Shenzhen PM-9000 Express, Руководство по обслуживанию

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Chapter 2 Principles
algorithm.
2.4.7 CO
CO measurement principle: The thermal dilution method is widely used in the clinical CO
monitoring. Introduce a floating catheter into the pulmonary artery through the right atrium,
and inject the physiological saline into the right atrium through the catheter whose front
end is connected to the temperature transducer. When the cold liquid mixes with the
blood, there will be a change of temperature. Thus, when the blood mixed with the
physiological saline flows into the pulmonary artery, its temperature will be sensed by the
temperature transducer. According to the injection time and temperature change, the
patient monitor can analyze the CO, and calculate the Cardiac Index (CI), Stroke Volume
Index (SVI), SVIs of the left atrium and right atrium, Pulmonary Vascular Resistance (PVR)
and so on.
2.4.8 CO
2
The CO
2
module works based on the infrared spectrum absorption principle. According to
different connection methods, the infrared light transducer is classified as the mainstream
infrared light transducer and sidestream infrared light transducer. The sidestream CO
2
module is composed of the circuit board, inbuilt sidestream infrared light transducer,
deflation pump and control. When used, this module requires the external water trap,
drying pipe and sampling tube. The mainstream CO
2
module is composed of the circuit
board and external mainstream infrared light transducer. The infrared light transducer
needs to be preheated. In the sidestream mode, the deflation rate can be set to
100ml/min, 150ml/min or 200ml/min according to the patient situation. In the AG
monitoring, multiple compensations can be set, such as hydrosphere, oxygen,
temperature and desflurane (Des). When the CO
2
measurement is not being conducted,
the sidestream deflation pump, the transducer of the mainstream module, and the infrared
source are expected to be shut down, thus to extend the service life and reduce the power
consumption of the module. In the mainstream mode, the infrared light transducer takes a
longer time to be preheated, and there is no windpipe which is available in the sidestream
mode.
2.4.9 AG
The Anesthesia Gas (AG) can be used to measure the AG and respiration gas of the
anesthetized patient. The AG concentration is measured based on the principle that the
AG has the property of absorbing the infrared. All gases that the AG module can measure
have the property of absorbing the infrared, and every gas has their own specific
absorption peculiarity.
AG measurement procedure:
1. Send the gas to be measured to a sampling chamber;
2. Use an optical infrared filter, select a specific band of infrared, and transmit it
through the gas;
3. Measure the infrared that gets through the gas to obtain the gas concentration.
For a given volume, the higher the gas concentration is, the more absorbed infrared is,
and the less the infrared that gets through the gas is. For the measurement of multiple
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