Datex-Ohmeda 7800 User manual

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Page 1

7800 Ventilator International Operation and Maintenance Manual

Software Revision 4.XX

Page 2

User Responsibility

This Product will perform in conformity with the description thereof contained in this operating manual and accompanying labels and/or inserts, when assembled, operated, maintained and repaired in accordance with the instructions provided. This Product must be checked periodically. A defective Product should not be used. Parts that are broken, missing, plainly worn, distorted or contaminated should be replaced immediately. Should such repair or replacement become necessary, Datex-Ohmeda recommends that a telephonic or written request for service advice be made to the nearest Datex-Ohmeda Field Service Support Center. This Product or any of its parts should not be repaired other than in accordance with written instructions provided by Ohmeda and by Datex-Ohmeda trained personnel. The Product must not be altered without the prior written approval of Datex-Ohmeda’s Quality Assurance Department. The user of this Product shall have the sole responsibility for any malfunction which results from improper use, faulty maintenance, improper repair, damage, or alteration by anyone other than Datex-Ohmeda.

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; “Y” = 1995, “Z” = 1996, “A” = 1997, etc. “I” and “O” are not used.

Page 3

Table of Contents

1/Introduction 1-1

How to use this manual 1-2

2/Getting Started 2-1

General 2-1 Unpacking 2-2 Checking the ~ voltage 2-2 Setting the reverse flow alarm, sigh, contrast, audio volume 2-2 Adjusting the altitude or changing the language 2-4 Checking the supply gas 2-4 Matching the ventilator to anesthesia systems 2-5 Setting up the control module when the ventilator is used as a stand-

alone device 2-8 When the bellows assembly is mounted on an Ohmeda GMS Ab-

sorber 2-9 Setting up the control module with an Ohmeda Excel Anesthesia Sys-

tem 2-10

Connect sensor interface 2-10 Connect sensor interface cable 2-10 The control module’s location in an Ohmeda Excel Anesthesia Sys-

tem 2-12 When the bellows assembly is remotely located on an arm 2-13

Making the monitoring connections 2-15

Connecting the pressure sensing tube 2-15 Connecting the volume sensor 2-17 Connecting the oxygen sensor 2-19

Charging the battery 2-22

Long Term Ventilator Storage 2-22

3/General Information 3-1

The controls, connectors, and display 3-1

The ventilator control module’s front panel 3-1 The ventilator control module’s rear panel 3-5

The ventilator’s modes 3-7

The sigh function 3-7

The alarm system 3-8

Alarm quick reference charts 3-9 Alarm definitions 3-11 Theory of operation 3-16

The ventilation cycle 3-16

Volume monitoring 3-18

Airway pressure monitoring 3-18

Oxygen monitoring 3-18

Control range computation 3-18

Tidal volume compensation 3-20

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Table of Contents

4/Preoperative Checkout Procedure 4-1

Checking the ventilator connections 4-1 Checking the monitoring connections 4-1 Testing the bellows assembly 4-4 Testing the ventilator alarms 4-5

Testing the low and high oxygen alarms 4-5

Testing the low minute volume, reverse flow, and apnea alarms 4-6

Testing the high, low, and sustained pressure alarms 4-8

5/Operating the Ventilator 5-1

Using the setup page 5-1 Setting the alarm limits 5-3 Setting the ventilation parameters, beginning ventilation 5-5 Responding to alarms 5-8

6/Maintaining the Ventilator 6-1

Maintenance schedule 6-1

Long Term Ventilator Storage 6-1 Cleaning and sterilizing 6-2

Cleaning the control module 6-2

Cleaning and sterilizing the bellows assembly 6-2

Cleaning and sterilizing the volume sensor clip assembly 6-3

Cleaning and sterilizing the volume sensor cartridge 6-3 Checking the volume sensor 6-4 O2 sensor maintenance 6-5

Maintenance schedule 5 Installing a cartridge or disassembling the O2 sensor for cleaning 6-5

Cleaning and sterilization 6-7 100% O2 calibration 6-8 Cleaning the supply gas filter 6-9

Operation 6-9

Filter servicing 6-9

7/Service Procedures 7-1

Repair policy 7-1 Troubleshooting guide 7-2

Ventilator problems 7-2 Ventilator problems, continued 7-3

Troubleshooting ventilator failure messages 7-4

Ventilator failure messages 7-5

Ventilator failure messages, continued 7-6

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Table of Contents

8/Autoclavable Bellows Assembly 8-1

Introduction 8-1 Getting started 8-1 Ventilator Connections 8-2 Post Assembly Test 8-6 Cleaning and Sterilization 8-7

Cleaning 8-8

Sterilization 8-8 Periodic maintenance 8-9

Visual inspection 8-9

Pressure leak test. 8-9 Illustrated Parts List 8-11

9/Appendix 9-1

Specifications 9-1

Electrical 9-1

Controls 9-2

Monitoring 9-2

Performance characteristics 9-4

Physical characteristics 9-5 Accessories 9-6

Ventilator mounting kits 9-6 Replaceable parts 9-7

Monitoring 9-7

Drive gas tubes 9-7

Supply gas filter, ventilators set up for air 9-7

Adapters 9-7 Ventilator communications protocol 9-8

Device Commands—sent to ventilator 9-9

Format for data in compressed mode 9-10 Analog outputs 9-14 Using a Bain circuit 9-14 Non-autoclavable bellows assembly, cleaning and sterilizing 9-15

Disassembling the bellows assembly 9-15

Cleaning the bellows assembly 9-17

Sterilizing the bellows assembly 9-18

Reassembling the bellows assembly 9-19

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Notes

Table of Contents

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1/Introduction

This instrument combines an electronically-controlled, pneumaticallydriven ventilator with built-in monitoring for exhaled volume, inspiredoxygen concentration, and airway pressure. The ventilator also features controls with clinically significant ranges, selectable inspiratory pause, and an adjustable inspiratory pressure limit control. The Ohmeda 7800 Ventilator is designed to be used as a stand-alone ventilator; or as an integrated part of the Ohmeda Excel Anesthesia System.

The following symbols are used on Ohmeda products and technical manuals. No one product or manual has every symbol listed. Refer to this listing concerning symbols found on various products and manuals.

ø On (power) O Off (power o Standby q Standby or preparatory state

for a part of the equipment

p “ON” only for part of the equipment œ “OFF” only for part of the equipment † Direct Current ∏ Alternating Current x Protective earth ground y Earth Ground r Frame or chassis ground å Alarm silence button Y Equipotential

P Lamp, lighting, illumination N Movement in one direction ˆ Movement in both directions z Lock Z Unlock Í Non-autoclavable m Type B equipment µ Type BF equipment H Type CF equipment ∑ Warning ISO 7000-0085 w Caution, ISO 7000-0434 wWAttention, consult accompany-

ing documents, IEC 601-1

Ê This way up t Variability T Variability in steps

+ Plus, positive polarity

Ë Minus, negative polarity

What warning and caution statements in this manual indicate

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No matter which part of the manual you are using, you should always be familiar with the CAUTIONS and WARNINGS that appear throughout this manual. WARNINGS alert you to conditions or actions that may cause harm to humans. CAUTIONS alert you to conditions or actions that may result in damage to equipment. Read the user responsibility statement; it describes what is expected of you to maintain the ventilator. Read the warranty; it describes Ohmeda’s responsibility in case of a functional defect.

π Dangerous Voltage

≈ Input

Ù Output

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1/Introduction

Keep this manual with the system for answering questions that arise about the ventilator’s operation, maintenance or, if necessary, repair.

WARNING: Before using the Ohmeda 7800 Ventilator, familiarize

∑

How to use this manual

yourself with it by reading through this entire manual. As with all medical equipment, attempting to use this device without a thorough understanding of its operation may result in injury to the patient.

This manual is designed both as a guide for you to follow when you are learning to operate the Ohmeda 7800 Ventilator, and as a reference tool for you to use once you are familiar with the system.

The Ohmeda 7800 Ventilator consists of two basic units: the bellows assembly, which contains the bellows and bellows housing, and the control module, which contains the ventilator’s control valves, processing circuits, controls, and display screen.

If you are setting up the system for the first time, thoroughly read all of the manual sections. The Ohmeda 7800 is available in two configurations: for use as a stand-alone device, or as an integrated component of an Ohmeda Anesthesia System. Refer to the specific section in “Getting Started” that tells you how to make the basic connections for your configuration.

If the system is already in place, but you haven’t used it before, pay particular attention to all of the sections starting with Section Three: “General Information.”

If you have used the Ohmeda 7800 Ventilator before, but need reminding about details of using the instrument, refer to Sections Four: “Preoperative Setup Procedures” and Section Five: “Operating the Ventilator.”

Section Six: “Maintaining the System” and Section Seven: “Service Procedures,” are included to inform you about routine maintenance of the ventilator and to help you solve problems that might occur with the instrument.

Throughout this manual we have provided step-by-step instructions to simplify the ventilator’s operation. To further clarify the instructions, we have used a special typeface to identify messages that appear on the ventilator’s screen. Messages from the ventilator are represented by a dot-matrix typeface that simulates the messages’ actual appearance. A low minute volume alarm message looks like this:

LOW MINUTE VOL!

In addition, the system’s alarm silence key is represented in a typeface similar to the one printed on the key itself. An instruction to push the key looks like this:

Press: å

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1/Introduction

What the manual’s symbols mean

What we mean by “powering ON” the control module

A number of Warnings ∑ and Cautions w are used throughout this

manual to draw attention to the possible hazards and/or adverse conditions which may occur if the information and instructions provided are not strictly observed

Warnings are used to draw attention to a condition which can endanger either the patient or operator. Cautions are used to draw attention to a condition which can result in damage to the equipment. Special attention must be paid to each Warning and Caution as it appears in the manual.

We have also used—both in the manual and on the device itself—symbols to represent some common terms. These symbols include:

25% TIEnable inspiratory pause at 25% of inspiratory time

inspiratory pause minute volume

tidal volume

ƒ frequency

I:E Inspiratory to Expiratory ratio E Expiratory time I Inspiratory time C Compliance PIP Peak Inspiratory Pressure

In this manual, when we say “power ON” the control module, use the control module’s power switch or the anesthesia system’s master switch, depending on your ventilator’s configuration.

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1/Introduction

Notes

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2/Getting Started

alone device 2-8 When the bellows assembly is mounted on an Ohmeda GMS Ab-

sorber 2-9 Setting up the control module with an Ohmeda Excel Anesthesia Sys-

tem 2-10

Connect sensor interface 2-10 Connect sensor interface cable 2-10 The control module’s location in an Ohmeda Excel Anesthesia Sys-

tem 2-12 When the bellows assembly is remotely located on an arm 2-13

Making the monitoring connections 2-15

Connecting the pressure sensing tube 2-15 Connecting the volume sensor 2-17 Connecting the oxygen sensor 2-19

General

∑

Charging the battery 2-22

Long Term Ventilator Storage 2-22

Many of the steps in the following sections will be performed when the ventilator is installed. However, during use, maintenance, or sterilization, ventilator components may be left disconnected or may be reconnected incorrectly. Read through the steps in each section to confirm that the system is set up properly. Perform any steps necessary to correctly connect your system’s components.

WARNING: To avoid explosion hazard, flammable anesthetic agents such as ether and cyclopropane must not be used in this machine. Only anesthetic agents which comply with requirements for non-flammable anesthetic agents in the IEC Standard, Particular requirements for safety of anesthetic machines, are suitable for use in this machine.

WARNING: As this machine is not suitable for use with flammable anesthetic agents such as ether and cyclopropane, the use of anti-static breathing tubes and face masks is not necessary. The use of anti-static or electrically conductive breathing tubes when utilizing high frequency electric surgery equipment may cause burns and is therefore not recommended in any application of this machine.

The following sections tell you how to set the ~ voltage, how to install the ventilator’s bellows assembly and control module, how to install the monitoring sensors, and how to charge the battery. Although these steps are straightforward, they should be performed only by someone experienced in working with anesthesia and monitoring equipment.

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2/Getting Started

Unpacking

Upon delivery, inspect the ventilator and its accessories for damage that may have occurred during shipment. If you detect any damage, immediately notify the transportation company and file a damage claim. Save the original shipping container and materials.

The Ohmeda 7800 Ventilator’s functions should be completely checked as soon as possible. Follow the instructions in this section to install the instrument. Then, after you have used this manual to familiarize yourself with the ventilator, confirm that it is working correctly by performing the preoperative checkout procedures described in “4/Preoperative Checkout Procedures.”

Checking the ~ voltage

CAUTION: The Ohmeda 7800 Ventilator can be set to operate on 100,

120, 220, or 240 volts ~. Either 50 or 60 Hertz supplies are acceptable and do not have to be set manually. Make sure the ventilator is set for the voltage used at your location.

To change the ventilator’s operating voltage

Figure 2-1

Changing the control module’s operating voltage with the voltage selector switch

1. Turn the control module upside down (disconnect any cables that interfere).

2. Pull out the preoperative checklist. This exposes the voltage selector, which you should be able to see through the hole labeled “Mains Voltage Selector.”

3. Use a large, flat-blade screwdriver to align the arrow on the voltage selector to the correct voltage.

4. Make sure an appropriate power connector is installed.

120

220

240

100

Mains Voltage Selector

AA.10.113

Setting the reverse flow alarm, sigh, contrast, audio volume

Parameters set in the setup page are saved when the ventilator is turned OFF and then back ON. The ventilator uses those parameters established in the setup page when the power was cycled OFF.

1. Move the mechanical ventilation switch to OFF.

2. Power ON the control module. With the Excel, move the system master switch to ON.

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2/Getting Started

3. Press and continue to hold down the alarm silence button, å, then

press in the inspiratory pause button. Release both buttons. The ventilator displays:

321

7800 REV 4.XX /O ENGLISH 1300 m

1. Ventilator Model

2. Software Version

3. Ventilator Supply Gas (A=Air; O=O

4. Language

5. Altitude

WARNING: Pay attention to the information on the setup page. If

∑

the model number or supply gas is incorrect, have a trained Ohmeda service representative service the ventilator.

Note: The ventilator stores the original inspiratory pause setting (ON or

OFF) in memory when the inspiratory pause button is used to access setup pages. At the end of the setup page, the ventilator will use the stored setting.

1 meter (3.28 feet)

)

4. Press å. The ventilator displays:

FLOW KNOB TO SET REV FLOW ALM ON or OFF

Turn the flow control to switch the alarm selection ON or OFF. If the volume sensor is at the proximal end of the Y, select OFF to disable the alarm. If the volume sensor is at the expiratory port of the absorber, select ON to enable the alarm.

5. Press å. The ventilator displays:

FLOW KNOB TO SET SIGH ON or OFF

Turn the flow control to switch sigh breaths ON or OFF. When sigh is ON, the ventilator delivers one and a half times the tidal volume (up to a maximum 1500 mL) once every 64 breaths.

6. Press å. The ventilator displays:

FLOW KNOB TO SET CONTRAST: XX

Turn the flow control to adjust the ventilator display contrast (XX) from 1 (lowest contrast) to 10 (highest).

7. Press å. A tone sounds and the ventilator displays:

FLOW KNOB TO SET AUDIO VOLUME: XX

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2/Getting Started

Turn the flow control to adjust the ventilator alarm volume (XX) from 1 (lowest) to 10 (highest). Tone volume changes to the selected level.

8. Press å. The ventilator beeps once and displays:

CHECK SETTINGS!

To exit the setup pages at any step, repeatedly press å, set the me-

chanical ventilation switch to ON, or do not adjust a control for 30 seconds. All previous changes will be saved in the ventilator memory.

Adjusting the altitude or changing the language

1. Set the mechanical ventilation switch and the control module power to OFF. With the Excel, set the system master switch to OFF.

2. Hold down the inspiratory pause button and power ON the control module. With the Excel, move the system master switch to ON. Turn the flow control to set the altitude (meters).

FLOW KNOB TO SET ALTITUDE: 1300 m

Normally the altitude compensation needs to be set only when the system is first installed.

3. Press å to display the language page. Turn the Flow control to

select language.

FLOW KNOB TO SET ENGLISH

Checking the supply gas

CAUTION: If the supply gas displayed is other than the supply gas you

How to determine your ventilator’s drive-gas setting

are using (“/O” for oxygen or “/A” for air), have an Ohmeda trained service representative reset the ventilator. Using a supply gas that does not match the displayed supply gas will result in operational errors.

Either oxygen or medical-grade air can be used to power the ventilator. Before changing from one supply gas to another, however, qualified service personnel must set up the ventilator to operate correctly with the new supply gas.

On the first line of ventilator’s setup page a character is displayed that indicates the current supply-gas setting. “O” indicates oxygen and “A” indicates medical-grade air.

Note: To enter the setup page: make sure the mechanical ventilation switch is

off, press and continue to hold down the alarm silence å button, press

the inspiratory pause button, then release both buttons.

To return to normal operations press the alarm silence å button to

move through the menu or, leave the Setup Page display on without any parameter changes for 30 seconds.

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2/Getting Started

Matching the ventilator to anesthesia systems

This chart describes how certain components of the Ohmeda 7800 Ventilator’s two configurations are installed, connected, or controlled. Some of these attributes, such as the placement of the bellows assembly, are optional, so more than one can apply to a configuration. Attributes are marked with figure numbers that refer to relevant illustrations that follow this chart. (The Ohmeda Excel configuration is listed twice because the control module can be installed in two different positions on the anesthesia machine.)

Figure 2-2

Possible Configurations of the Ohmeda 7800 Ventilator

Ohmeda Excel Ohmeda Excel

(control module (control module Attributes of mounted on hung from configurations Stand-alone optional arm) shelf)

Bellows assembly Figure 2-3 Figure 2-4 on control module

Bellows assembly Figure 2-4 Figure 2-5 or 2-6 on optional arm

Connect monitor Figure 2-7 Figure 2-7 device to sensor interface panel on anesthesia machine

Connect monitor Figure 2-8 devices to control module

Use master ON/ Figure 2-9 Figure 2-9 OFF to power ON ventilator

Use control module Figure 2-8 power switch to power ON ventilator

Figure 2-3

Bellows assembly mounted on control module

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300 600

900 1200 1500

W V (mL)

z Z

Ohmeda 7800 Ventilator

•

(L/min) (%)

Rate

(mL)

300

200

100

500

1000

1500

B/min

Low v

+ + + + + +

60 21 00

- - - -

L/min % %

100

L/min

(25% T )

AA.32.130

Low O

High O

208010010 100

cm H O

2-5

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2/Getting Started

Figure 2-4

Bellows assembly mounted on control module that is attached to an optional arm on Ohmeda Excel Anesthesia System

Figure 2-5

Bellows Assembly on optional arm on Ohmeda Excel Anesthesia System

AA.32.013

Figure 2-6

Bellows assembly on a GMS absorber Ohmeda Excel Anesthesia System

AA.32.015AA.32.158

APL

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2/Getting Started

Figure 2-7

Sensor interface panel on Ohmeda Excel Anesthesia System

Figure 2-8

Sensor interface panel on stand-alone Ohmeda 7800 Ventilator

Vol

Monitors

Ohmeda 7800 Ventilator L

(25% T )

Low O2 High O

Low v

+ + + + + +

60 21 00

- - - -- -

L/min % %

AA.32.004

Figure 2-9

System master switch on Ohmeda Excel Anesthesia System

300

200

500

100

1500

1 2 3 4 5

1. Sensor interface

2. Mains indicator

3. Volume monitor port

4. Oxygen monitor port

5. Power switch

1000

B/min

100

L/min

PUSH

TURN

cm H O

10010 100

AA.32.033

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AA.11.007

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2/Getting Started

Setting up the control module when the ventilator is used as a stand-alone device

When the bellows assembly is mounted on the control module

1. Connect the correct supply gas hose to the control module’s connector that is labeled either “Use Only Oxygen” or “Use Only Medical Grade Air.”

2. A 23-cm long, drive-gas tube carries gas from the control module to the bellows assembly. Connect one end of this tube to the connector labeled “connect to bellows ass’y inlet” on the control module’s rear panel.

3. Connect the free end of the drive-gas tube to the 17-mm inlet on the bellows assembly.

Figure 2-10

Connecting the drivegas tube to a control module that has a bellows mounted on top

300 600

900 1200 1500

Benutzen Sie nur Keimfreie Luft

(241-517 kPa)

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Verbinden Sie mit der Inspirations - seite des Beatmungssystems

Verbinden Sie mit dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

Serieller Ventilatoranschluß

AA.32.007

1. Supply gas connection

2. Supply gas filter, ventilators with air supply gas only

3. Drive-gas tube

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2 3

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2/Getting Started

When the bellows assembly is mounted on an Ohmeda GMS Absorber

Figure 2-11

Connecting the drivegas tube to a remote control module and absorber interface manifold

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Ohmeda 7800 Ventilator

Verbinden Sie mit der

Inspirations - seite des

Beatmungssystems

Verbinden Sie mit

dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen

Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

Restricted to nonflammable agents.

Serieller Ventilatoranschluß

Ohmeda L 7800 Ventilator

7800 Ventilator Lagernummer 7800 Ventilator Seriennummer

~ 100/120V , 0.5A 220/240V , 0.25A

50/60 Hz

Ohmeda Madison WI 53707 7550 A Division of BOC Health Care Inc

BOC Health Care

Made in USA

AA.32.006AA.32.129

3 4

576

1. Supply gas connection

2. Drive-gas connection to 17-mm inlet port

3. GMS Absorber

4. Interface manifold

5. Bellows assembly

6. 17-mm inlet port

7. 19-mm or 30-mm exhaust port

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2/Getting Started

Setting up the control module with an Ohmeda Excel Anesthesia System

For the ventilator to function as an integrated component of an Ohmeda Excel Anesthesia System, the anesthesia system must contain internal wiring that is designed to accommodate the 7800 Ventilator. All Excel systems built since November 1989 contain this wiring. Older Excel systems must be modified by trained service personnel to work with the 7800 Ventilator.

Your machine may be equipped with a sensor interface panel. Check for this panel under the table top of your Excel machine. If the panel is not present, contact your Ohmeda service representative.

Included with the ventilator configuration for Ohmeda Excel Anesthesia Systems are two additional components that you, the user, can install. These components, which connect to the internal wiring, are the interface cable and the sensor interface.

Connect sensor interface

Connecting the sensor interface

Connecting the interface cable

Sensors for the oxygen and volume sensors connect to the sensor interface, which is a small box that attaches to a “D” connector that is under the anesthesia system’s table. You need a small screwdriver to install this component.

1. Check the left side of the anesthesia machine, under the table, to see if the sensor interface is already installed. The sensor interface is a small box that includes two connectors labeled “vol” and “O2.” If the sensor interface is already in place, move to “installing the interface cable.”

2. A plastic cover protects the 15-pin, female “D” connector that is on the left side of the anesthesia machine, under the table. Remove this cover.

3. Align the 15-pin, male “D” connector that is on the interface box with the 15-pin, female connector that is on the anesthesia machine. Make sure the two captive bolts in the box align with the corresponding threaded posts in the anesthesia machine. Press up gently.

4. Use a small screwdriver to tighten the two screws.

Connect sensor interface cable

Signals from the sensor interface panel and the system master switch are routed to a 25-pin male “D” connector at the rear of the anesthesia system. This connector is labeled “ventilator/monitor pod interface.” The Excel interface cable carries these signals from the 25-pin connector to the 15-pin connector that is on the ventilator’s Excel interface panel.

1. Route the interface cable from the rear of the ventilator to the lower right of the anesthesia machine’s back.

2. Insert the 15-pin male “D” connector that is on the cable into the 15pin female “D” connector that is labeled “Excel interface” on the ventilator.

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2/Getting Started

3. Tighten the two screws that hold the connector in place.

4. A plastic cover protects the 25-pin, male “D” connector (labeled “ventilator/monitor pod interface”) that is mounted vertically at the lower right of the anesthesia machine’s back. Remove this cover.

5. Insert the 25-pin, female “D” connector that is on the cable into the 25-pin, male “D” connector that is on the anesthesia machine.

6. Tighten the two screws that hold the connector in place.

Figure 2-12

Installing the Excel sensor interface panel

Oxygen Power Outlet

Monitors

Vol

Figure 2-13

Excel interface cable

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Use Only Oxygen 35-75 psig (241-517-kPa)

Inspirations - seite des Beatmungssystems

dem Einlaß an der Balgeinheit des Ventilators

∑Warnung:Verschließen

Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

Serieller Ventilatoranschluß

Verbinden Sie mit der

Verbinden Sie mit

AA.11.009

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AA.32.017

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2/Getting Started

The control module’s location in an Ohmeda Excel Anesthesia System

On all Ohmeda Excel Anesthesia Systems, the ventilator’s control module can be mounted on a shelf or on an optional arm that is installed in the dovetail mounting groove.

Figure 2-14

Control module mounted from shelf.

∑

Figure 2-15

Control module mounted on arm on dovetail groove track

AA.32.015

WARNING: When the ventilator is mounted on a dovetail groove on an Ohmeda Excel Anesthesia Machine, extra weight must be added to the machine’s base to reduce the possibility of the machine tipping over.

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AA.32.013

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2/Getting Started

When the bellows assembly is remotely located on an arm

To make these connections you’ll need one of the optional kits that are listed in “Accessories” in the appendix.

1. Connect the supply gas hose to the control module’s connector that is labeled either “use only oxygen” or “use only medical grade air.”

Figure 2-16

Connecting the drivegas tube to a bellows assembly that is mounted on an arm on an Ohmeda Excel Anesthesia System

Benutzen Sie nur Keimfreie Luft

(241-517 kPa)

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Verbinden Sie mit der Inspirations - seite des Beatmungssystems

Verbinden Sie mit dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

AA.32.018

To Anesthesia Machine

Exhause Inlet

1. 17-mm Inlet

2. Drive-gas tube

3. Supply gas filter, ventilators set up for air supply gas only

4. Supply gas connection

2. An optional 100-cm long, drive-gas tube carries drive-gas from the control module to the bellows assembly. Connect one end of this tube to the optional 90-degree adapter that connects to the control module. The 90-degree adapter has an internal O-ring; make sure it is in place.

3. Use the set screws on the 90-degree adapter to attach the adapter to the connector labeled “connect to bellows ass’y inlet” on the control module’s rear panel.

4. Connect the other end of the tubing to the far right 17-mm port on the rear of the bellows assembly.

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2/Getting Started

Figure 2-17

Connections between an absorber and a bellows assembly

Verbinden Sie mit der Inspirations - seite des Beatmungssystems

Verbinden Sie mit

dem Einlaß an der Balgeinheit des

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Ventilators

∑

Warnung:Verschließen Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

AA.32.024

1. Drive-gas tube

2. 30-mm/19-mm port

3. 17-mm port

4. To waste gas scavenging system

5. 22-mm port

6. Supply gas

7. Supply gas filter, ventilators set up for air supply gas only

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2/Getting Started

Making the monitoring connections

Where monitors connect

How you make the monitoring connections depends upon the type of anesthesia system and breathing system you use. The Ohmeda Excel Anesthesia System includes a sensor interface panel that connects the ventilator’s oxygen- and volume-sensor cables to the control module. On other systems, all of which use the stand-alone configuration, these cables connect directly to the front of the control module. At the sensor end of the connections, the Ohmeda GMS Absorber provides ports that connect the oxygen sensor and pressure-sensing tube to the inspiratory side of the breathing system. To provide these ports for other types of breathing systems you must use the adapters that are provided with the ventilator.

Connecting the pressure sensing tube

The airway-pressure sensor is housed in the control module. A clear, 3mm (1/8-inch) tube connects between the control module and the distal sensing tee, which must be in the inspiratory limb of the breathing system.

For pressure monitoring to function correctly, the distal-sensing tee must connect to the inspiratory side of the breathing system.

1. A barbed connector on either the absorber system or the patientcircuit adapter provides the distal-sensing tee for the ventilator’s pressure sensor. Install one end of the sensing tube onto the barbed fitting.

∑

2. Install the tube’s free end onto the barbed connector labeled “connect to inspiratory limb of breathing system” on the control module’s rear panel.

WARNING: Position the pressure-sensing tube so that the absorber arm cannot pinch the tube. If the tube is pinched, the system’s pressure monitoring will not function correctly

WARNING: When used, the oxygen-sensor adapter and the pressure-sensor’s patient-circuit adapter must be connected to the inspiratory side of the patient breathing system. If these devices are not correctly connected to the inspiratory side of the patient breathing system, oxygen and pressure monitoring and related alarms will not function properly.

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Figure 2-18

Connecting the pressure-sensing tube to the Ohmeda GMS Absorber or the patient circuit pressure-sensing tee

Figure 2-19

Connecting the pressure-sensing tube to the ventilator

2-16 1500-0134-000 02/01/93

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Ohmeda 7800 Ventilator

Verbinden Sie mit der

Inspirations - seite des

Beatmungssystems

Verbinden Sie mit

dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen

Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

Restricted to nonflammable agents.

Serieller Ventilatoranschluß

Ohmeda L 7800 Ventilator

7800 Ventilator Lagernummer 7800 Ventilator Seriennummer

~ ~

100/120V , 0.5A

Made in USA

220/240V , 0.25A

50/60 Hz

Ohmeda Madison WI 53707 7550 A Division of BOC Health Care Inc

BOC Health Care

AA.32.006 AA.15.007; AA.33.005,6,9

2-16

Page 27

2/Getting Started

Connecting the volume sensor

The volume sensor cartridge must be placed in the expiratory limb of the breathing system, either in the distal or proximal position. Placing the cartridge at the distal position in the expiratory limb lets the system detect reverse flow and generate reverse flow alarms. You may also place the volume sensor cartridge at the proximal end of the “Y” connector; however, you then must use the setup page to disable the reverse flow alarms that would otherwise be generated when the patient inhales.

WARNING: When the volume sensor is in the distal position of the

∑

breathing system, confirm that the reverse-flow alarm is enabled. Do not use the system with the reverse-flow alarm disabled if the volume sensor is in the distal position.

To install the volume sensor assembly

Figure 2-20

Connecting the volume sensor to the Excel machine’s sensor interface panel

Figure 2-21

Connecting the volume sensor to the control module on a standalone ventilator.

1. Insert the sensor cable plug into the volume monitor receptacle on either the anesthesia machine’s sensor interface panel or the ventilator’s control module.

Vol

Monitors

(25% T )

Ohmeda 7800 Ventilator L

300

200

100

500

1500

1000

100

B/min

Low v

+ + + + + +

60 21 00

L/min % %

L/min

Low O2 High O

- - - -- -

PUSH

TURN

cm H O

10010 100

AA.32.008

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AA.32.034

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2/Getting Started

2. The volume sensor cartridge must be placed in the expiratory limb of the breathing system, either in the distal or proximal position.

If you are using a Bain circuit

Figure 2-22

Inserting the volume sensor into the distal location in the breathing system

Figure 2-23

Inserting the volume sensor into the proximal location in the breathing system

If you connect a Bain circuit and Bain circuit adapter to the Ohmeda 7800 Ventilator, you must place the volume sensor assembly in the proximal Bain circuit position, between the end of the Bain circuit and the patient connector to the ET (Endotracheal Tube) or mask. (See “Using a Bain circuit” in the appendix.)

AA.33.007

∑

AA.33.002

3. Clip the sensor over the cartridge. The arrows on the sensor must point in the direction of gas flow during expiration; the arrows must point away from the patient.

WARNING: Take care not to crack or break the volume sensor cartridge. When you are placing the cartridge on the absorber, be certain to obtain a secure fit, but do not force the cartridge in place as tightly as possible. Avoid striking the cartridge. A broken or cracked cartridge could cause a circuit disconnection and a break in the breathing system.

WARNING: The volume cartridge and sensor must be correctly installed at either the distal location in the patient circuit’s expiratory limb or the proximal end of the “Y” connector. If the cartridge and sensor are installed incorrectly, volume data will be inaccurate and associated alarms, including the apnea and low-minute-volume alarms, will not function properly.

AA.33.002

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WARNING: Destroy old or malfunctioning volume sensor cartridges to

∑

Figure 2-24

Attaching the volume clip to the volume sensor cartridge

prevent inadvertent reuse. WARNING: Position the volume sensor’s cable so that the absorber arm

cannot pinch the cable. If the cable is pinched, the system’s volume monitoring may not function correctly.

MD.10.016

Figure 2-25

Volume clip correctly installed on volume sensor cartridge

∑ w

MD.10.017

Connecting the oxygen sensor

General

WARNING: Disconnecting the O2 sensor without removing and short- ing the sensor cartridge can cause false high O2 readings that may take hours to stabilize.

CAUTION: The cable on the O2 sensor must point up to help keep the contacts and the front of the cartridge free of condensate.

A newly installed O2 sensor cartridge needs five minutes of connection time to stabilize. This waiting period has nothing to do with the sensor response time which is much faster.

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See “6/Maintaining the Ventilator.” for information on sensor housing disassembly and reassembly as well as maintaining and replacing the oxygen sensor cartridge.

1. Insert the sensor cable plug into the oxygen monitor receptacle marked either on the anesthesia machine’s sensor interface panel or on the ventilator’s control module. To reduce cartridge wear, avoid leaving the sensor unplugged.

Figure 2-26

Oxygen sensor, exploded view

MD.02.032

Figure 2-27

Connecting the oxygen sensor to an Excel machine’s sensor interface panel

1 2 3 4

1. Sensor Housing

2. Oxygen sensing cartridge

3. Inner O-ring

4. Outer O-ring

Vol

Monitors

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AA.11.272

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2/Getting Started

Figure 2-28

Connecting the oxygen sensor to the ventilator’s interface panel on a stand alone ventilator.

(25% T )

Ohmeda 7800 Ventilator

300

200

100

500

1000

1500

B/min

100

L/min

Low v

Low O

High O

+ + + + + +

60 21 00

- - - -- -

L/min % %

208010010 100

PUSH

TURN

cm H O

2. Insert the sensor into either the absorber’s sensor port or the port provided by the oxygen-sensor tee in the inspiratory limb.

3. Calibrate the oxygen sensor as described in “6/Maintaining the Ventilator.”

AA.32.035AA.33.008AA.15.027

Figure 2-29

Oxygen sensor locations, see “Accessories and Replaceable parts for oxygen sensor tee part number

If any part of the sensor assembly is damaged or malfunctions, replace the entire assembly. In addition, the oxygen cartridges wear out and must be periodically replaced. See “6/Maintaining the Ventilator.” for information about maintaining and replacing the oxygen sensor cartridge.

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2/Getting Started

If, during operation, the sensor’s temperature is lower than or equal to the breathing gas dew point temperature, water vapor will condense on the sensor’s sensor screen. This condensate may reduce the amount of oxygen reaching the sensor’s screen, which causes the ventilator to display lower than actual oxygen-concentration values.

WARNING: Position the oxygen sensor’s cable so that the absorber arm

∑

Charging the battery

cannot pinch the cable. If the cable is pinched, the system’s oxygen monitoring may not function correctly.

WARNING: When used, the oxygen-sensor adapter and the pressuresensor’s patient-circuit adapter must be connected to the inspiratory side of the patient breathing system. If these devices are not correctly connected to the inspiratory side of the patient breathing system, oxygen and pressure monitoring and related alarms will not function properly.

CAUTION: When in use, the oxygen sensor should always point down to reduce condensation collecting on the sensor surfaces.

A built-in rechargeable battery provides backup power to the ventilator. This battery is shipped uncharged. Before using the ventilator on a patient, plug the control module into an energized ~ outlet for at least 24 hours to charge the battery.

CAUTION: If the integrity of the protective earth ground is in question, the ventilator may be run on its fully charged battery. However, this internal battery is for backup and not intended to operate the ventilator unless there is an emergency situation.

Long Term Ventilator Storage

It is not necessary to disconnect the rechargeable batteries before long term storage.

If the ventilator is to be stored for an extended period of time, the batteries will eventually discharge. This is not destructive to the ventilator or the batteries, however, the ventilator must be plugged into a wall outlet for at least 24 hours prior to use to fully recharge the batteries.

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3/General Information

The controls, connectors, and display 3-1

The ventilator control module’s front panel 3-1 The ventilator control module’s rear panel 3-5

The ventilator’s modes 3-7

The sigh function 3-7

The alarm system 3-8

Alarm quick reference charts 3-9

Alarm definitions 3-11 Theory of operation 3-16

The ventilation cycle 3-16 Volume monitoring 3-18 Airway pressure monitoring 3-18 Oxygen monitoring 3-18 Control range computation 3-18 Tidal volume compensation 3-20

The controls, connectors, and display

The control module serves three functions: it controls mechanical ventilation; it contains the ventilator’s integrated monitors, which provide oxygen, airway-pressure, and exhaled-volume monitoring; and it supplies the ventilator’s alarm system. By using the control module’s front panel knobs, pushwheels, and display, you can set and view the ventilator’s operating parameters and alarm limits, view output from the integrated monitors, and initiate mechanical ventilation. Switching ON the ventilator’s power (with either the control module’s power switch or the anesthesia system’s master switch, depending on your system’s configuration) enables the ventilator’s monitors and alarm system, even if the mechanical ventilation switch is OFF.

The ventilator control module’s front panel

Display screen The ventilator’s Liquid Crystal Display screen serves three functions: on

its top line it provides numeric readouts for expired tidal volume, breath rate, expired minute volume and inspired oxygen concentration; on its bottom line it displays messages such as alarms and control settings. For certain functions, such as the setup page, the ventilator will display instructions on both lines of the screen.

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Figure 3-1

Front panel controls for a stand-alone ventilator.

Excel system ventilators have the same controls.

Ohmeda 7800 Ventilator

300

200

100

1. Inspiratory pause button

2. Alarm set pushwheels

3. Inspiratory pressure limit knob

4. Oxygen calibration knob

5. Inspiratory flow knob

6. Breath rate knob

7. Tidal volume knob

8. Alarm silence button

9. Mechanical ventilation switch

10. Screen

500

1000

1500

(25% T )

B/min

100

Low v

+ + + + + +

60 21 00

- - - -- -

L/min % %

L/min

Low O

High O

PUSH

TURN

cm H O

10010 100

AA.32.033

567

Tidal volume knob The tidal volume knob lets you set the tidal volume at levels from 50 mL

to 1500 mL. As you turn the knob , the ventilator displays the tidal volume setting as well as the resulting I:E ratio. The resolution varies within four ranges, depending on the tidal volume knob ’s position. In the range from 50 mL to 100 mL, the tidal volume can be set in 2-milliliter increments. In the range from 100 mL to 250 mL, the tidal volume can be set in 5-milliliter increments. In the range of 250 mL to 1000 mL, the tidal volume can be set in 10-milliliter increments. And in the range of 1000 mL and up, the tidal volume resolution is 20-mL.

To check the tidal volume setting without changing its value, just touch the front of the knob ; the ventilator will then display the current tidal volume setting and I:E ratio.

Breath rate knob Turning the rate knob changes the breath rate used for mechanical

ventilation. The ventilator displays the rate as it changes as well as the resulting I:E ratio. The rate is adjustable from 2 breaths per minute to 100 breaths per minute in whole number increments. Touching the rate knob will display the current rate and I:E ratio setting on the screen.

Inspiratory flow knob The inspiratory flow knob lets you set the inspiratory flow rate, which is

continuously variable from 10 liters per minute to 100 liters per minute in increments of 1. Whenever you adjust or just touch the inspiratory flow knob , the ventilator will display the current I:E ratio, which it calculates based on the set inspiratory flow, tidal volume, breath rate, and the inspiratory pause status. Because the inspiratory flow is continuously variable within its range, the ventilator’s actual I:E ratios are continuously variable from 1:0.5 to 1:999. Rather than display I:E ratios in non-

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standard increments, such as 1:2.13 or 1:1.97, the ventilator displays the I:E ratio rounded to the nearest 0.5. For example, when the ventilator uses a ratio of 1:2.13, it displays 1:2. And when it uses 1:1.97, it displays 1:2.

Inspiratory pressure limit knob

Both the maximum inspiratory pressure and sustained-pressure alarm limits are set by the inspiratory pressure limit knob , which must be pushed in while turning to change the settings; the ventilator sets the sustained pressure limit to correspond to the inspiratory pressure limit knob setting. The maximum inspiratory pressure limit range is 20 to 100 cm H2O with a resolution of 1 cm. For inspiratory pressure limits of 20 cm H2O to 60 cm H2O, the ventilator sets the sustained pressure limit to one half the inspiratory pressure limit. Any inspiratory pressure limit setting higher than 60 cm H2O will result in a sustained pressure limit of 30 cm H2O.

As you push and turn the inspiratory pressure limit knob , the ventilator will display both the maximum-pressure-limit and sustained-pressurelimit settings. However, unlike the other three control knobs, just touching this knob will not generate a display.

During mechanical ventilation, the maximum inspiratory pressure limit you set is used by the ventilator’s electronically-controlled, automatic, high-pressure-relief system to manage excessive airway pressure. If, while the mechanical ventilation switch is ON, the ventilator detects airway pressure higher than the limit you set, it will generate a high pressure alarm and terminate the inspiratory cycle.

The ventilator also displays a message if you set the inspired pressure limit to more than 60 cm H2O. This message is displayed in the nonmechanical ventilation mode only; during mechanical ventilation this message is not displayed.

Inspiratory pause button

Mechanical ventilation ON/OFF switch

Pressing the inspiratory pause button adds an inspiratory pause—an inflation hold—to the inspiratory cycle. When the inspiratory pause function is active, the ventilator adds an inspiratory pause equal to 25 percent of the set inspiratory time. The ventilator, to maintain the original breath rate, then decreases the expiratory time by the same amount that the inspiratory time is increased; pressing the inspiratory pause button alters the I:E ratio.

After you press the inspiratory pause button, the ventilator displays the new I:E ratio and lights the green indicator on the button to indicate that the inspiratory pause function is active. To disable the inspiratory pause, press the button again; the ventilator will switch OFF the indicator light and display the I:E ratio, which is calculated from the other front-panel control settings.

You can continue to adjust the ventilator’s front panel controls even when the inspiratory pause function is active. If, while the function is ON, you adjust a front panel control, the instrument takes the inspiratory pause formula into account when it calculates and displays a new I:E ratio.

The mechanical ventilation switch controls mechanical ventilation only. When the switch is OFF, the monitors still function and the alarm system is still active, although certain alarms are enabled only during mechanical ventilation. When you want to start mechanical ventilation, move the switch to ON.

Always switch ON the ventilator (using either the power switch or the anesthesia system’s master switch, depending on your system’s configu-

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ration) and set the ventilator’s controls before switching ON mechanical ventilation.

Alarm set pushwheels Use the three alarm-set pushwheels to change the low-minute-volume,

low-oxygen and high-oxygen alarms’ set points. To increase the value of an alarm set point, push the button directly over the digit you want to change. To decrease the value, push the button under the digit you are changing.

Anytime you change the value of an alarm set point, the ventilator will display, for a few seconds, that alarm’s value. Although all of the digits can be set to zero, the ventilator will not accept certain oxygen alarm settings, and will generate warning messages for others.

The system will not accept low oxygen alarm limits of less than 18 percent. The system also warns you if you set a high oxygen alarm limit below or equal to the low oxygen alarm limit. Setting the high oxygen alarm limit to 00 disables the high O2 alarm.

The oxygen alarm limits are 18 percent to 99 percent in one percent increments. The low minute volume alarm limits are zero liters per minute to 9.9 liters per minute in 0.1 liters per minute increments.

Oxygen calibration thumbwheel

Alarm silence button To silence an audible alarm, press the alarm silence å button. If that

The oxygen calibration thumbwheel is used to calibrate the oxygen monitor’s sensor. Use this thumbwheel during the oxygen monitor calibration procedure only.

alarm condition continues, the alarm will sound again in 30 seconds. If, however, a new alarm condition occurs, its audible alarm will sound immediately. Certain alarms can be silenced permanently, even if the alarm conditions continue. These permanently silenceable alarms include power failure, oxygen sensor failure, low battery, ventilator failure, oxygen calibration error, and volume sensor failure.

When the mechanical ventilation switch is OFF—when the ventilator is in its non-mechanical ventilation mode—pressing the alarm silence button cancels and resets the apnea and low minute volume alarms; the “VOL MON STANDBY” message will be displayed and the two alarms will not sound again even if the alarm conditions continue. However, if the ventilator senses another breath, the alarm timers and sensor circuits will again be activated and any alarm condition that occurs will trigger an appropriate alarm.

The alarm silence button å — combined with the inspiratory pause

button — also provides a way to enter and step through the setup page mode. To enter the setup page, move the mechanical ventilation switch to OFF, hold down the alarm silence button, then press the inspiratory pause button. Once the setup page is displayed, press the alarm silence button again to move from step to step.

Alarm indicator LEDs The two light emitting diodes (LEDs) embedded in the alarm silence å

button indicate the status of alarms. When an alarm condition first occurs, a message will appear on the screen, a tone will sound, and an LED will flash. Once the alarm silence button is pressed, the ventilator will light the LED continuously to remind you that the alarm condition still exists. The red LED is lighted during alarm conditions that require immediate operator response. The yellow LED indicates alarm conditions that require prompt operator response or operator awareness.

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Stand-alone power switch

∑

Figure 3-2

Stand-alone configuration power switch and sensor connectors

The ventilator’s control module has two power modes: ON and “STANDBY.” The power switch determines whether the ventilator is ON or in STANDBY. For the ventilator to operate, the control module must be ON (in standby electrical power is delivered to the module but all of the module’s functions are disabled).

WARNING: Switching ON the ventilator before setting the controls may result in inappropriate ventilation of the patient and may activate alarms.

(25% T )

Ohmeda 7800 Ventilator L

300

200

100

500

1000

1500

B/min

100

Low v

+ + + + + +

60 21 00

- - - -- -

L/min % %

L/min

Low O

High O

PUSH

TURN

cm H O

10010 100

AA.32.033

1. Sensor connectors

2. Power switch

Powering ON configurations other than the stand-alone ventilator

How you power ON the control module will depend on your system’s configuration. If your ventilator is a stand-alone device, you will use the power switch on the lower panel of the control module to power ON the ventilator. If, however, your ventilator has been installed in an Ohmeda Excel Anesthesia System, your control module doesn’t have a power switch; instead you will use your anesthesia system’s master switch to power ON the module. When you turn the master switch to ON, the control module will also be powered ON.

WARNING: Switching ON mechanical ventilation before setting the

∑

controls may result in inappropriate ventilation of the patient and may trip alarms that relate to mechanical ventilation.

The ventilator control module’s rear panel

Supply gas input The supply gas is introduced to the ventilator via a connector located on

the rear panel of the control module and is labeled for the type of gas and pressure to be used.

Either oxygen or medical-grade air can be used as a supply gas to the ventilator. Before changing from one supply gas to another, however, qualified service personnel must set the ventilator’s software to operate

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correctly with the new supply gas. (See “Setting the supply gas” in “2/ Getting Started.”)

Drive gas output The ventilator bellows’ drive gas is delivered from the connector labeled

“Connect to Bellows Ass’y Inlet.”

Figure 3-3

The ventilator’s rear panel

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Verbinden Sie mit der Inspirations - seite des Beatmungssystems

Verbinden Sie mit dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

AA.32.021

345

1. Pressure sensing input

2. Drive gas output

3. Excel interface connection

4. RS232 serial interface connection

5. Electrical power connection

6. Supply gas filter, ventilators set up for air supply gas only

7. Supply gas inlet

Pressure sensing input A 3-mm (1/8-inch) inside diameter tube connects to the distal-sensing tee

located in the inspiratory limb of the breathing system to the connector marked “Connect to Inspiratory Limb of Breathing System” on the control module’s rear panel.

Serial interface connector

For remote recording, a 25-pin female “D” type connector that is labeled “Ventilator Serial Interface” provides access to the ventilator’s RS232C serial port, which conforms to the Ohmeda standard communications protocol (see the appendix).

WARNING: When specific DIP switches are set, writing to the

∑

ventilator’s RS232 port can alter the operation of the ventilator’s software, which may result in unpredictable performance. Do not alter the ventilator’s hardware or software.

The Excel interface connector

The Excel interface, which is a 15-pin female “D” connector, appears in only the Excel configuration. Mounted on the back of the control module’s lower panel, the interface connects to the anesthesia machine’s power switch and sensor interface panel, which provides inputs for the volume and oxygen sensors.

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The ventilator’s modes

The Ohmeda 7800 Ventilator uses three basic modes:

• setup page mode The setup page groups parameters not normally adjusted during a

case, such as the screen contrast and the alarm volume.

• mechanical ventilation mode In the mechanical ventilation mode—when the mechanical ventila-

tion switch is ON—patient monitoring and alarms are active, and the control module is driving the bellows assembly.

• non-mechanical ventilation mode In the non-mechanical ventilation mode—when the mechanical

ventilation switch is OFF—mechanical ventilation is OFF but all patient monitors still function and the alarm system is still active, although certain alarms are enabled only during mechanical ventilation.

When you first enter the setup page, the ventilator displays the ventilator model, the software version number it is using, the supply gas setting, the selected language and selected altitude compensation . The ventilator then lets you enable or disable the reverse flow alarm and sigh function, and adjust the screen contrast and audio alarm volume. These parameter settings are stored in the ventilator’s memory even when the system’s power is disconnected; if you are satisfied with these parameter settings, you can skip past the setup page.

In both the non-mechanical ventilation mode and the mechanical ventilation mode, the patient monitoring and the alarms systems are active.

The sigh function

When the sigh function is selected, the ventilator delivers 150 percent of the set tidal volume once every 64th breath. The ventilator accomplishes this by adding 50 percent to the inspiratory and expiratory times while maintaining the set inspiratory flow and I:E ratio. The maximum sigh breath is limited to 1.5 liters. For example, if the set tidal volume is 1 liter, the sigh breath will be 1.5 L (1 L plus 50 percent). But if the set tidal volume is 1.4 L, the sigh breath will still be 1.5 L , because the inspiratory flow decreases to maintain the I:E and limits the VT to 1.5 L.

To turn ON the sigh function, select “sigh on” from the setup page. Once the sigh function is ON, the ventilator will display “sigh on” on the bottom line of its screen. When the ventilator actually delivers the sigh breath, the ventilator will display “sigh breath.” These messages will alternate with other messages the ventilator displays.

When using the sigh function, pay particular attention both to the high pressure alarm setting and to apnea alarms. Because circuit pressure is higher during the sigh breath than during normal cycles, you must set the inspiratory pressure limit knob to compensate for the sigh breath. Also, at low rates the sigh function can cause apnea alarms. The apnea alarm will be triggered if the ventilator does not sense a complete breath in a 30-second period. At a breath rate of two, the sigh function increases the breath period from 30 seconds to 45 seconds, triggering the apnea alarm.

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The alarm system

When the ventilator senses an alarm condition, it will display an appropriate message, which is updated every one-and-a-half seconds until the condition is resolved (apnea alarms are updated at one-second intervals). If a second alarm condition occurs before the first is resolved, the ventilator will alternate the messages for each condition. The ventilator will alternate, at one-and-a-half-second intervals, the alarm messages for as many alarm conditions as exist at one time.

Audible alarms Although when more than one alarm is active the ventilator displays the

messages for all of the alarms (by alternating the messages), it sounds the audible alarm for only the highest priority alarm. If that condition is resolved, the ventilator will then sound the alarm for the next highest priority alarm that occurred. The priority of the audible alarms, from high to low, is:

• Warble

• Intermittent

• Continuous

• Single beep

What the LEDs indicate The two light emitting diodes (LEDs) embedded in the alarm silence å

Silencing alarms To silence an audible alarm, press the alarm silence button. If that alarm

condition continues, the alarm will sound again in 30 seconds. If, however, a new alarm condition occurs, its audible alarm will sound immediately. Certain alarms can be silenced permanently, even if the alarm conditions continue. These permanently silenceable alarms include power failure, oxygen sensor failure, low battery, ventilator failure, oxygen calibration error, and volume sensor failure.

The ventilator’s built-in computer must be functioning correctly for the alarm system to work correctly. If the ventilator’s computer fails, the screen may flash erratically and an intermittent tone will sound; the alarm silence button will not terminate the alarm if the ventilator’s computer fails. Do not attempt to continue using the ventilator if this failure occurs.

Responding to alarms See section 5, “Responding to alarms” for more information.

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Alarm quick reference charts

Alarm Message Alarm Condition LED Tone

APNEA ** Insufficient tidal volume Red, Continuous warble

measured in greater than flashing 120-second period

APNEA ALARM OFF! Tidal volume set to less Yellow, One beep, silences

(Active during non- than 300 mL and continuous automatically mechanical ventilation mechanical ventilation only.) switch set to OFF

APNEA xxx SEC Insufficient tidal volume Yellow, Staged: 30 seconds—

measured in a greater than flashing one warble; 60 seconds— 30-second period two warbles; 90 seconds—

three warbles

CHECK O

SENSOR! Measured oxygen less Yellow, Continuous, permanently

alternating with than five percent flashing silenceable

CHECK GAS SUPPLY

CHECK SETTINGS! Displayed when setup None One beep, silences

page is exited automatically

DRIVE CKT OPEN! Incorrect exhalation valve Yellow, Continuous, permanently

feedback or pressure flashing silenceable switch engaged

HARDWARE ERROR X Hardware malfunction Yellow, Continuous, permanently

flashing silenceable

HIGH OXYGEN! Oxygen concentration Yellow, Intermittent beep

greater than or equal to flashing set limit

HIGH PRESSURE! Circuit pressure above Red, Warble per occurrence

set limit flashing

LIMIT SET ERROR! High oxygen alarm limit Yellow, Continuous

below or same as Low O alarm limit. Or Low O

flashing

alarm limit less than 18 percent

LOW BATTERY! Insufficient battery charge Yellow, Continuous, permanently

flashing silenceable

LOW MINUTE VOL! Minute volume below Yellow, Intermittent beep

set limit flashing

LOW OXYGEN! Oxygen concentration Red,

below set limit flashing Continuous warble

LOW PRESSURE! Pressure change less Red, One warble per breath

(Active during than threshold for at least flashing mechanical ventilation 20 seconds only)

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Alarm Message Alarm Condition LED Tone

LOW SUPPLY PRES! Internal, regulated supply Yellow, Intermittent beep

gas pressure less than flashing 152 kPa (22 psig)

MAX PRES=xxx cm Pressure limit set to more Yellow, One beep, silences

(Active during non- than 60 cm H2O continuous automatically mechanical ventilation only.)

O2 CAL ERROR! Measured oxygen greater Yellow, Continuous, permanently

than 109 percent flashing silenceable

POWER FAIL! a-c power failure Yellow, Continuous, permanently

flashing silenceable

REVERSE FLOW! Flow in wrong direction Yellow, Continuous

(Active during non- equals volume of more flashing mechanical ventilation than 100 mL or 20 mL only.) (when tidal volume knob

set below 300 mL)

REV FLOW ALM OFF Reverse flow alarm Yellow, None

disabled on setup page continuous

SIGH ON Sigh feature on Yellow, None

(Active during continuous mechanical ventilation only.)

SIGH BREATH Sigh breath delivered Yellow, None

(Active during continuous mechanical ventilation only.)

SOFTWARE ERROR X Invalid data or N/A Tone, permanently

malfunctioning alarm silenceable system

SUB-ATMOS PRES! Pressure less than -10 cm Red, Continuous warble

H2O flashing

SUSTAINED PRES! Pressure exceeds set limit Red,

for 15 seconds or more flashing Continuous warble

VENT FAIL xx! Ventilator hardware failure, Yellow, Continuous, permanently

see Vent Fail definition flashing silenceable

VENT SET ERROR! Combination of settings of Yellow, Continuous

ventilator controls out of flashing range

VOL MON STANDBY! System waiting for first Yellow, One beep, silences

breath to activate volume continuous automatically monitoring and apnea timer

VOL SENSOR FAIL! Volume sensor disconnected Yellow, Continuous, permanently

or defective flashing silenceable

- - - - - - - No volume measured during None None

????????? mechanical ventilation

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Alarm definitions

Apnea If the ventilator doesn’t detect a sufficient breath for 30 seconds, an

apnea alarm will be generated. The alarm message will indicate the number of seconds that have passed since the last sufficient breath was detected. The tone will warble once at 30 seconds, twice at 60 seconds, and three times at 90 seconds. At 120 seconds the tone will warble continuously and the alarm message will be “apnea **” only.

The ventilator uses the volume-sensing circuits to activate the apnea alarm. When the ventilator is first powered ON it displays the “vol mon standby” message to indicate that a set threshold of flow is not being sensed and the apnea alarm is not activated. Then, once the ventilator senses a sufficient volume level, it removes the “vol mon standby” message and starts a timer that controls the apnea alarm. Each time the ventilator senses sufficient volume, it resets this apnea timer.

The actual volume threshold required to start or reset the apnea timer varies depending on the level you set on the tidal volume knob. For tidal volume settings between 180 mL and 400 mL, the threshold varies linearly from 20 mL to 100 mL. For tidal volume settings below 180 mL, the threshold is always 20 mL. And for tidal volume settings above 400 mL, the threshold is always 100 mL. In the manual mode, however, once the apnea timer starts, the volume threshold required to reset the timer is 20-mL.

For example, if the tidal volume knob is set to 250 mL, and mechanical ventilation is switched ON, the timer starts and is reset when the ventilator senses a breath of at least 46 mL. If you then increase the tidal volume knob to 320 mL, the ventilator will increase the threshold to 71 mL. In either case, if the timer reaches 30 seconds (because the ventilator didn’t sense enough volume to indicate a breath), the first in the series of four apnea alarms will sound.

Apnea alarm off Because very low flow levels that are not sufficient to trigger the volume-

sensing circuits may occur in spontaneously breathing patients, the ventilator disables the apnea alarm when the tidal volume knob is set to less than 300 mL and mechanical ventilation is switched OFF.

Whenever tidal volume is set to less than 300 mL and the mechanical ventilation switch is OFF, the ventilator, once it has detected a breath, will display “APNEA ALARM OFF.” To enable the apnea alarm while the patient is breathing spontaneously, increase the tidal volume knob to 300 mL or more. Although you should always carefully set the low minute volume pushwheel to enable the low minute volume alarm at an appropriate level, the low minute volume alarm is especially important when the tidal volume knob is set to less than 300 mL, disabling the apnea alarm.

Check O2 sensor/check gas supply

If the ventilator detects less than five percent oxygen, it assumes that either the oxygen sensor has failed or that insufficient oxygen is in the breathing system, and it generates an alarm. A check O2 sensor/check gas supply alarm will also be generated if the sensor isn’t connected correctly, if the sensor is broken, or if no oxygen is in the area of the sensor.

Check settings In the setup page the front panel controls are used to set parameters not

normally adjusted during a case, such as the screen contrast and the alarm volume. Before you use the ventilator on a patient, you must readjust any controls you used in the setup page. To remind you to check your control settings, when you exit the setup page the ventilator displays the “check settings” message.

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Drive circuit open One type of ventilator failure—exhalation valve failure—does not display

a numbered message; instead DRIVE CKT OPEN is displayed. This message can also appear if, during mechanical ventilation, the absorber’s Bag/APL-ventilation switch is in the “BAG/APL” position. During this alarm, the ventilator will attempt to continue monitoring and mechanical ventilation.

1. Check the patient.

2. If mechanical ventilation is ON, make sure the absorber’s Bag/APLventilation switch is in the “ventilator” position, if applicable.

Hardware error This display (error A, B, and C) and alarm should not occur unless there

is a problem with the ventilator control module hardware. The alarm is

silenceable with the alarm silence å button. Mechanical ventilation

does not turn OFF.

∑

High oxygen If the ventilator detects an oxygen concentration equal to or higher than

High pressure If, during mechanical ventilation or while in the non-mechanical ventila-

Limit setting error If you attempt to set the high oxygen alarm limit for a level below or

Low battery Two sources can power the control module: the ventilator’s power

WARNING: Do not use the ventilator if this display and alarm occur.

the one you set using the high-O2 pushwheel, the ventilator will generate a high oxygen alarm.

tion mode, the ventilator detects airway pressure higher than the limit you set using the inspiratory pressure limit control, the ventilator will generate a high pressure alarm. In addition, during mechanical ventilation only, the ventilator uses automatic, high-pressure relief to manage excessive airway pressure. If, while the mechanical ventilation switch is ON, the airway pressure rises to a level that causes a high pressure alarm, the ventilator will release the remaining drive gas into the atmosphere and end inspiration.

equal to the low oxygen limit, the ventilator will generate a limit setting error alarm. This alarm will also be generated if you attempt to set the low oxygen alarm limit for less than 18 percent.

supply and the ventilator’s backup battery. If the power supply fails, either because of an electronic failure or because a-c power is lost, the backup battery takes over.

If the battery’s voltage discharges below a set threshold, the ventilator

generates a “low battery” alarm. Pressing the alarm silence å button

permanently silences the alarm tone. To remind you of the condition the LED remains lighted and the alarm message will still appear.

Low minute volume If the ventilator detects that the minute volume is less than the level you

set using the low minute volume pushwheel, the ventilator will generate an alarm. To reduce nuisance alarms that can be generated when control settings are changed, whenever you adjust the tidal volume knob or the rate knob, move the mechanical ventilation switch to ON, or exit the volume monitor standby condition, the ventilator will disable the low minute volume alarm for 40 seconds.

WARNING: Always correctly set the low minute volume alarm and use

∑

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CO2 monitoring to aid in the detection of breathing system disconnections.

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Low oxygen If the ventilator detects an oxygen concentration lower than the one you

set using the low-O2 pushwheel, the ventilator will generate a low oxygen alarm.

Low pressure The ventilator generates a low pressure alarm if, for at least 20 seconds,

the airway pressure fails to change by a value that varies proportionally to the setting of the inspiratory flow knob. To determine the change in airway pressure, the system compares the airway pressure at a point 50 milliseconds after the peak pressure to a point at the end of patient exhalation. The amount of change required to prevent an alarm from triggering will vary between 4 cm H2O to 9 cm H2O to correspond to the inspiratory-flow range of 10 liters per minute to 100 liters per minute. For example, if the inspiratory flow is set to 30 liters per minute, the low pressure alarm will activate if the pressure doesn’t change by at least 5.1 cm H2O. But if the inspiratory flow is set to 80 liters per minute, the change must be at least 7.9 cm H2O to keep the alarm from activating.

Unlike other alarms, the low pressure alarm is active only when mechanical ventilation is switched ON.

Low supply pressure If the ventilator’s internal, regulated supply gas pressure is less than

152 kPa (22 psig), the ventilator will generate a low supply pressure alarm.

Maximum pressure limit Anytime you adjust the inspiratory pressure limit knob, the ventilator

will briefly display the pressure limit in centimeters of water. However, if the ventilator is in the non-mechanical ventilation mode and the inspiratory pressure limit is set to more than 60 cm H2O, the ventilator will also light the yellow alarm LED and will continuously display the “max pres=xxx cm” reminder. The pressure limit reminder is displayed in the non-mechanical ventilation mode only; during mechanical ventilation this reminder is disabled.

Oxygen calibration error Some oxygen sensors may deliver a signal that is out of the ventilator’s

range. If the ventilator senses too large of a sensor signal, it will display the “O2 cal error” message. To remove the message, continue to turn the O2 calibration knob.

Power failure If the a-c power to the ventilator is interrupted, the ventilator will gener-

ate a power failure alarm.

Reverse flow If the ventilator senses reverse flow of an unacceptable volume, it will

generate an alarm. The volume that will trigger a reverse flow alarm depends on the tidal volume you set. If you set the tidal volume knob for less than 300 mL, then 20 mL or more will trigger an alarm. However, if you set the tidal volume knob for 300 mL or more, the ventilator will allow up to 100 mL before triggering an alarm. Once the alarm has been triggered, two forward breaths must be sensed before the ventilator will automatically switch OFF the alarm.

The reverse flow alarm is intended to warn you of inadvertent reverse flow conditions, such as those caused by a defective or sticking exhalation check valve. These kinds of conditions will be detected only when the volume sensor is correctly placed at the distal position of the expiratory limb of the breathing system. If you place the volume sensor at the proximal end of the “Y” connector, volume monitoring will still function. However, when the volume sensor is located at the proximal position, a reverse flow condition will exist each time the patient inhales and the reverse flow alarm will activate for each breath. To disable the reverse flow alarm, select “rev flow alm off” from the setup page (see “Using the setup page” in “5/Operating the Ventilator”).

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WARNING: The reverse flow alarm will function correctly only if the

∑

Reverse flow alarm off To advise you that the reverse flow alarm is disabled, in the non-me-

Sigh alarms Sigh breath replaces sigh on until the next breath is delivered

volume sensor cartridge is working correctly and is properly placed in the distal position of the expiratory limb of the breathing system.

WARNING: When the volume sensor is in the distal position of the breathing system, check the ventilator’s setup page to confirm that the reverse flow alarm is enabled. Do not use the system with the reverse flow alarm disabled if the volume sensor is in the distal position.

chanical ventilation mode the ventilator will repeatedly flash this message. If you power ON the control module with the alarm disabled and mechanical ventilation ON (although you should always have the mechanical ventilation switch set to OFF when you power ON), the message will be displayed once.

Placing the volume sensor cartridge at the distal position in the expiratory limb lets the system detect reverse flow and generate reverse flow alarms. You may also place the volume sensor cartridge at the proximal end of the “Y” connector; however, you then must use the setup page to disable the reverse flow alarms that would otherwise be generated when the patient inhales.

Software error This display (error A through F) and alarm should not occur unless there

is a problem with the ventilator software programs. The alarm is

silenceable with the alarm silence å button. Mechanical ventilation

does not turn OFF.

∑

Sub-atmospheric pressure

Sustained pressure The ventilator sets the sustained pressure limit to correspond to the

Ventilator failure Ventilator failure messages can indicate anything from a defective IC

WARNING: Do not use the ventilator if this display and alarm occur.

If the ventilator detects airway pressure of less than -10 cm H2O, it will generate a sub atmospheric pressure alarm. For example, airway pressure of -12 cm H2O will cause an alarm.

inspiratory pressure limit knob’s setting. For maximum inspiratory pressure limits of 20 cm H2O to 60 cm H2O, the ventilator sets the sustained pressure limit to one half the inspiratory pressure limit. For example, if the inspiratory pressure limit is 42 cm H2O, the sustained pressure limit will be 21 cm H2O. However, any inspiratory pressure limit setting of more than 60 cm H2O will result in a sustained pressure limit of 30 cm H2O. For example, inspiratory pressure limits of 65 cm H2O and 80 cm H2O will both result in a sustained pressure limit of 30 cm H2O.

Anytime the airway pressure exceeds—for 15 seconds or more—the sustained pressure limit set by the inspiratory pressure limit knob, the ventilator will generate a sustained pressure alarm.

chip to excessive pressure in the ventilator’s gas supply. However, some ventilator problems may not generate any ventilator failure message, even though the ventilator may not be functioning correctly.

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WARNING: Do not attempt to use the ventilator while a ventilator

∑

failure message is displayed.

And, even if no ventilator failure message is displayed, do not use the ventilator if you suspect a malfunction has occurred.

IMPORTANT

If the ventilator experiences extreme electrical interference, it may interrupt mechanical ventilation. If this interruption occurs, the ventilator generates an internal reset function and resumes normal operation after two (2) seconds. For situations where continuous electrical interference is experienced by the ventilator, causing a continuous interruption, the ventilator’s internal reset repeats until the interference ceases.

If the electrical interference is continuously present and mechanical ventilation is interrupted for approximately 30 seconds, the ventilator produces a continuous beeping audio alarm. Manual ventilation of the patient must be performed while the mechanical ventilation is interrupted. When the electrical interference ceases, the continuous beeping audio alarm can be silenced only by turning, as applicable, the ventilator or anesthesia machine power switch OFF and after five seconds back ON.

WARNING: Manual ventilation must be performed when electrical

∑

Ventilator setting error If you attempt to set a combination of the inspiratory-flow, tidal-volume,

interference causes interruption of ventilator delivered mechanical ventilation. Manual ventilation must be continued until the ventilator resumes normal operation or an alternate ventilator/anesthesia system can be used.

See the “7/Service Procedures” for descriptions of specific ventilator failure messages.

WARNING: The use of electrosurgical units or other devices that radiate high-intensity electrical fields can affect the operation of the ventilator and monitors attached to the patient. Maintain as much distance as possible between the electrosurgical leads and the cables to the flow and oxygen sensors. Do not drape the electrosurgical leads across the absorber or the anesthesia machine. Do not let the electrosurgical leads rest on any surface of the anesthesia system. Constant surveillance of all monitoring and life support equipment is mandatory whenever electrosurgical devices are in operation, on, or in the vicinity of the patient.

rate, and inspiratory-pause controls that results in a level the ventilator is not designed to deliver, the ventilator will continue to use the most recent acceptable settings, and will generate a “VENT SET ERROR” alarm until the control combination is corrected. For example, a tidal volume of 500 mL, combined with a rate of 20 B/min., and an inspiratory flow of 10 liters per minute will trigger a ventilator setting error. To remove the error, either decrease the tidal volume setting, or decrease the rate setting, or Increase the flow setting.

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WARNING: Do not use the ventilator while the “vent set error” mes-

∑

Volume monitor standby When the ventilator is first powered ON, or when the ventilator is

Volume sensor failure This message will be displayed if the volume sensor’s heater voltage is

sage is displayed; when this message is displayed, the control settings do not reflect the settings the ventilator is using. If the “vent set error” message is displayed during mechanical ventilation, the system will use the most recent acceptable settings. If, however, the ventilator is powered ON in the “vent set error” condition, moving the ventilation switch to ON will not start mechanical ventilation until the controls are moved to an acceptable setting.

switched from mechanical ventilation to the non-mechanical ventilation mode, or when—while the ventilator is in the non-mechanical ventilation mode—the alarm silence button is pressed, the ventilator displays the “VOL MON STANDBY” message to indicate that the alarm system is waiting for a sufficient breath. Once the ventilator senses a sufficient volume level, it removes the “VOL MON STANDBY” message and starts the timers that control the apnea alarms.

too low, which can happen if the volume sensor clip is broken or disconnected.

Dashes displayed in place of readings

Question marks displayed in place of readings

If the system doesn’t measure any volume during mechanical ventilation, it will display dashes in place of the volume and rate data.

Certain combinations of ventilator front panel control settings can result in ventilation conditions the ventilator can deliver but the volume sensor cannot measure. If you set a control combination the ventilator can deliver, but the volume monitor cannot measure, or if—in the nonmechanical ventilation mode—breathing occurs that the monitor cannot measure, the ventilator will display question marks in place of the VT, VE, and rate readings.

Theory of operation

The ventilation cycle

The bellows assembly is the interface between the control module’s driving-gas circuit and the patient breathing system. During inspiration, driving gas from the control module compresses the bellows; during expiration, breathing system gas fills the bellows, forcing it to rise. As the ventilator cycles from inspiration to expiration, a set of valves controls the pressure in the two circuits.

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Figure 3-4

Ventilation cycle

AA.04.039

1. Exhalation valve

2. Driving gas

3. Patient circuit gas

4. Pressure relief valve

5. To patient circuit

Inspiration starts when the ventilator’s control module closes the exhalation valve (1) and delivers driving-gas (2) to the bellows housing. As the driving-gas pressure increases, the pressure relief valve (4) closes and the bellows is compressed. This bellows compression forces gas out of the bellows, into the patientcircuit (5), breathing system, and into the patient’s lungs. The control module computes the volume, rate, and timing of driving-gas needed, and delivers drive gas until it reaches the calculated gas volume; then flow stops. If the ventilator detects airway pressure higher than the limit you set using the inspiratory pressure limit control, the ventilator generates a high pressure alarm, opens the exhalation valve, and ends inspiration.

6. Driving gas

7. From patient circuit

At the start of expiration, the exhalation valve opens and the gas-flow direction in driving-gas (6) and the patient-circuit (7) breathing system reverses. Fresh gas from the anesthesia machine and exhaled gases from the breathing system enter the bellows’ interior, forcing the bellows to expand; the extending bellows displaces the drive-gas (6), which is released to the atmosphere.

8. Excess patient circuit gas

If the pressure inside the bellows exceeds 2.5 cm H during the expiratory cycle (when the bellows has extended completely), the pressure relief valve opens and releases any excess breathing system gas (8)through the bellows assembly exhaust port.

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Volume monitoring

Two volume measurements—tidal volume (VT) and expired minute volume (VE)—and the breath rate (Rate) are displayed on the ventilator’s front panel. The ventilator measures all of these displayed values directly, based on the readings of a single volume sensor in the breathing system. Because of compliance losses and fresh gas gains in the breathing system, these measured and displayed values may be different than the values you set using the ventilator’s front panel controls.

To measure the exhaled patient volume, the ventilator uses a volume sensor cartridge which contains a vane that is forced to rotate by gas traveling through the breathing system. A clip-on, optically coupled sensor translates the direction and speed of the vane’s rotation into electrical pulses for the ventilator’s microprocessor to analyze. The sensor clip also contains a heater, which is used to help prevent condensation in the transducer cartridge. Anytime the control module is ON, the heater is ON.

Airway pressure monitoring

The Ohmeda 7800 Ventilator continuously monitors airway pressures in the patient breathing system, and then uses this information to generate alarms and manage airway pressure. This airway pressure monitoring information is used only internally by the ventilator; the ventilator does not display this information.

The ventilator’s airway pressure monitoring uses a transducer located inside the ventilator control module. A flexible tube fastened to a sensing port in the breathing system connects to this transducer in the control module.

Oxygen monitoring

The Ohmeda 7800 Ventilator uses a galvanic fuel cell to measure the concentration of inspired oxygen. In addition to displaying the oxygen concentration, the ventilator uses this information to generate highoxygen and low-oxygen alarms based on the levels set using the front panel pushwheels.

Oxidation gradually consumes the electrode inside the oxygen sensor, so it must be calibrated periodically and occasionally replaced (See Section 6, “Maintaining the Oxygen Sensor”).

Control range computation

The control module establishes four operating parameters directly from the settings of the four front panel controls:

• The tidal-volume knob sets (VT), the volume of each breath in mL.

• The rate knob sets (R), the number of breaths per minute.

• The inspiratory flow knob sets (F), the instantaneous gas flow in liters per minute. However, the ventilator doesn’t display this flow; instead it calculates and displays the I:E ratio.

• The inspiratory pause button determines the status of the inspiratory pause function, which adds an inspiratory pause—an inflation hold— to the inspiratory cycle.

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Then, based on the settings of the tidal volume, rate, and inspiratory flow knobs, the control module calculates three more operating parameters (these calculations assume that the sigh and inspiratory pause functions are OFF):

I =

E =

I:E =

V x 60

F x 1000

60 - I

R I

• Inspiratory time (I), in seconds, is derived from the tidal-volume and flow settings.

• Expiratory time (E), in seconds, is derived from the inspiratory time and the rate setting.

• I:E ratio (I:E), is the ratio of the inspiratory time to the expiratory time. The inspiratory side of the ratio is always expressed as “1.” Whenever the inspiratory flow knob is touched, the control module displays the approximated I:E ratio. Because the inspiratory flow is continuously variable within its range, the ventilator’s actual I:E ratios are continuously variable from 1:0.5 to 1:999. However, the ventilator displays the I:E ratio rounded to the nearest 0.5.

Although all of the front panel knobs can be set independently to their full-scale limits, certain combinations of the tidal-volume, rate, and inspiratory-flow knobs will result in I:E ratios the ventilator is not designed to deliver. The control module will not accept I:E levels less than 1:0.5. Instead, the ventilator continues to use the most recent acceptable settings, and displays the ventilator setting error message until the I:E ratio is corrected.

For example, if the tidal volume is set to 250 mL, the rate is set to 40 BPM, and the flow is set to 10 liters per minute, the I:E ratio will be only 1:0.33. To increase the I:E ratio to 1:0.5 or more, you must either decrease the tidal volume, decrease the rate, or increase the inspiratory flow. Once the ventilator senses an acceptable control combination, it removes the “vent set error” message and implements the new settings.

Figure 3-5

Diagram of the ventilator’s range

100

Flow L/min

"B"

"C"

2 4 10 20 30 40 50 60 70 80 90 100

Rate B/min TV mL

1500 1250 1000 750 500 250 066 50

"A"

"D"

This diagram illustrates the ranges of front-panel control combinations the ventilator is designed to deliver. Control combinations that result in I:E ratios the ventilator can deliver are represented as the solid area at the back of the cube; the cutaway area at the cube’s front represents I:E ratios that are out of the ventilator’s range. A control combination—as in

AA.32.019

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the example above—of 250 mL tidal volume, 60 BPM rate, and 10 liters per minute flow sets the I:E ratio at point “A,” which is in the cutaway area. Increasing the flow moves the point up and out of the cutaway area to point “B.” Decreasing the rate moves the point to the left and out of the cutaway area to point “C.” And, decreasing the tidal volume moves the point to the right and out of the cutaway area to point “D.”

Tidal volume compensation

You may notice that the exhaled tidal volume (VT) the ventilator measures and displays usually does not match the setting on the tidal volume knob. In most cases this is normal: the ventilator measures the patient’s actual exhaled volume, which—because of a number of factors—will usually be different than the set tidal volume; use the measured volume as a guide when setting tidal volume. Factors contributing to differences between the set tidal volume and the measured tidal volume include breathing system compliance, fresh gas flow, breathing system leakage, the location of the volume sensor within the breathing system, and airway resistance.

Compliance Because of the compressibility of gases and the expansion of some

breathing system components under pressure, not all of the gas delivered from the ventilator enters the patient’s lungs. Instead of reaching the patient, some of the gas the ventilator delivers is needed to raise the breathing system pressure to the peak inspiratory pressure. Higher peak inspiratory pressures results in greater tidal-volume losses.

Fresh gas flow Any fresh gas flow the anesthesia machine introduces to the breathing

system during inspiration will be delivered to the patient in addition to the gas the ventilator delivers. Higher fresh gas flows result in greater tidal volumes.

Leakage Breathing system leakage during inspiration reduces the delivered tidal

volume. In a properly maintained breathing system, leakage is usually small enough to ignore when calculating tidal volume compensation.

Location of the volume sensor

When the volume sensor is in the proximal location—on the patient side of the “Y” connector—the ventilator will measure only the patient’s exhaled tidal volume. If the volume sensor is placed in the distal location—at the absorber’s exhalation check-valve port—the ventilator measures the patient’s exhaled tidal volume plus the compliance volume in a portion of the patient circuit that is between the absorber’s inhalation and exhalation check valves and the patient; this compliance volume is not delivered to the patient.

Tidal volumes measured distally will always be artificially higher than those measured proximally; the difference between the measurements will usually be small (about 2 to 3 mL/cm H2O) when standard, 75 to 100 cm (30-to-40-inch) long, patient-circuit tubing is between the absorber and the patient. Adding volume to the circuit, for example by connecting a humidifier in the inspiratory limb, increases the differences between distally and proximally-measured tidal volumes.

Airway resistance High airway resistance, such as caused by a small endotracheal tube or

other airway obstruction, may reduce the tidal volume the ventilator delivers to the patient. A tidal volume delivered at a high inspiratory flow may be partially restricted from reaching the lungs, causing a larger-thannormal portion of that tidal volume to remain in the breathing system. You can determine if airway resistance is a factor in your system: if reducing the inspiratory flow or enabling the inspiratory pause function increases the measured tidal volume, then high airway resistance is a factor.

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These breathing system factors may cause the measured tidal volume indicated on the screen to be different than the level you set on the tidal volume knob. During operation compensate for these factors by adjusting the ventilator controls so the measured-and-displayed tidal volume indicates the ventilation level you want to use. Occasionally, however, you may want to calculate an expected tidal volume.

V = V + V - V

T s fgf c

V =

fgf

Vc = C x PIP C = compliance factor

in mL/cm H

FGF

R 1 +

( )

The exhaled tidal volume you would expect to measure (VT) equals the tidal volume set on the ventilator (Vs) plus the tidal volume fresh gas flow adds (V

) minus the tidal volume lost to breathing system compli-

fgf

ance (Vc). The equation above doesn’t account for leakage or high airway resis-

tance. You can compensate for high airway resistance by reducing inspiratory flow or using the inspiratory pause function.

Step One, calculating V

, the total volume of fresh gas delivered during

fgf

inspiration.

• FGF = total fresh gas flow from the anesthesia system, in mL per minute.

• R = breathing rate from the ventilator, in breaths/minute

• f(E,I) = inverse I:E ratio from the ventilator

Step Two, calculating Vc, the volume lost to breathing system compli- ance.

When the volume sensor is in the distal position, the compliance factor (C) for the Ohmeda GMS Absorber is about 8 mL/cm H2O with adult bellows and about 6 mL/cm H2O with pediatric bellows; because the volume sensor is located distally, however, actual patient volume will be somewhat less than the tidal volume the ventilator measures and displays. When the volume sensor is in the proximal position, the compliance factor is about 10 mL/cm H2O for the Ohmeda GMS Absorber with adult bellows, 150 cm (60-inch) long, disposable, patient-circuit tubes, and no humidifier. If your system includes components different from these, see step three to calculate your system’s compliance factor.

PIP = peak inspiratory pressure, as shown on the breathing system’s pressure gauge, in cm

For example, to verify the volume reading of a system connected to either a patient or a test lung: assume that the ventilator settings are V = 750 mL (on the tidal volume knob), R = 10/min. (on the rate knob), and the inspiratory flow is set so that I:E = 1:3. Assume also that fresh gas flows total 3 liters per minute (3000 mL per minute), that PIP = 30 cm H2O (peak inspiratory pressure as shown on the breathing system’s pressure gauge), and that the volume sensor is located in the distal position.

V =

fgf

V = C x PIP

V = V + V - V

T s fgf c

FGF

R 1 +

( )

3000 mL per minute

V = = 75 mL

fgf

10/min. 1 +

V = (8 mL/cm H O) x (30 cm H O) = 240 mL

c22

V = 750 mL + 75 mL - 240 mL = 585 mL

The expected tidal volume (VT) is 585 mL. Because of the number of variables in the equations above, measured tidal volumes within about 15 percent of the calculated value represent a reasonable correlation to the set tidal volume of 750 mL. Leakage will further reduce the measured value.

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( )

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3/General Information

Step Three, determining the compliance factor. The calculations above use an approximate compliance factor. Occasionally, you may want to determine the compliance for a specific breathing system.

Determining the breathing system compliance factor when the volume sensor is in the proximal position

∑

1. Connect the ventilator’s control module and bellows assembly to the breathing system as if ready for use.

2. If applicable, ensure that the absorber is full of absorbent as if ready for use.

3. If applicable, ensure that the absorber’s Bag/APL-Ventilator switch is in the “ventilator” position.

4. Connect all of the breathing system components—such as a humidifier, if included in the system, and patient-circuit tubing—as if ready to use.

5. Occlude the patient end—at the “Y” connector—of the patient circuit.

WARNING: When occluding the breathing system for test purposes, do not use any object small enough to slip completely into the system. Objects in the breathing system can interrupt or disrupt the delivery of breathing-system gases, possibly resulting in injury to the patient. Before using the breathing system on a patient, always check the breathing system components for foreign objects.

6. Move the ventilator’s mechanical ventilation switch to OFF.

7. Turn all of the fresh-gas flow controls fully clockwise.

8. Power the ventilator ON.

9. Set the tidal volume to 200 mL.

10. Set the rate to 10 B/min.

11. Turn the inspiratory flow knob completely counter-clockwise to 10 liters per minute.

12. Inflate bellows using O2 flush button.

13. Activate the inspiratory pause function.

14. Move the ventilator’s mechanical ventilation switch to ON.

15. Adjust the tidal volume knob until the peak inspiratory pressure— shown on the system’s pressure gauge—reads exactly 30 cm H2O.

16. Move the ventilator’s mechanical ventilation switch to OFF.

17. Touch the tidal volume knob to display the tidal volume that was required to achieve a peak inspiratory pressure of 30 cm H2O. Note the displayed value.

18. C = Vs ÷ PIP. Divide the tidal volume value you noted by 30 cm H2O to calculate the compliance of your system.

19. Power the ventilator OFF.

20. Remove the occlusion from the patient circuit.

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4/Preoperative Checkout Procedure

Checking the ventilator connections 4-1 Checking the monitoring connections 4-1 Testing the bellows assembly 4-4 Testing the ventilator alarms 4-5

Testing the low and high oxygen alarms 4-5 Testing the low minute volume, reverse flow, and apnea alarms 4-6 Testing the high, low, and sustained pressure alarms 4-8

WARNING: Always perform the preoperative checkout procedures

∑

before using the system. Failure to ensure proper setup and operation prior to use may result in patient injury.

WARNING: Ensure that all hoses, tubing, and other circuit connections are made properly before using any anesthesia system. Failure to do so may result in patient injury. Refer to the operation manuals for these devices.

Checking the ventilator connections

Before you use the ventilator on a patient, check that all of the ventilator connections are correct and secure.

1. Verify that the proper hose connections have been made between the bellows assembly and the control module.

2. Verify that the proper hose connections have been made between the bellows assembly and the patient breathing circuit.

3. Verify that the correct supply gas is securely connected to the control module.

4. On ventilators with air supply gas, check the supply gas filter bowl, if water has accumulated, drain as described in section 6.

5. Verify that the electrical power cord is plugged into a properly grounded outlet.

6. Verify that a properly functioning scavenging system is connected to the bellows assembly’s 30-mm/19-mm exhaust port . Do not connect the bellows exhaust directly to a vacuum source.

Checking the monitoring connections

Before you use the ventilator on a patient, check that all of the monitoring connections are correct and secure.

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4/Preoperative Checkout Procedure

Figure 4-1

The volume sensor cartridge must be correctly inserted in the breathing system. The cartridge must be clear and free of any obstructions.

Figure 4-2

The volume sensor clip must be attached to the volume sensor cartridge. The arrows on the clip must point in the direction of gas flow in the breathing system.

AA.15.046AA.15.045M D.10.017

Figure 4-3

The volume sensor

Ohmeda 7800 Ventilator

clip’s electrical cord must be plugged into the receptacle marked “volume monitor” on the sensor interface panel

300

200

500

100

1000

1500

4-2 1500-0134-000 02/01/93

(25% T )

Low v

Low O2 High O

+ + + + + +

60 21 00

- - - -- -

L/min % %

L/min

PUSH

TURN

208010010 100

cm H O

Vol

Monitors

AA.32.036

100

B/min

4-2

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4/Preoperative Checkout Procedure

Figure 4-4

One end of the clear, 3 mm (1/8 -inch) pressure sensor tube must connect to the barbed connector labeled “connect to inspiratory limb of breathing system” on the control module’s rear panel. The other end of the pressure sensor tube must connect to the inspiratory side of the breathing system. This tube must be free of obstructions and kinks.

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Ohmeda 7800 Ventilator

Verbinden Sie mit der

Inspirations - seite des

Beatmungssystems

Verbinden Sie mit

dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

Restricted to nonflammable agents.

Serieller Ventilatoranschluß

Ohmeda L 7800 Ventilator

7800 Ventilator Lagernummer 7800 Ventilator Seriennummer

~ 100/120V , 0.5A 220/240V , 0.25A

50/60 Hz

Ohmeda Madison WI 53707 7550 A Division of BOC Health Care Inc

BOC Health Care

Made in USA

AA.15.007; AA.32.006; AA.33.009

Figure 4-5

The oxygen sensor’s electrical cord must be connected to the receptacle labeled “oxygen monitor” on the sensor interface panel. If the sensor has been left unplugged, replace the oxygen sensor cartridge.

The oxygen sensor must be placed the inspiratory side of the breathing system.

Vol

Monitors

AA.15.043AA.32.032

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Testing the bellows assembly

Before each case, perform the preoperative checkout procedure that is recommended for your breathing system (check the operation and maintenance manual for your breathing system). If applicable zero the pressure gauge before each case. The breathing system must pass its leak test before the bellows assembly can be tested.

For more detailed maintenance, testing and exploded view with parts listed, see “Autoclavable bellows assembly,” section 8 of this O&M manual.

1. Occlude the patient end—at the “Y” connector—of the patient circuit.

Figure 4-6

Occluding the breathing system at the “Y” connector

AA.12.031

∑

2. If applicable, turn the breathing system’s Bag/APL-ventilator switch to the “ventilator” position.

3. Watch the breathing system’s pressure gauge. Press the oxygen flush button to fill the bellows. When full the bellows may swell, but it must remained installed on the bellows base. The pressure gauge reading must not exceed 15 cm H2O.

4. Examine the bellows and confirm that it is undamaged.

5. Release the oxygen flush button.

6. Watch the pressure gauge and adjust the oxygen flow from 200 mL per minute to 10 liters per minute and back. The pressure reading must stay within the range of 1.0 cm H2O to 5.0 cm H2O. This tests the bellows assembly’s pressure relief valve.

7. Shut off fresh gas flow, switch OFF the anesthesia machine. The bellows must not drop more than 100 mL per minute. If the bellows drops more than 100 mL per minute, either the bellows is leaking or the pressure relief valve is not functioning properly.

8. If any leak cannot be corrected, do not use the ventilator; have a qualified service representative make repairs.

9. Remove any occlusions you have added to the circuit.

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Testing the ventilator alarms

Testing the low and high oxygen alarms

1. Make sure the mechanical ventilation switch is set to OFF.

2. Power ON the ventilator.

3. Remove the oxygen sensor from the sensing port. Let the sensor sit in room air at least three minutes before you move to the next step.

4 Adjust the O2 calibration knob until the O2 (%) display reads 21

percent. (If you can not calibrate to 21 percent replace the cartridge, see section 6/Maintaining the ventilator.)

5. Use the low-O2 pushwheel to set the low O2 alarm limit to 18 percent. The ventilator displays: LOW O2 LIMIT = 18%

6. Use the high-O2 pushwheel to set the high O2 alarm limit to 40 percent.

Figure 4-7

Removing the oxygen sensor from the absorber

The ventilator displays: HI O2 LIMIT = 40%

AA.15.043

7. Use the low-O2 pushwheel to readjust the low O2 alarm limit to 22 percent.

The ventilator displays: LOW O2 LIMIT = 22% Within four seconds the ventilator sounds the warble tone, flashes

the red LED, and displays the “low oxygen” message. The ventilator displays: LOW OXYGEN!

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8. Now use the low-O2 pushwheel to readjust the low O2 alarm limit to 18 percent.

The ventilator displays: LOW O2 LIMIT = 18% Because you have resolved the alarm condition, the ventilator will

cancel the low O2 alarm within four seconds.

9. Use the high-O2 pushwheel to readjust the high oxygen alarm limit to 20 percent.

The ventilator displays: HI O2 LIMIT = 20% Within four seconds the ventilator sounds the intermittent tone,

flashes the yellow LED, and displays the “high oxygen” message. The ventilator displays: HIGH OXYGEN!

10. Use the high-O2 pushwheel to readjust the high oxygen alarm limit to 40 percent.

The ventilator displays: HI O2 LIMIT = 40% The ventilator cancels the high oxygen alarm within four seconds.

11. Return the oxygen sensor to the sensing port.

12. At least once a month perform the 100 percent calibration procedure as described in “6/Maintaining the Ventilator.” If you don‘t know when the sensor was last calibrated, do it now.

Testing the low minute volume, reverse flow, and apnea alarms

1. Add a breathing bag to the patient circuit at the patient end of the “Y” connector.

2. Make sure that inspiratory pause is OFF.

3. Set the tidal volume to 500 mL. The ventilator displays: 500 mL I:E 1:X.X

4. Set the rate to 10 breaths per minute. The ventilator displays: 10/min I:E 1:X.X Where X.X represents the current I:E depending upon the present

flow setting.

5. Set the inspiratory flow to 30 liters per minute to change the I:E ratio to 1:5.0.

The ventilator displays: I:E = 1:5.0

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Figure 4-8

Adding a breathing bag to the patient circuit

AA.15.093

6. Set the inspiratory limit to 40 cm H2O. The ventilator displays: PMAX=40 SUST=20

7. Use the low VE pushwheel to set the low VE alarm limit to 0.0 liters per minute.

The ventilator displays: VE LIMIT = 0.0 L/min

8. Set the anesthesia system’s oxygen flow to 2 liters per minute.

9. Ensure that the volume sensor cartridge is in the expiratory limb of the breathing system. Make sure that the arrows on the sensor clip point in the direction of exhaled gas flow.

10. Move the absorber’s bag/ventilator switch to “ventilator, if applicable.”

11. Use the anesthesia machine’s oxygen flush button to fill the bellows.

12. Switch ON mechanical ventilation, then wait 40 seconds.

13. Use the low VE pushwheel to readjust the low VE alarm limit to 9.9 liters per minute.

The ventilator displays: VE LIMIT = 9.9 L Then the ventilator sounds the intermittent tone, flashes the yellow

LED and displays: LOW MINUTE VOL!

14. Use the low VE pushwheel to set the low VE alarm limit to 0.0 liters per minute.

The ventilator cancels the low minute volume alarm.

15. Remove the volume-sensor clip from the volume-sensor cartridge.

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16. After 30 seconds the ventilator flashes the yellow LED, sounds the warble tone once, and displays: APNEA 31 SEC.

From this point on the ventilator displays the number of seconds since apnea was detected.

17. In 30 more seconds the tone warbles twice and the ventilator displays: APNEA 60 SEC.

18. Thirty seconds later the tone warbles three times and the ventilator displays: APNEA 90 SEC.

19. Wait until the ventilator displays: APNEA 120 SEC. The tone warbles continuously, the ventilator flashes the red LED,

and the ventilator displays: APNEA **

20. Push the alarm silence button å. The ventilator silences the audio

alarm. The red LED continues to flash

21. Put the volume sensor clip back on the volume cartridge. Make sure the arrows point in the direction of exhaled gas flow.

22. After one more ventilation cycle the red LED stops flashing and the ventilator clears the apnea alarm.

23. Use the setup page to verify the reverse flow detection is enabled. If reverse flow detection is OFF, switch it ON.

24. Remove the volume sensor clip from the volume cartridge.

25. Reinstall the volume sensor clip backwards (so the arrows point in the opposite direction of the exhaled gas flow) on the volume cartridge.

26. Switch ON mechanical ventilation. The ventilator sounds a continuous tone, flashes the yellow LED,

and displays: REVERSE FLOW!

27. Correctly reinstall the volume sensor clip back on the volume cartridge. Make sure the arrows point in the direction of exhaled gas flow.

After two ventilation cycles the ventilator clears the reverse flow alarm.

Testing the high, low, and sustained pressure alarms

1. Make sure that inspiratory pause is OFF.

2. Set the tidal volume to 500 mL. The ventilator displays: 500 mL I:E 1:XX

3. Set the Rate to 10 breaths per minute. The ventilator displays: 10/min I:E 1:XX

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4. Set the inspiratory flow to 30 liters per minute to change the I:E ratio to 1:5.0.

The ventilator displays: I:E = 1:5.0

5. Set the inspiratory pressure limit to 40 cm H2O. The ventilator displays: PMAX=40 SUST=20

6. Set the anesthesia machine’s oxygen flow to 2 liters per minute.

7. Make sure the pressure sensing tube is securely connected between the control module’s connector marked “Connect to Inspiratory Limb of Breathing System” and the distal-sensing tee on the inspiratory side of the breathing system.

8. Move the absorber’s Bag/APL-ventilator switch to “ventilator”, if applicable.

9. Connect the common gas outlet to the breathing system.

10. Open the breathing system at the “Y” connector.

11. Move the mechanical ventilation switch to ON. After 20 seconds of mechanical ventilation, the ventilator sounds the warble tone once, flashes the red LED, and displays the “low pressure” message. The ventilator displays: LOW PRESSURE!

Figure 4-9

Opening the patient circuit at the “Y” connector

∑

Figure 4-10

Occluding the patient circuit at the “Y” connector

AA.15.037

12. Move the mechanical ventilation switch to OFF. Within five seconds the ventilator cancels the low pressure alarm.

13. Occlude the patient end of the “Y” connector.

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AA.12.031

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4/Preoperative Checkout Procedure

14. Wait for the bellows to inflate. When the bellows are completely extended, move the mechanical ventilation switch to ON. Within two seconds the ventilator warbles once, flashes the red LED, and displays: HIGH PRESSURE!

15. Move the mechanical ventilation switch to OFF. Within ten seconds the ventilator clears the high pressure alarm.

16. Perform the APL valve test, if applicable to your system. a. Maintain the occlusion in the breathing circuit. b. Turn the APL valve fully clockwise. c. Connect a three-liter bag to the bag port. d. Move the Bag/APL-Ventilator switch to “Bag/APL.” (Maintain

the occlusion in the breathing system.)

e. As you press the anesthesia system’s oxygen flush button, watch

the absorber’s pressure gauge until the system pressure reaches at least 20 cm H2O. Release the flush button and wait 15 seconds more. Because the pressure still exceeds 20 cm H2O, the ventilator now sounds the warble tone continuously, lights the red LED, and displays: SUSTAINED PRES!

∑

f. Slowly open the APL valve to release the pressure in the system.

The ventilator silences the sustained pressure alarm when the pressure falls below 20 cm H2O and extinguishes the red LED.

17. Remove the occlusion from the “Y” connector.

18. If applicable, set the “Bag/APL-Ventilator” switch to the position you plan to use.

WARNING: After completing the preoperative checkout procedures, and before starting any procedure during which this device will be used, confirm that all hoses, tubing, and other circuit components are connected properly. Failure to do so may result in patient injury. Refer to the operation manuals for all devices in the system to confirm that they are setup and connected correctly

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5/Operating the Ventilator

Using the setup page 5-1 Setting the alarm limits 5-3 Setting the ventilation parameters, beginning ventilation 5-5 Responding to alarms 5-8

Using the setup page

In the setup page mode the front panel controls are used to set parameters normally not adjusted during a case, such as

• screen contrast,

• alarm volume.

• reverse flow detection

• sigh on/off

When you first enter the setup page, the ventilator displays

• ventilator model,

• software version number it is using,

• selected supply gas,

• and selected language and current altitude setting in meters.

The ventilator then lets you enable or disable the reverse flow alarm and sigh function, and adjust the screen contrast and audio alarm volume. These parameter settings are stored in the ventilator’s memory even when the system’s power is OFF. To adjust the setup parameters, turn the flow knob. To move from one parameter display to the next, press

å alarm silence button.

To exit the setup page, repeatedly press the alarm silence button to move through all the steps; make no changes to any parameters for 30 seconds; or, before you reach the final setup page step, move the mechanical ventilation switch to ON. When the ventilator exits the setup page, it stores any changes you’ve made, exits the setup page and begins normal operation. As the ventilator exits the setup page it beeps once and displays “CHECK SETTINGS.” Although you must press the inspiratory pause button to begin using the setup page, the ventilator retains the inspiratory pause function’s setting; you do not have to manually reset the inspiratory pause function when you are finished using the setup page.

To use the setup page 1. Move the mechanical ventilation switch to OFF.

2. Power ON the control module.

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5/Operating the Ventilator

3. Press and continue to hold down the alarm silence button å, then

press the inspiratory pause button. Release both buttons. The ventilator displays:

321

7800 REV 4.XX /O ENGLISH 1300 m

∑

1. Ventilator Model

2. Software Version

3. Ventilator Drive Gas (A=Air; O=O

4. Language

5. Altitude

WARNING: Pay attention to the model, software revision number, ventilator supply gas, language and altitude setting shown on the setup page. If the language displayed is other than the appropriate language, or if the altitude setting is incorrect, refer to section 2, “Getting Started, Checking and setting altitude compensation.” If model is other than “7800,” or if the drive gas abbreviation is incorrect (“/O” indicates oxygen, “/A” indicates air), have an Ohmeda-trained service representative reset the ventilator. Other languages, models, and drive gases have associated operating parameters that are not described in this manual.

4. Press: å

The ventilator displays:

FLOW KNOB TO SET REV FLOW ALM ON (or) OFF

1 meter (3.28 feet)

)

5. If you are using the volume sensor at the proximal end of the “Y” connector in the patient breathing system, you may want to disable the reverse flow alarm, which, in that position, can be triggered by normal breathing. Do not disable the reverse flow alarm if the sensor is mounted in the distal position of the expiratory limb; in this position the alarm provides valuable information about possible breathing-system malfunctions. (See “Connecting the volume sensor” in “2/ Getting Started” for information about installing the volume sensor).

To change the status of the reverse flow alarm, turn the flow knob until the display changes to either ON or OFF. When you are ready to move to the next step,

Press: å

The ventilator displays:

FLOW KNOB TO SET SIGH ON (or) OFF

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5/Operating the Ventilator

6. When the sigh function is selected, the ventilator delivers 150 percent of the set tidal volume once every 64th breath.

Note: The ventilator can only deliver a maximum 1500 mL per breath.

To change the status of the sigh function, turn the flow knob until the display changes to either ON or OFF. When you are ready to move to the next step.

7. Press: å

The ventilator displays:

FLOW KNOB TO SET CONTRAST: xx

If you want to adjust the LCD screen’s contrast, turn the flow knob. As you turn the knob, the ventilator will show a one-to-ten scale that indicates the screen contrast that will be used during normal operation. For best results, set the room lighting to the level that will be used while you are operating the ventilator. When you are ready to move to the next step,

8. Press: å

The audio alarm sounds continuously and the ventilator displays:

FLOW KNOB TO SET AUDIO VOLUME: xx

If you want to adjust the audio alarm’s volume level, turn the flow knob. The displayed number represents, on a scale of one to ten, the current volume level, which is also sounding. As you turn the knob, the ventilator will change the tone’s volume and the displayed number to indicate the level that will be used during normal operation. When you are ready to move to the next step,

9. Press: å

The ventilator silences the alarm, beeps once, clears the top display row and displays:

CHECK SETTINGS!

Any changes you selected are now saved and will be implemented (the inspiratory pause button remains in the state it was in when you selected the setup page).

Setting the alarm limits

Use the three alarm-set pushwheels to change the low-minute-volume, low-oxygen and high-oxygen alarms’ set points. To increase the value of an alarm set point, push the button directly over the digit you want to change. To decrease the value, push the button under the digit you are changing. Use the inspiratory pressure limit knob to set the inspiratory pressure limit and the sustained pressure limit. To adjust these limits, press the inspiratory pressure limit knob as you turn it.

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5/Operating the Ventilator

Anytime you change the value of an alarm set point, the ventilator will display that alarm’s value on the screen.

To set the alarm limits 1. Move the mechanical ventilation switch to OFF before powering ON

the ventilator.

2. Power ON the ventilator, if it is not ON already. Because the monitoring is active whenever the ventilator’s power is

ON, some alarms may sound.

3. Use the low-VE pushwheel to set the low minute volume alarm limit. The low minute volume alarm limits are 0.1 liters per minute to 9.9 liters per minute in 0.1 liter per minute increments. Setting 0.0 on the pushwheel disables low minute volume alarms.

WARNING: Always correctly set the low minute volume alarm and

∑

use CO2 monitoring to aid in the detection of breathing system disconnections.

4. Use the low-O2 pushwheel to set the low oxygen alarm limit. The low oxygen alarm limits are 18 percent to 99 percent in one percent increments.

Figure 5-1

Alarm push wheels and inspiratory pressure limit knob on a standalone ventilator. Controls are the same for an Excel system ventilator.

Although all the digits can be physically set to zero, the ventilator will not accept low oxygen alarm limits of less than 18 percent.

(25% T )

Ohmeda 7800 Ventilator

300

200

500

100

1000

1500

1. Alarm pushwheels

2. Inspiratory limit knob

B/min

100

Low v

+ + + + + +

60 21 00

- - - -- -

L/min % %

L/min

Low O

High O

PUSH

TURN

cm H O

10010 100

AA.32.033

If you set the low oxygen alarm pushwheel to less than 18 percent, the ventilator will continue to use 18 percent for the low oxygen alarm’s set point; and the ventilator will display a “LIMIT SET ERROR” message.

5. Use the high-O2 pushwheel to set the high oxygen alarm’s limit. The high oxygen alarm’s limits are 18 percent to 99 percent in one percent increments.

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If you set the high-O2 pushwheel to a level lower than or equal to the limit set by the low-O2 pushwheel, the ventilator will display a “LIMIT SET ERROR” message.

To disable the high oxygen alarm, set the high-O2 pushwheel to “00”; setting the high-O2 pushwheel to “00” will not generate a “LIMIT SET ERROR” message.

6. Use the inspiratory pressure limit knob to set the inspiratory pressure limit and the sustained pressure limit. If the sigh function is enabled, be sure to compensate for the additional pressure that will occur during the sigh breath.

Both the maximum inspiratory pressure and the sustained pressure alarm limits and pressure-release points are set by the inspiratory pressure limit knob, which must be pushed in while turned to change the settings; the ventilator sets the sustained pressure limit to correspond to the inspiratory pressure limit knob setting. For inspiratory pressure limits of 20 cm H2O to 60 cm H2O, the ventilator sets the sustained pressure limit to one half the inspiratory pressure limit. For example, if the inspiratory pressure limit is 42 cm H2O, the sustained pressure limit will be 21 cm H2O. However, any inspiratory pressure limit setting higher than 60 cm H2O will result in a sustained pressure limit of 30 cm H2O. For example, inspiratory pressure limits of 65 cm H2O and 80 cm H2O will both result in a sustained pressure limit of 30 cm H2O.

As you push and turn the inspiratory pressure limit knob, the ventilator will display both the maximum pressure limit and the sustained pressure limit settings. However, unlike the other three control knobs, just touching this knob will not generate a display.

If while the mechanical ventilation switch is OFF you set the inspired pressure limit for more than 60 cm H2O, the ventilator will beep, light the yellow LED, and continually display the maximum pressure setting. This pressure limit message is displayed in the non-mechanical ventilation mode only; during mechanical ventilation this reminder is disabled.

In addition to the three alarms set by the pushwheels and the two alarms set by the inspiratory pressure limit knob, the ventilator also sets trigger points for certain alarms based on the positions of other front panel controls. These alarms include the low pressure alarm, the apnea alarm, and the reverse flow alarm.

WARNING: The reverse flow alarm only works when the volume

∑

sensor cartridge is mounted at the distal end of the expiratory limb, reverse flow is ON and the volume sensor is working properly.

Setting the ventilation parameters, beginning ventilation

Set the ventilation parameters before moving the mechanical ventilation switch to ON. Because we recommend that you set the ventilator’s controls starting on the left and moving to the right, these instructions describe setting the ventilator’s controls from left to right. If you adjust either the tidal volume knob or rate knob after you have set the inspiratory flow knob, you may need to readjust the inspiratory flow to maintain the desired I:E ratio.

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It is possible to adjust the controls for a combination of settings that will result in a level the ventilator cannot deliver. If the combination of settings results in a level the ventilator is not designed to deliver, a “vent set error” alarm will be displayed. (See “Control range computation” in “3/General Information” for a description of the range of control settings.)

The measured tidal volume indicated on the screen may be different than the level you set on the tidal volume knob. Under pressure gases compress and certain breathing system components expand, which results in some loss of tidal volume in the breathing system. Also, any fresh gas introduced to the system will be measured by the volume sensor in addition to the gas the bellows assembly delivers. For instructions on calculating these breathing system losses and gains, see “Tidal volume compensation” in “3/General Information.”

You don’t, however, have to manually calculate the compliance effect to compensate for compliance losses. With the volume sensor correctly connected in the breathing system, adjust the tidal volume knob until the tidal-volume reading on the ventilator’s screen indicates the level you want to use.

To set the ventilation parameters and begin mechanical ventilation

1. Before connecting the ventilator to a patient, perform the preoperative checkout procedures described in “4/Preoperative Checkout Procedures.”

2. Move the mechanical ventilation switch to OFF.

3. Power ON the control module, if it is not ON already. The ventilator enters the non-mechanical ventilation mode. Because

the monitoring is active whenever the ventilator’s power is ON, some

alarms may sound. To silence any alarms, press å.

4. Set the alarm limits. Be sure to set the ventilation controls before moving the mechanical ventilation switch to ON.

5. Use the tidal volume knob to set the tidal volume. The tidal volume knob lets you set the tidal volume from 50 mL to

1500 mL. As you turn the knob, the ventilator will display the tidal volume setting. To check the tidal volume setting without changing its value, just touch the knob; the ventilator will then display the current tidal volume setting. Since changing the tidal volume may change the I:E ratio, the I:E ratio is displayed along with the tidal volume as a reminder. If the resulting I:E ratio is not as desired, be sure to readjust the inspiratory flow to maintain the desired I:E ratio.

Until the ventilator senses sufficient volume to indicate a breath, it will display “VOL MON STANDBY.” Once the ventilator senses a sufficient volume level, it will remove the “VOL MON STANDBY” message and start the timer that controls the apnea alarm.

If, however, while the mechanical ventilation switch is OFF, you set the tidal volume to less than 300 mL, the ventilator will disable the apnea alarm. Once the ventilator removes the “VOL MON STANDBY” message—after an activation breath—the ventilator will display the “APNEA ALARM OFF” message. If you want the apnea alarm enabled when the ventilator is in the non-mechanical ventilation mode , set the tidal volume knob to 300 mL or higher.

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Note: When switching from mechanical to non-mechanical ventilation mode

and the VOL MON STANDBY is displayed, the apnea timer does not begin until an initial breath has been sensed.

6. Use the rate knob to set the mechanical breath rate. Turning the rate knob changes the breath rate used for mechanical

ventilation and displays the rate. The rate’s range is 2 breaths per minute to 100 breaths per minute in whole number increments. Touching the rate knob will display the current rate on the screen. Since changing the breath rate may change the I:E ratio, the I:E ratio is displayed along with the breath rate as a reminder. If the resulting I:E ratio is not as desired, be sure to readjust the inspiratory flow to maintain the desired I:E ratio.

7. If you want to enable the inspiratory pause function, press the inspiratory pause key.

8. Set the desired I:E ratio by adjusting the inspiratory flow rate. The inspiratory flow knob lets you set the inspiratory flow rate,

which is continuously variable from 10 liters per minute to 100 liters per minute. Whenever you adjust or just touch the inspiratory flow knob, the ventilator will display the current I:E ratio, which the ventilator calculates based on the set inspiratory flow, tidal volume, inspiratory pause status, and breath rate. Adjusting any of these parameters will change the I:E ratio. However, you should use the inspiratory flow knob to adjust the I:E ratio once the tidal volume and breath rate have been correctly set. To check the current I:E ratio, touch the inspiratory flow knob.

9. Move the absorber’s Bag/APL-Ventilator switch to “ventilator”, if applicable.

10. Use the anesthesia system’s oxygen flush valve to fill the bellows. Set the oxygen flow to a level that keeps the bellows fully extended.

11. To start mechanical ventilation, move the mechanical ventilation switch to ON.

The mechanical ventilation switch controls mechanical ventilation only. When the switch is OFF, the monitors still function and the alarm system is still active. When you want to start mechanical ventilation, move the switch to ON.

Always turn ON the anesthesia system and set the control module’s front panel controls before switching ON ventilation. Starting mechanical ventilation before setting the controls may result in inappropriate ventilation of the patient and may trip alarms that relate to mechanical ventilation.

12. Once the ventilator is mechanically ventilating the patient, check the tidal volume. (See “3/General Information” for information about tidal volume compensation.) If necessary, adjust the front panel controls to modify the ventilator’s operating parameters. You can adjust any of the front panel controls while the ventilator is ON, see the preceding parameter setting steps.

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Responding to alarms

For detailed descriptions of the ventilator’s alarms, see “The alarm system” in “3/General Information.”

WARNING: Always respond to alarms promptly. Failure to respond to

∑

APNEA xxx SEC If for 30 seconds the ventilator doesn’t detect enough exhaled volume in

∑

Note: If a sigh breath occurs when a breath rate setting of two breaths per

alarms may result in injury to the patient.

the breathing system, an apnea alarm will be generated. The alarm message will indicate the number of seconds that have passed since sufficient flow was last detected.

WARNING: If you remove the sensor clip from the volume sensor cartridge before switching ON the anesthesia system, the apnea alarms will be inoperative. Do not use the ventilator without the sensor clip properly attached to the volume sensor cartridge.

minute is set, the apnea alarm will be triggered during the sigh breath.

1. Check the patient.

2. Check for disconnections in the patient breathing system.

3. Check for excessive moisture in the volume sensor cartridge.

4. If so equipped, check for excessive moisture in the absorber’s check valves.

5. Make sure the volume sensor clip is connected securely to the volume sensor cartridge.

6. Make sure the arrows on the volume sensor clip point toward the direction of exhaled gas flow.

7. Make sure the volume sensor clip is plugged into the sensor interface.

8. Replace the volume sensor cartridge. It may be worn out if its rotor is turning too slowly or not at all. (See “Checking the volume sensor” in “6/Maintaining the Ventilator.”)

9. Replace the volume sensor clip.

APNEA ALARM OFF! Whenever tidal volume is set to less than 300 mL and the mechanical

ventilator switch is OFF, the ventilator, once it has detected a breath, will display “APNEA ALARM OFF.” To enable the apnea alarm system while the patient is breathing spontaneously, increase the tidal volume knob to 300 mL or more.

1. The “APNEA ALARM OFF” message is normal if the tidal volume knob is set below 300 mL and the mechanical ventilation switch is set to OFF.

CHECK O2 SENSOR!/ CHECK GAS SUPPLY

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If the ventilator doesn’t detect at least five percent oxygen, it will assume that the oxygen sensor has failed, and generate an alarm. An alarm will also be generated if the sensr isn’t connected correctly, if the sensor is broken, or if no oxygen is in the area of the sensor.

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1. Check the oxygen supply.

2. Make sure the oxygen sensor is plugged into the anesthesia system’s sensor interface.

3. Check the oxygen-sensor cartridge’s surface for excessive moisture.

4. Has the oxygen sensor been left unplugged from the sensor interface? If it has, see “Maintaining, Replacing and Calibrating the Oxygen Sensor” in 6/Maintaining the Ventilator.

5. Replace the oxygen-sensor cartridge. It may be worn out. (See “Replacing the oxygen sensor” in “6/Maintaining the Ventilator.”)

DRIVE CKT OPEN! One type of ventilator failure—exhalation valve failure—does not display

a numbered message; instead “DRIVE CKT OPEN” is displayed. This message can also appear if, during mechanical ventilation, the absorber’s Bag/APL-Ventilation switch is in the “Bag/APL” position. During this alarm, the ventilator will attempt to continue monitoring and mechanical ventilation.

1. Check the patient.

2. If mechanical ventilation is ON, make sure the absorber’s Bag/APLVentilation switch is in the “ventilator” position, if applicable.

HARDWARE ERROR X This display (error A, B, and C) and alarm should not occur unless there

is a problem with the ventilator control module hardware. The alarm is

silenceable with the alarm silence å button. Mechanical ventilation

does not turn OFF.

∑

HIGH OXYGEN! If the ventilator detects an oxygen concentration equal to or higher than

HIGH PRESSURE! If the ventilator detects airway pressure higher than the limit you set

WARNING: Do not use the ventilator if this display and alarm occur.

the one you set using the high-O2 pushwheel, the ventilator will generate a high oxygen alarm.

1. Check the high-O2 alarm limit. Is it set correctly?

2. Check the anesthesia system settings.

3. Has the oxygen sensor been left unplugged from the sensor interface? If it has, see “Maintaining, Replacing and Calibrating the Oxygen Sensor” in 6/Maintaining the Ventilator.

using the inspiratory pressure limit knob, the ventilator will generate a high pressure alarm. And, during mechanical ventilation only, the ventilator will also terminate inspiration.

1. Check the patient.

2. Check for a blockage in the patient breathing system.

3. Check the inspiratory pressure limit knob. Is it set correctly?

4. Check for moisture in the pressure sensing tube that connects the breathing system to the ventilator’s control module.

5. Check for kinks in the pressure sensing tube.

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LIMIT SET ERROR! If you attempt to set the high oxygen alarm limit for a level below or

equal to the low oxygen limit, the ventilator will generate a limit setting error alarm. This alarm will also be generated if you attempt to set the low oxygen alarm limit for less than 18 percent.

Reset the alarm limits to acceptable values.

LOW BATTERY! If the battery’s voltage drops to an unacceptable level, the ventilator will

generate a “Low Battery” alarm. Leave the ventilator powered ON and connected to ~ power for at least

24 hours to recharge the battery.

LOW MINUTE VOL! If the ventilator senses that the minute volume is less than the level you

set using the low-VE pushwheel, the ventilator will generate an alarm.

1. Check the patient.

2. Check the low-VE alarm limit. Is it set correctly?

3. Check for breathing tube disconnections.

4. Check for excessive moisture in the volume sensor cartridge.

5. Check for excessive moisture in the absorber’s check valves.

6. Make sure the volume sensor clip is connected securely to the volume sensor cartridge.

7. Make sure the arrows on the volume sensor clip point in the direction of exhaled gas flow.

8. Make sure the volume sensor clip is plugged into the sensor interface.

9. Replace the volume sensor cartridge. It may be worn out if its rotor is turning too slowly or not at all. (See “Checking the volume sensor” in “6/Maintaining the Ventilator.”)

10. Replace the volume sensor clip.

LOW OXYGEN! If the ventilator detects an oxygen concentration lower than the one you

set using the low-O2 pushwheel, the ventilator will generate a low oxygen alarm.

1. Check the patient.

2. Check the anesthesia system’s flowmeter settings. Are they set correctly?

3. Check the anesthesia system’s pressure gauges.

4. Check the low-O2 alarm limit. Is it set correctly?

5. Check the oxygen supply.

6. Check the oxygen sensor assembly for damage.

7. Make sure the oxygen sensor is inserted securely into the oxygen sensing port.

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8. Make sure the oxygen sensor is plugged into the sensor interface.

9. Check the oxygen-sensor cartridge’s surface for excessive moisture.

10. Has the oxygen sensor been left unplugged from the sensor interface? If it has, see “Maintaining, Replacing and Calibrating the Oxygen Sensor” in 6/Maintaining the Ventilator.

11. Replace the oxygen-sensor cartridge. It may be worn out. (See “Replacing the oxygen sensor cartridge” in “6/Maintaining the Ventilator.”)

LOW PRESSURE! The ventilator will generate a low pressure alarm if, for at least 20

seconds, the airway pressure fails to change by a value that varies proportionally to the setting of the inspiratory flow knob. The low pressure alarm is active only when mechanical ventilation is switched ON.

1. Check the patient.

2. Check the breathing system for leaks or disconnections.

3. Check for moisture in the pressure sensing tube that connects the breathing system to the ventilator’s control module.

4. Check for kinks in the pressure sensing tube.

5. Is the patient breathing spontaneously? During mechanical ventilation spontaneous breathing may trip this alarm.

LOW SUPPLY PRES! If the ventilator’s regulated supply gas pressure is less than 22 psig, (155

kPa) the ventilator will generate a low supply pressure alarm. Low supply pressure will reduce delivered tidal volumes during mechanical ventilation.

1. Check the supply pressure.

2. Switch to cylinder use, if applicable.

3. Switch to manual ventilation, if necessary.

MAX PRES =xxx cm Anytime you adjust the inspiratory pressure limit knob, the ventilator

will briefly display the pressure limit in centimeters of water. If, however, the ventilator is in the non-mechanical ventilation mode and the inspiratory pressure limit is set to 60 cm or more, the ventilator will also light the yellow alarm LED and will continually display the “MAX PRES=XXX

CM” message. This pressure limit reminder is displayed in the non-

mechanical ventilation mode only.

O2 CAL ERROR! If the oxygen sensor delivers a signal that is out of the ventilator’s range,

the ventilator will generate an oxygen-calibration-error alarm.

• Calibrate the oxygen sensor as described in “Calibrating the oxygen sensor” in “6/Maintaining the Ventilator.”

POWER FAIL! If ~ power to the ventilator is lost, the ventilator will generate a power-

failure alarm.

1. Continue normal operation; a fully charged backup battery will allow you to continue for about 20 minutes with mechanical ventilation. To extend the monitoring time, discontinue mechanical ventilation, and manually ventilate the patient.

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2. Make sure the system power cord has not been disconnected.

3. Resolve the cause of the power failure.

REVERSE FLOW! If the ventilator senses reverse flow of an unacceptable volume, it will

generate a “Reverse Flow” alarm. For tidal volumes less than 300 mL, the reverse flow limit is 20 mL. For tidal volumes greater than 300 mL, this limit is 100 mL.

1. Make sure the volume sensor assembly is in the expiratory limb of the patient breathing system. If the sensor is in the expiratory limb, check the exhalation valve; its disk may be sticking.

2. Make sure the arrows on the volume sensor clip point in the direction of exhaled gas flow.

REV FLOW ALM OFF To advise you that the reverse flow alarm is disabled, in the non-me-

• If you want the reverse flow alarm enabled, use the setup page to set the reverse flow alarm status to ON.

SOFTWARE ERROR X This display (error A through F) and alarm should not occur unless there

is a problem with the ventilator software programs. The alarm is

silenceable with the alarm silence å button. Mechanical ventilation

does not turn OFF.

∑

SUB-ATMOS PRES! If the ventilator detects airway pressure of less than minus (-)10 centime-

WARNING: Do not use the ventilator if this display and alarm occur.

ters of water, it will generate a sub atmospheric pressure alarm.

1. Check patient.

2. Check for inadvertent vacuum hook-ups to the patient breathing system.

3. Check for kinks or occlusions in the breathing system.

4. The inspiratory check valve in the absorber may be stuck. Check the inspiratory check valve.

5. Is the patient breathing spontaneously? Spontaneous breathing may trip this alarm.

6. Check the gas-scavenging system for excessive vacuum.

7. Check for moisture in the pressure sensing tube that connects the breathing system to the ventilator’s control module.

8. Check for kinks in the pressure sensing tube.

SUSTAINED PRES! Anytime the sustained airway pressure exceeds—for 15 seconds or

more—the sustained pressure limit set by the inspiratory pressure limit knob, the ventilator will generate a sustained pressure alarm.

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1. Check the patient.

2. Check for kinks or blockages in the breathing system.

3. Check to make sure the absorber’s Bag/APL-Ventilator valve is in the correct position.

4. Check for moisture in the pressure sensing tube that connects the breathing system to the ventilator’s control module.

5. Check for kinks in the pressure sensing tube.

VENT FAIL xx! The number in the ventilator failure message, such as “VENT FAIL 8,”

corresponds to the specific type of failure occurring. Vent fail messages require that you take the ventilator out of service and call a qualified, trained Ohmeda Service Representative. If a ventilator failure alarm occurs, pressing the alarm silence button permanently silences the alarm tone, although the yellow LED and alarm message remains ON, and the ventilator may not function.

∑

WARNING: Do not use the ventilator if this display and alarm occur.

Some ventilator failure alarm conditions may be caused by transitory electrical interference that devices such as electrocautery instruments can generate. Although the ventilator will disable mechanical ventilation during most ventilator failure alarms, during certain of these alarms, whose causes may be transitory, the ventilator will attempt to maintain mechanical ventilation.

See the “7/Service Procedures” for descriptions of specific ventilator failure messages.

WARNING: Ventilator failure messages indicate that a problem exists in the ventilator. Do not attempt to use the ventilator while a ventilator failure message is displayed.

IMPORTANT

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audio alarm can be silenced only by turning, as applicable, the ventilator or anesthesia machine power switch OFF and after five seconds back ON.

WARNING: Manual ventilation must be performed when electrical

∑

VENT SET ERROR! If you attempt to set a combination of the inspiratory-flow, tidal-volume,

1. Manually ventilate the patient.

2. Have the ventilator checked by qualified service personnel.

Refer to “7/Service Procedures” for more information about ventilator failure messages.

inspiratory pause, and rate controls that results in a level the ventilator is not designed to deliver, the ventilator will continue to use the most recent acceptable settings, and will generate a ventilator setting error alarm until the control combination is corrected.

1. Readjust the ventilator’s controls within the ventilator’s operating limits.

WARNING: Do not use the ventilator while the “VENT SET ER-

∑

VOL MON STANDBY! Volume monitor standby indicates that, during mechanical or non-

VOL SENSOR FAIL! A volume sensor failure alarm will be displayed if the volume sensor’s

ROR” message is displayed; when this message is displayed, the control settings do not reflect the settings the ventilator is using. If the “VENT SET ERROR” message is displayed during mechanical ventilation, the system will use the most recent acceptable settings. If, however, the ventilator is powered ON in the “VENT SET ERROR” condition, moving the ventilation switch to ON will not start mechanical ventilation until the controls are moved to an acceptable setting.

mechanical ventilation, either the ventilator has not sensed sufficient breaths to check for apnea and volume alarm conditions, or that, while the mechanical ventilation switch is OFF, the alarm silence button has been used to cancel and reset the apnea and low minute volume alarms. If these two alarms have been canceled, they will not sound again even if these alarm conditions continue. However, if the ventilator senses another breath, the alarm timers and sensor circuits will again be activated and any alarm condition that occurs will trigger an appropriate alarm.

heater voltage is too low, which can happen if the volume sensor clip is broken or disconnected.

1. Check the connection between the volume sensor cartridge and the sensor clip.

2. Make sure the sensor clip is plugged into the sensor interface.

3. Replace the volume sensor clip.

- - - - - - - -displayed in place of readings

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If the system doesn’t measure any volume during mechanical ventilation, it will display dashes in place of the volume and rate data.

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1. Check the patient.

2. Check the breathing system for disconnections.

3. Check for obstructions in the volume-sensor cartridge that may be preventing the cartridge vanes from spinning.

4. Replace the volume sensor cartridge.

5. Replace the volume sensor clip.

???????? is displayed in place of VE ,

, or rate readings

If the alarm silence button will not silence the alarm

∑

Certain combinations of ventilator front panel control settings can result in ventilation conditions the ventilator can deliver but the volume sensor cannot measure. If you set a control combination the ventilator can deliver, but the volume monitor cannot measure, or if—in the nonmechanical ventilation mode —breathing occurs that the monitor cannot measure, the ventilator will display question marks in place of the VT, VE, and rate readings.

Certain electronic failures may be so significant as to cause the system to lose the ability to generate ventilator failure messages even though the ventilator has failed. If such a serious failure occurs, the alarm silence button will not silence the alarm. Do not attempt to use the ventilator if this type of failure occurs.

WARNING: Do not attempt to use the ventilator if the alarm silence

button å will not silence alarms.

1. Ventilate the patient manually.

2. Switch to a functioning system.

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Notes

5/Operating the Ventilator

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6/Maintaining the Ventilator

Maintenance schedule 6-1

Long Term Ventilator Storage 6-1

Cleaning and sterilizing 6-2

Cleaning the control module 6-2 Cleaning and sterilizing the bellows assembly 6-2 Cleaning and sterilizing the volume sensor clip assembly 6-3 Cleaning and sterilizing the volume sensor cartridge 6-3

Checking the volume sensor 6-4 O2 sensor maintenance 6-5

Maintenance schedule 6-5

Installing a cartridge or disassembling the O2 sensor for cleaning 6-5

Cleaning and sterilization 6-7

100% O2 calibration 6-8 Cleaning the supply gas filter 6-9

Operation 6-9 Filter servicing 6-9

Maintenance schedule

The following schedule is a recommended minimum standard that is based on normal usage and environmental conditions. Higher frequencies of use or unusual environments may dictate more frequent maintenance.

CAUTION: No repair should ever be undertaken or attempted by anyone not having proper qualifications and equipment.

Replace damaged parts with components manufactured or sold by Ohmeda. Then test the unit to ascertain that it complies with the manufacturer’s published specifications.

Full checkout and maintenance by Every three months trained service personnel

Calibrate oxygen sensor Daily Replace oxygen sensor As required at minimum yearly Clean bellows assembly As required Clean or replace pressure sensing tube As required Replace volume sensor cartridge As required at minimum

monthly

Replace air supply gas filter element Every six months or as

required by filter discoloration and flow resistance

Long Term Ventilator Storage

It is not necessary to disconnect the rechargeable batteries before long term storage.

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Cleaning and sterilizing

This chart is provided for quick reference once you are familiar with the cleaning and sterilization of the system. Refer to the following sections for cleaning-and-sterilization details. Use a cleaning and sterilization schedule that conforms to your institution’s sterilization and risk-management policies.

Item To clean To sterilize

Control module mild detergent n/a Bellows assembly see section 8 see section 8 or 9 Air supply gas filter Plastic bowl warm n/a

water only Other parts warm n/a

water and soap

Volume sensor damp cloth disinfectant assembly

Volume sensor damp cloth ethylene oxide or liquid cartridge sterilizing agent

Oxygen sensor damp cloth ethylene oxide housing (front section only)

Oxygen sensor white vinegar ethylene oxide cartridge

Clear plastic areas damp cloth n/a Rubber, plastic damp cloth, mild detergent, ethylene

(pH less than 9), oxide cold germicidal alkali detergent

Cleaning the control module

Clean the exterior surfaces of the control module with a soft, lint-free cloth lightly moistened in a solution of mild liquid detergent.

CAUTION: Use cleaning solution sparingly. Do not saturate system components. Excessive solution can damage internal devices.

CAUTION: Do not cover the system with any type of fabric or plastic covering. These types of coverings can generate static charges that may damage the equipment.

Cleaning and sterilizing the bellows assembly

See section 8 or 9 for disassembly, cleaning, sterilization, reassembly and checkout of the Ohmeda Bellows Assembly

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Cleaning and sterilizing the volume sensor clip assembly

Because no part of the sensor assembly—which includes the clip, cable and plug—is exposed to the breathing system, usually no sterilization is required. If the clip, cable and plug do need cleaning:

1. Unplug the sensor from the sensor interface panel.

2. Remove the sensor clip from the volume cartridge.

3. Wipe the clip, cable and plug with a cloth moistened in disinfectant (liquid sterilizing).

CAUTION: Never immerse any part of the volume sensor assembly

Figure 6-1

Disconnecting the volume sensor cartridge from its clip

in cleaning solution. Immersion will destroy the clip’s electrical contacts.

Cleaning and sterilizing the volume sensor cartridge

Replace the sensor cartridge at least every thirty days, or when the volume sensor checkout (see “Checking the volume sensor”) indicates the sensor has become inaccurate. If cleaning is required between replacements:

Note: Be very careful while you are handling the volume cartridge. The car-

tridge is a precision device containing jeweled bearings. Do not drop the cartridge. Do not allow any contaminant, such as hair or dust, to enter the cartridge.

1. Remove the cartridge from the breathing system.

2. Unsnap the sensor clip from the cartridge.

MD.10.016

3. Use an accepted gas or liquid sterilization technique to sterilize the sensor cartridge.

CAUTION: Never insert cleaning brushes or other foreign objects

6-3 1500-0134-000 02/01/93

through the cartridge vanes. Contacting the sensor’s moving vane may damage its precision movement.

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CAUTION: Following ethylene oxide sterilization, quarantine the

Checking the volume sensor

To check volume sensing 1. Add a bag to the patient circuit at the “Y” connector.

equipment in a well-ventilated area to allow dissipation of absorbed ethylene-oxide gas. In some cases, aeration periods of seven days or more may be required. Aeration time can be decreased when special aeration devices are used. Follow the sterilizer manufacturer’s recommendations for aeration periods required.

CAUTION: Always perform the preoperative checkout procedures for volume sensing functions after cleaning or replacing the volume sensor cartridge.

This volume-sensing checkout procedure, which you should perform before each case, tests both the sensor cartridge and the sensor assembly. If the checkout fails, replace the volume cartridge, then repeat the procedure. If the checkout still fails after you replace the cartridge, replace the sensor assembly and repeat the test again.

2. Set the tidal volume to 500 mL.

• The ventilator displays: 500 mL I:E 1:XX

3. Set the rate to 10 breaths per minute.

• The ventilator displays: 10/min I:E 1:XX

4. Using the inspiratory flow knob, set the I:E ratio to 5.0. This corresponds to a flow of 30 liters per minute.

• The ventilator displays: I:E=1:5.0

5. Set the inspiratory pressure limit to 40 cm H2O.

• The ventilator displays: PMAX=40 SUST=20

6. Make sure that the ventilator’s inspiratory pause function is OFF.

7. Set the low VE alarm limit to 0.0 liters per minute.

8. Set the anesthesia system’s oxygen flow to 2 liters per minute.

9. Ensure that the volume sensor cartridge is on the exhalation side of the breathing system. Make sure that the arrows on the sensor clip point in the direction of exhaled gas flow.

10. Move the absorber’s bag-to-ventilator switch to the ventilator position, if applicable.

11. Use the anesthesia machine’s O2 flush button to fill the bellows.

12. Switch ON mechanical ventilation and wait 40 seconds. The displayed VE should be between 3.3 liters and 4.3 liters assuming that your system:

• includes an adult bellows

• includes 60-inch patient tubes

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6/Maintaining the Ventilator

• does not include a humidifier

• has a peak inspiratory pressure of 15 cm H2O (If your system’s components and peak inspiratory pressure are

different than this, see “Tidal volume compensation” in “3/General Information” to calculate the compliance factor of your system. Then use this factor to calculate the expected minute volume.)

Figure 6-2

Adding a breathing bag at the patient circuit’s “Y” connector

AA.15.093

O2 sensor maintenance

Maintenance schedule

Before each use • Preoperative checkout procedure (includes 21% O Monthly • 100% O Annually • Replace the O

at 50% O2 and 24°C (77°F) . Different operating conditions (higher concentrations, high temperature, and elevated CO2 concentrations) can shorten cartridge life expectancy. Freezing can destroy the sensor cartridge

calibration

sensor cartridge. Cartridge life expectancy is one year

calibration

Installing a cartridge or disassembling the O2 sensor for cleaning

WARNING: Use protective gloves and eye-wear when you open the O

∑ w

sensor in case the cartridge is leaking. The sensor cartridge contains potassium hydroxide (caustic).

CAUTION: Handle the cartridge with care to avoid damaging it. Always perform the calibration and preoperative checkout procedures for oxygen-sensing functions after replacing a new sensor cartridge or a recently cleaned and sterilized oxygen sensor.

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6/Maintaining the Ventilator

Figure 6-3

Open the sensor housing and remove the old cartridge

1. Sensor screen

2. Probe section of housing

Figure 6-4

Remove the metal disk or clip

MD.02.055,56; OT.01.022

Figure 6-5

Install a new cartridge with circular contacts toward the cable end of the housing, screen facing out

MD.12.011

1. Shorting disk

2. Shorting clip

MD.02.032

1 23 456

1. Cable section

2. Contact rings

3. Sensor cartridge

4. Inner O-ring

5. Outer O-ring

6. Probe section

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6/Maintaining the Ventilator

Figure 6-6

Finger tighten the housing to a gas tight seal

MD.02.055AA.32.036

Figure 6-7

Immediately connect

sensor

the O

∑

(25% T )

Ohmeda 7800 Ventilator

300

200

100

500

1000

1500

B/min

100

Low v

Low O

+ + + + + +

60 21 00

- - - -- -

L/min % %

L/min

High O

PUSH

TURN

208010010 100

cm H O

Vol

Monitors

Cleaning and sterilization

WARNING: Use protective gloves and eye-wear when you open the O sensor in case the cartridge is leaking. The sensor cartridge contains potassium hydroxide (caustic).

WARNING: Do not inhale any fumes generated by the oxygen-sensor cleaning procedure. Such fumes can cause respiratory system or skin damage. This material is caustic.

CAUTION: Following ethylene oxide sterilization, quarantine the

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6/Maintaining the Ventilator

Figure 6-8

Cleaning and sterilization methods

1 23

1. Wipe with a damp cloth (liquid disinfectant, mild detergent, isopropyl

alcohol); do not immerse, gas sterilize, or autoclave; remove oxide from leaked electrolyte under a fume hood with vinegar using eye and skin protection

2. Gas sterilize with ethylene oxide (ambient temperature, no vacuum or

pressure) or wipe with a damp cloth (water, white vinegar, liquid disinfectant): do not immerse or autoclave; do not use alcohol

3. Gas sterilize with ethylene oxide or clean with liquid disinfectant, mild

detergent solution or isopropyl alcohol

MD.02.032MD.07.009

100% O2 calibration

At least once a month and following sensor cartridge replacement, calibrate the oxygen sensor using 100% O2:

1. Adjust the high O2 alarm to 00% (alarm disabled).

2. Expose the O2 sensor to pure oxygen and allow the display to stabilize for approximately two minutes as oxygen fills the patient circuit.

3. Adjust the calibration control until the display reads 99%.

4. Expose the O2 sensor to room air and allow the display to stabilize for approximately two minutes as room air fills the sensor housing. If the final reading is outside the allowed range 21 ± 3% (18 to 24%), the sensor cartridge is no longer linear and must be replaced. Refer to “Installing a cartridge or disassembling the O2.sensor for cleaning “ in this section.

5. If the system will not be used immediately, switch the monitor or system OFF.

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6/Maintaining the Ventilator

Cleaning the supply gas filter

Operation

Ventilators that are set up to use air as a supply gas have a 5 micron filter encased in a plastic sediment bowl. The bowl has a drain at the bottom which operates similar to the valve stem on an automobile tire. To release any collected sediment and/or moisture, push in the valve stem and the supply gas pressure should clear the bowl. See figure 6-9.

WARNING: The liquid and sediment in the plastic bowl are under

∑

ventilator supply gas pressure. Wear protective eye gear while draining. Use a container to catch the liquid.

A manual drain valve (7) allows the accumulation to be periodically removed from the bowl. The liquid level should never be allowed to reach the level of the filter mounting stud (4) or the liquid may be carried downstream damaging the internal workings of the ventilator.

Filter servicing

∑

This filter has a manual drain and must be drained as liquid and sediment build up in the bowl. To operate the drain valve, simply use a blunt object to push upward on the exposed plunger.

Ohmeda strongly recommends that the filters be replaced every six months and more frequently as the white filter element discolors or supply gas flow appears to be impeded. See section 8 “Replaceable Parts” for service kit and filter replacement. A dirt laden filter will impede the supply gas flow and may cause the minute volume alarm to occur.

WARNING: Clean the plastic bowl with warm water only. Plastic deteriorates when subjected to certain solvents, strong alkalis and compressor oils.

Disassembly, see figure 6-9

1. Shut OFF inlet supply gas pressure and push the drain valve stem (7) upward to reduce the pressure in the bowl (6) to zero.

2. Unscrew the clear filter bowl (6) from the supply gas block.

3. Unscrew the mounting stud (4). Remove the gasket (1), louver (2) and filter element (3).

4. Discard the O-ring (5), gasket (1) and filter (3).

5. Clean the louver and mounting stud in warm water and a mild soap solution. Clean the filter bowl (6) in warm water only.

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6/Maintaining the Ventilator

Figure 6-9

Supply gas filter assembly, ventilators setup for air supply gas only

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

1 2

Benutzen Sie nur Keimfreie Luft (241-517 kPa)

Verbinden Sie mit der Inspirations - seite des Beatmungssystems

Verbinden Sie mit

dem Einlaß an der Balgeinheit des Ventilators

∑

Warnung:Verschließen

Sie nicht die GasAuslaßöffnungen. Dies hätte erhöhten Druck im Patientenkreislauf zur Folge.

AA.32.039AA.32.038

1. Gasket

2. Louver

3. Filter element

4. Mounting stud

5. O-ring

6. Bowl

7. Drain valve

6. Install the new filter (3), stepped end toward the louver, louver (2), and gasket (1) onto the mounting stud (4).

CAUTION: Do not cross-thread the mounting stud. Carefully en-

gage the threads and turn slowly. The filter must be mounted correctly to help prevent possible damage to the ventilator from particles in the supply gas.

7. Screw the mounting stud (4) into the gas supply block, finger tight.

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6/Maintaining the Ventilator

8. Lubricate the filter bowl threads and the O-ring with an oxygen approved lubricant (KRYTOX®).

9. Slip the O-ring (5) over the lip on the filter bowl and carefully screw the filter bowl into the gas block hand tight. Do not cross-thread the filter bowl.

10. Connect the supply gas.

WARNING: Check for supply gas leaks around the filter bowl. A leaking filter bowl can deplete reserve cylinders, and a reserve gas supply may not be available for emergency use and patient injury could result.

11. Check around the filter bowl for leaks:

• Listen for a hiss sound

• Test the area around the top of the filter bowl with a leak check

fluid

• Periodically check the cylinder pressure gauge

® KRYTOX Trademark E.I. Du Pont de Nemours Co. (Inc.)

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Notes

6/Maintaining the Ventilator

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7/Service Procedures

Repair policy 7-1 Troubleshooting guide 7-2

Ventilator problems 7-2 Troubleshooting ventilator failure messages 7-4 Ventilator failure messages 7-5

Repair policy

Do not use malfunctioning equipment. Make all necessary repairs, or have the equipment serviced by an authorized Ohmeda representative. After repair, test the equipment to ensure that it is functioning properly, in accordance with the manufacturer’s published specifications.

To help ensure full reliability, have all repairs and service done by an authorized Ohmeda representative. If this cannot be done, replacement and maintenance of those parts listed in this manual may be undertaken by a competent, trained individual having experience in the repair of the Ohmeda 7800 Ventilator and having appropriate test and calibration equipment.

CAUTION: No repair should ever be undertaken or attempted by

anyone not having proper qualifications and equipment.

Replace damaged parts with components manufactured or sold by Ohmeda. Then test the unit to ascertain that it complies with the manufacturer’s published specifications.

In some cases, special diagnostic equipment may be required to properly service components of the Ohmeda 7800 Ventilator. The components must then be sent to the nearest Ohmeda Service Center.

Contact the nearest Ohmeda Service Center for service assistance. If you send any unit to an Ohmeda Service Center, package it securely in the original shipping container, if possible, and ship it prepaid. Enclose a letter with the unit describing in detail any difficulties experienced and the repairs felt necessary. In all cases, other than where Ohmeda’s warranty is applicable, repairs will be made at Ohmeda’s current list price for the replacement part(s) plus a reasonable labor charge.

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7/Service Procedures

Troubleshooting guide

This guide is divided into two sections: ventilator problems and ventilator failure messages.

Ventilator problems

Symptom Possible cause Recommended action

No display on the ~ power has failed and Plug control monitor into ventilator screen. No backup battery is working ~ source and alarms sounding. completely discharged. power it ON for 24-hours to

recharge battery.

Excel to ventilator cable Reattach and use screws to disconnected hold connector

Bellows does not expand Leak in the breathing system. Check breathing system during ventilation or tends hoses and connections. to collapse.

Bellows not installed properly. Check bellows to base

attachment.

Tear or leak in bellows. Check the entire surface of

the bellows. Pay close attention to the angles in the convolutions

Insufficient fresh gas flow. Check that settings on

flowmeter are adequate.

Bellows does not descend Exhaust valve failed Check exhaust valve during inspiration

Drive gas hose disconnected Reconnect drive gas hose Ventilator switch in APL/Bag Place switch in Vent position

position

Bellow is bad, distended, Incorrect scavenging system Check the scavenging system or slips off the base. pressure. for vacuum or high pressure.

Low pressure alarm sounds Leaks in pressure sensing tube. Replace pressure sensing continuously. tube.

Circuit disconnected. Reconnect circuit. Circuit occluded. Clear circuit.

Transient apnea alarm is Breath rate is set to two (2), This is normal. No action is triggered by sigh breath. sigh function is enabled, and required.

sigh breath occurring.

System sounds alarms at Liquid in pressure sensing tube Drain the sensing tube. incorrect pressures.

Tube disconnected. Reconnect the tube. Kink in tube. Replace the tube.

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7/Service Procedures

Ventilator problems, continued

Symptom Possible cause Recommended action

Volume readings are Low oxygen supply pressure Check, and repair, the oxygen consistently low. supply.

Failed volume sensor cartridge. Replace the volume sensor

cartridge. Breathing system leak. Find and repair leaks. Control module’s altitude Reset the altitude compensa-

compensation set incorrectly. tion as described in “Setting

the altitude compensation” in

section “2/Getting Started.”

Volume readings are high. Control module’s altitude Reset the altitude consis-

compensation set incorrectly tently compensation as

described in “Setting the

altitude compensation” in

section “2/Getting Started.”

Alarms sound without Certain electronic failures may Do not use the ventilator. apparent cause and cannot be so significant as to cause be silenced. the system to lose the ability to

generate ventilator failure messages even though the ventilator has failed. If such a serious failure occurs, the alarm silence button will not silence the alarm.

Reverse flow alarm is Expiratory check valve on Replace check valve disk. activated. (While the absorber is functioning volume sensor is in the incorrectly. distal position of the expiratory limb of the breathing circuit.)

Reverse flow alarm is If the volume sensor is located Either locate sensor in the activated during every in the proximal end of the “Y” distal position of the expirabreath. connector in the patient circuit, tory limb, (see “2/Getting

the alarm may sound for each Started”) or use the setup breath. page to disable the reverse

flow alarm. (see section

“5/Operating the Ventilator”) Volume sensor cartridge is Correctly connect the clip to

connected backwards to sensor the volume cartridge.(see clip. “2/Getting Started”)

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7/Service Procedures

Troubleshooting ventilator failure messages

Ventilator failure messages can indicate anything from a defective electronic chip to excessive pressure in the ventilator’s driving gas supply. Do not attempt to use the ventilator while a ventilator failure message is displayed. And, even if no ventilator failure message is displayed, do not use the ventilator if you suspect a malfunction has occurred.

IMPORTANT

∑

WARNING: Manual ventilation must be performed when electrical interference causes interruption of ventilator delivered mechanical ventilation. Manual ventilation must be continued until the ventilator resumes normal operation or an alternate ventilator/anesthesia system can be used.

If your ventilator displays a ventilator failure message, please note the failure number, any other symptoms, and any corrective actions you took, then call trained service personnel.

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7/Service Procedures

Ventilator failure messages

Vent fail message Possible cause

VENT FAIL 0 ! Electronic failure VENT FAIL 1 ! Electronic failure VENT FAIL 2 ! Electronic failure VENT FAIL 3 ! Electronic failure VENT FAIL 4 ! Regulated gas pressure more than 30 psig (210 kPa) VENT FAIL 5 ! ~ power failure and backup-battery voltage low VENT FAIL 6 ! Flow valve circuit failure DRIVE CKT OPEN ! Exhalation valve circuit failure or Bag/APL switch in wrong position VENT FAIL 8 ! Gas inlet circuit failure VENT FAIL 9 ! Electronic failure VENT FAIL 10 ! Electronic failure VENT FAIL 11 ! Electronic failure VENT FAIL 12 ! Electronic failure VENT FAIL 13 ! Electronic failure VENT FAIL 14 ! Electronic failure VENT FAIL 15 ! Auxiliary port selected on Excel dual port system, but French language

not selected

VENT FAIL 16 ! Electronic failure VENT FAIL 17 ! Electronic failur VENT FAIL 18 ! Electronic failure VENT FAIL 19 ! Electronic failure VENT FAIL 20 ! Electronic failure VENT FAIL 21 ! Electronic failure HARDWARE ERROR A Electronic failure HARDWARE ERROR B Electronic failure HARDWARE ERROR C Electronic failure SOFTWARE ERROR A Invalid data detected SOFTWARE ERROR B Invalid data detected SOFTWARE ERROR C Invalid data detected SOFTWARE ERROR D Invalid data detected SOFTWARE ERROR E Invalid data detected SOFTWARE ERROR F Invalid data detected

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Notes

7/Service Procedures

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8/Autoclavable Bellows Assembly

Introduction 8-1 Getting started 8-1 Ventilator Connections 8-2 Post Assembly Test 8-6 Cleaning and Sterilization 8-7

Cleaning 8-8 Sterilization 8-8

Periodic maintenance 8-9

Visual inspection 8-9 Pressure leak test. 8-9

Illustrated Parts List 8-11

Introduction

The Ohmeda Autoclavable Bellows Assembly (ABA) was specifically intended for use with Ohmeda 7000, 7800 ventilators; Modulus II Plus/ 7810 and Modulus CD/7850 Anesthesia systems. For detailed system information or information on setting up, theory of operation and preoperative checkout procedures, see the appropriate section of this O&M manual.

Getting started

∑

Special note: The ventilator manuals, anesthesia system manuals and the appendix of this manual may contain information that pertains to other versions of Ohmeda’s bellows assemblies. The information contained in this section pertains only to the Ohmeda ABA and DOES NOT APPLY TO OTHER BELLOWS ASSEMBLY VERSIONS.

WARNING: Disassembly, reassembly, cleaning and sterilization of the ABA should never be undertaken by any person who has not read this manual thoroughly and clearly understands the text. Failure to be totally familiar with the disassembly and reassembly of the ABA can result in equipment malfunction and injury to the patient.

This unit is not sterile as it is shipped from the factory. The ABA mounting plate mounts on any Ohmeda 7000 or 7800 series

ventilator control module, or in a remote mounting location using the four mounting screws provided. There are several possible orientations for the mounting plate and connection ports. See the exploded view illustrated parts list of the ABA at the end of this section.

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8/Autoclavable Bellows Assembly

Ventilator Connections

WARNING: Do not connect the 30-mm exhaust port directly to a high

∑

Figure 8-1

Port identification and typical adapter

vacuum source. The vacuum may remove required gases from the breathing circuit

∑

123

1. 22-mm port to breathing system

2. 30-mm port waste gas scavenging system

3. 17-mm port drive gas

4. 30-mm to 19-mm Adapter (see section 9.2)

WARNING: Disassembly, reassembly cleaning and sterilizing of the ABA should never be undertaken by any person who has not read this section thoroughly and clearly understood the text. Failure to be totally familiar with disassembly and reassembly of the ABA can result in equipment malfunction.

WARNING: Always perform the preoperative checkout procedures before using the system. Failure to ensure proper assembly, setup and operation prior to use may result in injury to the patient.

Note: Territorial standards may dictate gas scavenging ports other than 30-mm (see section

9.2). Adapters may have been included with your system. Contact your local Ohmeda representative for port conversion information.

AA.51.002 AA.51.001

Disassembly

The sequence of the following illustrated procedure is for disassembly of the bellows assembly — reassembly is the reverse of this sequence.

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Datex-Ohmeda 7800 User manual

Specifications and Main Features

Frequently Asked Questions

User Manual