S5 Airway Modules Technical Reference Manual June 2001

Table of contents

TABLE OF CONTENTS S/5 Airway modules and S/5 Gas Interface Board, B-GAS TABLE OF CONTENTS

i

TABLE OF FIGURES

iii

INTRODUCTION

1

1

2

Specifications

1.1 General specifications ...2 1.2 Typical performance ...2 1.2.1 CO2 ...2 1.2.2 Respiration rate...2 1.2.3 O2 ...2 1.2.4 N2O ...2 1.2.5 Hal, Iso, Enf...2 1.2.6 Sev ...2 1.2.7 Des...3 1.2.8 Agent identification ...3 1.2.9 Patient Spirometry...3 1.2.10 Airway Pressure (Paw)...3 1.2.11 Tidal Volume (TV)...3 1.2.12 Minute Volume (MV) ...3 1.2.13 Airway flow...3 1.3 Technical specification ...4 1.3.1 CO2 ...4 1.3.2 O2 ...4 1.3.3 N2O ...4 1.3.4 AA ...4

2

Functional Description

5

2.1 Measurement principle ...5 2.1.1 CO2, N2O and Agent measurement ...5 2.1.2 O2 measurement ...6 2.1.3 Agent identification ...7 2.1.4 Patient Spirometry...8 2.2 Main components...9 2.2.1 Gas sampling system...10 2.2.2 ACX-200 measuring unit...16 2.2.3 OM measuring unit ...17 2.2.4 ACX measuring board ...18 2.2.5 ASX agent identification bench...20 2.2.6 ASX measuring board ...20 2.2.7 PVX board ...22 2.2.8 Gas mother board...24 2.2.9 Gas interface board ...26 2.3 Connectors and signals...26 2.3.1 Module bus connector ...26 i Document No. 800 1005-1

Datex-Ohmeda S/5 Anesthesia Monitor 2.3.2 Gas mother board connectors...27

3

Service Procedures

31

3.1 General service information ...31 3.2 Service check...32 3.2.1 Recommended tools ...32 3.2.2 Recommended parts...32 3.3 Disassembly and reassembly...41 3.4 Adjustments and calibrations...42 3.4.1 Gas sampling system adjustment ...42 3.4.2 Flow rate measurement ...42 3.4.3 Oxygen measurement unit adjustments...44 3.4.4 Flow calibration...46

4

Troubleshooting

47

4.1 Troubleshooting chart ...47 4.1.1 Supply voltage troubleshooting...48 4.2 Gas sampling system troubleshooting ...49 4.2.1 Sampling system leak test...49 4.2.2 Water separation...49 4.2.3 Steam test for the special tubes...49 4.3 OM measuring unit troubleshooting...50 4.4 ACX troubleshooting ...50 4.4.1 Cleaning the measuring chamber of ACX measuring unit ...50 4.5 ASX agent identification unit troubleshooting...52 4.6 PVX board troubleshooting...53 4.7 Gas mother board troubleshooting ...53 4.7.1 Instructions after replacing the software or Gas mother board...53 4.8 Error messages...54

5

Service menu

55

5.1 Gas mother board...56 5.2 ACX service menu...59 5.3 PVX service menu ...61 5.3.1 Flow calibration...62 5.3.2 Temp & Hum service menu ...63 5.4 ASX service menu...64

6

Spare parts

65

6.1 Spare parts list ...65 6.1.1 G-AO rev. 01, G-AiO rev. 00 ...65 6.1.2 G-AO rev. 02, G-AiO rev. 01, G-AOV rev. 00, G-AiOV rev. 00 ...66 6.1.3 G-AO rev. 03, G-AiO rev. 02, G-AOV rev. 01, G-AiOV rev. 01 ...66 6.1.4 G-AO rev. 04, G-AiO rev. 03, G-AOV rev. 02, G-AiOV rev. 02, G-O rev. 00, G-OV rev. 00 ...67 6.1.5 G-AO rev. 05, G-AiO rev. 04, G-AOV rev. 03, G-AiOV rev. 03, G-O rev. 01, G-OV rev. 01 ...67 6.1.6 S/5 G-AO rev. 06, G-AiO rev. 05, G-AOV rev. 04, G-AiOV rev. 04 ...67 6.1.7 Panel stickers ...67 6.1.8 S/5 panel stickers ...68 6.1.9 Planned Maintenance (PM) Kits: ...69 6.1.10 Gas Interface Board, B-GAS ...69

7

Earlier Revisions

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70

Table of contents

APPENDIX A

71

Service check FORM

A-1

TABLE OF FIGURES Figure 1

CO2/N2O/AA gas absorption spectra...5

Figure 2

O2 measurement principle ...6

Figure 3

Anaesthetic Agents gas absorption spectra...7

Figure 4

Airway module block diagram ...9

Figure 5

Gas sampling system block diagram ...12

Figure 6

Gas sampling system layout...13

Figure 7

Gas sampling system block diagram ...13

Figure 8

Gas sampling system layout...14

Figure 9

ACX photometer (ACX-200 measuring unit)...16

Figure 10

CO2/N2O/AA measurement block diagram...17

Figure 11

ACX measuring board block diagram ...19

Figure 12

ASX measuring unit ...20

Figure 13

ASX measuring board block diagram ...21

Figure 14

PVX board block diagram ...23

Figure 15

Gas mother board block diagram ...25

Figure 16

Gas sampling system adjustment chart ...43

Figure 17

O2 measuring unit adjustments ...46

Figure 18

ASX troubleshooting flowchart...52

Figure 19

PVX board troubleshooting flowchart ...53

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iv Document No. 800 1005-1

S/5 Airway modules

INTRODUCTION The S/5 Airway Modules, G-AO, G-AiO, G-AOV and G-AiOV are designed for use with the S/5 Anesthesia Monitor and provide airway and respiratory parameters. Later in this manual modules can be called w/o system name S/5. This Technical Reference Manual Slot provides information for the maintenance and service of the airway modules. Please see also related Technical Reference Manual for information related to system e.g. related documentation, conventions used, symbols on equipment, safety precautions, system description, system installation, interfacing, functional check and planned maintenance. Letters in the name stand for: G = Side mountable gas module O = CO2, Patient O2, and N2O V = Patient Spirometry A = Anesthetic agents i = Agent identification Table 1

Options of Parameter Modules CO2

N2O

Patient O2

Agents

G-AO

•

•

•

•

G-AiO

•

•

•

•

G-AOV

•

•

•

•

G-AiOV

•

•

•

•

Agent id

Spirometry

• • •

•

NOTE: The Airway Modules and Compact Airway Modules cannot be used simultaneously in the same monitor. Gas Interface Board Gas Interface Board, B-GAS is used for connecting the airway module to the central unit. The connection can also be made through the Interface Board, B-INT.

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1

SPECIFICATIONS

1.1 General specifications Module size, W × D × H Module weight

135 × 410 × 135 mm/5.3 × 15.0 × 5.3 in 6 kg/13 lbs.

1.2 Typical performance Sampling rate Display update rate

200 ml/min nominal (180...220 ml/min) breath-by-breath

Automatic compensation for pressure, CO2-N2O, and CO2-O2 collision broadening effect. Warm-up time 3 min for operation, 30 min for full specifications. Auto-zeroing is performed at start-up, after 5 min + 5 min + 5 min + 15 min + 15 min + 15 min, and after that every 60 min at regular intervals.

1.2.1 CO2 Measurement range Extended range

0 to 10 %, (0 to 10 kPa), (0 to 76 mmHg) 10 to 15 %, (10 to 15 kPa), (76 to 114 mmHg) (unspecified)

If CO2 concentration is below 0.1 %, 0.0 % is displayed.

1.2.2 Respiration rate Breath detection Measurement range

1 % change in CO2 level 4 to 60 breaths/min

Measurement range

0 to 100 % O2

Measurement range

0 to 100 % N2O

1.2.3 O2

1.2.4 N2O

1.2.5 Hal, Iso, Enf Measurement range Extended range

0 to 5 % 5 to 15 % (unspecified)

Measurement range Extended range

0 to 8 % 8 to 15 % (unspecified)

1.2.6 Sev

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1.2.7 Des Measurement range Extended range

0 to 18 % 18 to 30 % (unspecified)

Resolution

two decimals when the AA concentration below 1.0 %

If AA concentration is below 0.10 %, 0.00 % is displayed.

1.2.8 Agent identification Identified agents Identification time Identification threshold

HAL, ENF, ISO, SEV, DES 30 seconds (typical value with pure agents) 0.15 vol% (typical)

Mixture warning when minor component concentration > 0.3 vol% and > 15 %of total agent concentration

1.2.9 Patient Spirometry Values are valid when: Respiratory rate adult 4...30 pedi 4...50 breaths/min I:E ratio 1:3 - 1:0.5 Inner diameter of ET tube is ≥ 5.5 mm (adult) or 3 to 6 mm (pediatric).

1.2.10 Airway Pressure (Paw) Accuracy Resolution Measuring range

±1.5 cmH2O 1 cmH2O -20 to +80 cmH2O

1.2.11 Tidal Volume (TV) Accuracy Resolution Measurement range

±6 % or 30 ml (adult); ±6 % or 4 ml (ped) 1 ml 150 to 2000 ml (adult) 15 to 300 ml (ped)

1.2.12 Minute Volume (MV) Resolution Measurement range

0.1 l/min 2 to 15 l/min (adult) 0.5 to 5 l/min (ped)

1.2.13 Airway flow Measurement range

1.5 to 100 l/min for both directions (adult) 0.25 to 25 l/min for both directions (ped)

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1.3 Technical specification 1.3.1 CO2 Measurement rise time Gain stability Gain temperature drift Nonlinearity error

<360 ms (from 10 to 90 %) ≤0.2 %CO2/24 h (0 to 8 %) ≤0.4 %CO2/24 h (8 to 10 %) ≤0.2 %CO2/10 °C (0 to 8 %) ≤0.4 %CO2/10 °C (8 to 10 %) ≤0.2 %CO2 (0 to 8 %) ≤0.4 %CO2 (8 to 10 %)

1.3.2 O2 Measurement rise time Gain drift Gain temperature drift Nonlinearity error

<480 ms (from 10 to 90 %) ≤2 % O2/24 h ≤3 % O2/10 °C ≤2 % O2

Measurement rise time Gain drift Gain temperature drift Nonlinearity error

<360 ms (from 10 to 90 %) ≤2 % N2O/24 h ≤3 % N2O/10 °C ≤2 % N2O

Measurement rise time Gain drift Gain temperature drift Nonlinearity error

<520 ms (from 10 to 90 %) ≤0.4 % AA/24 h ≤0.4 % AA/10 °C ≤0.2 % AA

1.3.3 N2O

1.3.4 AA

Protection against electrical shock Type BF

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S/5 Airway modules

2

FUNCTIONAL DESCRIPTION

2.1 Measurement principle 2.1.1 CO2, N2O and Agent measurement The CO2, N2O, and anesthetic agent gas measurements are based on absorption of infrared light as it passes through the gas sample in measuring chamber in the photometer. The light absorption is measured at three wavelengths using an infrared detector. One of the wavelengths is that of the CO2 absorption peak at 4.3 micrometers, the second is that of the N2O absorption peak at 3.9 micrometers, and the third is that of the anesthetic agent absorption peak at 3.3 micrometers. The signal processing electronics receive the signals from the IR detector and demodulate it to get DC components out of these signals which correspond to the content of each gas in the sample.

Figure 1

CO2/N2O/AA gas absorption spectra

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2.1.2 O2 measurement The differential oxygen measuring unit uses the paramagnetic principle in a pneumatic bridge configuration. The signal picked up with a differential pressure transducer is generated in a measuring cell with a strong magnetic field that is switched on and off at a frequency of 110 Hz. The output signal is a DC voltage proportional to the O2 concentration difference between the two gases to be measured.

Electromagnet Mixture out

Microphone Sample in Reference in Figure 2

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O2 measurement principle

Switched magnetic field

S/5 Airway modules

2.1.3 Agent identification The anesthetic agent identification bench identifies Halothane, Enflurane, Isoflurane, Desflurane and Sevoflurane. The bench measures the spectrum of the gas between 3.24 µm and 3.39 µm. Because the spectrum of each of the anaesthetic agents is different it is possible to identify them. The bench consists of an infrared source, a measuring chamber, a rotating filter and a detector. The peak wavelength of the narrow bandpass filter changes when the angle between the light path and the filter is changed. When the filter rotates the required spectrum is scanned through. The agent or a mixture of agents is identified by comparing the measured spectrum with stored reference spectra.

Anesthetic Agent Gas Absorption Spectra 500 450 400 Halothane 0

350

Enflurane 0

300

Isoflurane 0

250

Sevoflurane 0

200

Desflurane 0

150

Freon 0

100 50 3386

3306

3246

0

Wavelength [nm]

Figure 3

Anaesthetic Agents gas absorption spectra

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2.1.4 Patient Spirometry In anesthesia, CMV (Controlled Mechanical Ventilation) is the mostly used ventilation mode. In this mode, mechanical breaths are delivered to the patient by a ventilator with a proper tidal volume (TV), respiration rate (RR), and inspiration/expiration ratio in time (I:E) determined by the settings of the ventilator. Delivery of life support gases is based on pressure. However, without knowing volume measured of exhalation, one cannot be sure that a breath occurred. The ultimate goal of ventilation is to use the least amount of pressure to generate the most appropriate volume for each breath. The Patient Spirometry monitors ventilation in anesthesia. Both patient breathing circuit and the function of the ventilator are monitored. The following parameters are displayed: Expiratory and inspiratory tidal volume (TV) in ml. Expiratory and inspiratory minute volume (MV) in l/min. Expiratory volume in first second (V1.0) in per cent for adults and in 0.5 seconds for children. Inspiration/expiration ratio in time (I:E) Airway pressures: Peak pressure (Ppeak), End inspiratory pressure (Pplat), Positive end expiratory pressure (PEEP), Real time airway pressure waveform (Paw) Flow: Real time flow waveform (V') Compliance (C) Pressure volume loop Flow volume loop

Airway pressure PEEP, Ppeak, and Pplat are measured by pressure transducer on the PVX board. Atmospheric pressure is used as a reference in measurement. The pressure measurement is made from the airway part that is closest to the patient between patient circuit and intubation tube.

Airway flow The measurement is based on measuring the kinetic gas pressure and is performed using Pitot effect. Pressure transducer is used to measure the Pitot pressure. The obtained pressure signal is linearized and corrected according to the density of the gas. Speed of the flow is calculated from these pressure values and TV value is then integrated. MV value is further calculated and averaged using TV and RR (respiratory rate) values.

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Patient Spirometry sensor, D-lite Patient Spirometry is measured with a specific sensor, D-lite or Pedi-lite. D-lite and Pedi-lite sensors are designed to measure kinetic pressure by two-sided Pitot tube. The pressure reduction caused by measuring cross is taken into account, too, especially in small flows. Velocity is calculated from pressure difference according to Bernoulli's equation. Flow is then determined using the calculated velocity.

v=

2 × dP ρ

(from Bernoulli's equation)

F = v×A , where, F=flow (l/min) v=velocity (m/s) A=cross area (m2) dP=pressure difference (cmH2O) ρ=density (kg/m3) Finally the volume information is obtained by integrating the flow signal.

2.2 Main components The airway modules consist of ACX-200 and OM-101 gas measuring units, ASX-200 agent identification unit (G-AiO/AiOV), PVX board (G-OV/AiOV/AOV), gas sampling system, ACX measuring board and gas mother board. ACX Board

Lamp Supply Voltage

Signal outACX Bench

ASX Unit

PVX Board

Gas pressure and flow in

Supply voltages, Control X1

X1 X2

X8

X5

X9

X4

Oxygen Measuing Unit

O2 signal Supply ACX Valve voltages serial controls I/O Supply voltages

ASX serial i/O

Lamp Driver

ACX, ASX, PVX serial +5 VL I/O GND GNDD

Supply voltages

X1 Serial I/O

Lamp control Gas Module CPU

Serial I/O

Figure 4

X10 +24/+32 VD Fan

+15 VD, GNDD

Valve Driver

+15 VD

Valves

+15 VD

Pump

Pump control X7

Mod key in +5 Vref

+15 V

Supply voltages

X12

Pump control

+5 V +5 VL +15 VD +/-15 V +24 /+32 VD GND GNDD

PVX serial i/O

Lamp control Valve controls

+5 V, GND

X3

+15 VD, GNDD

Pump Driver

X11

Regulator GND Mod key in

Module Key

Gas Mother Board

Airway module block diagram 9 Document No. 800 1005-1

Datex-Ohmeda S/5 Anesthesia Monitor

2.2.1 Gas sampling system The gas sampling system samples the measured air to the module, and removes water and impurities from it. A sampling line is connected to the water trap on the front panel. The pump draws gas through the sampling line to gas measuring units. After the measurements, the gas is exhausted from sample gas out connector on the rear panel of the module.

Water trap, D-fend The gas sample enters the monitor through the water trap, where it is divided into two flows, main flow and side flow (see Gas sampling system block diagram). The main flow goes into the measuring system through a hydrophobic filter. The side flow creates a slight sub-atmospheric pressure within the water trap container. This facilitates gathering the fluid removed by the hydrophobic filter. Sampling line The sampling line is an integral part of the total sampling system. The resistance established by the sampling line is significant when the software determines the occlusion and air-leak alarm limits during the turn-on sequence. The small inner diameter causes fluids such as blood or mucus not to propagate within the tube, so that when the line is clogged, it is replaced. The NafionTM tube 1) A nafion tube (tubes A or B, and C: see figure 5) is used 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 humid gases are measured after calibration with dry gases. It is inserted between the water trap and the zero valve (G-AiO/AiOV) or between the zero valve and ACX-200 measuring unit (G-O/OV/AO/AOV). The tube is also inserted between the CO2 absorber and the zero valve. Zero valve The main flow passes through a solenoid valve before proceeding to the ACX-200 measuring unit. This valve is activated to establish the zero points for the ACX-200 and O2 measuring units at startup, at 5 minutes, and after that at regular intervals. After 1-hour monitoring, the auto-zeroing is performed once an hour. When the valve is activated, room air is drawn through the CO2 absorber into the internal system and the gas sensors.

1)

Nafion is a trademark of Du Pont

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Gas measuring units, ACX-200 and O2 unit After the zero valve, the gas passes through the ACX-200 and O2 measuring units. In the ACX-200 measuring unit, infrared light is passed through chambers containing the main flow gas (measurement) and a chamber containing reference gas. The measurement is made by determining the ratio between the two light intensities. The oxygen sensor has two inputs. One input accepts the main flow and the other draws in room air for reference. The sensor uses a differential pressure transducer to compare the pressure gradient produced when both gases are exposed to an oscillating magnetic field. Both gas flows exit from a single port. In i model, the ASX agent identification unit is installed in parallel with the oxygen sensor. The task of the ASX unit is to identify anesthesia agents by infrared light method used also in the ACX-200 unit.

Pressure valve The pressure valve is used to measure the pressure gradient between the O2 measurement flow and the O2 reference flow. This pressure gradient reflects the condition of the D-fend water trap filter. Normally the pressure gradient between the O2 measurement flow and the reference flow is approximately +8 mmHg. If the software detects the gradient to be between 0 and -5 mmHg, the pressure valve will initiate pressure measurement of the reference flow. If the gradient is greater than -5 mmHg, the software triggers the message ’Replace Trap’.

Flow cassettes The internal flow rates are set using flow cassettes. These cassettes are used to set the side flow rate and the O2 reference flow rate, the flow rates through the measuring units and the total flow rate of the sampling system.

Sampling pump and damping chamber The sampling pump is a vibrating membrane pump driven by a 50 Hz/12 V/0.4 A square wave current. The damping chamber is used to even out the pulsating flow and silence the exhaust flow.

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Figure 5

Gas sampling system block diagram

In G-AO, -AOV models, tube A is Teflon, B and C Nafion. In G-AiO, -AiOV models, tubes A and C are Nafion, B is Teflon. See new tubing since autumn 1998 in figure 7.

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Figure 6

Gas sampling system layout

See new sampling system layout since autumn 1998 in figure 8.

Ref IN Room AIR

Pressure valve

Filter

Pressure transducer

CO2 C absorber

D-fend

ASX-200 in G-AiO/AiOV

Sample Gas OUT

Zero valve B

main flow

Sample Gas IN

Sample pump

ACX-200

O2 sensor Damping chamber

A side flow

Figure 7

Constriction cassette

Gas sampling system block diagram

In G-AO, -AOV models, tube A is Teflon, B and C Nafion. In G-AiO, -AiOV models, tubes A and C are Nafion, B is Teflon. Figure 7 is valid for modules manufactured since autumn 1998.

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Figure 8

Gas sampling system layout

Figure 8 is valid for modules manufactured since autumn 1998.

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S/5 Airway modules Table 2

Flow cassettes

Flow cassette

Code

50/26.0 50/19.0 50/16.3 50/15.3 50/14.1 50/13.1 50/12.4 50/11.2 50/10.4 50/9.2 50/8.7 50/7.4 50/6.5 50/5.8 50/5.1 50/4.4 50/3.8 50/3.2 50/3.0 50/2.8 50/2.5 50/2.3 50/2.0 50/1.8 50/1.6 50/1.4 50/1.1

878048 873800 878047 873801 878046 873802 878045 874770 873803 874509 873804 873805 878044 873806 878043 873807 878042 873808 878040 878039 878038 873809 878037 873810 878036 873811 873812

NOTE: The number on the cassette represents relative flow when a specific pressure is applied. Therefore 50/26.0 presents the least resistance and 50/1.1 the most.

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