Datex-Ohmeda E-Modules Technical reference manual

Datex-Ohmeda

E-Modules

Technical Reference Manual

Conformity according to the Council Directive 93/42/EEC concerning Medical Devices amended by 2007/47/EEC.
CAUTION: U.S. Federal law restricts this device to sale by or on the order of a licensed medical practitioner.
Outside the USA, check local laws for any restriction that may apply.
All specifications subject to change without notice.

Order code for the Datex-Ohmeda E-Modules Technical Reference Manual, paper: M1065282
Order code for the S/5 Technical Reference Manuals CD: M1220141

th

4

edition

November 19, 2012

GE Healthcare Finland Oy
Kuortaneenkatu 2,
FI-00510 Helsinki
Finland
Tel: [phone]
Fax: [phone]

www.gehealthcare.com

 2012, 2011 General Electric Company. All rights reserved.

Responsibility of the manufacturer

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

• assembly, extensions, readjustments, modifications, servicing and repairs are carried out by
personnel authorized by GE.

• the electrical installation of the monitor room 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”.

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.

Trademarks

S/5, D-lite, D-lite+, Pedi-lite, Pedi-lite+, Mini D-fend, D-fend, D-fend+, MemCard, ComBar, ComWheel,
EarSat, FingerSat, FlexSat, PatientO2, Entropy and Patient Spirometry are trademarks of GE Healthcare
Finland Oy.

Datex, Ohmeda, and OxyTip+ are trademarks of GE Healthcare Finland Oy and Datex-Ohmeda, Inc.
A portion of the Entropy software is derived from the RSA Data Security, Inc. MD5 Message-Digest

Algorithm.

Masimo SET

Masimo SET is a licensed trademark of Masimo Corporation.

All other product and company names are property of their respective owners.

Product availability

Some of the products mentioned in this manual may not be available in all countries.
Please, consult your local representative for the availability.

Description

Master Table of Contents

Datex-Ohmeda E-Modules

M1065282

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV and E-sCO 1

Compact Airway Modules, E-CAiOVX, E-CAiOV,

E-CAiO, E-COVX, E-COV and E-CO

PRESTN Modules, E-PRESTN, E-RESTN, E-PRETN 3

Patient Side Modules, E-PSM, E-PSMP rev. 01 4

Cardiac Output Modules E-COP rev. 01 and E-COPSv rev. 01 5

Pressure Module, E-P, Pressure Temp Module, E-PT 6

Dual Pressure Module, E-PP 7

Masimo Module, E-MASIMO 8

Nellcor Compatible Saturation Module, E-NSAT, E-NSATX 9

Single-width Airway Module, E-miniC 10

Tonometry Module, E-TONO 11

Entropy Module, E-ENTROPY 12

EEG Module, E-EEG rev.00 and EEG Headbox, N-EEG rev. 01

BIS Module, E-BIS rev. 01

NeuroMuscular Transmission Module, E-NMT

Device Interfacing Solution, N-DISxxx rev. 01

13

14

15

16

Interface Module, E-INT 17

2

Recorder Module, E-REC 18

Memory Module, E-MEM 19

Remote Controllers, K-REMCO rev. 01, K-CREMCO 20

Anesthesia record keeping keyboard, K-ARKB, Keyboard Interface Board,

B-ARK and ARK Barcode Reader, N-SCAN

E-Modules, Spare Parts 22

Document no. M1181405B

21

i

Datex-Ohmeda E-Modules

ii

Document no. M1181405B

About this manual

Notes to the reader

This Technical Reference Manual is intended for service personnel and engineers who will
service and maintain the Datex-Ohmeda E-Modules as well as the anesthesia record keeping
keyboard, K-ARKB, remote controllers, K-REMCO and K-CREMCO, Device Interfacing Solution,
N-DISxxx, keyboard interface board, B-ARK, and ARK barcode reader, N-SCAN.

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

S/5 Compact Critical Care Monitor Technical Reference Manual. Later in this manual, the
monitors may be referred to as AM, CCM, CAM and CCCM.

The order code for the Datex-Ohmeda E-Modules Technical Reference Manual is M1065282.
The order code for the S/5 Technical Reference Manuals CD is M1220141. S/5 AM, CCM

Technical Reference Manual, S/5 CAM, CCCM Technical Reference Manual and Datex-Ohmeda
E-Modules Technical Reference Manual are included on the CD.

Each manual on the CD has an individual document number and is available for downloading
from GE Common Document Library in Adobe Acrobat PDF format.

• This Technical Reference Manual contains the information needed to maintain, service

and troubleshoot these products. Instructions for visual and functional inspection,
disassembly and reassembly as well as calibration of the modules are included. A service
check form for each product is included in the slots.

• In addition, this Technical Reference Manual contains detailed module specifications and

descriptions on the technical performance and functioning of the modules.

• Read the manual through and make sure that you understand the procedures described

before servicing the modules. To avoid risks concerning safety or health, strictly observe
the warning indications. If you need any assistance concerning the service, please do not
hesitate to contact your authorized distributor.

For information on safety precautions and symbols on equipment, installation, planned
maintenance and interfacing, refer to the AM and CCM Technical Reference Manual or the CAM
and CCCM Technical Reference Manual.

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

Related documentation

S/5 AM, CCM Technical Reference Manual
S/5 CAM, CCCM Technical Reference Manual

For more specific information about the clinical aspects refer to:
S/5 monitor’s User’s Guide
S/5 monitor’s User’s Reference Manual

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Document no. M1181405B

Datex-Ohmeda E-Modules

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 the

following way:

Menu Items Menu items are written in bold italic: ECG Setup.
‘Messages’ Messages displayed on the screen are written inside single quotes: ‘Please wait’.
“Sections” When referring to different sections in the same manual, the section name is enclosed in

double quotes: section “Cleaning and Service.”

“Other documents”

When referring to different documents, the document name is enclosed in double quotes: refer

to “User’s Reference Manual”.

Hypertext links Hypertext links on PDF versions are written in blue color.

WARNING Warnings are written in the following way:

WARNING Make sure that the electrodes, sensor and connectors do not touch any

electrically conductive material, including earth.

CAUTION Cautions are written in the following way:

ECG.

CAUTION The module electronics can only be repaired and calibrated at the factory.

NOTE Notes are written in following way:

NOTE: Handle all PC boards by their edges.

In this manual, the word “select” means choosing and confirming.

Revision history

Revision Date Comment

1st edition 10 May 2011 Initial

2nd edition 22 Sep 2011 Order code for paper manual added.

3rd edition 19 June 2012 E-PSM rev. 01, E-PSMP rev. 01, E-COP rev.01 and E-COPSv rev. 01

update.

4th edition 19 Nov 2012 Respiratory Modules E-sCAiOV, E-sCAiO, E-sCOV and E-sCO added .

2

Document no. M1181405B

GE Healthcare

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

Technical Reference Manual Slot

Conformity according to the Council Directive 93/42/EEC concerning Medical Devices amended by 2007/47/EEC.
CAUTION: U.S. Federal law restricts this device to sale by or on the order of a licensed medical practitioner.
Outside the USA, check local laws for any restriction that may apply.
All specifications subject to change without notice.

Document number M1214853C

June 21, 2012

GE Healthcare Finland Oy
Kuortaneenkatu 2,
FI-00510 Helsinki
Finland
Tel: [phone]
Fax: [phone]

www.gehealthcare.com

 2012 General Electric Company. All rights reserved.

Table of contents

Table of contents

Introduction 1

1 Technical specifications 3

1.1 Physical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3 Airway gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3.1 General characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3.2 Respiration rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3.3 Carbon dioxide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3.4 Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3.5 Nitrous oxide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3.6 Anesthetic agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.3.7 Non-disturbing gases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.3.8 Gas cross effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.4 Patient Spirometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4.1 General characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4.2 Airway pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4.3 Airway gas flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4.4 Tidal volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.4.5 Minute volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.4.6 Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.4.7 Airway resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.4.8 Inspiration to expiration ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 Functional description 8

2.1 Measurement principle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1.1 CO2, N2O, and agent measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1.2 O2 measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.1.3 Patient spirometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2 Main components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.2.1 Controls and connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.2.2 Gas sampling system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.2.3 MiniTPX measuring unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.2.4 MiniOM Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.2.5 MiniPVX measuring unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2.2.6 CPU board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.2.7 MiniOM board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.2.8 MiniPVX board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.2.9 Main Component Interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3 Service Procedures 22

3.1 Replacement of planned maintenance parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.1.1 Required parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.1.2 Planned Maintenance Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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3.1.3 Replacement procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2 Visual inspections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.3 Functional check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3.1 Test setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3.2 Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3.3 Test completion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.4 Disassembly and reassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.4.1 Disassembly guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.4.2 Disassembly and reassembly procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3.5 Adjustments and calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.1 Sample Flow Rate Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

3.5.2 Gas Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

3.5.3 Spirometry Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4Troubleshooting 47

4.1 Visual inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4.2 Troubleshooting checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4.2.1 Gas sampling system troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.2.2 MiniOM Measuring unit troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.2.3 MiniTPX Measuring unit troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.2.4 MiniPVX Measuring unit troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.2.5 CPU board troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

4.3 Service Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

4.4 Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4.4.1 Gas measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4.4.2 Spirometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

4.5 Troubleshooting charts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.5.1 CO2 measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.5.2 Patient spirometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

5Spare parts 56

5.1 Ordering parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

5.1.1 Planned Maintenance Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

5.2 Spare parts for E-sCAiOV, E-sCAiO, E-sCOV, E-sCO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.2.1 Front covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

6 Earlier revisions 61

Appendix A: Service check form A-1

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Document no. M1214853C

Introduction













This document provides information for the maintenance and service of the CARESCAPE

Respiratory modules, E-sCO, E-sCOV, E-sCAiO and E-sCAiOV. The CARESCAPE Respiratory

modules are single width plug-in modules.

The CARESCAPE Respiratory modules provide airway and respiratory measurements.

Letters in the module name stand for:

C = CO

identification

Table 1 Options for CARESCAPE Respiratory modules

and N2O, O = patient O2, V = patient spirometry, A = anesthetic agents, and i = agent

2

Modules Parameters / measurements

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

CO

N2OO2Anesthetic

2

Agent ID Spirometry

agents

E-sCOV X X X X

E-sCO X X X

E-sCAiOV X X X X X X

E-sCAiO X X X X X

NOTE: Anesthetic agents and N2O values are not displayed with ICU and ED software packages,

but when present in the module they are calculated for compensation of CO

and O2.

2

Figure 1 Airway gases measurement setup

(1) CARESCAPE Respiratory Module

(2) Gas sample, gas sampling line connector on the water trap

(3) Gas sampling line

(4) Gas sampling line connector on the airway adapter; place the connector upwards

(5) Airway adapter with sampling line connector

(6) Heat and moisture exchanger with filter (HMEF) (optional)

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Document no. M1214853C

Datex-Ohmeda E-Modules

System compatibility

The CARESCAPE Respiratory Modules can be used for respiratory monitoring

in the following S/5 monitors:

 S/5 Anesthesia Monitor, software versions L-ANE06(A) 24.1 or later

 S/5 Critical Care Monitor, software versions L-ICU06(A) 24.1 or later

 S/5 Compact Anesthesia Monitor, software versions L-CANE05(A) 19.6 or later

 S/5 Compact Critical Care Monitor, software versions L-CICU05(A) 19.6 or later

NOTE: Low sample gas flow situation is indicated with the message Replace D-Fend in the

L-xxx06(A) software versions 24.1 and L-xxx05(A) software versions 19.6.

NOTE: The CARESCAPE Respiratory Modules cannot be used in the S/5 Extension Frame.

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Document no. M1214853C

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

1 Technical specifications

1.1 Physical characteristics

Size (H x W x D) 112 x 37 x 205 mm ( 4.4 x 1.5 x 8.7 in)

Weight 0.75 kg (1.5 lb)

Power consumption 3.9 W

1.2 Operating characteristics

Warm-up time

- CO2, O2 and N2O measurements: 1 minute

-Anesthetic agent measurement

and identification: 5 minutes
Gas sampling rate: 120 ±20 ml/min
Automatic compensation for ambient pressure.

Operating conditions

Ambient temperature: +10°C to +40°C

Ambient pressure: 660 mbar to 1060 mbar

Ambient humidity: 10%RH to 98%RH, non-condensing

1.3 Airway gases

1.3.1 General characteristics

Specifications are valid at the following normal operating conditions:
Ambient temperature: +18°C to +28°C, within ±5°C of calibration

Ambient pressure: 660 mbar to 1060 mbar, ±67 mbar of calibration
Ambient humidity: 20%RH to 80%RH, non-condensing, ±20%RH of calibration
Sampling line length: 2, 3 and 6 meters
Respiration rate: 4 to 70 breaths/minute

Airway pressure: -20 mbar to +100 mbar
Module operating time: >20 minutes continuously

NOTE: The displayed ranges of parameter values depend on the host device. For more information, refer
to the host device’s user documentation.

1.3.2 Respiration rate

Breath detection: 1 vol% change in CO2 level
Measurement range: 4 to 100 breaths/min

Accuracy

at 4 to 20 breaths/min: ±1 breath/min

at 20 to 100 breaths/min: ±5%
RR value is updated breath-by-breath.

(Halothane 4 to 50 breaths/minute)

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1.3.3 Carbon dioxide

Measurement range: 0 vol% to 15 vol%, 0 kPa to 15 kPa,

Accuracy: ±(0.2 vol% +2% of reading)
Total system response time: < 3.0 s
Rise time: < 260 ms

drift: < 0.1 vol%

CO

2

EtCO2 and FiCO2 values are updated breath-by-breath.

Description of test method, data rate, and method of ET-calculation

The module uses gas concentration waveforms with data rate of 25Hz to calculate end-tidal (ET) gas
readings.

The module finds the time instant of the highest CO2 concentration in each breath. Concentration at that
instant is the ET CO2 reading. Because nitrous oxide and anesthetic agents are measured by the same
sensor as CO2, the ET-readings of those gases are obtained directly at the time instant of ET CO2. For
calculating ET-readings of oxygen, the module synchronizes the O2-waveform with the CO2 waveform.
The ET-reading of O2 is then determined as O2-concentration at the time instant of ET CO2. If no breaths
are detected for a given time (20s, for example), an apnea situation is triggered. During apnea, the ET
values are updated every two seconds to the current concentration of each gas.

The rated respiration rate range and the corresponding end-tidal gas reading accuracy were tested with
reference gases of known concentrations. The test gases were fed to the gas sampling system of the
module through an electrically actuated valve with very low internal volume. Depending on its actuation
status, the valve directed either room air or a test gas to the gas sampling line. The desired respiration
rates were set by the electrical actuating times of the valve.

The measurement accuracy of the end-tidal gas readings was tested using gas sampling lines of 3 meter
length, connected to the gas sample port on the D-fend Pro water trap. The gas sampled to the sampling
line was switched from room air to the test gases using an electrically actuated valve with low internal
dead space to generate step changes in the gas concentrations. The electric actuating signal of the valve
was generated using a higly accurate signal generator to accurately control the simulated respiration
rate.

The electronic sampling rate of the gas sensor signals is 25Hz, equaling a new data point on the gas
waveform traces every 40 milliseconds.

0 mmHg to 113 mmHg

1.3.4 Oxygen

Measurement range: 0 vol% to 100 vol%
Accuracy: ±(1 vol% +2% of reading)
Total system response time: < 3.0 s
Rise time: < 260 ms

drift: < 0.3 vol%

O

2

and FiO2 values are updated breath-by-breath.

EtO

2

1.3.5 Nitrous oxide

Measurement range: 0 vol% to 100 vol%
Accuracy:

N2O < 85 vol%) ±(2 vol% +2% of reading)

at (0 <
Total system response time: < 3.0 s

Rise time: < 320 ms

O drift: < 0.3 vol%

N

2

O and FiN2O values are updated breath-by-breath.

EtN

2

4

Document no. M1214853C

1.3.6 Anesthetic agents

Measurement range:

Sevoflurane: 0 vol% to 8 vol%

Desflurane: 0 vol% to 20 vol%

Isoflurane, enflurane, halothane: 0 vol% to 6 vol%
Accuracy: ±(0.15 vol% +5% of reading)
Total system response time: < 3.1 s (< 3.5 s for Halothane)
Rise time: < 420 ms (< 800 ms for Halothane)
Hal drift: < 0.1 vol%
Enf drift: < 0.1 vol%
Iso drift: < 0.1 vol%
Sev drift: < 0.1 vol%
Des drift: < 0.3 vol%
EtAA and FiAA values are updated breath-by-breath.

The module automatically identifies the anesthetic agent present in the sampled gas and measures the
concentration of the identified agent.

Identification threshold: 0.15 vol%
Identification time: < 20 s
The module automatically identifies mixtures of two anesthetic agents present in the sampled gas and

measures the concentrations of the two identified agents.

Identification threshold for the 2

at 1 MAC of the 1

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

nd

agent

st

agent: 0.2 vol% +10% of the concentration of the 1st agent

1.3.7 Non-disturbing gases

A gas is considered non-disturbing if its effects to the measured gas are as follows:
CO

:< 0.2 vol%

2

O2, N2O: < 2 vol%
Anesthetic agents: < 0.15 vol%

The following gases are non-disturbing when tested according to ISO21647(2004B):
ethanol, acetone, isopropanol, methane, nitrogen, carbon monoxide, nitric oxide, freon R134A (for CO

O), water vapor.

and N

2

The effects caused by N2O to the measurement of CO2, O2 and anesthetic agents are automatically
compensated for.

The effects caused by anesthetic agents to the measurement of CO2 and N2O are automatically
compensated for.

1.3.8 Gas cross effects

Helium (50 vol%): Decreases CO2 readings by less than 0.5 vol% at 5 vol% of CO

Xenon (80 vol%): Decreases CO2 readings by less than 0.5 vol% at 5 vol% of CO

Decreases O2 readings by less than 2 vol% at 50 vol% of O

Decreases O2 readings by less than 1.5 vol% at 14 vol% of O

, O2

2

2

2

2

2

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1.4 Patient Spirometry

1.4.1 General characteristics

These specifications are valid in the following operating conditions:
The module has been operating continuously for 10 minutes

Airway adapter, adult: D-lite
Airway adapter, pediatric: Pedi-lite
Respiration rate

- adults: 4 to 35 breaths/min

- pediatric patients: 4 to 70 breaths/min
I:E ratio: 1:4.5 to 2:1
Airway humidity: 10 %RH to 100 %RH
Ambient temperature: +10°C to +40°C
Ambient pressure: 660 mbar to 1060 mbar
Ambient humidity: 10 %RH to 98 %RH (non-condensing)
NOTE: The displayed ranges of parameter values depend on the host device. For more information, refer

to the host device’s user documentation.

1.4.2 Airway pressure

Measurement range: -20 cmH2O to +100 cmH2O
Accuracy: ±1 cmH
Time resolution: 10 ms

Values calculated from the measured airway pressure data:

Peak pressure (Ppeak)
Plateau pressure (Pplat)
Mean pressure (Pmean)
Positive end expiratory pressure (PEEPtot, or PEEPi and PEEPe)
Static positive end expiratory pressure (static PEEPe and static PEEPi)

1.4.3 Airway gas flow

Measurement range

- adults: -100 l/min to +100 l/min

- pediatic patients: -25 l/min to +25 l/min
Time resolution: 10 ms
Flow measurement has automatic compensation for airway pressure and effects caused by variation in

the concentrations of the gas components measured by the module.

1.4.4 Tidal volume

The module calculates the volume by integrating the measured gas flow over time. Tidal volumes (TVinsp
and TVexp) are obtained as the change of volume during inspiration and expiration.

O

2

Measurement range

- with D-lite: 150 ml to 2000 ml

- with Pedi-lite: 5 ml to 300 ml
Accuracy

- with D-lite: ±6% or 30 ml (whichever is greater)

- with Pedi-lite: ±6% or 4 ml (whichever is greater)

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1.4.5 Minute volume

The module calculates the inspired and expired minute volumes as the sum of inspired (MVinsp) and
expired (MVexp) gas volume during one minute.

Measurement range

- with D-lite: 2 l to 20 l

- with Pedi-lite: 0.5 l to 5 l

1.4.6 Compliance

The module calculates both the compliance (Compl) and static compliance (static Compl). Compliance is
calculated by dividing the expired gas volume (TVexp) by the change in the airway pressure (Pplat ­PEEPtot). Static compliance is calculated by dividing TVexp by the difference of static Pplat and static
PEEPtot.

Measurement range

- adults: 4 ml/cmH2O to 100 ml/cmH2O

- pediatric patients: 1 ml/cmH2O to 100 ml/cmH2O

1.4.7 Airway resistance

The module calculates the airway resistance (Raw) by solving the lung model equation P(t) = Raw * F(t) +
V(t) / Compl + PEEPtot

where: P(t), F(t) and V(t) are the time dependent waveforms of pressure, flow, and volume, respectively.
Measurement range: 0 cmH

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

O/l/s to 40 cmH2O/l/s

2

1.4.8 Inspiration to expiration ratio

The module measures ratio of the inspiratory and expiratory time (I:E).
The inspiratory time is the time from the start of inspiration to the start of expiration. The end inspiratory
pause, if one exists, is included in the inspiration. Accordingly, expiratory time is the time from the start of
expiration to the start of the next inspiration.

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2 Functional description

2.1 Measurement principle

2.1.1 CO2, N2O, and agent measurement

MiniTPX is a side stream gas analyzer, measuring real time concentrations of CO2, N2O, and
anesthetic agents (Halothane, Enflurane, Isoflurane, Desflurane, and Sevoflurane).

Figure 2 MiniTPX sensor principle

Anesthetic agents or mixtures of two anesthetic agents are automatically identified, and
concentrations of the identified agents are measured. MiniTPX also detects mixtures of more
than two agents and issues an alarm.

MiniTPX is a non-dispersive infrared analyzer, measuring absorption of the gas sample at
seven infrared wavelengths, which are selected using optical narrow band filters.

The infrared radiation detectors are thermopiles.
Concentrations of CO

and N2O are calculated from absorption measured at 3-5 m.

2

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Figure 3 Absorbance of N2O and CO

2

Identification of anesthetic agents and calculation of their concentrations is performed by
measuring absorptions at five wavelengths in the 8-9 m band and solving the concentrations
from a set of equations.

Figure 4 Infrared absorbance of AAs

The measuring accuracy is achieved utilizing numerous software compensations. The
compensation parameters are determined individually for each MiniTPX during the factory
calibration.

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2.1.2 O2 measurement

The differential oxygen measuring unit uses the paramagnetic principle in a pneumatic bridge
configuration. The signal picked up with a differential pressure transducer unit is generated in
a measuring cell with a strong magnetic field that is switched on and off at a main frequency of
164 Hz. The output signal is a DC voltage proportional to the O

between the gas to be measured and the air reference.

concentration difference

2

Figure 5 O2 measurement principle

2.1.3 Patient spirometry

In mechanical ventilation, breaths are delivered to the patient by a ventilator with a proper tidal
volume (TV), respiration rate (RR), and inspiration / expiration ratio in time (I:E) determined by
the settings of the ventilator.

The Patient Spirometry monitors patient ventilation.

The following volume parameters are displayed:

 Expiratory and inspiratory tidal volume (TV) in ml
 Expiratory and inspiratory minute volume (MV) in l/min
 Expiratory spontaneous minute volume in l/min
 Inspiration/expiration ratio (I:E)

The following airway pressure parameters are displayed:

 Peak pressure (P
 Mean airway pressure (P

monitors

 End inspiratory pressure (P
 PEEPi, PEEPe; available only in S/5 Critical Care and Compact Critical Care monitors

 Total positive end expiratory pressure (PEEP

Compact Anesthesia monitors

 Real time airway pressure waveform (P
 Static Positive end expiratory pressures (Static PEEPi and Static PEEPe); available only in

S/5 Critical Care and Compact Critical Care monitors

 Static Plateau pressure (Static Pplat); available only in S/5 Critical Care and Compact

Critical Care monitors

 Static Compliance (Static Compl); available only in S/5 Critical Care and Compact Critical

Care monitors

peak

)

); available only in S/5 Critical Care and Compact Critical Care

mean

)

plat

; available only in S/5 Anesthesia and

tot)

)

aw

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Document no. M1214853C

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

PEEP, P

peak

, P

mean

, and P

are measured by a pressure transducer on the MiniPVX board.

plat

Ambient pressure is used as a reference in measurement. The pressure measurement is made
from the airway part that is closest to the patient between the patient circuit and intubation
tube.

PEEP

=intrinsic PEEP, PEEP

i

-PEEP

tot

e

Static pressure measurement maneuvers are automatically identified based on an increased
zero flow period at the end of the inspiration or expiration.

Static Compliance is calculated, if Static PEEP and Static P

measurements were made within

plat

a 2 minute period.

The following airway flow parameters are displayed:

 Real time flow waveform (V')
 Compliance (Compl)
 Airway resistance (Raw)
 Pressure volume loop
 Flow volume loop

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

D-lite

Patient Spirometry uses specific sensors called D-lite+/D-lite and Pedi-lite+/Pedi-lite flow
sensors. Different types of sensors are available: adult sensor for measuring adults and
pediatric sensor for children. Both are available as reusable and disposable versions.

D-lite and Pedi-lite adapters are designed to measure kinetic pressure by a two-sided Pitot
tube. Velocity is calculated from pressure difference according to Bernoulli's equation. Flow is
then determined using the calculated velocity.

(from Bernoulli's equation) Formula 1

where:

2

V’ = flow (l/min), v = velocity (m/s), A = cross area (m



= density (kg/m3)

), dP = pressure difference (cmH2O),

Finally, the volume information is obtained by integrating the flow signal.

Compliance and airway resistance

Compliance is calculated for each breath from the equation

Formula 2

Compliance describes how large a pressure difference is needed to deliver a certain amount of
gas to the patient.

The airway resistance, Raw, is calculated using an equation that describes the kinetics of the
gas flow between the lungs and the D-lite. The equation states that the pressure at the D-lite
can at any moment of the breath be approximated using the equation

11

Document no. M1214853C

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







where P(t), V’(t) and V(t) are the pressure, flow and volume measured at the D-lite at a time t,
Raw is the airway resistance, Compl is the compliance and PEEP

expiratory pressure (PEEP

2.2 Main components

The respiratory modules consist of:

• Gas sampling system

• MiniTPX measuring unit

• MiniOM measuring unit

• MiniPVX measuring unit

• CPU board

2.2.1 Controls and connectors

Formula 3

+PEEPi is the total positive end

e

).

tot

Figure 6 Front of CARESCAPE Respiratory Module, E-sCAiOV, and the back of

the module

(1) D-fend Pro water trap

12

Document no. M1214853C

(2) Gas sample, sampling line connector on the water trap
(3) Water trap container
(4) Connectors for Patient Spirometry
(5) Gas exhaust, connector for the gas exhaust line (sampling gas out

Module keys Module Description

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Save Loop E-sCOV, E-sCAiOV Save Loop saves a reference

Change Loop E-sCOV, E-sCAiOV Change Loop changes a

Connector Module Description

D25 connector all modules Module bus connector

2.2.2 Gas sampling system

The gas sampling system draws a 120ml/min sample from the patient's airway to the
module. The sampling system also takes about 30ml/min flow of room air to the oxygen
sensor. When the gas sensors are zeroed, room air is taken through the CO

the gas sensors instead of the sampled gas from the patient's breathing.
The gas sampling line is connected between the patient circuit and the Gas Sample port

on the water trap. The water trap protects the sampling system and gas sensors from
liquids and dust.

The diagram of the gas sampling system is shown in the figure below:

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

loop.

pressure/volume loop to a
flow/volume loop or vice
versa.

-absorber to

2

Figure 7 Gas sampling system

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The sampling system has a self diagnostics that detects disturbances in the gas flow, reveals
the most common reasons for disturbances, such as occluded sampling line or blocked gas
exhaust line, and communicates relevant status messages to the patient monitor.

The system is designed so that gas the sampled gas will not flow from the sampling line back to
the patient circuit. The parts and connections of the sampling system are streamlined for
minimal dead spaces and turbulences in gas flows.

All gas inputs of the module have dust filters protecting the sampling system and gas sensors.
The water trap acts as a dust filter for the sampled gas and the module should always have the
water trap connected.

NOTE: It is very important to prevent dust from entering the open gas connections during
service operations.

D-fend Pro(+) water trap

The gas sampling line is connected to the input of the water trap where a special membrane
passes gases and vapors but stops liquids. The gas flowing through the membrane continues
via the main flow connector of the water trap to the module. The main flow is about 90% of the
sample flow.

Liquids stopped below the membrane are moved to the water container by a side flow that
goes through the water container and the water separation membrane before entering the
side flow connector of the water trap. Thus, the side flow also is free of liquids when it gets into
the module. In the module, the side flow is connected directly to the pump input and it does not
enter the gas sensors.

NOTE: The water trap acts as a dust filter for the sampling system and gas sensors. Thus, the
module should always have the water trap connected.

Zero valve and CO2 absorber

The zero valve is activated during gas sensor zeroing. Room air is drawn through the
CO

-absorber and the zero valve to the gas sensors, and the main flow of sample gas is

2

stopped. The zero gas comes to the sensors through the CO

. The side flow of the water trap flows in the gas sampling line even during zeroing.

CO

2

During normal monitoring, the zero valve is not activated and the sampled gas gets through
the zero valve to the gas sensors.

Figure 8 Absorber

Nafion tubes

The Nafion tube between the water trap and the zero valve equalizes the humidity of the
sampled gas to ambient level. This will prevent calibration errors caused by the difference in
humidities in the sampled breathing gas and the totally dry calibration gas.

Another Nafion tube is used between the CO
condensation of water generated in the CO

1 Nafion is a registered trademark of Perma Pure Inc.

1)

-absorber that chemically absorbs

2

absorber and the zero valve to prevent

2

absorber as by-product of CO2-absorption.

2

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Document no. M1214853C

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

Gas sensors

After the zero valve, the gas flows trough the MiniTPX sensor that measures the concentrations
of all gases but oxygen.

The oxygen concentration is measured in the MiniOM sensor that has two inputs. One input
draws in a part of the main flow and the other draws in room air as reference gas for the O

measurement.

2

Sample flow differential pressure transducer

The module measures total flow at the input of the gas pump and reference flow at the OM
reference line. The sample flow is the difference of these two flows.

Working pressure transducer

The working pressure transducer measures absolute working pressure near the MiniTPX unit
and MiniOM unit. It is used for messages: ‘Sample line blocked’, ‘Check D-fend’, ‘Replace D-fend’
and ‘Check sample gas out’.

Pneumatics unit

The pneumatics unit contains the zero valve, the occlusion valve and the pneumatics block
with tubing connections.

The zero valve is activated during the zero level calibrations of gas sensors. The occlusion and
zero valves are activated when the sampling line or water trap is occluded. With the activated
valves, the gas pump generates maximal suction trough the “side flow” connector of the water
trap, thus maximizing the transfer of liquids from the wet side of the water trap to the
container.

The pneumatics block contains a network of constrictions to divide the sampled gas in correct
proportions to different parts in the module. The first branching takes place in the water trap
where incoming flow is divided to the “main flow” and “side flow”. The second branching takes
place before the MiniOM sensor.

The pneumatics block also contains a pneumatic low pass filter between gas sensors and gas
pump. The filter consists of constrictions (resistors) and volumes (capacitors) and it attenuates
the pressure pulsation generated in the gas pump so that they do not disturb the operation of
the gas sensors.

Gas pump unit

The gas pump is a membrane pump run by a brushless DC-motor. The pump is adjusted so
that the sample gas flow is kept close to its nominal value even when the flow resistances in
the sampling line of water trap change.

15

Document no. M1214853C

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The pump is in a plastic enclosure to minimize the operating noise and mechanical vibration of
the pump unit. A pneumatic damping chamber is integrated to enclosure to attenuate the
pressure pulsation and noise conducted to the gas exhaust port.

Pressure measurements

The four pressure sensors on the CPU board are used to measure ambient pressure, working
pressure of the MiniTPX and MiniOM sensors and pressure of the reference gas flow to the
MiniOM sensor.

Sample flow control

The gas flow in the sampling line is monitored by measuring the gas flow at the input of the gas
pump and the reference flow to the oxygen sensor is estimated by measuring the pressure in
the reference gas flow branch. The sample flow is calculated by subtracting the reference flow
from the total gas flow. A control loop adjusts the rotation speed of the pump motor so that the
gas flow is kept close to 120ml/min.

Gas sampling self-diagnostics

The sample flow and the vacuum in the sampling system are used for continuous monitoring
of the gas sampling system. The vacuum is calculated in real time as difference of the
measured ambient and working pressures.

The self-diagnostics of the gas sampling system sends the following status data to the patient
monitor when specific triggering conditions are met: ‘Check water trap’, ‘Check sample gas
out’, ‘Replace water trap’, ‘Sample line blocked’ and ‘Continuous blockage’.

The gas pump is stopped when the 'Sample line blocked' has lasted for more than 1 minute.
The module automatically restarts the pump to check whether the abnormal situation has
been resolved so that normal gas sampling operation is possible.

The gas pump repeats 1 minute full pump, 30 seconds pump off when the ‘Continuous
blockage’ message is shown.

Figure 9 Gas tubing layout

2.2.3 MiniTPX measuring unit

The MiniTPX unit is a non dispersive infrared analyzer, measuring the absorption of the gas
sample at seven infrared wavelengths, which are selected using optical narrow band filters.
The IR source is a micro-machined heating element with an integrated collimator. From the
output of the source, the radiation is passed to a flow optimized measuring chamber.

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Document no. M1214853C

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From the sample chamber, radiation goes via a specially designed beam splitter to two
detector units, each with four thermopile detectors and integrated optical filters. The miniTPX
measuring unit has two detector units for redundancy purposes. A more detailed description of
the measuring principle can be found in section “2.1.1. CO2, N2O, and agent measurement”.

Each detector unit also measures the unit's temperature. The module CPU uses it for further
processing and temperature compensation of the measured raw signals.

The miniTPX unit includes an amplifier board with the following functions:

• On-board 5V regulator and 2.5V reference source.

• Preamplifiers for the eight thermopile detectors and for the two temperature sensors.

A 16 channel buffered multiplexer is used to transfer the signals to the CPU board.

• PWM controlled power for the IR source.

• An EEPROM memory for storing factory calibration coefficients of the sensor.

The input to the amplifier board comprises a 7V DC feed and CPU control signals for the PWM,
the multiplexer and the EEPROM. When the module starts up, the calibration coefficients are
read to the module CPU and then used for calculating the gas concentrations from the raw
data received from the sensor multiplexer.

Figure 10 MiniTPX measuring unit

2.2.4 MiniOM Oxygen sensor

The miniOM sensor measures the concentration of Oxygen in the gas sample.
The measurement is based on the magnetic properties of oxygen. The sensor measures the

sound pressure generated in the air gap of the magnet at the 164Hz operating frequency. Two
microphones are used for detection and the Oxygen concentration is calculated from the RMS
value of the difference of the microphone outputs. The measurement principle is described in
more detail in section ”2.1.2. O2 measurement”.

The sensor consists of the following functional parts

• Pneumatic system

• Amplifier board

• MiniOM board

• Magnet

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The sensor is shown in the picture below.

Figure 11 MiniOM oxygen sensor

NOTE: The sensor is assembled in the module using flexible suspension to prevent the
mechanical vibrations of the gas pump and cooling fan from disturbing the Oxygen
measurement. All gas lines to the sensor must also be carefully assembled so that they do not
pick up mechanical vibrations of the module mechanics.

Pneumatic System

The pneumatic system, together with the gas sampling system of the module creates the gas
flows and pressures needed for the oxygen measurement and protection of the microphones
from excessive pressure. About 30 ml/min flow of sampled gas comes to the In connector on
the MiniOM sensor. Room air is drawn to the Ref input of MiniOM also at 30 ml/min rate. About
75% of these flows are conducted to a pressure equalization chamber so that only about a
8 ml/min flow of the two gas streams continue into the air gap of the magnet. All the internal
gas flows finally get to a volume enclosed by the sensor board and the sensor body, and then
flow out through the Out connection of the sensor. Some of the gas channels and flow
restrictors are integrated into the preamplifier electronics board utilizing the multi-layer
structure of the LTCC (Low Temperature Co-fired Ceramics) circuit board technology.

NOTE: It is very important to prevent dust or liquids from getting into the pneumatic circuit of
MiniOM and thus, the gas connections should always be closed with a protecting cap when the
sensor is not connected to the module pneumatics.

Amplifier Board

The amplifier board located in the sensor has two electric microphones for the differential
detection of pressure pulses generated in the magnet's air gap. The microphone signals are fed
to two identical signal conditioning channels with a band-pass filter and a digitally controlled
amplifier. The voltage gains of the amplifiers are set during factory calibration so that the
responses of the microphone channels match in spite of differences in microphone's
sensitivities. The amplifier board also has an amplifier for the thermistor measuring the
temperature of the magnet.

MiniOM Board

The MiniOM board has five functions

• Drive the magnet coil.

• Convert the microphone and temperature signals into digital format.

• Filter digitally the microphone signals and perform the RMS-conversion.

• Communicate digitally with the module CPU.

18

Document no. M1214853C

• Store factory calibration data in permanent memory and communicate them to the

module CPU.

The module CPU provides the coil drive and communication enabling signals and also clock
signal for MiniOM board. The FPGA takes care of the coil drive and has also back-up clock in
case of CPU clock does not work. The FPGA takes care of the A/Dconversions which are
performed with a serial controlled SAR A/D-converter.

The digital band pass filtering and RMS conversion of the microphone signals is made with
FPGA circuit controlled by the VHDL code stored in the circuit. In order to filter out the
disturbances caused by acoustic noise, mechanical vibration and amplifier noise, the band
pass filters are designed to have as narrow a pass band as possible without slowing down the
filter's response to changes in the amplitude of the 164 Hz signal.

The FPGA circuit takes care of the digital communication between the miniOM sensor and the
module CPU.

The factory calibration coefficients of the sensor are stored in an EEPROM memory on the
miniOM board. When the module starts up, the calibration coefficients are read to the module
CPU and then used for calculating the O2 concentration from the Oxygen raw data received
from the sensor.

2.2.5 MiniPVX measuring unit

Respiratory Modules, E-sCAiOV, E-sCAiO, E-sCOV, E-sCO

NOTE: Never apply the overpressure or negative pressure of more than 300 cmH2O to the flow
and volume tubing. Differential pressure max 25 cmH
when connecting tubes.

When Patient Spirometry is used, a special sensor, D-lite, replaces the normal airway adapter
in the patient circuit. A double lumen tubing is attached to the two connectors on the adapter
and on the module front panel.

The Patient Spirometry provides patient respiration monitoring capabilities using the D-lite and
Pedi-lite flow sensors.

O is allowed on one port at a time e.g.

2

Figure 12 MiniPVX measuring unit

The measurement is based on measuring the kinetic gas pressure and is performed using the
Pitot effect. A pressure transducer is used to measuring the Pitot pressure. The signal is then
linearized and corrected according to the density of the gas. Speed of the flow is calculated
from the pressure and TV is integrated from it.

19

Document no. M1214853C

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Patient Spirometry consists of airway connections, two pressure transducers, valves and
preamplifiers. The preamplifiers are connected to the A/D-converter on the module main CPU.

The patient’s breathing flow passing through the D-lite adapter creates a pressure difference.
This pressure difference is measured by a pressure transducer, B1. Overpressure and negative
pressure in airways are measured by another pressure transducer, B2.

2.2.6 CPU board

The CPU board contains the processor, memories and an A/D-converter that is common to the
whole module.

The CPU board also contains sensors for pressure, temperature and humidity as well as drivers
for valves, the fan and the pump. The module is connected to the module bus through an
RS-485 serial channel.

Figure 13 Signal processing on CPU board

2.2.7 MiniOM board

20

Document no. M1214853C

The miniOmM board contains electronics specific to the MiniOM sensor: FPGA circuit, coil drive,
A/D-converter etc. It also contains EEPROM memory that stores calibration data of the oxygen
measurement.