Datex-Ohmeda S-5 Service Manual M-EEG

Datex-Ohmeda

S/5TM EEG Module, M-EEG (rev. 01)

TM
S/5
EEG Headbox, N-EEG (rev. 01)

Technical Reference Manual Slot

Datex-Ohmeda Inc. 3030 Ohmeda Drive 53707-7550 MADISON, WIS USA Tel. +1-608-221 1551,Fax +1-608-222 9147
www.us.datex-ohmeda.com
All specifications are subject to change without notice.

Document No. 800 1011-1

Datex-Ohmeda Division,
Instrumentarium Corp.
P.O. Box 900, FIN-00031
DATEX-OHMEDA, FINLAND
Tel. +358 10 394 11 Fax +358 9 146 3310
www.datex-ohmeda.com
Instrumentarium Corp. All rights reserved.

Table of contents

TABLE OF CONTENTS
EEG Module, M-EEG and EEG Headbox, N-EEG
TABLE OF CONTENTS I
TABLE OF FIGURES II
INTRODUCTION 1
1 SPECIFICATIONS 2
1.1 General specifications ..............................................................................................................................2
1.1.1 Headbox..........................................................................................................................................2
1.1.2 Module............................................................................................................................................2
1.2 Technical specifications............................................................................................................................2
1.2.1 EEG .................................................................................................................................................2
1.2.2 AEP..................................................................................................................................................3
1.2.3 EMG ................................................................................................................................................3
1.2.4 Impedance measurement.................................................................................................................3
2 FUNCTIONAL DESCRIPTION 4
2.1 Measurement principle .............................................................................................................................4
2.1.1 EEG .................................................................................................................................................4
2.1.2 FEMG...............................................................................................................................................4
2.1.3 AEP..................................................................................................................................................4
2.1.4 Impedance measurement.................................................................................................................5
2.2 Main components.....................................................................................................................................5
2.2.1 Neuro board.....................................................................................................................................5
2.2.2 Headbox board.................................................................................................................................6
2.3 Connectors and signals.............................................................................................................................7
2.3.1 Module bus connector......................................................................................................................7
2.3.2 Module front panel connectors..........................................................................................................8
2.3.3 Headbox input connector..................................................................................................................8
3 SERVICE PROCEDURES 9
3.1 General service information.......................................................................................................................9
3.2 Service check .........................................................................................................................................10
3.2.1 Recommended tools ......................................................................................................................10
3.3 Disassembly and reassembly..................................................................................................................14
3.3.1 M-EEG ...........................................................................................................................................14
3.3.2 N-EEG............................................................................................................................................14
4 TROUBLESHOOTING 15
4.1 Troubleshooting chart .............................................................................................................................15
4.2 Troubleshooting flowcharts......................................................................................................................16
5SERVICE MENU 18
5.1 EEG & EP service menu...........................................................................................................................19
6 SPARE PARTS 23
6.1 Spare part list.........................................................................................................................................23
6.1.1 M-EEG rev. 00................................................................................................................................23
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6.1.2 S/5 M-EEG rev. 01.........................................................................................................................23
6.1.3 N-EEG rev. 00 ................................................................................................................................24
6.1.4 S/5 N-EEG rev. 01 .........................................................................................................................24
6.1.5 Front panel stickers ........................................................................................................................25
7 EARLIER REVISIONS 26
APPENDIX A 27
SERVICE CHECK FORM A-1

TABLE OF FIGURES

Figure 1 Measurement setup .............................................................................................................................1
Figure 2 Neuro board block diagram ..................................................................................................................5
Figure 3 Audio stimulator circuitry ...................................................................................................................... 6
Figure 4 EEG headbox board block diagram........................................................................................................6
Figure 5 EEG module troubleshooting flowchart ................................................................................................16
Figure 6 Headbox troubleshooting flowchart .....................................................................................................17
Figure 7 Exploded view of module box and EEG module ....................................................................................23
Figure 8 Exploded view of headbox...................................................................................................................24
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Document No. 800 1011-1

INTRODUCTION

This Technical Reference Manual Slot provides information for the maintenance and service of the Datex-Ohmeda S/5 EEG Module, M-EEG and Datex-Ohmeda S/5 EEG Headbox, N-EEG. The EEG module is a single width plug-in module designed for use with the S/5 monitors. Later in this manual modules can be called w/o system name S/5.
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.
The EEG module and the EEG headbox together measure:
electroencephalography (EEG)
spontaneous facial muscular activity with frontal electromyography (FEMG)
auditory evoked potentials (AEP)
The EEG Headbox, N-EEG, is responsible for EEG and FEMG signal amplification, filtering and digitalization and electrode impedance measurement. It is situated close to the patient’s head. The Headbox has connectors for the EEG leads, either for a referential or a bipolar montage, and for the AEP stimulation earphones.
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
The EEG module M-EEG creates auditory stimulus pulses and takes care of AEP signal processing. It has one connector for the EEG headbox.
1
2
3
4
5
Figure 1 Measurement setup
(1) EEG module measuring EEG and EP
(2) Module-headbox cable
(3) EEG Headbox
(4) Organizer
(5) Earphones (for AEP measurement only)
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1 SPECIFICATIONS

1.1 General specifications
1.1.1 Headbox
Box size, W × D × H 96 × 170 × 34 mm/3.8 × 6.7 × 1.3 in Box weight 0.5 kg/1.1 lbs Power consumption 1.9 W
1.1.2 Module
Module size, W × D × H 37 × 180 × 112 mm/1.5 × 7.1 × 4.4 in Module weight 0.37 kg/0.8 lbs Power consumption 3.1 W
1.2 Technical specifications
1.2.1 EEG
Amplification 10 000 Resolution 60 nV Max amplitude 800 µV Sampling frequency 100 Hz per channel Range ±400 µV Frequency range 0.5...30 Hz Input impedance 8 M @ 10 Hz Noise level <0.5 µV rms from 0.5 Hz to 30 Hz CMRR >100 dB @ 50 Hz Parameters from power spectrum SEF, MF, relative power in frequency bands Burst suppression calculated burst-suppression ratio (BSR) Defibrillation protection 5000V, 360 J Allowable Input Offset ±300 mV
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1.2.2 AEP
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
Amplification 10 000 Resolution 60 nV Max amplitude 1000 µV
pp
Stimulation
Click (condensating) duration 100 µs Frequency 1.1...9.1 Hz (1 Hz steps) @ 10 ms measurement
1.1...8.1 Hz (1 Hz steps) @ 100 ms measurement
Intensity 10...90 dB nHL, 10 dB steps
Measurement
Sampling frequency 2400 Hz for MLAEP/ 4800 for BAEP Frequency range 0.5...1000 Hz Highpass filter off/10/30/50/75/100/150 Hz
Single average: Averaged responses 100...2000 stimuli
Moving average: Gross average 100...2000 stimuli Update interval after every 100 stimuli (200, when gross average is 2000)
1.2.3 EMG
Amplification 50 000 Resolution 100 nV Max amplitude 100 µV Frequency range 60...300 Hz Amplitude Root Mean Square (RMS)
1.2.4 Impedance measurement
Measurement frequency 75 Hz Current 10 µA Range 0...30 k Resolution 100 Accuracy ±1k or ±10 % whichever is greater Measurement time, all leads 3 s Start of measurement manual/automatic Leads off detection >3 M, continuous
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2 FUNCTIONAL DESCRIPTION

2.1 Measurement principle
2.1.1 EEG
EEG is differential voltage signal measured from electrodes attached to the patient’s skin. EEG measures the spontaneous electrical activity of the brain. This electrical activity reflects the state of the brain.
Electrode connections can be made with two different principles: bipolar or referential montage. In bipolar montage every channel has two electrodes and the signal is the potential difference between these two electrodes. In referential montage the referential electrode delivers its potential to every channel’s minus-input. The signal is the potential difference between this common reference electrode and the electrode connected to plus input. Purpose of the ground electrode is to reduce common mode noise. It cannot be used as referential electrode.
2.1.2 FEMG
Bipolar connection
The EEG signal is amplified, antialias filtered, digitised and software filtered. After that the EEG signal is shown on the screen and various characteristics are calculated out of it. These include spectrum, rms amplitude, spectral edge frequency, median frequency, burst-suppression ratio and percentage of total power in four different bands: theta (1...4 Hz), delta (5...9 Hz), alpha (9...13 Hz) and beta (>13 Hz).
FEMG is electrical signal originating from facial muscles. In the headbox the signal of channel 1 is divided to two different amplification and filtering paths. One is the EEG path and the other is the FEMG path. FEMG signal has much broader spectrum than EEG and it overlaps with EEG at low frequencies. Because of this the rms amplitude of FEMG signal is calculated from band
60...300 Hz. Mains power frequency and its harmonics are digitally filtered away to reject interference noise from power lines.
Referential connection
2.1.3 AEP
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AEP is an electrical response of the nervous system to external auditory stimulus. It is measured using same electrodes as in EEG measurement, but the sampling frequency and bandwidth are different. The electrical signal resulting from one stimulus is weaker than the spontaneous activity
of the brain. To overcome this the stimulus is repeated several times (100...2000), and average of all responses is calculated. Responses containing big artefacts are removed from the average to improve the signal to noise ratio.
2.1.4 Impedance measurement
The impedance measurement is done from one channel at a time and the EEG or EP measurement is stopped during the impedance measurement.
Differences in electrode impedance of the electrodes causes common mode noise coupling to measured signal. To minimise this the electrode impedance is measured and a warning of unsatisfactory impedance level is generated when necessary. The impedance of an electrode is measured by applying a known current through the electrode and measuring the voltage drop over the electrode. This way the impedance of a single electrode can be resolved instead of a sum impedance of an electrode pair.
2.2 Main components
2.2.1 Neuro board
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
The Neuro board consists of the following functional sections:
audio stimulator
microprocessor for stimulation and measurement control, and for counting the
measurement results
two serial communication drivers
The serial bus speed to monitor is 500 kbps and the bus itself is half duplex, i.e. data can be transferred to both directions but only one way at a time.
The serial bus speed to the headbox is 500 kbps and the bus is full duplex i.e. data can be transferred to both directions at the same time.
Module
Keys
CPU
3048
+15 V
Data
RS-422
driver
AEP stimulus
AEP
Stimulator
Module Bus
Power +15 V
Reset
Data
Power
supply
Patient Isolation 5 kV
Opto
Isolation
±5 V
±12V
EEPROM
RAM
RS485
Driver
To
To
EEG
EEG
Head-
Head-
box
box
Figure 2 Neuro board block diagram
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H83048
CTRL
Figure 3 Audio stimulator circuitry
2.2.2 Headbox board
The Headbox board consists of the following functional sections:
input protection
EEG amplifiers and filters
FEMG amplifier and filter
current feeding circuitry and amplifiers for impedance measurement
microprocessor
serial communication
PWM
Audio level adjustment
Timing control
Audio generator
Earphones
Headbox
RS
422
driver
±5 V
±12V
CPU
3048
A / D
+15 V
Data
AEP stimulus
Power
supply
Opto
Isolation kV
Isolation
Headbox
Keys
Figure 4 EEG headbox board block diagram
1 p
EEG signal
1-4
1-4
AEP stimulus
Impedance
check
a t i e n t
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2.3 Connectors and signals
2.3.1 Module bus connector
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
13
25
1
14
Table 1 Module bus connector (X1) pin description
Pin No. I/O Signal
1 I RESET_RS485
2 I -15 VDC
3 I +15 VDIRTY
4 I +15 VDC
5 I/O -DATA_RS485
6 I/O DATA_RS485
7 - Ground & Shield
8 I -RESET_RS485
9 I CTSB
10 O RTSB
11 I RXDB
12 O TXDB
13 - Ground & Shield
14 I +32 VDIRTY
15 I GroundDIRTY
16 I CTSC
17 O RTSC
18 I RXDC
19 O TXDC
20 - ON/STANDBY
21 - PWM_ECG
22 - RXDD_RS232
23 - TXDD_RS232
24 I +5 VDC
25 I +5 VDC
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2.3.2 Module front panel connectors
Table 2 Headbox connector
Pin No. Signal
Ground
1
Ground
6
3
1
2
9
4
7
0
5
8
2
3
4
5
6
7
8
9
0
+15 V
TXD+
EP Audio
Power sync 43 kHz
RXD+
EP Sync
RXD-
TXD-
2.3.3 Headbox input connector

Table 3 Headbox input connector

15
610
Pin No. Signal
Lead set id
1
1+
2
2+
3
3+
4
4+
5
Ground
6
1- / Ref
7
2-
8
3-
9
10
4-
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S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG

3 SERVICE PROCEDURES

3.1 General service information

Field service of the M-EEG and N-EEG is limited to replacing faulty circuit boards or mechanical parts. Faulty circuit boards should be returned to Datex-Ohmeda for repair.
Datex-Ohmeda is always available for service advice. Please provide the unit serial number, full type designation, and a detailed description of the fault.
The Datex-Ohmeda EEG Simulator (order No. 90502) is recommended for functional checks.
CAUTION Only trained personnel with appropriate equipment should perform the tests and
repairs outlined in this section. Unauthorized service may void warranty of the unit.
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Datex-Ohmeda S/5 monitors

3.2 Service check

These instructions include complete procedures for a service check. The service check is recommended to be performed after any service repair. However, the service check procedures can also be used for determining possible failures.
The procedures should be performed in ascending order.
The instructions include a check form, Appendix A, which should be filled in when performing the procedures.
The mark
the procedure.
The procedures are designed for monitors with S/5 monitor software of revision 01. However, most of the procedures also apply to monitors, which contain some other monitor software type/revision.
? in the instructions means that the check form should be signed after performing
3.2.1 Recommended tools
Tool Order No. Notes
EEG simulator 90502
Screwdriver
Earphones
Detach the module box by removing the two screws from the back of the module. Be careful
with the loose latch and spring pin for locking.
Detach also the cover of the EEG headbox by removing the four screws from the bottom of the
box. Be careful with the two wired connectors in the circuit board attached to the cover.
1. Check internal parts of the module and the headbox:
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Document No. 800 1011-1
screws are tightened properly
cables are connected properly
the EMC cover is attached properly in the module
there are no loose objects inside the module or the headbox
?
2. Check external parts of the module:
the front cover and the front panel sticker are intact
connectors are intact and are attached properly
the module box, latch and spring pin for locking are intact
?
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
3. Check external parts of the headbox
cover and the base of the headbox are intact
the headbox sticker is intact
connectors are intact and attached properly
?
Reattach the module box and the cover of the EEG headbox.
Turn the monitor on and wait until the normal monitoring screen appears.
Configure the monitor screen so that information regarding the EEG measurement is shown:
Monitor Setup - Screen 1 Setup - Waveform Fields - Field 1 - EEG1 Monitor Setup - Screen 1 Setup - Waveform Fields - Field 2 - EEG2 Monitor Setup - Screen 1 Setup - Waveform Fields - Field 3 - EEG3 Monitor Setup - Screen 1 Setup - Waveform Fields - Field 4 - EEG4
Others - EEG - Montage - EEG Channels - 4 Others - EEG - Montage - Montage type - Bip Others - EEG - EEG Setup - Numeric 1 - MF Others - EEG - EEG Setup - Numeric 2 - Ampl.
4. Plug in the module. Check that it goes in smoothly and locks up properly
?
5. Check that the module is recognized, i.e. the EEG header with related information appears in
the chosen waveform fields and ‘Headbox off’ message is shown on the four fields.
?
6. Connect the headbox to the module. Check that the headbox is recognized i.e. message ‘EEG
measurement off’ is shown on the four waveform fields. If the EEG leads are connected ‘EEG measurement off’ message disappears after 15 seconds.
?
7. Enter the service menu:
Monitor Setup - Install/Service (password 16-4-34) - Service (password 26-23-8)
Record the information regarding the software of M-EEG and N-EEG by selecting SCROLL VERS and turning the ComWheel.
?
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8. Enter the EEG module service menu:
Parameters - More… - EEG & EP
Check that the ‘Timeouts’, ‘Bad checksums’ and ‘Bad c-s by mod’ values in the module view are not increasing faster than by 50 per second. Check that the memories of the module have passed the internal memory test, i.e. ‘RAM’, ‘ROM’ and ‘EEPROM’ all state OK.
?
9. Check that the ‘HB Mod Timeouts’, ‘HB Mod Bad Checksum’ and ‘Mod HB Bad Checksum’
values are not increasing faster than by 50 per second. Check that the memory of the headbox has passed the internal memory test, i.e. ‘HB Rom Error’ in the headbox view states 0.
?
10. Check the EP Start/Stop and Imp. Check membrane keys both of the module and the
headbox. Go to module view and press each key for at least one second and check that the key being pressed is identified, i.e. the corresponding text is highlighted in the service menu. Repeat in headbox view with headbox keys.
?
11. Select 10 k as imped. pos. and imped. neg. value on the simulator. Go to EEG & EP service
menu and select Check Electr. From the headbox view check that the impedances in all four channels are 10 kΩ ±1 kΩ .
?
12. Connect the EEG simulator to the headbox. Select 2 k as imped. pos. and imped. neg.
value on the simulator. Select 10 Hz 200 µV sinewave on the simulator and check that all the four waveforms have same form. Check that the size of the waveforms is 200 µV Check that the MF value is 10 ±0.5 Hz. Check that the amp value is 71 µV ±3 µV.
±5 µV.
pp
?
13. Select 75 Hz 50 µV signal on the simulator. Check that the FEMG value is 16 ±3 µV.
?
Preset the AEP measurement settings:
Others
EP - Cycle - Cont. EP - AEP Setup - AEP Channels - 2 EP - AEP Setup - Responses -100 EP - AEP Setup - Stim. Frequency - 1.1Hz EP - AEP Setup - Stim. Intensity - 60 dB EP - AEP Setup - Sweep length - 100 ms
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S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
14. Plug in the earphones to the headbox. Be careful with load stimulation from the earphones
when starting AEP stimulation. Start AEP stimulation by pressing the on the module. Check that the clicking sound comes from the earphones in 1.1 Hz frequency. Stop the stimulation by pressing again the EP Start/Stop button on the module. Check that the clicking stopped.
EP Start/Stop button
?
Modify the AEP measurement settings:
Others
EP - AEP Setup - Stim. Frequency - 8.1Hz EP - AEP Setup - Stim. Intensity - 90 dB EP - EP Size - 1
15. Connect the AEP testing cable between the simulator and the headbox. Select 2 k as
imped. pos. and imped. neg. value on the simulator. Select 40 µV amplitude in the EP waves menu on the simulator and start AEP measurement in the get the response on the display. Check that the shape of the response is one period of a sine wave. Save EP and adjust the markers to minimum and maximum level of the response curve in both channels. Check that the amplitude is 40 µV ±5 µV.
Others - EP menu. Wait until you
?
16. Perform an electrical safety check and a leakage current test.
?
17. Check that the module functions normally after performing the electrical safety check.
?
18. Clean the module with suitable detergent.
?
Fill in all necessary documents.
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3.3 Disassembly and reassembly
3.3.1 M-EEG
Disassemble the M-EEG in the following way. See Figure 7 Exploded view of module box and EEG module
1. Remove the two screws from the back of the module.
2. Pull the module box slowly rearward and detach it from main body. Be careful with the loose
latch and spring locking pin.
3. Detach the Neuro board by removing the two screws located near the front panel frame,
disconnect the cable and pull out the front panel frame.
To reassemble the module, reverse the order of the disassembly steps.
CAUTION When reassembling the module, make sure that the cables are reconnected
properly.
3.3.2 N-EEG
Disassemble the N-EEG in the following way. See Figure 8 Exploded view of headbox.
1. Remove the four screws from the bottom of the headbox.
2. Lift off the cover and disconnect the two cables connected to the EEG headbox board.
3. Disconnect the module-headbox cable and the headbox input unit connectors from the EEG
headbox board.
4. Remove the four screws on the corners of the EEG headbox board and detach the EEG
headbox board.
To reassemble the N-EEG, reverse the order of the disassembly steps.
CAUTION When reassembling the headbox, make sure that the cables are reconnected
properly.
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S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG

4 TROUBLESHOOTING

4.1 Troubleshooting chart
Trouble Cause Treatment
No EEG waveforms on screen. EEG waveforms not selected on screen. Press Monitor Setup key and select EEG
waveforms on the screen.
No EEG waveforms on screen and ‘EEG measurement off’ message shown in the number field.
All EEG Waveforms not drawn on screen even if electrodes and cables are OK.
Number fields show ‘---‘ and message ‘High EMG’ is displayed.
EEG signal looks noisy and artefact message is displayed in the number fields.
Leads off message is shown on other channels than channel 1 in referential connection.
Electrode impedance measurement is not available on menus.
Electrode impedance measurement is not available on menus.
Electrode impedances show ‘---‘ and check ground electrode message is displayed on number fields after impedance measurement.
Electrode impedances show ‘---‘ The electrode impedances are too high and
Start EP measurement not available on EP menu.
EP measurement parameters cannot be changed.
All or most of the EP epochs are rejected (Rej. counter on EP screen increases more rapidly than Ave. counter).
EP wave is shown only on one channel even if two channels EP measurement is selected.
No clicks can be heard from earphones. The earphones connector is not in place. Check that the earphones plug is firmly
Electrodes not attached properly to skin or electrode cables not connected to headbox.
The number of channels chosen on montage setup is smaller than the number of channels connected to patient.
Patient has high muscle activity in the head region or noise from some equipment is coupling to electrode cables.
Electrodes are poorly connected or electrical interference is coupling to electrode cables.
The montage chosen in monitor is not referential.
EEG measurement is off. EEG measurement starts 15 seconds after
EP measurement is on. Wait until EP measurement ends or stop EP
Ground electrode is poorly connected to patient or ground electrode cable is not connected to headbox.
out of measurement range.
The EEG measurement is off. Connect electrodes and wait 15 seconds
The EP measurement is on. Stop EP measurement.
The signal has too much noise/artefacts in EP measurement band. Especially coupled 50/60 Hz is not shown on EEG waveform because of filtering, but may be present in EP signal.
Leads are off in the channel where the EP wave is not shown.
Check electrodes and electrode cables.
Check that the number of channels in menu
Others -EEG - Montage is same as the
number of channels connected to patient.
Relax the patient or remove the noise source.
Check the electrodes and electrode impedances. Remove noise sources if necessary.
Change the montage to referential from monitor menu
first electrode pair is connected.
measurement.
Check the electrode and cable. If the electrode has too high impedance (>50k) the measurement fails even if the electrode is properly attached. Cure for this is to use better electrodes or prepare the skin better.
Prepare the skin better or use better electrodes.
and the measurement starts.
Check that electrode impedances are below 5k and the impedances of the same channel are close to one another. If this does not help then try to remove noise sources.
Check the electrodes and electrode cables.
pushed into the headbox’s earphone connector.
Others -EEG - Montage.
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4.2 Troubleshooting flowcharts
Possi bly fa ulty EEG
module.
Take all modules out of
the frame.
Insert M-EEG and turn
power on
Does fault
stil l appear?
Yes
Enter the EEG Service
menu
Check are the Timeouts,
Bad checksums or Bad
c-s by mod running?
OK?
Yes
Check RAM, ROM and
EEPROM
OK? Replace Neuro board
Yes
Connect headbox into
module connector
Check from headbox
view are the Ti meouts,
HB Mod Bad
Checksums or Mod Hb
Bad Checksums running
OK?
Yes
Check front panel k ey
functions
No
No
No
No
Fault not i n EEG module
No
Does another modul e wor k i n the same slot ?
Yes
Yes
Does another
modul e work wi th
headbox?
No
Fault not in EEG modul e
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Document No. 800 1011-1
OK?
Yes
Connect earphones into
the headbox and start
AEP measurement
Can clicks be heard?
No Connect the keypadNo
No
Is the keypad
connected?
Yes
Does the test
pass with
another
keypad?
No
Replace Neuro board
No
Can clicks be heard
with another
headbox?
Replace the keypadYes
Yes Fault not in EEG module
WHI T E
Figure 5 EEG module troubleshooting flowchart
Possib ly f ault y EEG
headbox.
Take all modules out of
the frame.
Insert M-EEG and EEG headbox and turn power
on
Does
fault still
appear?
Yes
Does the
headbox work
with another
module?
No
Enter t he EEG Servi ce
menu
Check from headbox
view are the Timeouts,
HB Mod Bad
Checksums or Mod Hb
Bad Checksums running
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
No
Fault not in EEG
headbox
Yes
OK?
Yes
Check HB Rom Error
OK? No
Yes
Check front panel key
functions
OK?
Yes
Connect earphones into
the headbox and start
AEP measurement
Can clicks be heard?
Yes
Check EP waveforms
with EEG simulator
Try with another
headbox - module cable
or check the cable by
hand
No Connect the keypadNo
No
Is the keypad
connected?
Yes
Does the test
pass with
another
keypad?
No
Replace Neuro board
Try with another
headbox - module cable
or check the cable by
hand
Fault i n cabl e?No
No
Replace the Headbox
board
Replace the keypadYes
Fault in cable?
Yes
Replace the headbox -
module cable
Yes
Replace the headbox -
Yes
Yes
No
module cable
Is earphone jack int act
and connected to
headbox circuit board?
No
Connect or replace the
earphones jack
Try with another
OK?
Yes
Check EEG waveforms,
FEMG reading,
impedance measurement and lead off detection with EEG
simulator
OK?
No
Text
headbox - module cable
or check the cable by
hand
Check the headbox input
connector and input
board
Fault in cable? Replace Neuro boardNo
Replace the input
connector
Figure 6 Headbox troubleshooting flowchart
No
OK? Yes
Replace the Headbox
board
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5 SERVICE MENU

Press the Monitor Setup key - select Install/Service (password: 16-4-34) - select Service
(password: 26-23-8) - select Parameters - More... - EEG & EP.
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5.1 EEG & EP service menu
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
EEG & EP
Check Electr. Headbox measures impedance of electrodes. Works same way as from EEG menu or
headbox/module button.
Start AEP AEP measurement is started with current AEP settings.
Module Service data is changed to module view (some of the data in this view is though from headbox).
Measurement shows whether the EEG measurement is ON or OFF. Measurement should start by
itself when the leads have been on about 15 seconds.
Montage shows the active montage in monitor. HB Montage shows the montage attached to headbox. 0 means no montage, 1 basic, 2 general,
3 AEP, 4 Mont4 etc. up to 8, which means Mont8.
Montage type shows whether the montage is bipolar or referenced.
EP Start/Stop is highlighted when the EP Start/Stop button is pressed in headbox or module. Imp. Check is highlighted when the Imp. Check button is pressed in headbox or module.
Imp. Meas. shows 1 if the impedance measurement is on in the module. Headbox Off shows 1 if the headbox cable is not connected to module.
EP Meas. shows 1 if the evoked potential measurement is active in module. Sending EP shows 1 if the module has acquired 100/200 new epochs and is sending them to
monitor. Par. Error shows 1 if the evoked potential parameters active in module are conflicting with each other.
Reserved 1 is reserved for future use. Reserved 2 is reserved for future use.
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HB Mod Timeouts is a cumulative number that indicates how many times the headbox has not responded to module’s inquiry. HB Mod Bad Checksum is a cumulative number that indicates how many times there has been an error in the message from headbox to module.
Mod HB Bad Checksum is 1 if there has been errors in the messages from module to headbox.
Mod Mon Timeouts is a cumulative number that indicates how many times the module has not
responded to monitor’s inquiry. Mod Mon Bad Checksum is a cumulative number that indicates how many times there has been an error in the message from module to monitor. Mon Mod Bad Checksum is a cumulative number that indicates how many times there has been an error in the message from monitor to module.
RAM indicates the state of the RAM memory. ROM indicates whether the checksum at the EPROM is accordance with the one the software has
calculated. EEPROM indicates if the values stored in permanent memory are valid. The states in memory checks are OK, Fail or ? (module not in place or a communication error).
Headbox Service data is changed to headbox view.
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EP Start/Stop is highlighted when the EP Start/Stop button is pressed in headbox or module. Imp. Check is highlighted when the Imp. Check button is pressed in headbox or module.
Active shows 1 if the channel is active. Lead off+ shows the lead off status of all plus electrodes. 0 means that the lead is on and 1 that
the lead is off. Lead off- shows the lead off status of all minus electrodes. 0 means that the lead is on and 1 that the lead is off.
Imped+ shows the impedance of plus electrodes of last impedance check in all channels. Imped- shows the impedance of minus electrodes of last impedance check in all channels.
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
BSR shows the burst-suppression classification of EEG waveforms. 0 means artifact, 1 suppression, 2 burst and 3 invalid (the EEG is not classified). Artefact shows the artefact status of all channels. 0 means that there are no artefacts on the signal and 1 means that there are artefatcs. Noise shows 1 if the activity of FEMG is too high for clean EEG signal and that EEG is not probably reliable.
EMG AD shows the latest AD conversion result of FEMG signal without any filtering or scaling. Leadset AD shows the latest AD conversion result of lead set signal without any scaling.
Bipolar shows the montage type that is active in module and headbox. 1 means bipolar and 0
referenced.
60 Hz is 1 if the power frequency filter is set for 60 Hz power frequency. Imp. Meas. shows 1 if the impedance measurement is on in the headbox. Imp. Check Failed shows 1 if the impedance check has failed.
EP Meas. shows 1 if the evoked potential measurement is active in headbox. High EP Sampl. Rate shows 1 if the headbox uses higher sampling rate for 10 ms EP
measurement.
EP Epoch Points shows the number of samples collected for each epoch. EP Channels shows the number of channels used in EP measurement.
Setup
Hb ROM Error is 1 if the checksum at the EPROM is not accordance with the one the software has
calculated.
The items in setup menu are collection of items in normal EEG and EP menus. There are no special service settings in this menu.
Imp. Cycle Impedance measurement repetition time.
Select Montage Selection of headbox’s electrode configuration.
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EEG Channels Number of active channels in EEG measurement.
Montage Type Selection of bipolar (Bip)/referenced (Ref) montage.
Cycle EP measurement repetition time.
Stim. Frequency Ep measurement’s stimulation frequency.
Stim. Intensity Intensity of EP stimulus.
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S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG

6 SPARE PARTS

6.1 Spare part list
NOTE: Accessories are listed in the Patient monitor and supplies catalogue.
6.1.1 M-EEG rev. 00
Item Description Order code Item Description Order code
1 Module box (single width) 886167 5 Neuro board 898806
2 Latch 879181 6 Cross cylinder head screw, M3×12 628700
3 Spring pin 879182 9 EEG input board 896571
4 Cross recess screw M3×8 black 616215 10 Metal frame 879184
7 Front panel unit 896484 11 Cross cylinder head screw, M3×6 61721
8 Membrane keypad 880101 - - -
6.1.2 S/5 M-EEG rev. 01
Figure 7 Exploded view of module box and EEG module
No new spare parts.
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6.1.3 N-EEG rev. 00
Item Description Order
code
1 Headbox board 898805 6 Membrane keypad 880101
2 Module-headbox cable 895610 7 Cover 896457
3 Headbox input unit 896558 8 Base 896557
4 AEP connector 896461 9 Cross cylinder head screw, M3x6 617210
5 EMC cover 898276 10 Screw, MRX-Z, M3x12 FZB DIN 8985 61736
- Screw, to connect cable shield to EMC cover 61721 - - -
- Nut, to connect cable shield to EMC cover 63116 - - -
- Washer, to connect cable shield to EMC cover 63407 - - -
Item Description Order
code
6.1.4 S/5 N-EEG rev. 01
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Figure 8 Exploded view of headbox
No new spare parts.
S/5 EEG Module, M-EEG and S/5 Headbox, N-EEG
6.1.5 Front panel stickers
Adaptation S/5 M-EEG (Rev. 01) S/5 N-EEG (Rev. 01) Electrode sticker
DA 898693 898708 898207
DE 898684 898699 897858
EN 898683 898698 897858
ES 898687 898702 898203
FI 898690 898705 897858
FR 898685 898700 898201
IT 898688 898703 898204
JA 8000381 8000382 8000393
NO 898692 898707 898208
NL 898686 898701 898202
PT 898689 898704 898205
SV 898691 898706 898206
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7 EARLIER REVISIONS

Revision Manual slot/main manual Note
M-EEG rev. 00 and N-EEG rev. 00 896622-1/896624
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APPENDIX A, Service check form, S/5 M-EEG and N-EEG

APPENDIX A

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APPENDIX A, Service check form, S/5 M-EEG and N-EEG

SERVICE CHECK FORM

EEG Module, M-EEG and EEG Headbox, N-EEG
Customer
Service
Service engineer Date
OK = Test OK N.A. = Test not applicable Fail = Test Failed
OK N.A. Fail OK N.A. Fail
1. Internal parts 2. External parts of
3. External parts of
headbox
5. Recognition of module 6. Recognition of headbox
7. Module software
8. Communication and
memories of module
10. Membrane keys
M-EEG
N-EEG
Module type S/N
module
4. Installation
9. Communication and
memories of headbox
11. Impedances + -
Channel 1 9...11 k
Channel 2 9...11 k
Channel 3 9...11 k
Channel 4 9...11 k
12. Checks with simulator Allowed range
Waveforms 195...205 µV
MF 9.5...10.5 Hz
Amp value 68...74 µV
13. FEMG value
FEMG 13...19 µV
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A-1(2)
Datex-Ohmeda S/5 monitors
OK N.A. Fail OK N.A. Fail
14. AEP stimulation
15. AEP response
Channel 1 35...45 µV
Channel 2 35...45 µV
16. Electrical safety check 17. Functioning after
electrical safety check
18. Final cleaning
Notes
Used Spare Parts
Signature
A-2(2)
Document No. 800 1011-1
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