Aspect Medical Systems BISPECTRAL INDEX A-2000 User manual

Aspect Medical Systems
A-2000
TM
BISPECTRAL INDEX



(BIS



) MONITORING SYSTEM
S E R V I C E M A N U A L
Caution:
U.S. Federal law restricts this device
to sale by or on the order of a physician.
© Copyright, 1999, Aspect Medical Systems. All rights reserved. Copying or other reproduction of
this document is prohibited without prior written consent of Aspect Medical Systems.
Aspect Medical Systems, Inc.
2 Vision Drive
Natick, MA 01760-2059
U.S.A.
508-653-0603
800-442-7688
[e-mail]
www.aspectms.com 075-0002 1.00

TABLE OF CONTENTS
1. INTRODUCTION .............................................................................. 1-1
1.1 ABOUT THIS MANUAL ....................................................................................1-1
1.2 INTRODUCING THE A-2000 BIS MONITORING SYSTEM.............................1-2
1.2.1 Principal Components ................................................................................1-2
1.2.2 How The A-2000 Works .............................................................................1-3
1.3 INSTRUMENT IDENTIFICATION .....................................................................1-3
1.3.1 A-2000 Monitor ...........................................................................................1-3
1.3.2 A-2000 Digital Signal Converter .................................................................1-3
1.3.3 Software Revision Numbers .......................................................................1-3
1.4 PROPRIETARY INFORMATION AND DEVICES.............................................1-3
2. SAFETY PRECAUTIONS................................................................. 2-1
2.1.1 WARNINGS, CAUTIONS, AND NOTES....................................................2-1
2.1.2 Warnings: ...................................................................................................2-1
2.1.3 Cautions: ....................................................................................................2-3
2.2 KEY TO SYMBOLS ..........................................................................................2-5
3. PRINCIPLES OF OPERATION........................................................ 3-1
3.1 SYSTEM ARCHITECTURE...............................................................................3-1
3.1.1 The Digital Signal Converter (DSC)............................................................3-1
3.1.2 The A-2000 Monitor....................................................................................3-7
3.1.3 A-2000 Printer ............................................................................................3-8
4. PREPARATION FOR USE AND INSTALLATION ........................... 4-1
4.1 ENVIRONMENT ................................................................................................4-1
4.1.1 Shipping and Storage Environment............................................................4-1
4.1.2 Operating Environment...............................................................................4-1
4.1.3 Power Requirements and System Grounding ............................................4-2
4.1.4 Site Preparation..........................................................................................4-2
4.2 INSTRUMENT CONNECTIONS .......................................................................4-3
4.2.1 Digital Signal Converter Connections.........................................................4-3
4.2.2 Power Cord Connections............................................................................4-3
4.2.3 Printer Connector .......................................................................................4-3
4.3 INSTALLATION AND VERIFICATION PROCEDURE .....................................4-4
4.4 REPACKAGING FOR SHIPPING AND STORAGE..........................................4-4

5. PREVENTIVE MAINTENANCE, CARE AND CLEANING ............... 5-1
5.1 CARE AND CLEANING ....................................................................................5-1
5.1.1 Cleaning the Monitor and Digital Signal Converter.....................................5-1
5.1.2 Disinfecting the Monitor and Digital Signal Converter ................................5-1
5.1.3 Cleaning the Monitor Display......................................................................5-1
5.2 ROUTINE MAINTENANCE ...............................................................................5-2
5.2.1 Checking the Battery ..................................................................................5-2
5.2.2 Checking Leakage Current.........................................................................5-2
5.2.3 Monitor System Checkout Procedure.........................................................5-4
5.2.4 DSC Checkout Procedure ..........................................................................5-5
5.2.5 Patient Interface Cable (PIC) Checkout Procedure....................................5-5
6. DIAGNOSTICS AND TROUBLESHOOTING................................... 6-1
6.1 GENERAL TROUBLESHOOTING....................................................................6-1
6.2 THE A-2000 DIAGNOSTIC PROCEDURES.....................................................6-4
6.2.1 Power-Up Diagnostics ................................................................................6-4
6.2.2 Automatic Diagnostics ................................................................................6-8
6.2.3 Manual Diagnostics ..................................................................................6-13
7. DISASSEMBLING AND REASSEMBLING THE A-2000................. 7-1
7.1 REQUIRED TOOLS AND SUPPLIES...............................................................7-2
7.2 THE MONITOR CASE.......................................................................................7-3
7.2.1 Opening the Monitor Case..........................................................................7-3
7.2.2 Closing the Monitor Case ...........................................................................7-3
7.3 THE ELECTRO/LUMINESCENT DISPLAY......................................................7-7
7.3.1 Removing the E/L Display Board................................................................7-7
7.3.2 Reattaching the E/L Display Board.............................................................7-7
7.4 THE FRONT PANEL SWITCH SET..................................................................7-9
7.4.1 Removing the Switch Set ...........................................................................7-9
7.4.2 Installing the New Switch Set .....................................................................7-9
7.5 THE PRINTED CIRCUIT BOARD ASSEMBLY .............................................. 7-11
7.5.1 Removing the Printed Circuit Board assembly.........................................7-11
7.5.2 Installing the Printed Circuit Board Assembly...........................................7-11
7.6 THE MAIN PCB...............................................................................................7-14
7.6.1 Removing the Main PCB ..........................................................................7-14
7.6.2 Installing the Main PCB ............................................................................7-14
7.7 THE POWER SUPPLY PCB ...........................................................................7-19
7.7.1 Removing the Power Supply PCB ............................................................7-19
7.7.2 Installing the Power Supply PCB ..............................................................7-19

7.8 THE BATTERY................................................................................................7-22
7.8.1 Removing the Battery...............................................................................7-22
7.8.2 Installing the Battery .................................................................................7-22
7.9 THE FAN .........................................................................................................7-24
7.9.1 Removing the Fan ....................................................................................7-24
7.9.2 Installing the Fan ......................................................................................7-24
7.10 THE CLAMP SHOE ASSEMBLY....................................................................7-26
7.10.1 Removing the Clamp Shoe Assembly......................................................7-26
7.10.2 Installing the Clamp Shoe Assembly........................................................7-26
7.11 FUSE REPLACEMENT ...................................................................................7-27
8. A-2000 SPECIFICATIONS.............................................................. 8-1
8.1 GENERAL SPECIFICATIONS: .........................................................................8-1
8.1.1 Type of Protection against Electric Shock of the System:..........................8-3
8.1.2 Degree of Protection against Electric Shock of the System: ......................8-3
8.1.3 Degree of Protection against the Ingress of Water: ...................................8-3
8.1.4 Mode of Operation of the System:..............................................................8-3
8.1.5 Classification: .............................................................................................8-3
8.2 OPTIONS AND ACCESSORIES:......................................................................8-3
8.3 Digital Signal Converter (DSC) Connector....................................................8-4
8.4 WARRANTY ......................................................................................................8-5
9. APPENDICES .................................................................................. 9-1
9.1 APPENDIX I - A-2000 PARTS LIST................................................................9-1
9.2 APPENDIX II - SENSOR SIMULATOR - INSTRUCTIONS FOR USE ...........9-2

TABLE OF FIGURES
Figure 1-1 The A-2000 BIS Monitoring System................................................................1-4
Figure 1-2 Rear View of Monitor .....................................................................................1-5
Figure 3-1 The A-2000 System Block Diagram................................................................3-2
Figure 3-2 The A-2000 Signal Flow Diagram ...................................................................3-3
Figure 3-3 The Digital Signal Converter (DSC) ................................................................3-6
Figure 7-1 Opening the Monitor Case............................................................................7-5
Figure 7-2 The E/L Display Cable ...................................................................................7-5
Figure 7-3 The Keypad Cable Tension Flange ...............................................................7-6
Figure 7-4 The Four Mounting Screws............................................................................7-8
Figure 7-5 The Cable Access Port ................................................................................7-10
Figure 7-6 Remove the covering on the back of the new switch set.............................7-10
Figure 7-7 Place rear case assembly face down on a scratch free work surface.........7-13
Figure 7-8 Fan Cable ....................................................................................................7-13
Figure 7-9 Release standoff tab by squeezing with needle-nose pliers ........................7-15
Figure 7-10 The L bracket.............................................................................................7-15
Figure 7-11 Gently pull and flex to separate PCBs .......................................................7-16
Figure 7-12 Line up Interconnect PCB pins to Main PCB socket..................................7-16
Figure 7-13 Align standoffs and push in until standoff tabs snap into place .................7-17
Figure 7-14 Install L bracket by holding long side; short side connects to Main PCB...7-17
Figure 7-15 The L Bracket Installed ..............................................................................7-18
Figure 7-16 Gently flex and pull Power Supply PCB free of pins ..................................7-20
Figure 7-17 Remove four screws on rear of Power Supply PCB ..................................7-20
Figure 7-18 Remove shield from rear of Power Supply PCB........................................7-21
Figure 7-19 Battery and cable .......................................................................................7-23
Figure 7-20 Fan wiring orientation and Clamp Shoe screws ........................................7-25
Figure 7-21 Updated System with 2 Fan Mounting screws and Copper Tape..............7-25
Figure 7-22 Releasing the plastic locking tabs of the fuse holder.................................7-28
Figure 7-23 Re-installing the fuse holder ......................................................................7-28

SECTION I INTRODUCTION
- 1-1 -
SECTION I
1. INTRODUCTION
1.1 ABOUT THIS MANUAL
This Service Manual contains information necessary to diagnose, troubleshoot and repair
the Aspect Medical Systems A-2000™ BIS

Monitoring System. Also included are
instructions for the unit’s installation, maintenance, care and cleaning. A parts list is
provided in the appendices at the back of the manual.
This manual is intended for Aspect Medical Systems service technicians and/or
authorized Aspect distributors who have been trained by Aspect to perform the service
procedures described within this manual. It assumes prior knowledge and experience
with the internal workings of medical devices and electronics.
Caution:
Refer to the section on disassembling and reassembling before
attempting to service the inside of the A-2000.
Section I provides a functional overview of the A-2000, its principal components, and
instrument identification.
Section II discusses important safety precautions. Before attempting to set up or service
the A-2000, please familiarize yourself with the safety information provided in this section.
Section III describes the A-2000 monitor hardware and how it operates. Included are the
assemblies and parts that make up the monitor and the Digital Signal Converter (DSC).
Section IV provides preparation for use and installation instructions, including
environmental considerations, instrument connections and system setup and check out.
Section V describes normal maintenance, care and cleaning procedures.
Section VI describes the A-2000 diagnostic tools and provides tables to aid in
troubleshooting the system.
Section VII describes the removal and replacement procedure for each subassembly.
Note:
This manual was not designed for repairing the unit to the level of its
individual components (e.g. the chips on the main board). The manual is
intended solely for the troubleshooting and replacement of its
subassembly modules (e.g. the electro-luminescent display and power
supply).
Section VIII contains the A-2000 specifications.
Appendix I contains a list of replaceable parts and subassemblies.
Appendix II contains the Sensor Simulator instructions for use.

SECTION I INTRODUCTION
- 1-2 -
1.2 INTRODUCING THE A-2000 BIS MONITORING SYSTEM
Aspect Medical Systems A-2000 BIS Monitoring System is a user-configurable patient
monitoring system designed to monitor the hypnotic state of the brain based on
acquisition and processing of EEG signals. The A-2000 processes raw EEG signals to
produce a single number, called the Bispectral Index

, or BIS, which correlates to the
patient’s level of hypnosis. It operates from an AC power source of 100V to 240V,
47/63Hz, and provides a minimum 20 minutes of automatic back-up battery power.
The monitor is menu-driven with fixed keys for choosing the options available.
1.2.1 Principal Components
The system is composed of a monitor and a digital signal converter, with a patient
interface cable (PIC), and BIS Sensor.
1.2.1.1 Monitor
The monitor contains the operator control panel, an electro-luminescent display screen,
and connectors for the digital signal converter and printer.
Front Panel Controls:
The [SILENCE] key toggles audible alarms on and off.
The left [←] and right [→] arrow keys are used to enter Review
mode and to scroll data back and forth while in Review mode.
The [MENU/EXIT] key is used to enter and exit the Setup Menu.
In Review mode it will return the user to the main screen. It is
also used to halt certain procedures, such as the sensor check,
and to answer "no" to a question.
The up [↑] and down [↓] arrows are used to move from one
menu selection to another.
The [SELECT] key is used to move between menu selections, to
confirm an entry, and to answer "yes" to a question.

SECTION I INTRODUCTION
- 1-3 -
1.2.1.2 Digital Signal Converter (DSC)
The Digital Signal Converter is about the size of a computer mouse. It contains the EEG
amplifiers and analog filters. The DSC digitizes EEG waveforms for transmission to, and
processing by, the monitor. The DSC’s long flexible Monitor Interface Cable connects to
the front of the monitor, and the shorter “DSC pigtail” cable connects to the Patient
Interface Cable (PIC).
The attachment clip on the DSC is used to secure it in a convenient location near the
patient’s head. The patient connection is accomplished by attaching the Aspect BIS
Sensor to the PIC.
1.2.2 How The A-2000 Works
A detailed description of how the A-2000 works is contained within Section V of the A-
2000 Operating Manual and will not be discussed in this Service Manual. Please refer to
the A-2000 Operating Manual (070-0015) for additional information.
1.3 INSTRUMENT IDENTIFICATION
1.3.1 A-2000 Monitor
Monitor identification information is permanently marked on the rear panel. This
information includes instrument model and serial numbers, power ratings, cautions, and
the Aspect Medical Systems shipping address.
1.3.2 A-2000 Digital Signal Converter
The A-2000 Digital Signal Converter identification information is permanently marked on
the rear panel of the Digital Signal Converter. This information includes instrument model
and serial numbers and cautions.
1.3.3 Software Revision Numbers
Software revision numbers are displayed in the Diagnostic Menu.
1.4 PROPRIETARY INFORMATION AND DEVICES
Information and descriptions contained in this guide are the property of Aspect Medical
Systems and may not be copied, reproduced or distributed without prior written
permission. Portions of the A-2000 design are proprietary and are the subject of patents
and patents pending.

SECTION I INTRODUCTION
- 1-4 -
Figure 1-1 The A-2000 BIS Monitoring System

SECTION I INTRODUCTION
- 1-5 -
Figure 1-2 Rear View of Monitor
Clamp
Shoe
Fuse
Holder
Serial
Port
Potential
Equalization
Terminal