Mindray Gas Module User manual
Gas Module SETM with Spirometr
y
Gas Module SE
TM
Gas Module II
TM
Gas Module 3
Service Manual Addendum
AION™ is a trademark of Artema Medical AB.
f
™
D-Lite
is a trademark of GE Medical Systems Information Technologies.
DRYLINE
™
is a trademark of Artema Medical AB.
Gas Module II
Gas Module SE
™
Nafion
Passport
Passport 2
Spectrum
is a trademark of Perma Pure Inc.
®
XG is a U.S. registered trademark of Mindray DS USA, Inc.
®
is a U.S. registered trademark of Mindray DS USA, Inc.
®
is a U.S. registered trademark of Mindray DS USA, Inc.
Spectrum OR
®
is a U.S. registered trademark of Mindray DS USA, Inc.
™
is a U.S. trademark of Mindray DS USA, Inc.
™
is a U.S. trademark of Mindray DS USA, Inc.
Copyright
©
Mindray DS USA, Inc., 2008. All rights reserved. Contents of this publication may not be reproduced in any
orm without permission of Mindray DS USA, Inc.
0070-10-0522 Gas Module Service Manual Addendum
Table of Contents
Introduction.................................................................................................................................................... v
Warnings, Precautions and Notes.....................................................................................................................vi
Warnings ......................................................................................................................................................vi
Caution .........................................................................................................................................................vii
Theory Of Operation......................................................................................................... 1 - 1
Gas Sampling System...................................................................................................................................... 1 - 2
Water Trap............................................................................................................................................. 1 - 3
Zero Valve and Absorber ......................................................................................................................... 1 - 4
™
Nafion
Tube ......................................................................................................................................... 1 - 4
Gas Analyzers ........................................................................................................................................ 1 - 4
Sample Flow Differential Pressure Transducer .............................................................................................. 1 - 4
Working Pressure Transducer.................................................................................................................... 1 - 4
Pneumatic Unit ........................................................................................................................................ 1 - 4
Connection Block..................................................................................................................................... 1 - 4
Occlusion Valve ...................................................................................................................................... 1 - 5
Sampling Pump and Damping Chamber..................................................................................................... 1 - 5
Anesthetic Agent Sensor .................................................................................................................................. 1 - 6
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 1 - 6
Gas Module 3 ........................................................................................................................................ 1 - 8
Sensor ..................................................................................................................................................... 1 - 11
O
2
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 1 - 11
Gas Module 3 ........................................................................................................................................ 1 - 12
CPU Board..................................................................................................................................................... 1 - 14
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 1 - 14
Gas Module 3 ........................................................................................................................................ 1 - 15
Board ...................................................................................................................................................... 1 - 16
O
2
Communication Interface Board........................................................................................................................ 1 - 17
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 1 - 17
Gas Module 3 ........................................................................................................................................ 1 - 18
Electrical Wiring Diagram................................................................................................................................ 1 - 19
Gas Module 3 Electronics ................................................................................................................................ 1 - 20
Power Supply ................................................................................................................................................. 1 - 22
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 1 - 22
Gas Module 3 ........................................................................................................................................ 1 - 23
Spirometry (Gas Module SE with Spirometry Only) Overview ............................................................................... 1 - 24
Measured Parameters .............................................................................................................................. 1 - 24
Measurement Principles............................................................................................................................ 1 - 25
PVX Measuring Unit ................................................................................................................................. 1 - 25
Specifications.................................................................................................................... 2 - 1
Performance Specifications .............................................................................................................................. 2 - 2
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 2 - 2
Gas Module 3 ........................................................................................................................................ 2 - 3
Gas Measurements ......................................................................................................................................... 2 - 6
Normal Conditions .................................................................................................................................. 2 - 6
Non-disturbing Gases .............................................................................................................................. 2 - 6
Disturbing Gases ..................................................................................................................................... 2 - 7
Gas Module 3 Interference Specifications................................................................................................... 2 - 7
...................................................................................................................................................... 2 - 8
CO
2
......................................................................................................................................................... 2 - 9
O
2
O...................................................................................................................................................... 2 - 10
N
2
Anesthetic Agents .................................................................................................................................... 2 - 10
Accuracy specifications at conditions exceeding normal............................................................................... 2 - 12
Gas Module Service Manual Addendum 0070-10-0522 i
Table of Contents
ISO Mode Accuracy specifications for Gas Module 3 .................................................................................. 2 - 13
Patient Spirometry........................................................................................................................................... 2 - 15
Normal Conditions for Gas Module SE with Spirometry ............................................................................... 2 - 15
Accuracy specifications at conditions exceeding normal............................................................................... 2 - 16
Power Input Ratings......................................................................................................................................... 2 - 17
Environmental Conditions................................................................................................................................. 2 - 17
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 2 - 17
Gas Module 3 ........................................................................................................................................ 2 - 17
Physical Characteristics ................................................................................................................................... 2 - 18
Gas Module II......................................................................................................................................... 2 - 18
Gas Module SE....................................................................................................................................... 2 - 18
Gas Module 3 ........................................................................................................................................ 2 - 18
Agency Compliance........................................................................................................................................ 2 - 18
Gas Module II......................................................................................................................................... 2 - 18
Gas Module SE....................................................................................................................................... 2 - 19
Gas Module 3 ........................................................................................................................................ 2 - 19
Repair Information ........................................................................................................... 3 - 1
Introduction.................................................................................................................................................... 3 - 1
Safety Precautions........................................................................................................................................... 3 - 2
Troubleshooting .............................................................................................................................................. 3 - 2
General Troubleshooting Guidelines .......................................................................................................... 3 - 2
Gas Module Technical Troubleshooting ...................................................................................................... 3 - 3
Patient Spirometry Trouble Shooting........................................................................................................... 3 - 6
Exchange Program .................................................................................................................................. 3 - 7
Equipment and Special Tools Required .............................................................................................................. 3 - 8
Disassembly Instructions................................................................................................................................... 3 - 9
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 3 - 9
Gas Module 3 ........................................................................................................................................ 3 - 12
Mounting Hardware and Accessories................................................................................................................ 3 - 13
Passport XG/Gas Module Mounting .......................................................................................................... 3 - 13
Expert/Gas Module Mounting................................................................................................................... 3 - 15
Passport 2/Spectrum/Spectrum OR Gas Module Mounting .......................................................................... 3 - 17
Gas Module II/Gas Module SE Accessories ....................................................................................................... 3 - 21
Gas Module SE with Spirometry Accessories ...................................................................................................... 3 - 22
Gas Module 3 Accessories .............................................................................................................................. 3 - 23
Replacement Parts ............................................................................................................ 4 - 1
Introduction.................................................................................................................................................... 4 - 1
Available Replacement Parts and Sub-Assemblies ............................................................................................... 4 - 1
Exchange Program.......................................................................................................................................... 4 - 2
Replacement Parts Pricing Information ............................................................................................................... 4 - 2
Ordering Information ...................................................................................................................................... 4 - 3
Abbreviations................................................................................................................................................. 4 - 4
Isometric Drawing and Parts Lists ...................................................................................................................... 4 - 5
Calibration ....................................................................................................................... 5 - 1
Introduction.................................................................................................................................................... 5 - 1
Warnings and Guidelines................................................................................................................................ 5 - 1
Test Equipment and Special Tools Required........................................................................................................ 5 - 2
Power-Up Verification...................................................................................................................................... 5 - 2
Passport XG Configuration for Gas Module ................................................................................................ 5 - 2
Expert Configuration for Gas Module......................................................................................................... 5 - 3
Passport 2/Spectrum/Spectrum OR Configuration for the Gas Module .......................................................... 5 - 4
Gas Module 3 Pneumatic Leakage Test.............................................................................................................. 5 - 5
ii 0070-10-0522 Gas Module Service Manual Addendum
Table of Contents
Gas Module 3 Zero Reference Valve Test .......................................................................................................... 5 - 5
Calibration..................................................................................................................................................... 5 - 6
Passport XG Gas Calibration .................................................................................................................... 5 - 6
Expert Gas Module Calibration................................................................................................................. 5 - 8
Gas Monitor Calibration - Passport 2/Spectrum/Spectrum OR...................................................................... 5-10
Power Supply PC Board Calibration .......................................................................................................... 5 - 16
Patient Spirometry Calibration Measurement (Spectrum OR only)...................................................................5-18
Patient Spirometry Leak Test Verification (Spectrum OR Only)........................................................................ 5 - 20
Gas Module Leakage Current Checks................................................................................................................ 5 - 21
Preventive Maintenance.................................................................................................... 6 - 1
Preventive Maintenance Introduction ................................................................................................................. 6 - 1
Preventive Maintenance Schedule ..................................................................................................................... 6 - 1
Performance Verification.................................................................................................................................. 6 - 2
Perform as required, or at 6 month intervals................................................................................................ 6 - 2
Perform as required, or 1 Year intervals ..................................................................................................... 6 - 2
Patient Spirometry Leak Test Verification (Spectrum OR Only)........................................................................ 6 - 2
Mechanical / Physical / Visual Inspection ......................................................................................................... 6 - 2
Perform at 6 month intervals...................................................................................................................... 6 - 2
Consumable Item Replacement ......................................................................................................................... 6 - 2
Replace at 1 month intervals ..................................................................................................................... 6 - 2
Replace at 2 month intervals ..................................................................................................................... 6 - 2
Replace at 12 month intervals ................................................................................................................... 6 - 2
Replace at 24 month intervals ................................................................................................................... 6 - 2
Internal Adjustments/Calibration....................................................................................................................... 6 - 3
Perform at 12 month intervals or as required............................................................................................... 6 - 3
Patient Spirometry Calibration Measurement (Spectrum OR only)...................................................................6-3
Care and Cleaning of Gas Module................................................................................................................... 6 - 4
Gas Module II, Gas Module SE, and Gas Module SE with Spirometry ........................................................... 6 - 4
Gas Module 3 ........................................................................................................................................ 6 - 5
Gas Module Service Manual Addendum 0070-10-0522 iii
Table of Contents
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iv 0070-10-0522 Gas Module Service Manual Addendum
Introduction Introduction
Introduction
The Gas Module is a companion to several Patient Monitors. It is capable of automatically
identifying and measuring five anesthetic agents (Desflurane, Enflurane, Sevoflurane,
Halothane and Isoflurane), as well as N
sidestream sampling.
The following models are referenced in this manual: Gas Module II, Gas Module SE, Gas
Module SE with Spirometry, and Gas Module 3. When information is common to all models,
the generic name “Gas Module” is used. Information that is unique to a specific model is
identified accordingly.
The system connects to the Patient Monitor via an RS232 connector.
A special “Y” shaped power cord is used to supply AC voltage to both the Gas Module and
the Monitor power supply. All Gas Module data displays on the monitor screen. All user
commands are entered on the monitor and then electronically transmitted to the Gas Module.
This addendum provides Gas Module information on theory of operation, specifications,
repair, parts, calibration and preventive maintenance. For related information on the Patient
Monitor, refer to the associated Service Manual and Operating Instructions.
O, CO2 and O2. The unit monitors all gases via
2
• Passport XG Operating Instructions
• Passport 2 Operating Instructions (Domestic)
• Passport 2 Operating Instructions (International)
• Expert Operating Instructions (Domestic)
• Spectrum Operating Instructions (Worldwide)
• Spectrum OR Operating Instructions (Worldwide)
NOTE: The Gas Module SE with Spirometry can only be used with
NOTE: The Gas Module 3 can only be used with Passport 2,
WARNING: Calibration gas is considered Dangerous Goods/Hazardous
the Spectrum OR monitor.
Spectrum, and Spectrum OR monitors.
Materials per I.A.T.A. and D.O.T. Regulations.
It is a violation of federal and international law to offer any
package or over pack of dangerous goods for
transportation without the package being appropriately
identified, packed, marked, classified, labeled and
documented according to D.O.T. and I.A.T.A. regulations.
Please refer to the applicable I.A.T.A. Dangerous Goods
Regulations and/or the Code of Federal Regulations 49
(Transportation, Parts 171-180) for further information.
Gas Module Service Manual Addendum 0070-10-0522 v
Introduction Warnings, Precautions and Notes
Warnings, Precautions and Notes
Please read and adhere to all warnings, precautions and notes listed here and in the
appropriate areas throughout this manual.
A WARNING is provided to alert the user to potential serious outcomes (death, injury, or
serious adverse events) to the patient or the user.
A CAUTION is provided to alert the user to use special care necessary for the safe and
effective use of the device. They may include actions to be taken to avoid effects on patients
or users that may not be potentially life threatening or result in serious injury, but about which
the user should be aware. Cautions are also provided to alert the user to adverse effects on
this device of use or misuse and the care necessary to avoid such effects.
A NOTE is provided when additional general information is applicable.
Warnings
WARNING: Always Remove Power from the Gas Module BEFORE
WARNING: Remove Power from the Gas Module BEFORE removing the
WARNING: If the water trap breaks or becomes damaged during
WARNING: The airway adapter and sampling line are intended for
WARNING: The water trap, sampling line, and airway adapter should
WARNING: To avoid high sampling flow with the Gas Module 3, do not
WARNING: Connect only approved gas sampling lines to the water
WARNING: The Gas Module must not be used with flammable
WARNING: The use of gas sampling accessories other than specified
Disassembly.
Enclosure.
operation, there is a risk that bacteria and/or mucus may
contaminate the Gas Module.
single use only.
be disposed of in accordance with local regulations for
contaminated and biologically hazardous items.
use Adult/Pediatric water traps and/or sampling lines with
neonates.
trap.
anesthetic agents.
may cause significant measurement errors and patient risk.
WARNING: With the Gas Module 3, use only Neonate sampling lines
and water traps for Neonate patients. Do not use Neonate
sampling lines and water traps for Adult/Pediatric patients.
WARNING: Do not allow the sampling tubing to become kinked.
WARNING: Do not reuse disposable devices.
vi 0070-10-0522 Gas Module Service Manual Addendum
Cautions Introduction
WARNING: Trace Gas Hazard – When using the optional Gas Module, a
WARNING: When monitoring CO
WARNING: Connection of the Gas Module exhaust port to the hospital’s
WARNING: Equipment not suitable for use in the presence of a
WARNING: Do not connect devices that are not specified as part of the
WARNING: Do not clean the Gas Module while it is on and/or
health hazard exists when trace amounts of vaporized
anesthetic agents are chronically inspired by operating
room personnel. See Appendix A in NFPA 56A on Inhalation
Anesthetics. During any procedure where such agents are
employed, the Gas Module exhaust output should be
connected to a medical gas-scavenging system.
, connection from the exhaust port to
the hospital’s waste gas-scavenging system is
recommended to prevent exposure of hospital personnel to
the patient’s respiratory sample.
waste gas-scavenging system is recommended to prevent
exposure of hospital personnel to the patient’s respiratory
sample. Vacuum (negative pressure) should not exceed 1
mmHg at the Gas Module exhaust fitting. Excessive
scavenge vacuum may result in damage to the Gas
Module’s internal pump.
flammable anesthetic mixture with air or with nitrogen or
nitrous oxide.
system.
plugged in.
2
WARNING: The contents of the water trap should be handled as a
potential infection hazard.
Cautions
CAUTION: The internal sampling system of the Gas Module does not
need to be cleaned or sterilized. There is no reverse flow
back to the patient. If the internal sampling system is
suspected to be clogged or dirty, the module should be
serviced by an authorized service person only.
CAUTION: If the dust filter for the fan cannot be cleaned or is
damaged, replace it with part number 0378-00-0040. Use
of another type of filter may decrease the cooling effectivity
and cause damage to the Gas Module.
CAUTION: Do not disinfect or open the water trap. Do not touch the
water trap membrane.
CAUTION: Dispose of the water trap in accordance with hospital policy.
Gas Module Service Manual Addendum 0070-10-0522 vii
Introduction Cautions
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viii 0070-10-0522 Gas Module Service Manual Addendum
1.0
Theory Of Operation
Contents of this chapter .................................................................... Page
1.1 Gas Sampling System ............................................................... 1-2
1.2 Anesthetic Agent Sensor ........................................................... 1-6
1.3 O
1.4 CPU Board ................................................................................ 1-14
1.5 O2 Board .................................................................................. 1-16
1.6 Communication Interface Board ................................................ 1-17
1.7 Electrical Wiring Diagram ......................................................... 1-19
1.9 Power Supply ........................................................................... 1-22
1.10 Spirometry (Gas Module SE with Spirometry Only) Overview . 1-24
Sensor ................................................................................. 1-11
2
This Theory of Operation section provides block diagrams, a functional overview of the main
components and the gas sampling / measurement principle for the Gas Module.
The Gas Module consists of the following main components:
• Gas Sampling System
• Anesthetic Agent Sensor
Sensor
•O
2
•CPU Board
•O
Board
2
• Communications Interface Board
• Power Supply
• Spirometry Module (PVX unit)
• Water Trap
• Internal Tubing
Gas Module Service Manual Addendum 0070-10-0522 1 - 1
Gas Sampling System Theory Of Operation
1.1 Gas Sampling System
The sampling system draws in a patient sample to the analyzers at a fixed rate.
The gas sampling system draws patient sample into the module, and removes water and
impurities from it in a water trap. The pump draws gas through the sampling line, through the
water trap and into the gas measuring units. After the measurements, the gas is expelled
through the exhaust port. The sample flow rates are as follows:
• For Gas Module II, Gas Module SE, and Gas Module SE with Spirometry, the sample
flow rate is 200 ml/min.
• For Gas Module 3, the sample flow rate is 200 ml/min with the Adult/Pediatric water
trap and 120 ml/min with the Neonatal water trap.
A number of flow restrictors are utilized to create a pressure difference with ambient pressure
in the gas sensors.
A larger pressure difference makes the presentation of the gas concentration curves less
sensitive to variations in the airway pressure thus meeting the accuracy requirements.
Refer to the FIGURE 1-1 and FIGURE 1-2 for the Gas Tubing Layout and Gas Sampling
Component Block Diagram for Gas Module II, Gas Module SE, and Gas Module SE with
Spirometry. Refer to the FIGURE 1-3 for the combination Gas Tubing Layout and Gas
Sampling Component Block Diagram for Gas Module 3.
CO2 absorber
Nafion tube
Pneumatic
unit
Pressure
transducers
G
F
E
D
C
B
A
P
OUT
OM unit
REF
IN
Water trap
Nafion tube
B1
B2
OUT
IN
Damping chamber
Sampling pump
TPX unit
IN
OUT
Connection
block
FIGURE 1-1 Gas Tubing Layout – Gas Module II, Gas Module SE, and Gas Module SE
with Spirometry
1 - 2 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation Gas Sampling System
Room air
Filter
Reference gas
Filter
Room air
Pressure
Transducer
p
dp
OM
Occlusion
valve
Pump
Sample
line
Zero
valve
Absorber
TPX
Pressure
Transducer
p
FIGURE 1-2 Gas Sampling Component Block Diagram – Gas Module II, Gas Module SE,
and Gas Module SE with Spirometry
Servomex
AION
™
Gas
Measurement
Bench
O2 Sensor
Pump
Module
EVAC Outlet Connection
FIGURE 1-3 Combination Gas Tubing Layout and Gas Sampling Component Block
1.1.1 Water Trap
The sample is drawn through a sample line. Then gas enters the monitor through the water
trap, where it is divided into two flows, a main flow and a side flow. The main flow goes into
the analyzers. This flow is separated from the patient side by a hydrophobic filter. The side
flow creates a slight subatmospheric pressure within the water trap which causes fluid
removed by the hydrophobic filter to collect in the bottle.
The Gas Module 3 uses the DRYLINE
Purge
Valve
to O2
Sensor
from O2
Sensor
to EVAC
Diagram – Gas Module 3
™
Sample
Zero Valve
Pneumatic
Module
water trap system.
DRYLINE
Water Trap
Purge
Sample In
™
Patient
Gas Module Service Manual Addendum 0070-10-0522 1 - 3
Gas Sampling System Theory Of Operation
1.1.2 Zero Valve and Absorber
The main flow passes through a magnetic valve before proceeding to the analyzers. This
valve is activated to establish the zero points for the Anesthetic Agent and O2 Sensors.
When the valve is activated, room air is drawn through the absorber into the internal system
and the gas sensors. Paralyme is used as the absorbent. The Absorber is for Gas Module II,
Gas Module SE, and Gas Module SE with Spirometry.
1.1.3 Nafion™ Tube
A nafion tube is used between the water trap and the zero valve to balance the sample gas
humidity with that of ambient air. The tube will prevent errors caused by the effect of water
vapor on gas partial pressure when the humid gases are measured after calibration with dry
gases.
*Nafion is a trademark of Perma Pure Inc.
*
1.1.4 Gas Analyzers
After the zero valve and nafion tube the gas passes through the Anesthetic Agent and O2
Sensors. The oxygen sensor has two inputs. One input accepts the gas sample and the other
draws room air for reference. The gas sample finally exits through the exhaust port on the
rear of the unit. Refer to sections 1.2 and 1.3 for more information on the Anesthetic Agent
and O
Sensors.
2
™
The Gas Module 3 uses an AION
Oxygen Sensor. The AION
must be a matched pair.
™
multigas analyzer and a Servomex Paramagnetic
multigas analyzer and Servomex Paramagnetic Oxygen Sensor
1.1.5 Sample Flow Differential Pressure Transducer
The sample flow differential pressure transducer (Gas Module II, Gas Module SE, and Gas
Module SE with Spirometry) measures pressure drop across the O2 Sensor inlet restrictor and
calculates sample flow from the pressure difference.
1.1.6 Working Pressure Transducer
The working pressure transducer (Gas Module II, Gas Module SE, and Gas Module SE with
Spirometry) measures absolute working pressure between the Anesthetic Agent and O
Sensors. It is used to detect situations which will post messages for occlusion and replace
trap.
2
1.1.7 Pneumatic Unit
The pneumatic unit contains the zeroing valve, occlusion valve and tubing connections. There
is a series of restrictors and chambers forming a pneumatic filter to prevent pressure
oscillations in the pump from reaching the measuring units. Zeroing and occlusion valve
connections to room air include a dust filter.
1.1.8 Connection Block
The connection block contains a sample gas outlet connector and an O2 Sensor reference
gas inlet. The inlet is equipped with a dust filter.
1 - 4 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation Gas Sampling System
1.1.9 Occlusion Valve
The valve (Gas Module II, Gas Module SE, and Gas Module SE with Spirometry) is activated
when the sample line gets occluded. The main flow is diverted to the side flow of the water
trap to help remove the occlusion faster.
1.1.10 Sampling Pump and Damping Chamber
The Gas Module II, Gas Module SE, and Gas Module SE with Spirometry gas sampling
pump is a membrane pump that is run by a brushless DC motor. The gas flow rate is
measured with a sample flow differential pressure transducer across a known restriction. The
motor is automatically controlled to maintain a constant flow, even when the water trap ages
and starts to get occluded. It also enables use of sample tubes with varying lengths and
diameters.
The damping chamber is used to even out the pulsating flow and silence the exhaust flow.
The Gas Module 3 pump module is a low power, high reliability membrane pump and flow
controller including preamplifier and pump power driver.
NOTE: Flow is never reversed towards the patient.
Gas Module Service Manual Addendum 0070-10-0522 1 - 5
Anesthetic Agent Sensor Theory Of Operation
1.2 Anesthetic Agent Sensor
1.2.1 Gas Module II, Gas Module SE, and Gas Module SE with Spirometry
FIGURE 1-4 Gas Module II, Gas Module SE, and Gas Module SE with Spirometry
Anesthetic Agent Sensor
The Anesthetic Agent Sensor is a sidestream gas analyzer, measuring real time
concentrations of CO
Desflurane, and Sevoflurane).
The Anesthetic Agent Sensor is a non-dispersive infrared analyzer, measuring absorption of
the gas sample at seven infrared wavelengths, which are selected using optical narrow band
filters. The IR lamp is a 4W filament, surrounded by thermal isolation. There is a hole in the
isolation, passing the radiated light to a conical measuring chamber with a 4 mm length.
, N2O and five anesthetic agents (Halothane, Enflurane, Isoflurane,
2
Temp sensor
Sample
chamber
Thermopile
detectors
Sample
gas out
FIGURE 1-5 Anesthetic Agent Sensor Principle
From the sample chamber, radiated light goes into seven tubular light guides with reflective
inner surfaces. At the other end of each light guide there is a thermopile infrared radiation
detector with an optical filter in front of it.
Sample
gas in
The Temp sensor measures the Anesthetic Agent Sensor’s temperature and uses it for
temperature compensation.
1 - 6 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation Anesthetic Agent Sensor
Anesthetic agents or mixtures of two anesthetic agents are automatically identified and
concentrations of the identified agents are measured. The Anesthetic Agent Sensor also
detects mixtures of more than two agents.
FIGURE 1-6 Infrared Absorbance of N
O and CO
2
2
Concentrations of CO2 and N2O are calculated from the absorption measured at 3 to 5 μm.
FIGURE 1-7 Infrared Absorbance of Anesthetic Agents
Identification of anesthetic agents and calculation of their concentrations is performed by
measuring absorptions at five wavelengths in the 8 to 9 μm band and solving for the
concentrations from a set of five equations.
The measuring accuracy is achieved utilizing numerous software compensations. The
compensation parameters are determined individually for each Anesthetic Agent Sensor
during factory calibration.
Gas Module Service Manual Addendum 0070-10-0522 1 - 7
Anesthetic Agent Sensor Theory Of Operation
1.2.2 Gas Module 3
FIGURE 1-8 Gas Module 3
FIGURE 1-9 Gas Module 3 Anesthetic Agent Sensor
The Anesthetic Agent Sensor is a sidestream gas analyzer, measuring real time
concentrations of CO
Desflurane, and Sevoflurane).
The Anesthetic Agent Sensor is a non-dispersive infrared analyzer, measuring absorption of
the gas sample at up to eight infrared wavelengths, which are selected using optical narrow
band filters.
Anesthetic agents or mixtures of two anesthetic agents are automatically identified and
concentrations of the identified agents are measured. The Anesthetic Agent Sensor also
detects mixtures of more than two agents.
1 - 8 0070-10-0522 Gas Module Service Manual Addendum
, N2O and five anesthetic agents (Halothane, Enflurane, Isoflurane,
2
Theory Of Operation Anesthetic Agent Sensor
The absorption spectra for CO2, N2O, and the five anesthetic agents Halothane, Enflurane,
Isoflurane, Sevoflurane, and Desflurane are shown in FIGURE 1-10 and FIGURE 1-11.
N2O
CO
Absorbance
2
3.5 4 4.5 54.5
FIGURE 1-10 Infrared Absorption Spectra for N
Desflurane
Absorbance
78 10
Wav ele ngt h ( )μm
O and CO
2
Isoflurane
Enflurane
Sevoflurane
91112
Wav ele ngt h ( )μm
2
Halothane
FIGURE 1-11 Infrared Absorption Spectra for Anesthetic Agents
To identify seven different gases in a mixture, measurements are done at seven different
wavelengths. Measurements are done at an eighth wavelength for reference. The AION
Multigas Analyzer uses the absorption peaks at 4.2 and 3.9 for measuring CO
N
O respectively and the absorption peaks in the 8–12 range for measuring anesthetic
2
μm
μm
and
2
agents. See FIGURE 1-10 and FIGURE 1-11.
™
A set of narrow optical band pass filters intercepts a broadband infrared source to provide
these wavelengths. The individual filters are mounted in a rapidly rotating filter wheel that
intersects the light path. The filtered light passes into a cylindrical measurement chamber. At
the other end of the chamber, there is an infrared radiation detector, whose output is directed
to the host interface through the signal processor. See FIGURE 1-12.
Gas Module Service Manual Addendum 0070-10-0522 1 - 9
Anesthetic Agent Sensor Theory Of Operation
Gas Inlet Gas Outlet
Infrared
Detector
Light
Source
Filter Wheel &
Optical FIlters
Measurement
Chamber
Host
Interface
Signal
Processor
FIGURE 1-12 Optical Path
No radiation is absorbed if the measurement chamber is empty. The output signal from the
detector is at maximum amplitude at a concentration of zero. Lower amplitudes indicate the
presence of gases in the measurement chamber.
To establish the zero reference, the AION
™
Multigas Analyzer occasionally switches the zero
valve to direct ambient air through the measurement chamber.
1 - 10 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation O2 Sensor
El
1.3 O2 Sensor
1.3.1 Gas Module II, Gas Module SE, and Gas Module SE with Spirometry
FIGURE 1-13 O2 Sensor
The differential O
configuration. The gas sample along with reference room air are conducted into a gap in an
electromagnet with a strong magnetic field switched on and off at a frequency of
approximately 165 Hz.
An alternating differential pressure is generated between the sample and reference inputs
due to forces acting on the oxygen molecules in a magnetic field gradient.
The pressure is measured with a sensitive differential transducer, rectified with a synchronous
detector and amplified to produce a DC voltage proportional to the O
difference between the two gases to be measured.
Sensor uses the paramagnetic principle in a pneumatic bridge
2
concentration
2
ectromagnet
Mixture
out
Switched
Magnetic
Microphone
Sample in
field
Reference in
FIGURE 1-14 O
Gas Module Service Manual Addendum 0070-10-0522 1 - 11
Measurement Principle
2
O2 Sensor Theory Of Operation
1.3.2 Gas Module 3
Oxygen measurements are essential for correct gas measurement in the AION™ Multigas
Analyzer. Because oxygen does not absorb infrared light to the same extent as other
breathing gases and must be measured using another method, there is no built in oxygen
measurement module. The Gas Module 3 uses a Servomex Paramagnetic Oxygen Sensor.
FIGURE 1-15 Servomex Paramagnetic Oxygen Sensor
The Servomex Paramagnetic Oxygen Sensor uses the paramagnetic susceptibility of oxygen,
which is physical property that distinguishes oxygen from most common gases. Inside the
sensor are two nitrogen-filled glass spheres mounted on a strong rare metal taut-band
suspension. The assembly is suspended in a symmetrical non-uniform magnetic field. In the
presence of paramagnetic oxygen, the glass spheres are pushed further away from the
strongest part of the magnetic field. The strength of the torque acting on the suspension is
proportional to the oxygen concentration (see FIGURE 1-16).
Paramagnetic technology is non-depleting, which means there are no consumable parts,
ensuring consistent performance over time. The selectivity of the paramagnetic measurement
for oxygen means there is no interference from other respiratory gases. The small volume
chamber allows a rapid gas exchange, giving the capability for fast response oxygen
measurement.
1 - 12 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation O2 Sensor
Photo Detector
Permanent
Magnets
Light Source
Feedback
Signal
Current proportional
to O
concentration
2
Output Voltage proportional
to O
concentration
2
R
FIGURE 1-16 The Paramagnetic Oxygen Sensor Measurement Principle
Gas Module Service Manual Addendum 0070-10-0522 1 - 13
CPU Board Theory Of Operation
1.4 CPU Board
1.4.1 Gas Module II, Gas Module SE, and Gas Module SE with Spirometry
The CPU board contains the processor, memory and A/D converters that are common to the
whole module. The CPU board also contains preamplifiers for the Anesthetic Agent Sensor
and the drivers for the valves, fan and pump. The module is connected to the module bus
through a RS-485 serial channel.
Signal Processing
Signal Processing
TPX Board
IR Thermopile Sensors
Anaes.
Agents
N2O
CO
2
T Sensor
T Sensor
O
Flow Press
PVX Board
OM Board
MUX
2
preamps
MUX
and
buffer
Signal Processing
CPU Board
x 5
x 2
FIGURE 1-17 CPU Signal Processing
Control Logic
Control Logic
Lamp Unit
TPX
Lamp
CPU Board
Lamp
Current
Sensing
MUX
and
buffer
2 ch
A / D
16 bit
CPU
80C196NT
Valves
pneumatics
unit
Valves
Fan
Module Bus
RS-485
driver
Gas press
Diff press
OM Board
PVX Board
MUX
PVX
valves
Control Logic
MUX &
buffer
Temp
sensor
A / D
A / D
CPU
80C196NT
Module Bus
reset
data
FIGURE 1-18 CPU Control Logic
1 - 14 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation CPU Board
1.4.2 Gas Module 3
1.4.2.1 PCB
Power is a dedicated routing from the 12 V power filter. Power ground and signal ground
are connected on this board. The screws that attach the board to the enclosure are also
connected to chassis ground.
1.4.2.2 Power
To reduce noise from the power supply, both the 5 V and 12 V power lines are filtered. A 5 V
to 3.3 V linear regulator supplies power to the microcontroller. If the 5 V power supply drops
below 4.3 V, a reset signal is sent to the microprocessor.
1.4.2.3 Microcontroller
The microcontroller supports the following communication ports:
•AION
•Spirometry
• Patient Monitor
•Service
All ports use the RS-232 communication protocol. A real time clock (RTC) powered by either
3.3 V or by battery enables logging of malfunctions. If the RTC fails due to battery depletion
during battery mode, functionality is not affected.
™
1.4.2.4 Battery
The battery that supports the RTC in the microcontroller has a minimum lifetime of 7 years.
When the device is running on AC power, there is zero drain on the battery, thus prolonging
its lifetime.
Immediately after installing a new battery, the device should be power cycled to avoid high
battery currents (~540 µA). Follow the battery supplier’s handling recommendations.
The battery is installed at component number B401 on the PCB. The battery positive node is
marked with a “+” on the PCB and has two holes to differentiate it from the negative node
which has one hole on the PCB.
1.4.2.5 SPI Memory
The 8 Mb capacity of the SPI memory can store an error log with timestamps to facilitate
debugging and service.
Gas Module Service Manual Addendum 0070-10-0522 1 - 15
O2 Board Theory Of Operation
1.5 O2 Board
The O2 board is only used in the Gas Module II, Gas Module SE, and Gas Module SE with
Spirometry.
The O2 board contains the specific electronics for the O2 sensor. Sample flow measurement
and sampling system pressure sensors are on this board. It also contains EEPROM’s that store
factory calibration data of both the Anesthetic Agent and O
Calibration Data Stored in
Calibration Data Stored in
EEPROM
EEPROM
TPX Board
OM Board
EEPROM
EEPROM
OM Board
Factory calibration
data for OM and TPX
CPU Board
EEPROM
Correction data for
amplification and
offset of all amplification
channels
CPU
80C196NT
sensors.
2
RS-485
driver
Module Bus
EEPROM
PVX Board
FIGURE 1-19 O
Factory calibration
data for PVX
Calibration Data Stored in EEPROM
Board Calibration Data Stored in EEPROM
2
1 - 16 0070-10-0522 Gas Module Service Manual Addendum
Theory Of Operation Communication Interface Board
1.6 Communication Interface Board
1.6.1 Gas Module II, Gas Module SE, and Gas Module SE with Spirometry
This board is a converter between the Patient Monitor and the Gas Module. It converts the
proprietary RS-232 hardware protocol to the Gas Module’s RS-485 hardware protocol and
vice versa. The board contains a programmable micro-processor (Intel 87C196KD), a
QUART (Exar82C684CJ) and line drivers for RS-232 and RS-485 communication lines. For
production test purposes the RS-485 lines have been connected to D-connector X2 pins 1,5,6
and 8. Refer to the figure below.
FIGURE 1-20 Connectors Pin Configurations
Gas Module Service Manual Addendum 0070-10-0522 1 - 17
Communication Interface Board Theory Of Operation
1.6.2 Gas Module 3
1.6.2.1 Patient Monitor
The interface to the patient monitor is a D-sub, 25-pin, female connector that uses the RS-232
communication protocol.
1.6.2.2 AION
™
The interface to the AION™ is a 2 x 17-pin IDC with locking clips. Communication between
the HOST and the AION
distributed from the communication board to the AION
™
is with the RS-232 communication protocol. 12 V power is
1.6.2.3 Servomex
The interface to the Servomex is a 2 x 8-pin IDC with locking clips. All communication is to
the AION
™
through the communication board.
1.6.2.4 DRYLINE™ Receptacle
The interface to the DRYLINE™ receptacle is a 4-pin picoblade. All communication is to the
™
AION
through the communication board.
1.6.2.5 OXIMA Receptacle
The interface to the OXIMA receptacle is a 10-pin DF20 from Hirose. All communication is to
the AION
™
through the communication board.
1.6.2.6 LED
Power ON indication is a green LED. Flash programming mode is indicated with a green LED
close to the flash programming switch for the AION
™
.
™
.
1.6.2.7 Switches
• SW201 is the flash programming initialization button for the AION
• SW202 is for future use
• SW501 is a reset switch for the microprocessor
1 - 18 0070-10-0522 Gas Module Service Manual Addendum
™
Theory Of Operation Electrical Wiring Diagram
1.7 Electrical Wiring Diagram
Host Monitor
Gas Module II
Exhaust
Air Input
Ext.
Com.
Cable
Host Monitor
X3
Interface Board
Gas Module SE
TPX
Agent Bench
Nafion
Pneumatics
M-GAS Assy
CPU PCB
OM
Oxygen Module
Filter
A
b
s
o
r
b
e
r
Front Bezel Assy
Power Supply PCB
Ext.
Com.
Cable
Host Monitor
Ext.
Com.
Cable
X3
Interface Board
TPX
Agent Bench
Nafion
Gas Module SE with Spirometry
X3
Interface Board
TPX
Agent Bench
Pneumatics
PVX
Unit
Nafion
Exhaust
Air Input
CPU PCB
Pneumatics
Exhaust
Air Input
M-GAS Assy
CPU PCB
OM
Oxygen Module
Filter
M-GAS Assy
OM
Oxygen Module
Filter
A
b
s
o
r
b
e
r
Front Bezel Assy
A
b
s
o
r
b
e
r
Power Supply PCB
Power Supply PCB
Front Bezel Assy
FIGURE 1-21
Gas Module Service Manual Addendum 0070-10-0522 1 - 19
Gas Module 3 Electronics Theory Of Operation
1.8 Gas Module 3 Electronics
AION™ Multigas Analyzer
Servomex Paramagnetic
Oxygen Sensor
RS-232 Connector
FRONT
Mains Connector
Power Supply
FIGURE 1-22 Top View of the Component Layout of Gas Module 3
1 - 20 0070-10-0522 Gas Module Service Manual Addendum
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