is
used to measure the remaining infrared energy and convert it to electric signal, which will
be compared with the energy of infrared light source and adjusted so as to correctly reflect
the CO
2
concentration in the gas sample.
There are two methods for measuring carbon dioxide in the patient’s airway:
1. Mainstream: Uses a CO
2
sensor attached to an airway adapter directly inserted into
the patient’s breathing system.
2. Sidestream/Microflow: Takes a sample of the respiratory gas with a constant sample
flow from the patient’s airway and analyzes it with the CO
2
sensor.
15.2. Safety information
WARNING:
 When placing pipes such as sampling tubes, prevent the pipes from suffocating
the patient’s throat.
CAUTION:
 When the patient is being treated with aerosolized drugs, the measured EtCO2
value may be inaccurate and is not recommended for use in this situation.
 The EtCO2 value measured by the CO2 module may differ from the CO2
partial pressure value measured by blood gas analysis.
 The CO2 module has an automatic alarm suppression function, and the CO2