Datex-Ohmeda Aestiva 7900 SmartVent Technical Reference Manual

Aestiva/5

7900 Anesthesia Ventilator

Technical Reference Manual

Aestiva 7900 Anesthesia Ventilator

Datex-Ohmeda products have unit serial numbers with coded logic which indicates a product
group code, the year of manufacture and a sequential unit number for identification.

AAA A 12345

This alpha character indicates the year of product manufacture
and when the serial number was assigned;
“D” = 2000, “E” = 2001, “F” = 2002, etc.
“I” and “O” are not used.

Aestiva

and

SmartVent

are registered trademarks of Datex-Ohmeda Inc.

Other brand names or product names used in this manual are trademarks or registered
trademarks of their respective holders.

05/04 1006-0453-000

Technical Reference Manual

Aestiva 7900 Anesthesia Ventilator
Software Revisions 1.X, 3.X, and 4.X

This document is not to be reproduced in any manner, nor are the contents to be disclosed to
anyone, without the express authorization of the product service department, Datex-Ohmeda,
Ohmeda Drive, PO Box 7550, Madison, Wisconsin, 53707.

©

2004 Datex-Ohmeda Inc.

1006-0453-000 05/04

i

Aestiva 7900 Anesthesia Ventilator

Important

The information contained in this service manual pertains only to those models of products
which are marketed by Datex-Ohmeda as of the effective date of this manual or the latest
revision thereof. This service manual was prepared for exclusive use by Datex-Ohmeda service
personnel in light of their training and experience as well as the availability to them of parts,
proper tools and test equipment. Consequently, Datex-Ohmeda provides this service manual to
its customers purely as a business convenience and for the customer's general information only
without warranty of the results with respect to any application of such information. Furthermore,
because of the wide variety of circumstances under which maintenance and repair activities
may be performed and the unique nature of each individual's own experience, capacity, and
qualifications, the fact that customer has received such information from Datex-Ohmeda does
not imply in anyway that Datex-Ohmeda deems said individual to be qualified to perform any
such maintenance or repair service. Moreover, it should not be assumed that every acceptable
test and safety procedure or method, precaution, tool, equipment or device is referred to within,
or that abnormal or unusual circumstances, may not warrant or suggest different or additional
procedures or requirements.

This manual is subject to periodic review, update and revision. Customers are cautioned to
obtain and consult the latest revision before undertaking any service of the equipment.
Comments and suggestions on this manual are invited from our customers. Send your
comments and suggestions to the Manager of Technical Communications, Datex-Ohmeda,
Ohmeda Drive, PO Box 7550, Madison, Wisconsin 53707.

wwww CAUTION

Servicing of this product in accordance with this service manual should never be
undertaken in the absence of proper tools, test equipment and the most recent revision
to this service manual which is clearly and thoroughly understood.

Technical Competence

The procedures described in this service manual should be performed by trained and authorized
personnel only. Maintenance should only be undertaken by competent individuals who have a
general knowledge of and experience with devices of this nature. No repairs should ever be
undertaken or attempted by anyone not having such qualifications.

Datex-Ohmeda strongly recommends using only genuine replacement parts, manufactured or
sold by Datex-Ohmeda for all repair parts replacements.

Read completely through each step in every procedure before starting the procedure; any
exceptions may result in a failure to properly and safely complete the attempted procedure.

ii

05/04 1006-0453-000

Table of Contents

Important . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ii

Technical Competence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ii

1 Introduction

1.1 What this manual includes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.1.1 Software versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.2 Standard service procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.1 Operation manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.2 Service manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.3 Ventilator tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.3 Symbols used in the manual or on the equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1009-0357-000 11/03 iii

Table of Contents

2 Theory of Operation

2.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.2 Aestiva 7900 Ventilator features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.2.1 Safety features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.3 Aestiva 7900 Ventilator components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.3.1 Ventilator control electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.3.2 Control panel and display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2.3.3 Sensor Interface Board (SIB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2.3.4 Pneumatic Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2.4 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.4.1 Electrical (original) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.4.2 Electrical (integrated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2.4.3 Power supply (original) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2.4.4 Power supply (integrated CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

2.4.5 Sealed lead acid battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.4.6 CPU assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.4.7 Sensor Interface Board (SIB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.5 Mechanical subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

3 Post-Service Checkout

2.5.1 Supply gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.2 Gas Inlet Valve (GIV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.5.3 Flow control valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.5.4 Drive Gas Check Valve (DGCV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.5.5 Bellows Pressure Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.5.6 Exhalation valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.7 Mechanical Overpressure Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.8 Bleed resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.9 Free breathing valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

2.5.10 Breathing circuit flow sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

3.1 Post-service checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

3.1.1 Test the Aestiva 7900 Ventilator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

3.1.2 Test the Aestiva Anesthesia Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

iv 11/03 1009-0357-000

Table of Contents

4a Tests and Calibration — Software Revision 4.X

4a.1 Self tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-3

4a.2 Service Mode Confirmation menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-4

4a.3 Main Menu - Service Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-5

4a.3.1 Alarm Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-6

4a.3.2 Error Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-7

4a.3.3 System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4a-8

4a.3.4 User Select Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-12

4a.3.5 Test CPU and Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-14

4a.3.6 Test EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-15

4a.3.7 Test GIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-16

4a.3.8 Test Flow Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-17

4a.3.9 Test Drive Pressure Limit Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-18

4a.3.10 Test 5V Fail Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-19

4a.3.11 Test Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-20

4a.3.12 Breathing System Leak Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-21

4a.3.13 Display A/D Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-22

4a.3.14 Display Discrete I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-24

4a.3.15 Display Battery Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-25

4a.3.16 Test Panel Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-26

4a.3.17 Flow Valve Test Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-27

4a.3.18 Adjust Drive Gas Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-28

4a.3.19 O2 Calibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-29

4a.3.20 Calibrate Flow Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-30

4a.3.21 Pressure Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-31

4a.3.22 Calibrate Flow Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-32

4a.3.23 Bleed Resistor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-33

4a.3.24 Service Calibrations Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4a-34

4b Tests and Calibration — Software Revisions 1.X and 3.X

4b.1 Self tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-3

4b.2 Service Mode Confirmation menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-4

4b.2.1 Set the altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-5

4b.2.2 Set the language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-5

4b.2.3 Set the serial connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-5

4b.3 Main Menu - Service Calibration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-6

1009-0357-000 11/03 v

Table of Contents

4b.4 Diagnostic Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-7

4b.4.1 Test CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-7

4b.4.2 Test External RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-7

4b.4.3 Test Display RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-8

4b.4.4 Test Flash ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-8

4b.4.5 Test EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-9

4b.4.6 Test Panel Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-9

4b.4.7 Test Serial Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-10

4b.4.8 Test Flow Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-11

4b.4.9 Test GIV (Gas Inlet Valve) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-12

4b.4.10 Test DPL (Drive Pressure Limit) switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-13

4b.4.11 Test 5V Fail Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-14

4b.5 Diagnostic Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-15

4b.5.1 Display A/D channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-15

4b.5.2 Display I/O signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-17

4b.5.3 Battery Charge Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-18

4b.5.4 System Error Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-19

4b.5.5 Alarm log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-19

4b.6 Flow Valve Test Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-20

4b.7 Test Breathing System For Leak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-21

4b.8 Adjust Drive Gas Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-22

4b.9 Calibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-23

4b.9.1 Calibrate O2 Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-23

4b.9.2 Calibrate Flow Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-24

4b.9.3 Pressure Sensitivity Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-25

4b.9.4 Calibrate Flow Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-26

4b.9.5 Calibrate Bleed Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-27

4b.10 Schedule Service Calibration — Software 3.X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-28

4b.11 Sensor(s) cal due — Software 1.X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-29

4b.12 User Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-30

4b.12.1 Select Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-30

4b.12.2 Select Drive Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-30

4b.12.3 Adjust Brightness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-31

4b.12.4 Select Heliox Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-31

4b.12.5 VE Alarm Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-32

4b.12.6 User Select Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4b-32

vi 11/03 1009-0357-000

Table of Contents

5 Troubleshooting

5.1 Troubleshooting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2

5.2 System Error Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

5.2.1 Error messages for Software Revision 4.X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.2.2 Error codes for Software Revisions 1.X and 3.X . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.3 Alarm messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7

5.4 Mechanical/electrical troubleshooting guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24

5.5 Troubleshooting Flowcharts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26

5.5.1 Ventilator assessment process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26

5.5.2 No display troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27

5.5.3 Inaccurate volume ventilation troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28

5.5.4 No ventilation troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29

5.5.5 High intrinsic PEEP troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30

5.6 Power supply test points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31

6 Maintenance

7 Repair Procedures

5.6.1 Power supply board (original CPU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31

5.6.2 Original CPU. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32

5.6.3 Power supply (Integrated CPU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33

6.1 Supply gas inlet filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3

6.2 Free breathing valve maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4

6.3 MOPV differential relief valve test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5

6.4 MOPV pressure relief valve test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6

7.1 Control panel assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2

7.2 Keyboard and EL display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3

7.3 Encoder switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

7.4 Alarm speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5

7.5 Access to electrical enclosure components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6

7.5.1 CPU Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8

7.5.2 Firmware replacement procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9

7.5.3 Power supply board (for original CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10

7.5.4 Power supply (for Integrated CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

7.5.5 Toroid (original CPU only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

7.5.6 Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

7.6 Vent Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14

7.7 Non-relieving regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16

1009-0357-000 11/03 vii

Table of Contents

8 Illustrated Parts

7.8 Flow control valve 7-17

7.9 Gas inlet valve 7-18

7.10 Mechanical Overpressure Valve (MOPV assembly) 7-20

7.10.1 To service the original MOPV assembly: 7-20

7.10.2 To service the MOPV assembly with the molded housing: 7-22

7.11 Drive gas check valve assembly 7-23

8.1 Special instructions 8-2

8.2 Service tools 8-2

8.3 Ventilator Harnesses 8-3

8.4 Electrical enclosure parts (original CPU) 8-4

8.5 Electrical enclosure parts (integrated CPU) 8-6

8.6 Display Module 8-8

8.6.1 Rear housing parts 8-8

8.6.2 Front housing parts 8-9

8.7 Aestiva 7900 Vent Engine 8-10

8.7.1 Gas Inlet Valve 8-11

8.7.2 Mechanical Over Pressure Valve (MOPV) 8-12

8.7.3 Inlet filter 8-13

8.7.4 Free Breathing Valve 8-14

8.7.5 Manifold 8-15

8.7.6 Tube Assembly 8-16

8.7.7 Twin Tube Lifter 8-17

8.8 Vent Engine mounting bracket 8-18

8.9 Sensor Interface Board (SIB) 8-19

viii 11/03 1009-0357-000

1 Introduction

In this section

1006-0453-000 05/04 1-1

1.1 What this manual includes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.1.1 Software versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.2 Standard service procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.1 Operation manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.2 Service manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.3 Ventilator tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.3 Symbols used in the manual or on the equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1 Introduction

1.1 What this manual includes

This manual covers the service information for the Aestiva 7900 SmartVent
Anesthesia Ventilator which is an integral component in the Aestiva Anesthesia
Machine.

The Aestiva Anesthesia Machine has its own service manual
(Stock Number 1006-0452-000).

Special notice

1.1.1 Software versions

Some information in this manual can possibly point the reader to electronic
troubleshooting and component/repair replacement level of service. This
information, when supplied, is only supplied to add clarity to service or
troubleshooting statements. Datex-Ohmeda Service Personnel are mandated
by Company Policy to service electronic equipment to a board replacement
level only.

• Read completely through each step in every procedure before starting
the procedure; any exceptions can result in a failure to properly and
safely complete the attempted procedure.

• Unless otherwise specified, values in this manual are nominal.

• Sections in this manual begin on odd numbered or right-hand pages.
If there is no text on the preceding, backup even numbered page, it is
labeled “Notes” for your use if you wish.

• Figures that require more than one page have the title and main text
on the left (even numbered) page. Additional figure information is on
the facing (odd numbered) page.

The revision level is displayed on the ventilator start-up menu. This manual
includes test and calibration procedures for Revision 1.X, 3.X, and 4.X
software.

1-2 05/04 1006-0453-000

1.2 Standard service procedures

1 Introduction

1.2.1 Operation
manuals

1.2.2 Service
manuals

1.2.3 Ventilator
tests

wwwwWARNING

You must have, and be familiar with, the Operation manuals for this product.
Study the Aestiva Operation manuals if you need further information about the
operation of the system.

You must determine where a problem is located before you can determine
which service manual to use:

• Use this manual for 7900 Ventilator related problems.

• Use the Anesthesia Machine service manual (1006-0452-000)
for all other components of the Aestiva Anesthesia Machine.

Service calibration functions let Datex-Ohmeda trained users and Datex­Ohmeda service personnel perform ventilator setup functions, tests,
calibration and measurements from the front panel display.

Normal operational tests, calibration, and troubleshooting can be performed
on your Aestiva 7900 Ventilator without removing components from the
system. Repair may require removing the ventilator components from the
anesthesia machine.

Section 4,
whenever you access any internal component of the Ventilator to verify
that all critical parts of the Ventilator are still operational and within
specification.

“Service Mode Tests and Calibration”

must be performed

wwwwWARNING

wwwwWARNING

After the Ventilator has been serviced, you must perform

Checkout”

before the system can be returned to clinical use.

Do not perform testing or maintenance on this instrument while it is
being used to ventilate a patient, possible injury may result.

to verify the entire Anesthesia System is properly functioning

“Post -Service

1006-0453-000 05/04 1-3

1 Introduction

1.3 Symbols used in the manual or on the equipment

w

Warnings and

w

can occur if you do not follow all instructions in this manual.

Warnings tell about a condition that can cause injury to the operator or the
patient.

Cautions tell about a condition that can cause damage to the equipment.
Read and follow all warnings and cautions.

Other symbols replace words on the equipment or in Datex-Ohmeda manuals.
No one device or manual uses all of the symbols. These symbols include:

Cautions tell you about dangerous conditions that

m

L

l

n
M

N

†

p

On (power)

Off (power)

Standby

Standby or preparatory state for part of
the equipment

“ON” only for part of the equipment

“OFF” only for part of the equipment

Direct current

Alternating current

A

j

J

D

w

wW

O

Alarm silence button

Alarm silence touch key
(Tec 6).

Type B equipment

Type BF equipment

Type CF equipment

Caution, ISO 7000-0434

Attention, refer to product
instructions, IEC 601-1

Dangerous Voltage

x

Protective earth ground

Earth ground

y

Frame or chassis ground

P

Equipotential

Y

Plus, positive polarity

+

Minus, negative polarity

-

1-4 05/04 1006-0453-000

h

G

k

E

REF

SN

Input

Output

Movement in one direction

Movement in two directions

Stock Number

Serial Number

1 Introduction

t

T

g

o

z

Z

U

Variability Read top of float.

Variability in steps Vacuum inlet

This way up Suction bottle outlet

Lamp, lighting, illumination

Cylinder

Lock

Isolation transformer

Unlock

Close drain

Linkage system

Risk of Explosion.

u

134°C

Í

q

t

Open drain (remove liquid)

Autoclavable

Low pressure leak test

Mechanical ventilation

r

Not autoclavable

Bag position/ manual ventilation

R

Inspiratory flow

Q

O2+

O2 sensor connection.

Alarm silence touch key. Volume alarms On/Off touch key.

Expiratory flow

O2 Flush button

End case touch key Menu touch key.

1006-0453-000 05/04 1-5

1 Introduction

< 345 kPa

< 414 kPa

Absorber on.

The primary regulator is set to
pressure less than 345 kPa
(50 psi).

Absorber off (CO

Bypass active). The primary regulator is set to

2

European Union Representative.

pressure less than 414 kPa
(60 psi).

Systems with this mark agree with
the European Council Directive
(93/42/EEC) for Medical Devices
when they are used as specified in
their Operation and Maintenance
Manuals. The xxxx is the
certification number of the
Notified Body used by Datex­Ohmeda’s Quality Systems.

1-6 05/04 1006-0453-000

2 Theory of Operation

In this section This section provides functional descriptions and theory of operation for the major

components of the Aestiva 7900 Ventilator.

2.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.2 Aestiva 7900 Ventilator features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.2.1 Safety features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.3 Aestiva 7900 Ventilator components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.3.1 Ventilator control electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.3.2 Control panel and display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2.3.3 Sensor Interface Board (SIB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2.3.4 Pneumatic Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2.4 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.4.1 Electrical (original) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.4.2 Electrical (integrated) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2.4.3 Power supply (original) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2.4.4 Power supply (integrated CPU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

2.4.5 Sealed lead acid battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.4.6 CPU assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.4.7 Sensor Interface Board (SIB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

2.5 Mechanical subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.1 Supply gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.5.2 Gas Inlet Valve (GIV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.5.3 Flow control valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24

2.5.4 Drive Gas Check Valve (DGCV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.5.5 Bellows Pressure Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2.5.6 Exhalation valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.7 Mechanical Overpressure Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.8 Bleed resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2.5.9 Free breathing valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

2.5.10 Breathing circuit flow sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

1006-0453-000 05/04 2-1

2 Theory of Operation

2.1 General description

The Aestiva 7900 Ventilator is a microprocessor based, electronically­controlled, pneumatically-driven ventilator with built in monitoring systems
for inspired oxygen, airway pressure and exhaled volume. The ventilator is
designed to be used as a medical device assisting in the delivery of
anesthesia and is part of the Aestiva Anesthesia Machine.

2.2 Aestiva 7900 Ventilator features

• Sensors in the breathing circuit are used to control and monitor patient

ventilation and measure inspired oxygen concentration. This lets the
ventilator compensate for compression losses, fresh gas contribution, valve
and regulator drift and small leakages in the breathing absorber, bellows
and system.

• Positive End Expiratory Pressure (PEEP) is regulated electronically. During

mechanical ventilation the software maintains the set airway pressure. PEEP
is not active when mechanical ventilation is off.

• User settings and microprocessor calculations control breathing patterns.

User interface settings are kept in non-volatile memory.

•Mechanical ventilation is started with the Bag/Vent switch on the breathing

system.

• The Aestiva 7900 Ventilator reads the status of the Bag/Vent switch and the

breathing circuit type (Circle, Bain-Mapleson D). The operator does not have
to set the breathing circuit type from a menu.

• The Aestiva 7900 Ventilator has an operator-selectable Heliox mode to

permit gas composition compensation when Heliox gas is used.

• All Aestiva 7900 Ventilators have minimum monitoring and alarms

managed on the ventilator panel (there is no other panel for safety
relevant alarm management, etc.).

• Ventilator hardware is regularly monitored by software tests.

• An RS-232 serial digital communications port connects to and

communicates with external devices.

• An exhalation valve modulates flow in the pressure mode.

• Pressure and volume modes are selectable by the operator.

• All pneumatic components are located on one manifold.

• Exhausted drive gas and bellows pressure relief valve gases are mixed and

go through the ventilator exhalation valve.

• Exhalation valve block is autoclavable.

• Excess fresh gas released from the bellows and ventilator drive gas is

transferred from the exhalation valve to the Anesthesia Gas Scavenging
System (AGSS).

• Optimized for service with a low number of components.

2-2 05/04 1006-0453-000

2.2.1 Safety features • Dual redundant airway overpressure protection, linked to Pmax

setting.

• Volume over-delivery limits and protection.

• Proprietary hose connections and fixed manifolds.

• 10 VA electrical power limiting to potential oxygen enriched environment.

• 150 psi burst overpressure protection.

2.3 Aestiva 7900 Ventilator components

Components of the ventilator are found in different locations on the Aestiva
Anesthesia Machine. The ventilator package consists of:

1. Ventilator control electronics

2. Control panel and display (two mounting options shown)

3. Sensor interface board (SIB)

4. Pneumatic engine

2 Theory of Operation

Note For the Aestiva/5 MRI machine, the display is centrally mounted above the

flowhead.

1

2

3

4

1

2

3

4

Figure 2-1 • Aestiva Anesthesia Machine with hinged and outboard arm options

1006-0453-000 05/04 2-3

2 Theory of Operation

2.3.1 Ventilator control
electronics

100-120 VAC
220-240 VAC

50/60 Hz

AC Inlet Module

-Fuses

-Voltage Selector

-Filter

The ventilator control electronics is found in the electrical enclosure of the
Aestiva machine behind the AC Inlet module.

In the original Aestiva machines, the power supply and the CPU are on
separate boards, as shown in Figure 2-2.

The ventilator control electronics includes the power supply and the CPU. The
power supply receives AC power from the machine’s AC Inlet module. All the
power necessary to operate the ventilator and light package comes from the
power supply. The CPU controls operation of the ventilator.

Tec6 Outlet

Toroid

AB.29.087

Battery

Connector Board

Front Panel

Assembly

Power Supply

Board

CPU Board

Connector Board

Pneumatic

Engine

Task Light

Proprietary RS232C
Primary RS232C On/StandBy

Vent On/StandBy Switch
O2 Supply Switch and O2 Flush Switch

BCID

Sensor

Interface Board

Patient Interface Harness
ACGO
Oxygen Sensor

Figure 2-2 • Aestiva 7900 Ventilator functional block diagram (Original CPU)

2-4 05/04 1006-0453-000

100-120 VAC
220-240 VAC

50/60 Hz

2 Theory of Operation

In current Aestiva machines, the regulated power supplies and the CPU are
included on a single board (Integrated CPU Board), as shown in Figure 2-3.

A universal power supply is used to convert AC to DC that feeds into the power
supply circuits of the integrated CPU board. The universal power supply
eliminates the need for the toroidal transformer.

Tec6 Outlet

AC Inlet Module

-Fuses

-Voltage Selector

-Filter

Battery

Power Circuits

Integrated

CPU Board

Digital Circuits

Universal

Power Supply

Task Light

Proprietary RS232C
Primary RS232C On/StandBy

Vent On/StandBy Switch
O2 Supply Switch and O2 Flush Switch

Connector Board Connector Board

Front Panel

Assembly

AB.29.082

Pneumatic

Engine

Sensor

Interface Board

BCID
Patient Interface Harness

ACGO
Oxygen Sensor

Figure 2-3 • Aestiva 7900 Ventilator functional block diagram (Integrated CPU)

1006-0453-000 05/04 2-5

2 Theory of Operation

2.3.2 Control panel and
display

The control panel on the Aestiva 7900 Ventilator is either outboard (on an
arm) or on a hinge to fold flat against the machine (depending on the option
ordered) and is made to permit you to grip the panel and push the buttons
with your thumbs. The ventilator control panel position is easily adjusted.

For the Aestiva/5 MRI machine, the display is centrally mounted above the
flowhead.

The front panel assembly has four submodules:

• The electroluminescent (EL) display

• The keyboard front panel

•A rotary encoder

•A speaker

Figure 2-4 • Ventilator control panel with software version 4.X

The keyboard and rotary encoder are used to control the operations of the
ventilator. The front panel uses a three step — selection, change, and approve
— setting scheme to prevent unwanted selections. The speaker supplies audio
input to the operator.

Logical layout of primary controls is left to right in the sequence: tidal volume
or inspiratory pressure level, respiratory frequency, I:E ratio, maximum
inspiratory pressure, and PEEP (positive end expiratory pressure).

Primary Ventilator interfaces include:

• Display

• Soft keys

• Rotary encoder (control wheel)

• Knob button (control wheel)

• LED

• Audio

2-6 05/04 1006-0453-000

2 Theory of Operation

2.3.3 Sensor Interface
Board (SIB)

Figure 2-5 • Sensor Interface Board (SIB)

A Sensor Interface Board (SIB) serves as the interface between the ventilator
CPU board and the breathing circuit sensors.

The SIB processes signals from the:

• Inspiratory and expiratory flow transducers
sensor

•O

2

• Auxiliary Common Gas Outlet (ACGO) switch (optional)

•Module ID board

• Canister release switch

• Absorber CO

Bypass switch

2

• Bag/Vent switch

• Control panel switch

• Drive Pressure Limit (DPL) switch

•Manifold pressure transducer

• Patient airway pressure transducer

The SIB for the Aestiva 7900 Ventilator is located in the cable duct under the
rear subfloor of the breathing circuit chassis. The SIB uses a 50-conductor
cable that supplies the link between the Aestiva 7900 Ventilator CPU and the
breathing system signals.

2.3.4 Pneumatic Engine The pneumatic engine enclosure is located in the back chamber of the

breathing system and is shielded to contain EMI emissions. The enclosure
includes the Pneumatic Engine and a Pneumatic Engine Connector Board.

The Pneumatic Engine comprises the hardware that drives the ventilator
bellows. It includes:

•a 5-micron inlet filter

•a gas inlet valve (GIV)

•a pressure regulator

•a flow control valve

•a drive gas check valve

•a mechanical over-pressure relief valve

•a differential pressure relief valve

•a free-breathing check valve

Figure 2-6 • Pneumatic Engine

1006-0453-000 05/04 2-7

2 Theory of Operation

2.4 Electrical

Power

Cord

2.4.1 Electrical
(original)

AC Inlet

Line Filter
Fuse
Voltage Selector

The original (non-integrated) Aestiva 7900 Ventilator electronic/electrical
subassemblies or modules include:

• Power entry toroid

• Power supply board

• CPU board

• Display and front panel assembly

• Sensor interface board

• Sealed lead acid battery

Inside Machine

Power Supply Board

EL voltage = +10--14.5V 10.5W max

2

Toroid

+12V light output @ 15W max
+15V @ 170mA max

-15V @ 100mA max
+5V @ 1.8A max
+5.5 @ 1.4A max

50

12 Volt Battery

2

& Harness

CMS

RS232

CPU Board

68340 Microcontroller
Memory and I/O Decoding
Flash, SRAM & EEPROM
SCR Circuitry
D/A Converter
Watchdog System
Inlet Valve Control & Drive
(10 VA limited)
Flow Valve Control & Drive
(10 VA limited)
A/D Converter
15 VDC Supply (10VA limited)
DC Supply Monitoring

2

2

O2 supply

O2 Flush

4

Machine/Ventilator
On/Standby switch

Shielded Cable

50

Shielded Cable

50

Shielded Cable

7

Pneumatic Engine

Connector board
Flow valve
Inlet valve

Breathing System

EL Display &

Membrane Switch

Key Components
EL Display
Membrane Switch
Connector Board
50 Pin Connector Series 3
50 Pin Ribbon Cable Header
Optical Encoder
50 Pin Ribbon Cable
20 Pin Ribbon Cable
Speaker

Inspiratory & Expiratory flow transducers
Drive Pressure Limit Switch
Manifold Pressure Transducer
Patient Airway Pressure Transducer

O2 Sensor

ACGO Switch

SIB

Flow Sensors

Bag/Vent Switch
Control Panel Switch
Canister Release Switch
Absorber Bypass Switch
Breathing Circuit ID

Figure 2-7 • Electronic functional block diagram (Original CPU)

2-8 05/04 1006-0453-000

2 Theory of Operation

Pow er

Cord

CMS

RS232

2.4.2 Electrical

(integrated)

AC Inlet

Line Filter
Fuse
Voltage Selector

EL voltage = +10 –14.5V 10.5W max
+12V light output @ 15W max
+15V @ 170mA max

-15V @ 100mA max
+5V @ 1.8A max
+5.5 @ 1.4A max

Integrated
CPU Board

68340 Microcontroller
Memory and I/O Decoding
Flash, SRAM & EEPROM
SCR Circuitry
D/A Converter
Watchdog System
Inlet Valve Control & Drive
(10 VA limited)
Flow Valve Control & Drive
(10 VA limited)
A/D Converter
15 VDC Supply (10VA limited)
DC Supply Monitoring

The integrated Aestiva 7900 Ventilator electronic/electrical subassemblies or
modules include:

• Universal power supply (AC to DC converter)

• CPU board (with power supply and digital circuits)

• Display and front panel assembly

• Sensor interface board

• Sealed lead acid battery

Inside Machine

AC to DC Power Supply

2

5

2

12 Volt Battery

& Harness

7

VCHGR = 16.0 V Typical
VMAIN = 12.5 V Typical

50

Shielded Cable

Shielded Cable

50

Shielded Cable

Pneumatic Engine

Connector board
Flow valve
Inlet valve

EL Display &

Membrane Switch

Key Components
EL Display
Membrane Switch
Connector Board
50 Pin Connector Series 3
50 Pin Ribbon Cable Header
Optical Encoder
50 Pin Ribbon Cable
20 Pin Ribbon Cable
Speaker

Inspiratory & Expiratory flow transducers
Drive Pressure Limit Switch
Manifold Pressure Transducer
Patient Airway Pressure Transducer

SIB

O2 supply

2

O2 Flush

2

4

Machine/Ventilator
On/Standby switch

Breathing System

O2 Sensor

ACGO Switch

Flow Sensors

Bag/Vent Switch
Control Panel Switch
Canister Release Switch
Absorber Bypass Switch
Breathing Circuit ID

Figure 2-8 • Electronic functional block diagram (Integrated CPU)

1006-0453-000 05/04 2-9

AB.29.083

2 Theory of Operation

2.4.3 Power supply

Power

30-60 VDC

VBOOT

Linear

Regulator

+16.6V

Primary

DC to DC

Converter

VBUS

(original)

Cord

0.25A

The power supply performs seven functions:

• AC to DC converter

• DC to DC step-down converter

• Battery charger

•Multiple output DC regulator

• Battery charge/discharge current monitor

• Battery voltage monitor

• Task light power supply 12V

Entry Module

- EMI Filter

- Fuse

- Voltage Selector

VSW

Linear

Regulator

VB

Toroid

Isolation

Transformer

Secondary

DC to DC

Converter #1

Secondary DC to DC

Converter #2

Linear

Regulator

24-45
VAC

Rectifier

& Filter

Bridge Rectifier

& Filter Caps

ON/Standby

Regulator

Switch

Linear

AC_LED

VSW
(+5V VDD Fail Buzzer

Rem_On

+12V (Task Lights)

+10-14.5V
VH_EL

-15V Analog

AB.29.097

Battery Charge

Controller

Thermal
Breaker

12 V Battery

Battery Voltage &

Current Sense

Transformer

Step-Down

Controller

+5.8V

Rectifier

& Filter

OVP &

Current Limit

Linear

Regulator

Linear

Regulator

+15V Analog

+5.5V Valves Supply

+5V VDD Digital

IBatt,VBatt

Charger
Disconnect

Figure 2-9 • Ventilator power supply (Original CPU)

2-10 05/04 1006-0453-000

2 Theory of Operation

2.4.4 Power supply
(integrated CPU)

11

11
88

88
00

00

..

..
99

99
22

22

..

..
BB

BB
AA

AA

AB.29.081

CHARGER and TRICKLE

DISABLE

BATTERY CHARGER

BULK CHARGE = 400mA

12V BATTERY

THERMAL AUTO

RESETABLE FUSE

Aestiva machines with an integrated CPU board use a universal power supply
for AC to DC conversion. The remainder of the power supply functions are
derived in the power supply circuits on the integrated CPU:

• DC to DC step-down converter

• Battery charger

•Multiple output DC regulator

• Battery charge/discharge current monitor

• Battery voltage monitor

• Task light power supply 12V

VOLTAGE and CURRENT

MONITOR

VBatt, IBatt

TASK LIGHTS LDO

TYPICALLY 11.718V

VHEL DISPLAY LDO

TYPICALLY 11.718V

AC TO DC POWER SUPPLY

85 -- 264 VAC

VCHGR = 16.0 TYPICAL

VMAIN = 12.5V TYPICAL

AC INLET

POWER CORD

DIODE OR

VMAIN

VCHGR

VBAT

MOSFET

SWITCHES

SELECT VMAIN OR VBAT

AS OUTPUT TO VBUS

VBUZZER

OUTPUT TO VDD FAIL

BUZZER

VSWITCH

ON / STANDBY SWITCH CIRCUIT

VBUS

SIMPLE SWITCHER

DUAL OUTPUT

SWITCHER

POSITIVE OUTPUT

NEGATIVE OUTPUT

VALVES SUPPLY

5.8V OUTPUT and 10VA

VDD DIGITAL
OUTPUT LDO

5V +/- 2.5%

SIB_12V OUTPUT

and 10VA LDO

+15V ANALOG

SUPPLY LDO

-15V ANALOG
SUPPLY LDO

Rem_On

AC_LED

Figure 2-10 • Ventilator power supply (Integrated CPU)

1006-0453-000 05/04 2-11

2 Theory of Operation

2.4.5 Sealed lead acid
battery

A sealed lead acid battery supplies battery backup for the Aestiva 7900
Ventilator. The Aestiva 7900 Ventilator is not a portable unit. Batteries for the
ventilator are used as back up power in case of a power failure. Thus the
battery is in a float charge state most of the time. Batteries meet the
following:

• Capacity to operate unit for 30 minutes.

• Long float charge life.

• Battery pack is internally fused - in line replaceable.

• Battery terminals and connecting wires are protected against short circuits.

tt

IIIInnnnppppuuuutt

Nominally 13.7 VDC at 25

tt

OOOOuuuuttttppppuuuutt

+10V to +14.8VDC during discharge

o

C during float charge.

2-12 05/04 1006-0453-000

2 Theory of Operation

2.4.6 CPU assembly The CPU assembly contains all of the major circuit functions necessary to

control ventilator operation. In the original Aestiva 7900 machines, these
functions are on a separate CPU board. For current machines, they are part of
the digital circuits section of the integrated CPU board.

Production Connector

DRIVER

RS232C

Proprietary RS232C

Primary RS232C

Connector

Connector

FLASH MEM
( 512K X 16 )

STATIC RAM
( 128K X 16 )

EEPROM

( 2K X 8 )

VIDEO SRAM

( 32K X 8 )

VA0-VA11

VD8-VD15

SED1351F

VIDEO

CONTROLLER

FERRITE

BEADS

Front Panel Assembly

AUDIO AMP

+5VVH_EL

9

Connector

A0-A18,
D0-D15

3

A0-A18,
D0-D15

3

A0-A10,
D8-D15

3

A0-A11,
D8-D15

4

LM4860M

MICROCONTROLLER

SYSTEM DATA BUS & ADDRESS BUS

EPLD-EPM7064

WATCHDOG

LOGIC

ADDRESS

DECODING

YM2413

D0-D15

AUDIO

CHIP

1

2

O2 Supply
Connector

MC68340

A0-A20
D0-D15

A20, A0, A1
A14-A17,
D8-D10

FREQUENCY

DIVIDER

Connector

14

14

ADC

SEQUENCER

VENTILATION

CONTROL

1

O2 Flush

DS1232

WATCHDOG

& RESET

1

INTERFACE

D8-D15

2

2

SERIAL

EEPROM

12-BIT A/D

D0-D15

CONVERTER

6

D0-D15

1

12-BIT D/A

CONVERTER

4

D0-D15

1

12

7

SIB_+12V

10VA LIMIT

5

SIB Connector

DIGITAL
INPUT 0

DIGITAL
INPUT 1

11

+15V

+15V

1

-15V
P12V_LIGHT

INLET VALVE

DRIVE

FLOW VALVE

DRIVE

+5V LOSS

ALARM

VOLTAGE TEST

POINTS

+5V +5.8V +15V

Pneumatic Engine

Connector

2

4

Buzzer

-15V

24-CHANNEL
MUTIPLEXER

6

2

5

+5.8V

VSW

1.225V
VH_EL

SIB_12V

1

1

2

V

ANALOG
SIGNALS

1

10

DD

MONITOR

VH_EL

Power Supply Connector

Figure 2-11 • Ventilator CPU block diagram

Motorola 68340 processor core The CPU core consists of the following internal functions:

• Bus access control signals for all memory and peripheral devices

• Interrupt handling

• Clocks and timers for the system

• Background software development mode

• Two RS232C serial I/O ports

• Baud rate generator for serial ports

• Hard (power-up) and soft (watchdog error) reset generation

• Data bus buffers

•Memory and I/O decoding

• Program memory

• Safety Relevant Computing (SRC)

•Watchdog system

• Data acquisition

• Flow valve control

• Inlet valve drive

• Front panel interface

• Audio alarm

• Regulator output/manifold pressures

1006-0453-000 05/04 2-13

2 Theory of Operation

System clock

An external 32.768 kHz crystal is used with the internal clock synthesizer to
generate a 24.12 MHz system clock.

Periodic interrupt timer

The periodic interrupt timer is the time base for the Real Time Operating
System.

Software watchdog timer

The software controlled internal watchdog timer guards against program
execution going astray.

External bus interface

The external bus interface handles the transfer of information between the
CPU32, external memory and peripherals.

Serial communications module Timing reference

An external 3.6864 MHz clock oscillator is used as the timing reference for the
Baud Rate Generator.

Configuration

Both of the serial communication channels are configured as full-duplex
asynchronous RS232C ports. The internal Baud Rate Generator establishes
the communication baud rate, with a higher limit of 19.2k Baud.

Special operating modes

The serial channels are capable of operating in various looping modes for self
testing as well as for remote testing of serial communications. These tests
include automatic echo, local loop-back, and remote loop-back.

Memory and I/O decoding Microprocessor Chip Selects

The four programmable chip selects from Motorola 68340 access external
memory and peripheral circuits, providing handshaking and timing signals as
well as a wait state generation, watchdog logic and ventilation control signals.

I/O lines

Spare I/O lines are used for digital control and/or sense lines.

Timer modules Counter/timer #1

The first counter/timer module is used to monitor the MC68340 system clock
frequency. The external 3.6864 MHz baud rate clock is the time base for this
measurement.

Counter/timer #2

The second counter/timer module can be used as desired by the application
software. The time base for this timer is the internal 24.12 MHz system clock.

2-14 05/04 1006-0453-000