Datex-Ohmeda S-5 M-Modules Technical reference manual

Datex-Ohmeda

S/5™ M-Modules

Technical Reference Manual

Datex-Ohmeda, Inc.

P.O. Box 7550, Madison

WI 53707-7550, USA

Tel. [phone]

Fax [phone]

All specifications are subject to change without notice.

Document No. M1025359

June 2005

GE Healthcare Finland Oy Helsinki, Finland P.O. Box 900

FIN-00031 GE, FINLAND Tel. [phone] Fax [phone] www.datex-ohmeda.com www.gehealthcare.com ©2005 Copyright General Electric Company

Responsibility of the manufacturer

GE Healthcare Finland Oy(GE) is responsible for the safety, reliability and performance of the equipment only if:

−modifications, service and repairs are carried out by personnel authorized by GE.

−the electrical installation complies with appropriate requirements.

−the equipment is used in accordance with the User’s Guide and serviced and maintained in accordance with the Technical Reference Manual.

Trademarks

Datex, Ohmeda, S/5, D-lite, D-lite+, Pedi-lite, Pedi-lite+, Mini D-fend, D-fend,

D-fend+, OxyTip+, MemCard, ComWheel, EarSat, FingerSat, FlexSat, PatientO2, Entropy, Patient Spirometry and Tonometrics are trademarks of GE Healthcare Finland Oy. All other product and company names are property of their respective owners.

Copyright

©2005 Copyright General Electric Company

All specifications subject to change without notice.

Table of contents

Master Table of Contents

Technical Reference Manual, S/5™ M-Modules

M1025359

For S/5™ Anesthesia Monitor and Critical Care Monitor

and S/5™ Compact Anesthesia Monitor and Compact Critical Care Monitor

Document No.		Updated	Updated	Description
					1
8001008	-6			Hemodynamic Modules,
				M-NE12STPR, M-NE12STR, M-NE12TPR, M-NESTPR, M-NESTR,
				M-NETPR, M-ESTPR, M-ESTR, M-ETPR
					2
8001009	–5			Compact Airway Modules, M-CAiOVX, M-CAiOV,M-CAiO, M-COVX,
				M-COV, M-CO, M-C
					3
8001010	–4			Tonometry Module, M-TONO
					4
8001011	–4			EEG Module, M-EEG and EEG Headbox, N-EEG
					5
8001012	–4			Cardiac Output Modules, M-COP and M-COPSv
					6
8001013	–4			Pressure Module, M-P, Pressure Temp Module, M-PT
					7
8001014	–4			Dual Pressure Module, M-PP
					8
8001015	–5			NIBP Module, M-NIBP
					9
8001016	–3			Recorder Module, M-REC
					10
8005426	–1			Oxygen Saturation Modules, M-NSAT, M-OSAT
					11
8001018	–4			NeuroMuscular Transmission Module, M-NMT
					12
8003840	–1			Anesthesia recordkeeping keyboard for, K-ARKB, Keyboard
				Interface Board, B-ARK and ARK Barcode Reader, N-SCAN
					13
8001020	–5			Memory Module, M-MEM
					14
8001021	–4			Interface Module, M-INT
					15
8005676				Device Interfacing Solution, N-DISxxxx
					16
8003476-2				BIS Module, M-BIS
					17
8003934-1				Remote Controllers, K-REMCO, K-CREMCO
					18
8003487-3				Single-width Airway Module, M-miniC
					19
8004390				Entropy Module, M-ENTROPY
					20
8005571-1				PRETSN Module
					21
8001005-5				Airway Modules, G-AiOV, G-AiO, G-AOV, G-AO, Gas Interface Board
				B-GAS

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Introduction

INTRODUCTION

This Technical Reference Manual provides information for the maintenance and service of the Datex-Ohmeda S/5™ M-Modules, record keeping keyboard, remote controllers and Device Interfacing System. These Datex-Ohmeda devices are designed for use with S/5™ Anesthesia Monitor, S/5™ Critical Care Montor, S/5™ Compact Anesthesia Monitor, and S/5™ Compact Critical Care Monitor.

Please see also the Technical Reference Manual of the S/5 monitor for system specific information e.g. related documentation, conventions used, symbols on equipment, safety precautions, system description, system installation, interfacing, functional check and planned maintenance.

For more detailed information about compatibility with different monitor software types and levels se the "Introduction" chapter of the slot of the module or other device.

S/5™ parameter modules, Device Interfacing Solution, Record keeping keyboard and Remote Controller

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Notes to the reader

This Technical Reference Manual is intended for service personnel and engineers who will perform service and maintenance procedures on the Datex-Ohmeda S/5 Anesthesia Monitor,S/5 Critical Care Monitor, S/5 Compact Anesthesia Monitor or S/5 Compact Critical Care Monitor.

This Technical Reference Manual completes the Technical Reference Manual of the S/5 Anesthesia Monitor and S/5 Critical Care Monitor or S/5 Compact Anesthesia Monitor and S/5 Compact Critical Care Monitor.

•Document number M1025359 is the order number for the whole printed manual. This manual includes Technical Reference Manual Slots and every slot has own document number.

•The Technical Reference Manual, S/5 Modules gives detailed descriptions of paramter modules and other products that can be used with all S/5 modular monitors. Service check for each product is included in these slots.

For monitor or system specific information see:

The Technical Reference Manual of the S/5 Anesthesia Monitor and S/5 Critical Care Monitor or The Technical Reference Manual of S/5 Compact Anesthesia Monitor and S/5 Compact Critical Care Monitor.

The manufacturer reserves the right to change product specifications without prior notice. Although the information in this manual is believed to be accurate and reliable, the manufacturer assumes no responsibility for its use.

GE Healthcare Finland Oy (GE) assumes no responsibility for the use or reliability of its software in equipment that is not furnished by GE.

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	Introduction
Conventions used
	Throughout this manual, the following conventions are used to distinguish procedures or elements
	of text:
" Sign the check form after performing the procedure.
Hard Keys	Hard key names on the Command Board, the Remote Controller, and modules are written in bold
	D-O Sans (12 pt) typeface, e.g. ECG.
Menu Items	Menu items are written in bold italic, D-O Sans (11 pt) typeface, e.g. ECG Setup.
‘Messages’	Messages displayed on the screen are enclosed in single quotes, e.g. ‘Please wait’.
Chapters	When referring to different chapters in the same manual, the chapter name is written in italic
	typeface and is enclosed in double quotes, e.g. chapter “Cleaning and Care.”
Other documents
	When referring to different documents, the document name is written in italic typeface, e.g. refer to
	User’s Reference Manual.
Hypertext links	Hypertext links on PDF versions are written in blue color.
WARNING	Warnings are written in bold typeface (13 pt), for example:
WARNING	Use only hospital-grade electrical outlets and power cord.
CAUTION	Cautions are written in the following way (13 pt):
CAUTION	The circuit boards contain sensitive integrated circuits that can be damaged by an
	electrostatic discharge. Careful handling of the boards is therefore essential.

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Datex-Ohmeda Hemodynamic modules S/5TM NE12STPR Module, M-NE12STPR (rev. 02)

S/5TM NE12STR Module, M-NE12STR (rev. 02) S/5TM NE12TPR Module, M-NE12TPR (rev. 02)

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

Datex-Ohmeda, Inc.

P.O. Box 7550, Madison WI 53707-7550, USA

Tel. [phone] Fax [phone] www.us.datex-ohmeda.com

mailto:[e-mail]

All specifications are subject to change without notice.

Document No. 800 1008-6

October 2003

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
TABLE OF CONTENTS
HEMODYNAMIC MODULES
TABLE OF CONTENTS		i
Table of figures		iii
Introduction		1
1	Specifications	3
1.1	General specifications ..............................................................................................................................	3
1.2	Typical performance .................................................................................................................................	3
	1.2.1 NIBP ................................................................................................................................................	3
	1.2.2 ECG .................................................................................................................................................	4
	1.2.3 Pulse oximetry..................................................................................................................................	4
	1.2.4 Temperature.....................................................................................................................................	5
	1.2.5 Invasive blood pressure ....................................................................................................................	5
	1.2.6 Respiration ......................................................................................................................................	5
1.3	Technical specifications............................................................................................................................	6
	1.3.1 NIBP ................................................................................................................................................	6
	1.3.2 ECG .................................................................................................................................................	6
	1.3.3 Pulse oximetry..................................................................................................................................	7
	1.3.4 Temperature.....................................................................................................................................	7
	1.3.5 Invasive blood pressure ....................................................................................................................	7
	1.3.6 Respiration ......................................................................................................................................	7
2	Functional Description	8
2.1 Measurement principle .............................................................................................................................		8
	2.1.1 NIBP ................................................................................................................................................	8
	2.1.2 ECG .................................................................................................................................................	8
	2.1.3 Pulse oximetry..................................................................................................................................	8
	2.1.4 Temperature...................................................................................................................................	10
	2.1.5 Invasive blood pressure ..................................................................................................................	11
	2.1.6 Respiration ....................................................................................................................................	11
2.2 Main components...................................................................................................................................		11
	M-ESTPR/-ETPR/-ESTR modules...............................................................................................................	11
	M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules .................................................	12
	2.2.3 NIBP board ....................................................................................................................................	13
	2.2.4 ECG board in 3-and 5-lead measurement........................................................................................	15
	2.2.5 ECG board in 12-lead measurement ...............................................................................................	17
	2.2.6 ECG filtering ...................................................................................................................................	19
	2.2.7 STP board ......................................................................................................................................	20
2.3 Connectors and signals...........................................................................................................................		25
	2.3.1 Module bus connector ....................................................................................................................	25
	2.3.2 Front panel connectors ...................................................................................................................	26
	2.3.3 Test points on boards .....................................................................................................................	27
3	Service Procedures	29
3.1	General service information.....................................................................................................................	29
3.2 Service check .........................................................................................................................................		29
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	3.2.1 Recommended tools ......................................................................................................................	29
	3.2.2 Recommended parts......................................................................................................................	29
3.3 Disassembly and reassembly..................................................................................................................		40
	3.3.1 M-ESTPR, M-ESTR, and M-ETPR modules ........................................................................................	40
	3.3.2 M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules .......................................	40
3.4	Adjustments and calibrations..................................................................................................................	41
	3.4.1 Pressure safety level detection “OFFSET”.........................................................................................	41
	3.4.2 NIBP calibrations ...........................................................................................................................	41
	3.4.3 Temperature calibration .................................................................................................................	43
	3.4.4 Invasive pressure calibration ..........................................................................................................	43
4	Troubleshooting	45
4.1	Troubleshooting charts ...........................................................................................................................	45
	4.1.1 NIBP..............................................................................................................................................	45
	4.1.2 NIBP error code explanation ...........................................................................................................	48
	4.1.3 ECG...............................................................................................................................................	49
	4.1.4 Pulse oximetry (SpO2).....................................................................................................................	49
	4.1.5 Temperature ..................................................................................................................................	50
	4.1.6 Invasive blood pressure..................................................................................................................	51
	4.1.7 Impedance respiration ...................................................................................................................	52
4.2	Troubleshooting flowcharts .....................................................................................................................	53
	4.2.1 M-NE12STPR and M-NESTPR module troubleshooting.....................................................................	53
	4.2.2 M-ESTPR, M-ESTR, and M-ETPR module troubleshooting .................................................................	54
5	Service Menu	55
5.1 NIBP service menu .................................................................................................................................		56
	5.1.1 NIBP demo menu...........................................................................................................................	57
	5.1.2 NIBP calibration menu....................................................................................................................	58
	5.1.3 NIBP safety valve menu ..................................................................................................................	59
	5.1.4 NIBP pulse valve menu...................................................................................................................	60
	5.1.5 NIBP buttons/leds menu................................................................................................................	61
	5.1.6 NIBP pneumatics menu..................................................................................................................	62
	5.1.7 NIBP watchdog menu .....................................................................................................................	63
5.2 ECG service menu ..................................................................................................................................		64
	5.2.1 ECG setup menu ............................................................................................................................	66
5.3 STP service menu ...................................................................................................................................		67
	5.3.1 STP calibration menu .....................................................................................................................	69
6	Spare Parts	70
6.1	Spare parts list .......................................................................................................................................	70
	6.1.1 M-ESTP rev. 01, M-ETP rev. 00, M-EST rev. 00 .................................................................................	70
	6.1.2 M-NESTPR rev. 00, M-NETPR rev. 00, M-NESTR rev. 00....................................................................	74
	6.1.3 M-NE12STPR rev. 00, M-NE12STR rev. 00, M-NE12TPR rev. 00.......................................................	78
7	Earlier Revisions	81
APPENDIX A		83
Service Check Form		1

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	Table of contents
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..............	10
Figure 3	Front panel of M-ESTPR.....................................................................................................	11
Figure 4	Front panel of M-NESTPR ..................................................................................................	12
Figure 5	NIBP board functional block diagram.................................................................................	13
Figure 6	3- and 5- lead ECG board block diagram ...........................................................................	15
Figure 7	12-lead ECG measurement block diagram.........................................................................	17
Figure 8	STP board block diagram...................................................................................................	20
Figure 9	Temperature measurement principle .................................................................................	21
Figure 10	Pressure measurement principle .......................................................................................	21
Figure 11	Pulse oximetry measurement block diagram ......................................................................	22
Figure 12	Serial communication and opto isolation of M-NESTPR/-NE12STPR ...................................	23
Figure 13	Serial communication and opto isolation of M-ESTPR.........................................................	24
Figure 14	Module bus connector (X1) pin layout ................................................................................	25
Figure 15	M-NE12STPR and M-NESTPR module troubleshooting flowchart.........................................	53
Figure 16	M-ESTPR Module Troubleshooting Flowchart......................................................................	54
Figure 17	Exploded view of M-ESTP Module ......................................................................................	70
Figure 18	Exploded view of M-NESTPR Module..................................................................................	74
Figure 19	Exploded view of M-NE12STPR Module..............................................................................	78

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S/5 Hemodynamic modules

INTRODUCTION

This Technical Reference Manual Slot provides information for the maintenance and service of the hemodynamic modules. 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. Later in this manual modules may be referred to w/o the system name S/5 for simplicity.

Please refer to the Technical Reference Manual of the S/5 monitor 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 M-ESTPR/-ESTR/-ETPR and M-NE12STPR/-NE12STR/-NE12TPR/-NESTPR/-NESTR/-NETPR modules provide general hemodynamic parameters

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

	Figure 1	S/5 NE12STPR Module, M-NE12STPR
	Table 1	Options of S/5 hemodynamic modules
	Parameter	NE12STPR	NESTPR	NE(12)	NE(12)	ESTPR	ESTR	ETPR
				STR	TPR
12	12-lead ECG	•		(•)	(•)
N	NIBP	•	•	•	•
E	ECG	•	•	•	•	•	•	•
S	Pulse oximetry	•	•	•		•	•
T	Two temperatures	•	•	•	•	•	•	•
P	Two invasive blood pressures	•	•		•	•		•
R	Impedance respiration	•	•	•	•	•	•	•

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NOTE: 12-lead ECG measurement requires Display Controller, B-DISP.

NOTE: M-ESTP rev. 01, M-EST rev. 00 and M-ETP rev. 00 work only with S-STD93, S-STD94, S-ARK94, S-STD95, S- ARK95, S-STD96 and S-ARK96 software.

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S/5 Hemodynamic modules

1	SPECIFICATIONS
1.1	General specifications
	Module size	75 × 180 × 112 mm
	W × D × H	3.0 × 7.1 × 4.4 in
	Operation temperature	10 to 40 °C / 50 to 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

NOTE:Non-invasive blood pressure measurement is intended for patients weighing over 5 kg (11 lb.)

Oscillometric measurement principle.

Measurement range	adult	25 to 260 mmHg
	child	25 to 195 mmHg
	infant	15 to 145 mmHg
Pulse rate range accepted	30 to 250 bpm
Measurement interval	1, 2.5, 3, 5, 10, 15, 30, 60 min (=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 Lead selection, oher modules Sweep speeds

DISPLAY FILTER

Diagnostic, 12-lead ECG Diagnostic, other modules

Monitoring

I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, V6 I, II, III, aVR, aVL, aVF, V

12.5, 25, 50 mm/sec

0.05to 150 Hz

0.05to 100 Hz

0.5to 30 Hz (-3 dB, with 50 Hz reject filter)

0.5to 40 Hz (-3 dB, with 60 Hz reject filter)

ST filter	0.05 to 30 Hz (-3 dB, with 50 Hz reject filter)
	0.05 to 40 Hz (-3 dB, with 60 Hz reject filter)
HEART RATE FROM ECG
Range	30 to 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 to +9 mm (-0.9 to +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 to 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 to 100 %
Accuracy	100 to 80 %, ±2 digits
(% SpO2 ±1 SD)1	80 to 50 %, ±3 digits
	50 to 40 %, unspecified
Display resolution	1 digit = 1 % of SpO2
Display averaging time	20, 10 sec, beat-to-beat
Pulse beep pitch	varies with SpO2 level

The monitor is calibrated over the measurement range against functional saturation SpO2 func.

PULSE RATE FROM PLETH
Measurement range	30 to 250 bpm
Accuracy	30 to 100, ±5 bpm,
	100 to 250, ±5 %
Resolution	1 bpm
Display averaging	10 s

1 1 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 to 45 °C (50 to 113 °F)
(In rev. ESTP 03/ EST 02/ETP 02 or earlier: 15 to 45 °C (59 to 113 °F))
Measurement accuracy	±0.1 °C (25 to 45.0 °C)
	±0.2 °C (10 to 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 to 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 to 320 mmHg
Resolution	±1 mmHg
WAVEFORM DISPLAY
Range	-30 to 300 mmHg
PULSE RATE FROM ARTERIAL PRESSURE
Measurement range	30 to 250 bpm
Resolution	1 bpm
Accuracy	±5 bpm or ±5 % whichever is greater

1.2.6 Respiration

NOTE:The respiration measurement is intended for patients over three years old

Measurement range	4 to 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 to 13 mmHg/s
Inflation time	20 to 185 mmHg, 1 to 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

The 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 (>15 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 to 5.0 cm/mV
Pacemaker pulse detection	2 to 500 mV, 0.5 to 2 ms pulses
Protection against electrical
shock	Type CF defibrillator proof

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Input voltage

Filter

Zero set accuracy Calibration resolution Zero time

Protection against electrical shock

S/5 Hemodynamic modules

1.3.3 Pulse oximetry

Protection against electrical
shock	Type BF defibrillation proof

1.3.4 Temperature

Measurement accuracy	±0.1 °C (25.0 to 45.0 °C)
	±0.2 °C (10.0 to 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 refer to 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 5VDC

max current 20 mA

0 to 4 - 22 Hz adjustable

±1 mmHg

±1 mmHg less than 15 s

Type CF defibrillation proof

NOTE: The accuracy of the measurement may be different from the specified, depending on transducer/probe used. Please refer to 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 to 6 Ω manually adjustable minimum
	detection: 0.2, 0.4, 0.6, 0.8, 1.0
Input dynamic range	0.2 to 6 Ω
Input impedance range	100 to 5000 Ω
Respiration Rate	min. 4 bpm
	max. 120 bpm
Lead off detection	>3 MΩ

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2 FUNCTIONAL 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 (various 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 Guide or theUser'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 the light spectrum. These wavelengths are emitted by LEDs in the SpO2 probe, the light is transmitted through peripheral tissue and is finally detected by a PIN-diode opposite the LEDs in the probe. The pulse oximeter derives the oxygen saturation (SpO2) using an 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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S/5 Hemodynamic modules

A general limitation of pulse oximetry is that due to the use of only two wavelengths only two hemoglobin species can be discriminated by the measurement.

The modern pulse oximeters are empirically calibrated either against fractional saturation SaO2frac;

SaO2frac =			HbO2		Formula 1
	HbO2 + Hb + Dyshemoglobin
or against functional saturation SaO2func;
SaO2func =		HbO2			Formula 2
		HbO2 + Hb

Functional saturation is more insensitive to changes of carboxyhemoglobin and methemoglobin concentrations in blood.

The oxygen saturation percentage SpO2 measured by the Datex-Ohmeda module is calibrated against 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 oximeters are 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 DatexOhmeda.

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Intensity of
transmitted	Imax (DC-component)
light		Imax
		Imin	AC-component
Transmitted		Variable absorption
		due to pulse added
light
		volume of arterial
		blood
		Arterial blood
		Venous blood
		Tissue
	No pulsation	Time
		Pulsatile blood
Incident light
		SpO2 sensor connector
	SpO2	sensor cable
		6	GND
	Emitter	7	I LED
	IRED	4
	RED	5	GND
		8	VB
		R	C
	Detector	1	I S
		9	GND
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

•Applying a constant current through the resistor and measuring the voltage that is

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generated across it.

In Datex-Ohmeda modules the two methods are combined in the 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 respiration signal is made by supplying current between the 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 the respiration waveform is displayed on the screen.

2.2 Main components

2.2.1 M-ESTPR/-ETPR/-ESTR modules

		ECG
		Lead
	T1	P1
		Start
		Wedge
	T2	P2
		Zero
	ECG+	P1
		SpO2
	Resp
		Zero
		P2
	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 the M-ESTPR module, additionally, there are two small boards, the SP input and the ECG input boards, attached to the front panel of the module. The front panel has six connectors and four keys.

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The connectors are two for temperature measurement, two for invasive blood pressure measurement, one for ECG, and one for SpO2 measurement. The keys are for ECG lead, Start Wedge, P1 zero, and P2 zero.

In the 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 the 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 SpO2 measurement. 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

		Auto
		On/Off
NIBP		P1
		Start
		Cancel
T1	T2	P2
		Zero
ECG+		P1
Resp		SpO2
		Zero
		P2
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 the 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 SpO2 measurement. 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.

In the 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

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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 the 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 SpO2 measurement, 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

			Exhaust valve 1
Cuff
	Zero		Bleed valve
		Exhaust	Joining chamber
	valve	valve 2	Check valve	Pump
				M
B1	B2 Pressure		Overpressure control
	transducers
				Watchdog
				timer
		AD-		+15 VD
		converter	Address bus

Pump and valve driver

bus module to/from

X1

	CPU
Power-up	80C51FA
reset		Address
		decoder
RS485
interf.					Front	Software
			RAM	EPROM
		Address			panel
						control
	Internal	latch			keys
EEPROM	watchdog
(calibration
data)			Databus
Write protection switch

NESTPR_NIBP_board_blck_dgrm.vsd

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).

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Signal processing

Two signals from the pressure transducers are amplified and sent to the A/D converter. After the converter, digitized signals are sent to the 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 a 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 of the 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 powerup reset. See the section in the ECG board’s description: “RS485 communication”

Watchdog timer

The NIBP board is equipped with a software independent safety circuit to disconnect supply voltages from the pump and the valves if the cuff has been pressurized longer than the preset time. As soon as the cuff pressure rises over a specified pressure limit, timer starts counting. The timer is adjusted to stop the pump and open the valves after 2 minutes 10 seconds in adult/child mode and after 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. The valve opens at 165 mmHg. Exhaust valve 2 is also used as safety valve in adult mode and opens at 320 mmHg.

The bleed valve is used for emptying the cuff during measurement. The 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.

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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.

PATIENT

Overload protection

R L F C N

Defibrillation
detector	Analog switches
uP

				A/D	Slew-rate
				Micro-
	Supply			processor
	voltages			(uP)
	Power		Opto-	Direct
	source		coupler	ECG
	Power		Opto-	Direct
	source		coupler	ECG
Slew-rate		Slew-rate		Slew-rate
detector		detector		detector	detector
uP	uP		uP	uP	HP
	HP	HP		HP
uP	filter	filter		filter	filter
	uP		uP	uP
	Anti-	Anti-		Anti-	Anti-
	alias	alias		alias	alias

ISOLATION

Lead selection logic controlled by ECG lead selection

signals from uP

Resp

amplifier

31 kHz from uP

Sync. Rectifier

Amplifier

to STP Board

Figure 6

3- and 5- lead ECG board block diagram

Analog ECG section

The 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

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detector. Lower frequency is determined by high pass (HP) filter 0.5 Hz (monitor bandwidth) or 0.05 Hz (diagnostic or STbandwidth).

Respiration section

3-lead cable The analog switches control the current supply source of the impedance respiration measurement, and the lead selection for the 3-lead cable can be seen from the following table:

Table 2	Lead selection and coding for the 3-lead cable
Selected lead		Current source between	Signal measured from
I		R - L	N
II		R - N	L
III		L - N	R

Position on	IEC standard coding	AAMI standard coding
body surface
right arm	R = red	RA = white
left arm	L = yellow	LA = black
left leg	F = green	LL = red

5-lead cable When the 5-lead cable is used, the current source is between L-F and the signal is measured from the N, independently on the lead selection.

The respiration amplifier consist of the operational amplifiers, and the components around them. There is an analog switch for controlling the gain of the first stage of the preamplifier. Synchronous rectifier consists of the analog switches, which are used for detecting the respiration signal from 31 kHz amplitude modulated raw signal. The amplifier stage consists of the differential amplifier and the last amplifier. The differential amplifier consists of the operational amplifiers and the components around them. This stage is AC-coupled on both sides for minimising the offset voltages. The last amplifier is used for amplifying the signal derived from differential amplifier stage. The respiration signal is zeroed at the beginning of the measurement. Zeroing is also used for fast recovering the measurement after the motion artefact. This is done in amplifier section.

NOTE: The respiration measurement is switched OFF for 20 seconds when defibrillation is detected at the defibrillation detector.

Microprocessor section

Microprocessor contains RAM and EPROM memories. The processor uses external EEPROM memory. The microprocessor’s internal 8-channel A/D-converter converts the ECG-signals to digital form. See the section in ECG board’s description: “RS485 communication

Serial communication

Communication with the module bus is made through RXD and TXD pins. See the section in STP board’s description: “Serial communication”.

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