Datex-Ohmeda S/5 M-NE12STPR Use and care manual

Datex-Ohmeda Hemodynamic modules
S/5TM NE12STPR Module, M-NE12STPR (rev. 01)
S/5TM NE12STR Module, M-NE12STR (rev. 01)
S/5TM NE12TPR Module, M-NE12TPR (rev. 01)
S/5TM NESTPR Module, M-NESTPR (rev. 01)
S/5TM NESTR Module, M-NESTR (rev. 01)
S/5TM NETPR Module, M-NETPR (rev. 01)
S/5TM ESTPR Module, M-ESTPR (rev. 04)
S/5TM ESTR Module, M-ESTR (rev. 04)
S/5TM ETPR Module, M-ETPR (rev. 04)
Technical Reference Manual Slot
All specifications are subject to change without notice.
Document No. 800 1008-2
June 2001
Datex-Ohmeda Inc.
3030 Ohmeda Drive
53707-7550 MADISON, WIS
USA
Tel. [phone],Fax [phone]
www.us.datex-ohmeda.com
Datex-Ohmeda Division,
Instrumentarium Corp.
P.O. Box 900, FIN-00031
DATEX-OHMEDA, FINLAND
Tel. [phone] Fax [phone]
www.datex-ohmeda.com
Instrumentarium Corp. All rights reserved.

Table of contents
Document No. 800 1008-2
i
TABLE OF CONTENTS
HEMODYNAMIC MODULES
TABLE OF CONTENTS i
Table of figures iii
Introduction 1
1 Specifications 2
1.1 General specifications ..............................................................................................................................2
1.2 Typical performance .................................................................................................................................2
1.2.1 NIBP ................................................................................................................................................2
1.2.2 ECG .................................................................................................................................................3
1.2.3 Pulse oximetry..................................................................................................................................3
1.2.4 Temperature.....................................................................................................................................4
1.2.5 Invasive blood pressure ....................................................................................................................4
1.2.6 Respiration ......................................................................................................................................4
1.3 Technical specifications............................................................................................................................5
1.3.1 NIBP ................................................................................................................................................5
1.3.2 ECG .................................................................................................................................................5
1.3.3 Pulse oximetry..................................................................................................................................6
1.3.4 Temperature.....................................................................................................................................6
1.3.5 Invasive blood pressure ....................................................................................................................6
1.3.6 Respiration ......................................................................................................................................6
2 Functional Description 7
2.1 Measurement principle .............................................................................................................................7
2.1.1 NIBP ................................................................................................................................................7
2.1.2 ECG .................................................................................................................................................7
2.1.3 Pulse oximetry..................................................................................................................................7
2.1.4 Temperature.....................................................................................................................................9
2.1.5 Invasive blood pressure ..................................................................................................................10
2.1.6 Respiration ....................................................................................................................................10
2.2 Main components...................................................................................................................................10
M-ESTPR/-ETPR/-ESTR modules...............................................................................................................10
M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules .................................................11
2.2.3 NIBP board ....................................................................................................................................12
2.2.4 ECG board in 3-and 5-lead measurement........................................................................................14
2.2.5 ECG board in 12-lead measurement ...............................................................................................16
2.2.6 ECG filtering ...................................................................................................................................18
2.2.7 STP board ......................................................................................................................................19
2.3 Connectors and signals...........................................................................................................................24
2.3.1 Module bus connector....................................................................................................................24
2.3.2 Front panel connectors ...................................................................................................................25
2.3.3 Test points on boards .....................................................................................................................26
3 Service Procedures 28
3.1 General service information.....................................................................................................................28
3.2 Service check .........................................................................................................................................28

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3.2.1 Recommended tools ......................................................................................................................28
3.2.2 Recommended parts......................................................................................................................29
3.3 Disassembly and reassembly..................................................................................................................39
3.3.1 M-ESTPR, M-ESTR, and M-ETPR modules ........................................................................................39
3.3.2 M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules .......................................39
3.4 Adjustments and calibrations..................................................................................................................40
3.4.1 Pressure safety level detection “OFFSET”.........................................................................................40
3.4.2 NIBP calibrations ...........................................................................................................................40
3.4.3 Temperature calibration .................................................................................................................42
3.4.4 Invasive pressure calibration ..........................................................................................................42
4 Troubleshooting 43
4.1 Troubleshooting charts ...........................................................................................................................43
4.1.1 NIBP..............................................................................................................................................43
4.1.2 NIBP error code explanation ...........................................................................................................46
4.1.3 ECG...............................................................................................................................................47
4.1.4 Pulse oximetry (SpO2).....................................................................................................................47
4.1.5 Temperature ..................................................................................................................................48
4.1.6 Invasive blood pressure..................................................................................................................49
4.1.7 Impedance respiration ...................................................................................................................50
4.2 Troubleshooting flowcharts .....................................................................................................................51
4.2.1 M-NE12STPR and M-NESTPR module troubleshooting.....................................................................51
4.2.2 M-ESTPR, M-ESTR, and M-ETPR module troubleshooting .................................................................52
5ServiceMenu 53
5.1 NIBP service menu .................................................................................................................................54
5.1.1 NIBP demo menu...........................................................................................................................55
5.1.2 NIBP calibration menu....................................................................................................................56
5.1.3 NIBP safety valve menu ..................................................................................................................57
5.1.4 NIBP pulse valve menu...................................................................................................................58
5.1.5 NIBP buttons/leds menu................................................................................................................59
5.1.6 NIBP pneumatics menu..................................................................................................................60
5.1.7 NIBP watchdog menu.....................................................................................................................61
5.2 ECG service menu ..................................................................................................................................62
5.2.1 ECG setup menu ............................................................................................................................64
5.3 STP service menu ...................................................................................................................................65
5.3.1 STP calibration menu .....................................................................................................................67
6 Spare Parts 68
6.1 Spare parts list .......................................................................................................................................68
6.1.1 M-ESTP rev. 01, M-ETP rev. 00, M-EST rev. 00 .................................................................................68
6.1.2 M-ESTP rev. 02, M-ETP rev. 01, M-EST rev. 01 .................................................................................69
6.1.3 M-ESTP rev. 03, M-ETP rev. 02, M-EST rev. 02 .................................................................................69
6.1.4 M-ESTP rev. 04, M-ETP rev. 03, M-EST rev. 03 .................................................................................69
6.1.5 M-ESTP rev. 05, M-ETP rev. 04, M-EST rev. 04 .................................................................................69
6.1.6 M-ESTPR rev. 01, M-ETPR rev. 01, M-ESTR rev. 01...........................................................................70
6.1.7 M-ESTPR rev. 02, M-ETPR rev. 02, M-ESTR rev. 02...........................................................................70
6.1.8 M-ESTPR rev. 03, M-ETPR rev. 03, M-ESTR rev. 03...........................................................................70
6.1.9 M-ESTPR rev. 04, M-ETPR rev. 04, M-ESTR rev. 04...........................................................................70
6.1.10 M-NESTPR rev. 00, M-NETPR rev. 00, M-NESTR rev. 00 ...............................................................71
6.1.11 M-NESTPR rev. 01, M-NETPR rev. 01, M-NESTR rev. 01 ...............................................................72

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6.1.12 M-NE12STPR rev. 00, M-NE12STR rev. 00, M-NE12TPR rev. 00 ...................................................72
6.1.13 M-NE12STPR rev. 01..................................................................................................................72
6.1.14 Front panel stickers ....................................................................................................................73
6.1.15 Front panel stickers for S/5 modules...........................................................................................74
7 Earlier Revisions 76
APPENDIX A 77
Service Check Form A-1
TABLE OF FIGURES
Figure 1 S/5 NE12STPR Module, M-NE12STPR ................................................................................1
Figure 2 Absorption of infrared light in the finger probe parts layout and schematic diagram................9
Figure 3 Front panel of M-ESTPR.....................................................................................................10
Figure 4 Front panel of M-NESTPR ..................................................................................................11
Figure 5 NIBP board functional block diagram.................................................................................12
Figure 6 3- and 5- lead ECG board block diagram ...........................................................................14
Figure 7 12-lead ECG measurement block diagram.........................................................................16
Figure 8 STP board block diagram...................................................................................................19
Figure 9 Temperature measurement principle .................................................................................20
Figure 10 Pressure measurement principle .......................................................................................20
Figure 11 Pulse oximetry measurement block diagram ......................................................................21
Figure 12 Serial communication and opto isolation of M-NESTPR/-NE12STPR ...................................22
Figure 13 Serial communication and opto isolation of M-ESTPR.........................................................23
Figure 14 Module bus connector (X1) pin layout ................................................................................24
Figure 15 M-NE12STPR and M-NESTPR module troubleshooting flowchart.........................................51
Figure 16 M-ESTPR Module Troubleshooting Flowchart......................................................................52

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S/5 Hemodynamic modules
Document No. 800 1008-2
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INTRODUCTION
This Technical Reference Manual Slot provides information for the maintenance and service of the
hemodynamic 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.
The S/5 M-ESTPR/-ESTR/-ETPR and S/5 M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-
NESTR/-NETPR are double width modules designed for use with S/5 monitors. The modules
provide general hemodynamic parameters. Later in this manual modules can be called w/o
system name S/5.
NOTE: Do not use identical modules in
the same monitor simultaneously.
The following modules are considered
identical:
M-ESTP/-EST/-ETP
M-ESTPR/-ESTR/-ETPR
M-NESTPR/-NESTR/-NETPR
M-NE12STPR/-NE12STR/-NE12TPR
M-MRI/-MRIP
NOTE: 12-lead ECG measurement
requires Display Controller, B-DISP.
Figure 1 S/5 NE12STPR Module, M-NE12STPR
Table 1 Options of S/5 hemodynamic modules
Parameter NE12STPR NESTPR NE(12)
STR
NE(12)
TPR
ESTPR ESTR ETPR
12 12-lead ECG •(•)(•)
NNIBP ••••
EECG • • •••••
SPulse oximetry ••• ••
TTwo temperatures • • •••••
PTwo invasive blood pressures •• •• •
RImpedance respiration • • •••••

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1SPECIFICATIONS
1.1 General specifications
Module size 75 ×180 ×112 mm
W ×D ×H3.0×7.1 ×4.4 in
Operation temperature 10...40 °C / 50...104 °F
@ M-ESTPR/-ETPR/-ESTR
Module weight 0.6 kg / 1.3 lbs
Power consumption 6 W
@ M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR
Module weight 1 kg
Power consumption about 9 W
1.2 Typical performance
1.2.1 NIBP
Oscillometric measurement principle.
Measurement range adult 25...260 mmHg
child 25...195 mmHg
infant 15...145 mmHg
Pulse rate range accepted 30...250 bpm
Measurement interval from continuous to 1h, 2h, 4h
Typical measuring time adult 23 s
infant 20 s
Initial inflation pressure adult 185 ±10 mmHg
child 150 ±10 mmHg
infant 120 ±10 mmHg
Venous stasis adult 80 ±10 mmHg / 2 min.
child 60 ±10 mmHg / 2 min.
infant 40 ±10 mmHg / 1 min.
Cuff widths please see User’s Guide

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1.2.2 ECG
Lead selection @ 12-lead ECG I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, V6
Lead selection @ other modules I, II, III, aVR, aVL, aVF, V
Sweep speeds 12.5, 25, 50 mm/sec
DISPLAY FILTER
Diagnostic @ 12-lead ECG 0.05...150 Hz
Diagnostic @ other modules 0.05...100 Hz
Monitoring 0.5...30 Hz (-3 dB, with 50 Hz reject filter)
0.5...40 Hz (-3 dB, with 60 Hz reject filter)
ST filter 0.05...30 Hz (-3 dB, with 50 Hz reject filter)
0.05...40 Hz (-3 dB, with 60 Hz reject filter)
HEART RATE FROM ECG
Range 30...250 bpm
Accuracy ±5 bpm or ±5 %, whichever is greater
Resolution 1 bpm
Update interval 5 s
Averaging time 10 s
ST LEVELS (in main software)
ST level range -9...+9 mm (-0.9...+0.9 mV)
Resolution 0.1 mm (0.01 mV)
Averaging calculated from 8 QRS
SYNCHRONIZATION
Direct ECG analog output of ECG, 1 V/1 mV
Pacer 5 V and 0.5...2.5 ms pulse, < 30 ms after pacer peak
Defibrillator 5 V and 10 ms pulse, < 35 ms after R-point synchronization
1.2.3 Pulse oximetry
Measurement range 40...100 %
Accuracy 100...80 %, ±2 digits
(% SpO2±1 SD)180...50 %, ±3 digits
50...40 %, unspecified
Display resolution 1 digit = 1 % of SpO2
Display averaging time 20, 10 sec, beat-to-beat
Pulse beep pitch varies with SpO2level
The monitor is calibrated over the measurement range against functional saturation SpO2 func.
HEART RATE FROM PLETH
Measurement range 30...250 bpm
Accuracy 30...100, ±5 bpm,
100...250, ±5 %
Resolution 1 bpm
Display averaging 10 s
11 SD (standard deviation) = 68 % of all readings in the specified range in stable conditions.

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Adjustable pulse beep volume.
PLETH WAVEFORM
Scales 2, 5, 10, 20, 50 mod%, Auto
Start up scale is 20 mod% if AUTO is not selected to be the default setting.
1.2.4 Temperature
Measurement range 10...45 °C (50...113 °F)
(In rev. ESTP 03/ EST 02/ETP 02 or earlier: 15...45 °C (59...113 °F))
Measurement accuracy ±0.1 °C (25...45.0 °C)
±0.2 °C (10...24.9 °C)
Display resolution 0.1 °C (0.1 °F)
Temperature test automatic (every 10 min)
Probe type compatible with YSI 400 series
1.2.5 Invasive blood pressure
Measurement range -40...320 mmHg
Measurement accuracy ±2 mmHg or ±5 %
Zero adjustment range ±150 mmHg
Calibration range ±20 %
Scales upper limit is adjustable between 10 and 300 mmHg in steps of
10. Lower limit is 10 % of selected upper limit below zero.
Sweep speed 12.5, 25, 50 mm/s
DIGITAL DISPLAY
Range -40...320 mmHg
Resolution ±1 mmHg
WAVEFORM DISPLAY
Range -30...300 mmHg
HEART RATE FROM ARTERIAL PRESSURE
Measurement range 30...250 bpm
Resolution 1 bpm
Accuracy ±5 bpm or ±5 % whichever is greater
1.2.6 Respiration
Measurement range 4...120 bpm
Accuracy ±5 bpm or ±5 %
Resolution 1 bpm
Averaging time 30 s
Update interval 10 s
RESPIRATION WAVEFORM
Sweep Speeds 6.25 mm/s and 0.625 mm/s

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1.3 Technical specifications
1.3.1 NIBP
Deflation rate, PR dep. 5...13 mmHg/s
Inflation time 20...185 mmHg, 1...5 s
Automatic software control, max. inflation pressure
adult 280 ±10 mmHg
child 200 ±10 mmHg
infant 150 ±10 mmHg
Over pressure limit, stops measurement after 2 seconds
adult 320 mmHg
child 220 mmHg
infant 165 mmHg
Safety valve limits the maximum cuff pressure to 320 mmHg in adult/child mode or 165 mmHg in
infant mode. Independent timing circuit limits pressurizing (>5 mmHg) time to 2 minutes 10
seconds maximum in adult/child mode, and 1 minute 5 seconds in infant mode.
Zeroing to ambient pressure is done automatically.
Inflation pressure is adjusted according to the previous systolic pressure, typically 40 mmHg
above. If the systolic pressure is not found, inflation pressure is increased typically 50 mmHg.
Max. measurement time adult 2 min
child 2 min
infant 1 min
Pressure transducer accuracy is better than ±3 mmHg or ±2 % whichever is greater.
Max. error ±4 mmHg.
Protection against electrical
shock Type BF defibrillation proof
1.3.2 ECG
Defibrillation protection 5000 V, 360 J
Recovery time 2 s
Input impedance >2.5 MΩ(10 Hz)
CMRR >100 dB (ST)
System noise <40 µV (p-p, RTI)
Allowable offset ±300 mVDC
Gain range 0.2...5.0 cm/mV
Pacemaker pulse detection 2...500 mV, 0.5...2 ms pulses
Protection against electrical
shock Type CF defibrillator proof

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1.3.3 Pulse oximetry
Protection against electrical
shock Type BF defibrillation proof
1.3.4 Temperature
Measurement accuracy ±0.1 °C (25.0...45.0 °C)
±0.2 °C (10.0...24.9 °C)
Protection against electrical
shock Type CF defibrillation proof
NOTE: The accuracy of the measurement may be different from the specified, depending on
transducer/probe used. Please check the transducer/probe specification.
1.3.5 Invasive blood pressure
DIGITAL DISPLAY AVERAGING
Digital displays Art and P1 are averaged over 5 seconds and updated at 5 seconds intervals. All
other pressures have respiration artifact rejection.
Accuracy ±5 % or ±2 mmHg, whichever is greater
Transducer and input sensitivity
5 µV/V/mmHg, 5 VDC, 20 mA max current
Filter 0...4 - 22 Hz adjustable
Zero set accuracy ±1 mmHg
Calibration resolution ±1 mmHg
Zero time less than 15 s
Protection against electrical
shock Type CF defibrillation proof
NOTE: The accuracy of the measurement may be different from the specified, depending on
transducer/probe used. Please check the transducer/probe specification.
1.3.6 Respiration
Excitation frequency @ 12-lead ECG 62.5 kHz
Excitation frequency @ other modules 31.25 kHz
Breath detection automatic, range 0.3...6 Ωmanually adjustable minimum
detection: 0.2, 0.4, 0.6, 0.8, 1.0
Input dynamic range 0.2...6 Ω
Input impedance range 100...5000 Ω
Respiration Rate min. 4 bpm
max. 120 bpm
Lead off detection >3 MΩ

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2FUNCTIONAL DESCRIPTION
2.1 Measurement principle
2.1.1 NIBP
NIBP (Non-Invasive Blood Pressure) is an indirect method for measuring blood pressure.
The NIBP measurement is performed according to the oscillometric measuring principle. The cuff is
inflated with a pressure slightly higher than the presumed systolic pressure, and deflated at a
speed based on the patient’s pulse, collecting data from the oscillations caused by the pulsating
artery. Based on these oscillations, values for systolic, mean, and diastolic pressures are
calculated.
The following parts are necessary for the NIBP measurement:
•M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR (or M-NIBP) module
•twin hose (adult or infant model)
•blood pressure cuffs (different sizes)
2.1.2 ECG
Electrocardiography analyzes the electrical activity of the heart by measuring the electrical
potential produced with electrodes placed on the surface of the body.
ECG reflects:
•electrical activity of the heart
•normal/abnormal function of the heart
•effects of anesthesia on heart function
•effects of surgery on heart function
See the User's Reference Manual for electrodes positions and other information.
2.1.3 Pulse oximetry
A pulse oximeter measures the light absorption of blood at two wavelengths, one in the near
infrared (about 900 nm) and the other in the red region (about 660 nm) of light spectrum. These
wavelengths are emitted by LEDs in the SpO2probe, the light is transmitted through peripheral
tissue and is finally detected by a PIN-diode opposite to LEDs in the probe. Pulse oximeter derives
the oxygen saturation (SpO2)using empirically determined relationship between the relative
absorption at the two wavelengths and the arterial oxygen saturation SaO2.
In order to measure the arterial saturation accurately, pulse oximeters use the component of light
absorption giving variations synchronous with heart beat as primary information on the arterial
saturation.

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A general limitation of the above pulse oximetry principle is that due to only two wavelengths used
only two hemoglobin species can be discriminated by the measurement.
The modern pulse oximeters are empirically calibrated either against fractional saturation
SaO2frac;
binDyshemogloHbHbO
HbO
fracSaO
2
2
2++
=Formula 1
or against functional saturation SaO2func;
HbHbO
HbO
funcSaO
2
2
2+
=Formula 2
which is more insensitive to changes of carboxyhemoglobin and methemoglobin concentrations in
blood.
The oxygen saturation percentage SpO2measured by Datex-Ohmeda module is calibrated against
the functional saturation SaO2func. The advantage of this method is that the accuracy of SpO2
measurement relative to SaO2func can be maintained even at rather high concentrations of
carboxyhemoglobin in blood. Independent of the calibration method, pulse oximeter is not able to
correctly measure oxygen content of the arterial blood at elevated carboxyhemoglobin or
methemoglobin levels.
Plethysmographic pulse wave
The plethysmographic waveform is derived from the IR signal and reflects the blood pulsation at
the measuring site. Thus the amplitude of the waveform represents the perfusion.
Pulse rate
The pulse rate calculation is done by peak detection of the plethysmographic pulse wave. The
signals are filtered to reduce noise and checked to separate artifacts.
Probe
The standard probe is a finger clamp probe which contains the light source LEDs in one half and
the photodiode detector in the other half. Different kinds of probes are available from Datex-
Ohmeda.

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SpO sensor cable
2
6
7
4
5
8
1
9
RC
GND
LED
GND
V
B
S
Emitter
Detector
IRED
RED
SpO sensor connector
Imax (DC-component)
Imin
Imax
Intensity of
transmitted
light
Transmitted
light
No pulsation Pulsatile blood
AC-component
Variable absorption
due to pulse added
volume of arterial
blood
Arterial blood
Venous blood
Tissue
Time
Incident light
2
GND
I
I
Figure 2 Absorption of infrared light in the finger probe parts layout and schematic
diagram
2.1.4 Temperature
The temperature is measured by a probe whose resistance varies when the temperature changes,
called NTC (Negative Temperature Coefficient) resistor.
The resistance can be measured by two complementary methods:
•Applying a constant voltage across the resistor and measuring the current that flows through
it

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•Applying a constant current through the resistor and measuring the voltage that is generated
across it.
In Datex-Ohmeda modules the two methods are combined in a form of a voltage divider. The NTC-
resistor is connected in series with a normal resistor and a constant voltage is applied across them.
The temperature dependent voltage can be detected at the junction of the resistors, thus producing
the temperature signal from the patient. The signal is amplified by analog amplifiers and further
processed by digital electronics.
2.1.5 Invasive blood pressure
To measure invasive blood pressure, a catheter is inserted into an artery or vein. The invasive
pressure setup, consisting of connecting tubing, pressure transducer, an intravenous bag of normal
saline all connected together by stopcocks, is attached to the catheter. The transducer is placed at
the same level with the heart, and is electrically zeroed.
The transducer is a piezo-resistive device that converts the pressure signal to a voltage. The monitor
interprets the voltage signal so that pressure data and pressure waveforms can be displayed.
2.1.6 Respiration
Impedance respiration is measured across the thorax between ECG electrodes. The signal of the
respiration is made by supplying current between electrodes and by measuring the differential
current from the electrodes. The signal measured is the impedance change caused by breathing.
From these impedance changes, respiration rate is calculated, and respiration waveform is
displayed on the screen.
2.2 Main components
2.2.1 M-ESTPR/-ETPR/-ESTR modules
Figure 3 Front panel of M-ESTPR
The M-ESTPR, M-ETPR, and M-ESTR modules contain two main PC boards, the STP board and the
ECG board. They work independently. Both of them have their own processor and software EPROM.
Some components on the boards are not used in ETPR and ESTR modules.
In M-ESTPR module, additionally, there are two small boards, the SP input and the ECG input
T1
T2
P1
P2
ECG+
Resp SpO2
ECG
Lead
Zero
P1
Zero
P2
Start
Wedge

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boards, attached to the front panel of the module. The front panel has six connectors and four keys.
The connectors are two for temperature measurement, two for invasive blood pressure
measurement, one for ECG, and one for SpO2measurement. The keys are for ECG lead, Start
Wedge, P1 zero, and P2 zero.
In M-ETPR module,there are two small boards, the ECG input board and the 2P input board
attached to the front panel of the module. The front panel has five connectors and four keys. The
connectors are two for temperature measurement, two for invasive blood pressure measurement,
and one for ECG measurement. The keys are for ECG lead, Start Wedge, P1 zero, and P2 zero.
In M-ESTR module, there are two small boards: the S input board and the ECG input board,
attached to the front panel of the module. The front panel has four connectors and one key. The
connectors are two for temperature measurement, one for ECG, and one for SpO2measurement.
The key is for ECG lead select.
NOTE: M-ESTP rev. 03, M-ETP rev. 02 and M-EST rev. 02 and all earlier revisions have separate T
and SP input boards.
2.2.2 M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules
Figure 4 Front panel of M-NESTPR
The M-NESTPR, M-NETPR, and M-NESTR modules contain three main PC boards, the STP board,
the ECG board, and the NIBP board. They work independently. Each of these has their own
processor and software EPROM.
The M-NE12STPR, M-NE12TPR, and M-NE12STR contain three main PC boards, The STP board,
the ECG board and the NIBP board. They work independently. Each of them has their own
processor. The STP board and NIBP board have software EPROM. In the ECG board the software is
in flash memory. The STP and NIBP boards are the same as in M-NESTPR module but the ECG
board and ECG input board are different.
In M-NESTPR module, there are two small boards, the SP input and the ECG input board attached
to the front panel of the module. The front panel has seven connectors and four keys. The
connectors are two for temperature measurement, two for invasive blood pressure measurement,
one for ECG, one for NIBP, and one for SpO2measurement. The keys are for NIBP Auto On/Off,
NIBP Start/Cancel, P1 zero, and P2 zero. The structure of M-NE12STPR is similar except the ECG
board and ECG input board are different.
T2
P1
P2
T1
NIBP
ECG+
Resp
Auto
On/Off
Zero
P1
Zero
P2
Start
Cancel
SpO
2

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In M-NETPR module, there are two small boards, the 2P input board and the ECG input board,
attached to the front panel of the module. The front panel has six connectors and four keys. The
connectors are two for temperature measurement, two for invasive blood pressure measurement,
one for ECG, and one for NIBP. The keys are for Auto On/Off, Start/Cancel, P1 zero, and P2 zero.
The structure of M-NE12TPR is similar except the ECG board and ECG input board are different.
In M-NESTR module, there are two small boards, the ECG input board and the S input board,
attached to the front panel of the module. The front panel has five connectors and two keys. The
connectors are two for temperature measurement, and one for SpO2measurement, one for ECG,
and one for NIBP. The keys are for Auto On/Off, Start/Cancel. The structure of M-NE12STR is
similar except the ECG board and ECG input board are different.
2.2.3 NIBP board
ADDRESS
DECODER
POWER-UP
RESET
CPU
80C51FA
RS485
INTERF.
ADDRESS
LATCH
RAM
INTERNAL
WATCHDOG
EEPROM
(Calib-
ration
Data)
AD-CON-
VERTER
Write protect switch
EPROM
FRONT
PANEL
KEYS
SOFT-
WARE
CONTROL
DATABUS
ADDRESS BUS
WATCHDOG
TIMER
X1
JOINING
CHAMBER
CUFF
M
EXHAUST VALVE 1
BLEED VALVE
CHECK VALVE PUMP
EXHAUST
VALVE 2
PRESSURE
TRANS-
DUCERS
PUMP and
VALVE
DRIVER
OVERPRESSURE CONTROL
ZERO
VALVE
B1 B2
+15VD
to/frommodulebus
Figure 5 NIBP board functional block diagram
Pressure transducers
The NIBP board contains two pressure transducers. They are of piezoresistive type. One is used for
measuring the pressure of the blood pressure cuff and the pressure fluctuations caused by arterial
wall movement (B1). The other is used for detection of cuff hose type, cuff loose and cuff occlusion
situations etc. (B2). The transducers are internally temperature compensated. They are supplied by
a constant voltage and their output voltage changes up to 40 mV max. (50 kPa, 375 mmHg).

S/5 Hemodynamic modules
Document No. 800 1008-2
13
Signal processing
Two signals from the pressure transducers are amplified and sent to A/D converter. After the
converter, digitized signals are sent to microprocessor for data processing. Before the converter,
one of the signals is used to adjust the offset to the pressure safety level.
The NIBP board is controlled with 80C51FA microprocessor at 16 MHz oscillator frequency.
Memory
NIBP program memory (EPROM) size is 128k ×8. RAM size is 32k ×8 bit and it stores variable
values in NIBP measurement. EEPROM is size 64 ×16 bit and is used to store the calibration
values for the pressure transducers, the pulse valve constants gained during measurements, the
PC board identification, and module serial number.
Software control
Software controls valves and pump. In addition to the individual on/off signals for each component
there is a common power switch for the valves and the pump that can be used at pump/valve
failures.
In addition to external RS485 reset line the microprocessor system is equipped with its own power-
up reset. See the section in ECG board’s description: “RS485 communication”
Watchdog timer
The NIBP board is equipped with software independent safety circuit to disconnect supply voltages
from the pump and the valves if the cuff has been pressurized longer than preset time. As soon as
the cuff pressure rises over a specifiedpressure limit, timer starts counting. The timer is adjusted to
stop the pump and open the valves in 2 minutes 10 seconds in adult/child mode and in 1 minute
5 seconds in infant mode.
Valves
Exhaust valves are used for emptying the cuff and the joining chamber after the measurement.
Exhaust valve 1 is also used as safety valve in infant mode. Valve opens at 165 mmHg. Exhaust
valve 2 is also used as safety valve in adult mode and opens at 320 mmHg.
Bleed valve is used for emptying the cuff during measurement. Zero valve is used for connecting
the pressure transducer B1 to open air.
Power supply section
All connections are established via 25-pin connector (D-type, female). The module needs +5 V,
±15 V, and +15 VD (dirty) power supply to operate. The pump and the valves use separate +15 VD
power line. The supply voltages are generated in the power supply section of the S/5 monitor. The
reference voltages ±5 Vref and +10 Vref are generated on the NIBP board.

Datex-Ohmeda S/5 monitors
Document No. 800 1008-2
14
2.2.4 ECG board in 3-and 5-lead measurement
Patient signals are connected to overload protection circuits (resistors and gas-filled surge
arresters) and analog switches to instrumentation amplifiers. Then the signals are amplified by 480
and limited by slew rate. Then they are A/D-converted, analyzed and transferred to module bus in
digital form.
SLEW-
RATE
DETECTOR
SLEW-
RATE
DETECTOR
SLEW-
RATE
DETECTOR
ANTI-
ALIAS
ANTI-
ALIAS
ANTI-
ALIAS
A/D
MICRO-
PROCESSOR
(uP)
DIRECT
ECG
OPTO-
COUPLER
POWER
SOURCE
DIRECT
ECG
OPTO-
COUPLER
POWER
SOURCE
PATIENT
OVERLOAD PROTECTION
ANALOG SWITCHES
to STP Board
ISOLATION
uPuPuP
SUPPLY
VOLTAGES
HP
Filter
uP
HP
Filter
uP
HP
Filter
uP
SLEW-
RATE
DETECTOR
ANTI-
ALIAS
uP
HP
Filter
uP
RL FCN
LEAD SELECTION LOGIC
Controlled by ECG lead
selection signals from uP
Resp
amplifier
Sync. Rectifier
Amplifier
DEFIBRILLA-
TION
DETECTOR
uP
31 kHz
from uP
Figure 6 3- and 5- lead ECG board block diagram
Analog ECG section
ECG cable is connected to connector pins E1 to E6 on the input board which contains an overload
protection circuit. Leads are connected to amplifiers via analog switches. States of the switches
depend on the cable type. Lead-off, noise and pacemaker are detected by a slew rate detector.