9 Anesthetic Gas Module Introduction
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• Switching Power Supply.
• Pneumatic System.
• Agent Identification.
• O
2
Sensor.
• Infrared Measurement Assembly.
Main PC Board
This digital board:
• Controls the pneumatic system and the IR measurement assembly.
• Converts the preamplified analog output signal from the IR detector into a digital value. Under
software-controlled processing, this is then converted to a fully compensated gas concentration
value.
• Converts analog signals from the sample cell pressure sensor, transducer, sample cell temperature
thermistor, and the ambient temperature thermistor, into digital environmental data for gas
compensation and data reporting.
• Converts an analog O
2
signal, supplied by the O
2
measurement system, into O
2
concentration data
for CO
2
compensation and O
2
data reporting.
• Converts analog signals from the flow-control servo system and power supply into digital data for
status reporting.
• Processes the algorithm for end-tidal, inspired and respiration rate values.
• Controls the communication between the monitor and the Philips M1026A Anesthetic Gas Module
through an RS232 interface that uses a standard communications protocol.
• Contains the software program that controls the Philips M1026A Anesthetic Gas Module in a 128K
EPROM.
Power Supply
The input voltage is 100V - 240V. The output voltages are ±12V and +5V and the maximum output is
55W.
Pneumatic System
The main parts of the pneumatic system are:
• Watertrap.
• Pump assembly, including pump outlet filter.
• Two solenoid valves.
• Tubing system including:
– Differential pressure transducer and restrictor for control of the total flow.
– Measurement path.
– Drainage path parallel to measurement path.
• Ambient air reference filter.