Mindray PM-9000, Руководство по эксплуатации

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CO
2
Monitoring
17-22
17.4 Welch Allyn CO
2
Module
NOTE
z
This section is applicable to a monitor equipped with a Welch Allyn CO
2
module only.
17.4.1 Principles of Operation
WARNING
z
The CO
2
module should be protected against crash and vibration.
z
The Welch Allyn CO
2
module is applicable to neonate, pediatric as well
as adult patients.
The monitor adopts the mainstream Welch Allyn CO
2
module. The measurement of
this module is based on the feature that the CO
2
molecule absorbs 4.3um infrared ray.
The measurement procedure is as follows : send the CO
2
to a measurement chamber
inside the module through the airway system, and then irradiate infrared ray at one
side of the chamber and use the sensor to measure the attenuation degree of the
received infrared ray at the other side. Since the attenuation degree of the infrared
ray is proportional to the concentration of CO
2
, the CO
2
concentration is calculated.
The relation between the partial pressure and the CO
2
concentration is given below:
CO
2
partial pressure (mmHg)=
CO
2
concentration (%)×Pamp (ambient pressure, mmHg)/100
This module adopts the Autorun measurement. The rate of the waveform sampling is
once per 31 milliseconds. The operation sequence is as follows: when the monitor is
powered on, the CO
2
module starts warming up automatically for 45s
–
90s. Then
the sensor motor is activated. Around 5s – 10s later, the infrared ray source is turned
on, and about 10s later the module enters normal measurement mode.