Aspect Medical Systems XP PLATFORM A-2000 User manual

Aspect Medical Systems
A-2000TM XP PLATFORM
BISPECTRAL INDEXTM
(BISTM) MONITORING SYSTEM
SERVICE INFORMATION
MANUAL
Rx Only
©Copyright, 2009, Aspect Medical Systems. All rights reserved. Copying or other reproduction
of this document is prohibited without prior written consent of Aspect Medical Systems.
EC REP
Aspect Medical Systems, Inc. Aspect Medical Systems International B.V.
One Upland Road Rijnzathe 7d2
Norwood, MA 3454 PV De Meern
U.S.A. The Netherlands
(Tel) 617-559-7000 Tel: [phone]
(Tel) 888-BIS INDE(X) (U.S. only) Fax: [phone]
(Fax) 617-559-7400 [e-mail]
[e-mail]
www.aspectmedical.com 075-0014 1.04

i
TABLE OF CONTENTS
1SAFETY PRECAUTIONS........................................................................................1-1
1.1 WARNINGS...........................................................................................................1-1
1.2 CAUTIONS............................................................................................................1-3
1.3 KEY TO SYMBOLS...............................................................................................1-5
2A-2000 SYSTEM OVERVIEW .................................................................................2-1
2.1 INTRODUCING THE A-2000 BIS MONITORING SYSTEM..................................2-1
2.1.1 PRINCIPAL COMPONENTS......................................................................................2-1
2.1.2 HOW THE A-2000 WORKS ....................................................................................2-2
2.2 INSTRUMENT IDENTIFICATION..........................................................................2-2
2.2.1 A-2000 MONITOR.................................................................................................2-2
2.2.2 A-2000 DIGITAL SIGNAL CONVERTER....................................................................2-2
2.2.3 SOFTWARE REVISION NUMBERS............................................................................2-2
2.3 PROPRIETARY INFORMATION AND DEVICES .................................................2-2
3PRINCIPLES OF OPERATION ...............................................................................3-1
3.1 HOW THE A-2000 MONITORING SYSTEM WORKS...........................................3-1
3.2 SYSTEM ARCHITECTURE...................................................................................3-1
3.2.1 THE DIGITAL SIGNAL CONVERTER (DSC) ..............................................................3-4
3.2.2 THE A-2000 MONITOR..........................................................................................3-6
3.2.3 A-2000 PRINTER ..................................................................................................3-7
3.3 SYSTEM FEATURES............................................................................................3-7
3.3.1 SYSTEM SELF CHECKS .........................................................................................3-7
3.3.2 DATA MEMORY.....................................................................................................3-8
3.3.3 SAVED SETTINGS..................................................................................................3-8
3.3.4 BATTERY OPERATION ...........................................................................................3-8
3.3.5 DATA TRANSFER AND SOFTWARE UPDATES ..........................................................3-8
3.3.6 PRINTED REPORTS ...............................................................................................3-9
4PREPARATION 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:MOUNTING THE MONITOR ......................................................4-2
4.2 INSTRUMENT CONNECTIONS............................................................................4-3
4.2.1 DIGITAL SIGNAL CONVERTER CONNECTIONS .........................................................4-4
4.2.2 POWER CORD CONNECTIONS ...............................................................................4-4
4.2.3 PRINTER CONNECTOR ..........................................................................................4-4

ii
4.3 INSTALLATION AND VERIFICATION PROCEDURE..........................................4-5
5PREVENTIVE 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 PREVENTIVE MAINTENANCE.............................................................................5-2
5.2.1 CHECKING THE BATTERY ......................................................................................5-2
5.2.2 CHECKING LEAKAGE CURRENT .............................................................................5-2
5.2.3 A-2000 MONITOR SYSTEM CHECKOUT PROCEDURE..............................................5-3
5.2.4 DSC CHECKOUT PROCEDURE...............................................................................5-4
5.2.5 PATIENT INTERFACE CABLE (PIC) CHECKOUT PROCEDURE ...................................5-4
5.2.6 PHYSICAL INTEGRITY INSPECTION .........................................................................5-5
6DIAGNOSTICS AND TROUBLESHOOTING..........................................................6-1
6.1 GENERAL TROUBLESHOOTING........................................................................6-1
6.2 A-2000 BIS MONITOR SYSTEM TROUBLESHOOTING PROCEDURE..............6-2
6.2.1 MONITOR TROUBLESHOOTING PROCEDURE ........................................................6-2
6.2.2 DSC TROUBLESHOOTING PROCEDURE..................................................................6-4
6.2.3 PIC AND SENSOR TROUBLESHOOTING PROCEDURE...........................................6-5
6.2.4 DSC CABLE PROBLEM ISOLATION .........................................................................6-6
6.3 STATUS MESSAGES AND OPERATOR ACTIONS ............................................6-7
7SERVICING THE A-2000 SYSTEM.........................................................................7-1
7.1 REPLACING MAJOR COMPONENTS.................................................................7-1
7.1.1 TO REPLACE THE PIC: ..........................................................................................7-1
7.1.2 TO REPLACE THE DSC:.........................................................................................7-2
7.1.3 TO REPLACE THE MONITOR:..................................................................................7-2
7.2 FUSE REMOVAL AND INSTALLATION...............................................................7-2
7.3 WHAT TO DO WITH ACOMPONENT THAT REQUIRES SERVICE....................7-3
7.4 REPACKAGING FOR SHIPPING AND STORAGE..............................................7-3
7.5 DISASSEMBLING AND REASSEMBLING THE DSC..........................................7-4
7.5.1 REQUIRED TOOLS AND SUPPLIES..........................................................................7-4
7.5.2 THE DSC CASE....................................................................................................7-5
7.5.3 THE DSC CABLES (MONITOR AND PIGTAIL)...........................................................7-9
7.5.4 DSC CHECKOUT AND SAFETY TESTS..................................................................7-10
8A-2000 SPECIFICATIONS ......................................................................................8-1
8.1 INTRODUCTION:..................................................................................................8-1
8.2 WARRANTY..........................................................................................................8-4
9APPENDIX I.............................................................................................................9-1

iii
9.1 SPARES AND ACCESSORIES LIST....................................................................9-1
9.2 SENSOR SIMULATOR: P/N: 186-0137 FOR USE WITH DSC-XP: ....................9-2
9.3 TEST SENSOR......................................................................................................9-3
9.4 SAFETY TESTER CONNECTION WITH PIC........................................................9-5
9.5 PLACEMENT OF PIC SECURING STRAP ON BIS MONITORING SYSTEM......9-6
10 APPENDIX II........................................................................................................10-1
10.1 A-2000 SIGNAL FLOW DIAGRAM.....................................................................10-1
10.2 A-2000 BLOCK DIAGRAM .................................................................................10-2
10.3 DSC WIRING DIAGRAM; DSC CONNECTOR (WIRE SIDE).................................10-3
10.4 WIRING DIAGRAM; MONITOR CABLE.............................................................10-4
10.5 WIRING DIAGRAM; PIGTAIL CABLE................................................................10-5

iv
TABLE OF FIGURES
Figure 2-1 The A-2000 BIS Monitoring System .........................................................................................2-3
Figure 2-2 Rear View of Monitor...............................................................................................................2-4
Figure 3-1 The A-2000 System Block Diagram..........................................................................................3-2
Figure 3-2 The A-2000 Signal Flow Diagram ...........................................................................................3-3
Figure 4-1 Pole Clamp...............................................................................................................................4-3
Figure 7-1 Placement of PIC Securing Strap on BIS Monitoring System..................................................7-1
Figure 7-2 Remove the ground shield securing screw.................................................................................7-6
Figure 7-3 Remove shield by sliding along pigtail cable............................................................................7-6
Figure 7-4 Carefully separate the two printed circuit boards.....................................................................7-7
Figure 7-5 For a new gasket, cable passages need to be carefully cut.......................................................7-8
Figure 7-6 Verify that the strain relief is fully secured in its recess............................................................7-9
Figure 9-1 BIS Sensor................................................................................................................................9-3
Figure 9-2 Connecting electrodes #2 and #4.............................................................................................9-4
Figure 9-3 Connecting electrode #3 with #4, and #1 with #2. ................................................................... 9-4
Figure 9-4 Safety Tester Contact Points ....................................................................................................9-5

ABOUT THIS MANUAL
_____________________________________________________________________________
v
ABOUT THIS MANUAL
This manual contains information necessary for the customer to install, maintain, service, identify
and prepare for use the Aspect Medical System BIS™Monitoring System. Also included are
directions to diagnose, troubleshoot, and repair the system. A spare parts and accessories list
and system specifications are included.
This manual is intended to be used in combination with the A-2000™Operating Manual.
The A-2000 BIS Monitoring System is designed and manufactured using state-of-the-art
components and manufacturing processes. Field repair or customer repairs are therefore limited
by design to replacement of major component assemblies such as the Patient Interface Cable
(PIC), Digital Signal Converter (DSC), or the A-2000 Monitor itself.
This manual, in conjunction with the A-2000 Operating Manual, contains the maintenance and
diagnostic troubleshooting information necessary for customer qualified technical personnel to
test and replace those parts of the equipment that are replaceable by the customer. Aspect does
not authorize nor provide information to service or repair the internal components of the A-2000
Monitor.
Section I 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 II provides a functional overview of the A-2000, its principal components, and instrument
identification.
Section III describes the A-2000 monitor hardware and how it operates.
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 system components and how
to return a component for service. It also explains how to disassemble and reassemble the DSC
to replace cables. Note:
This manual was not designed for repairing the A-2000 BIS system to the level of
its electronic circuit boards. The manual is intended solely for the troubleshooting
and replacement of its major components or DSC cables.
Section VIII contains the A-2000 specifications and warranty.
Appendix I provides instructions for use for the Sensor Simulator and describes how to make a
test sensor. It also contains a list of spare parts and accessories.
Appendix II provides system diagrams.

ABOUT THIS MANUAL
_____________________________________________________________________________
vi

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-1
SECTION I
1 SAFETY PRECAUTIONS
INTRODUCTION
Caution:
Carefully read the A-2000 BIS Monitoring System Operating Manual entirely
before using the monitor in a clinical setting.
WARNINGS, CAUTIONS, AND NOTES
The terms warning, caution, and note have specific meanings in this manual.
•A WARNING advises against certain actions or situations that could result in personal injury
or death.
•A CAUTION advises against actions or situations that could damage equipment, produce
inaccurate data, or invalidate a procedure, although personal injury is unlikely.
•A NOTE provides useful information regarding a function or procedure.
KEY TO SYMBOLS
A key to the symbols used on the A-2000 appears at the end of this section.
1.1 WARNINGS
GROUND WIRE LEAKAGE CURRENT MUST BE CHECKED BY A QUALIFIED BIOMEDICAL
ENGINEERING TECHNICIAN WHENEVER INSTRUMENT CASE IS OPENED.
EXPLOSION HAZARD: DO NOT USE THE A-2000 IN A FLAMMABLE ATMOSPHERE OR
WHERE CONCENTRATIONS OF FLAMMABLE ANESTHETICS MAY OCCUR.
ELECTRICAL SHOCK HAZARD: DO NOT REMOVE MONITOR COVERS DURING
OPERATION OR WHILE POWER IS CONNECTED TO MONITOR.
ELECTRICAL SHOCK HAZARD: THE MANUFACTURER'S INSPECTION OF THIS
APPARATUS VERIFIED THAT THE GROUND LEAKAGE CURRENT AND THE PATIENT
SAFETY CURRENT WERE LESS THAN THE SPECIFIED LIMITS ESTABLISHED BY THE
APPLICABLE SAFETY STANDARDS. AS A MATTER OF SAFE PRACTICE, THE
INSTITUTION SHOULD CONDUCT PERIODIC TESTS TO VERIFY THESE CURRENTS.
SHOCK HAZARD: DO NOT ATTEMPT TO DISCONNECT THE POWER CORD WITH WET
HANDS. MAKE CERTAIN THAT YOUR HANDS ARE CLEAN AND DRY BEFORE TOUCHING
THE POWER CORD.
U.S.A. REQUIREMENT: FOR PROPER GROUNDING, THE POWER RECEPTACLE MUST BE
A THREE-WIRE GROUNDED OUTLET. A HOSPITAL GRADE OUTLET IS REQUIRED.
NEVER ADAPT THE THREE-PRONG PLUG FROM THE MONITOR TO FIT A TWO-SLOT
OUTLET. IF THE OUTLET HAS ONLY TWO SLOTS, MAKE SURE THAT IT IS REPLACED
WITH A THREE-SLOT GROUNDED OUTLET BEFORE ATTEMPTING TO OPERATE THE
MONITOR.

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-2
IF THE INTEGRITY OF THE EXTERNAL PROTECTIVE EARTH GROUND IS IN DOUBT, THE
A-2000 SHALL BE OPERATED FROM ITS INTERNAL BATTERY POWER SOURCE ONLY.
FOR A-2000s USED OUTSIDE OF NORTH AMERICA: A HARMONIZED LINE CORD WITH
CONDUCTORS HAVING A CROSS SECTIONAL AREA GREATER THAN 0.75 mm2MUST BE
USED.
THE CONDUCTIVE PARTS OF ELECTRODES OR SENSOR AND CONNECTORS,
INCLUDING THE NEUTRAL ELECTRODE, SHOULD NOT CONTACT OTHER CONDUCTIVE
PARTS, INCLUDING EARTH.
ANY PROCEDURES THAT REQUIRE THE REMOVAL OF THE DSC’s COVER AND
INTERNAL PARTS SHOULD BE PERFORMED BY A QUALIFIED BIOMEDICAL
ENGINEERING TECHNICIAN. POWER OFF THE UNIT BY DISCONNECTING FROM THE
MONITOR.
TO REDUCE THE HAZARD OF BURNS IN THE HIGH-FREQUENCY SURGICAL NEUTRAL
ELECTRODE CONNECTION, THE SENSOR OR ELECTRODES SHOULD NOT BE LOCATED
BETWEEN THE SURGICAL SITE AND THE ELECTRO-SURGICAL UNIT RETURN
ELECTRODE.
TO REDUCE THE HAZARD OF BURNS DURING USE OF BRAIN-STIMULATING DEVICES
(e.g., TRANSCRANIAL ELECTRICAL MOTOR EVOKED POTENTIAL), PLACE STIMULATING
ELECTRODES AS FAR AS POSSIBLE FROM THE BIS SENSOR AND MAKE CERTAIN THAT
SENSOR IS PLACED ACCORDING TO PACKAGE INSTRUCTIONS.
THE SENSOR MUST NOT BE LOCATED BETWEEN DEFIBRILLATOR PADS WHEN A
DEFIBRILLATOR IS USED ON A PATIENT CONNECTED TO THE A-2000.
TO MINIMIZE THE RISK OF PATIENT STRANGULATION, THE PATIENT INTERFACE CABLE
(PIC) MUST BE CAREFULLY PLACED AND SECURED.
WHENEVER AN EVENT SUCH AS SPILLAGE OF BLOOD OR SOLUTIONS OCCURS,
RE-TEST GROUND LEAKAGE CURRENT BEFORE FURTHER USE.
BE SURE THE MONITOR IS MOUNTED SECURELY IN PLACE TO AVOID PERSONAL
INJURY.
MONITOR IS NOT DESIGNED FOR USE IN MRI ENVIRONMENT.
UNIVERSAL PRECAUTIONS SHALL BE OBSERVED TO PREVENT CONTACT WITH BLOOD
OR OTHER POTENTIALLY INFECTIOUS MATERIALS. PLACE CONTAMINATED
MATERIALS IN REGULATED WASTE CONTAINER.
DO NOT MIX DISINFECTING SOLUTIONS (e.g., BLEACH AND AMMONIA), AS HAZARDOUS
GASES MAY RESULT.
WHEN CONNECTING EXTERNAL EQUIPMENT (e.g., DATA CAPTURE COMPUTER), THE
SYSTEM LEAKAGE CURRENT MUST BE CHECKED AND MUST BE LESS THAN THE
IEC601-1-1 LIMIT.

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-3
THE USE OF ACCESSORY EQUIPMENT NOT COMPLYING WITH THE EQUIVALENT
SAFETY REQUIREMENTS OF THIS EQUIPMENT MAY LEAD TO A REDUCED LEVEL OF
SAFETY OF THE RESULTING SYSTEM. CONSIDERATION RELATING TO THE CHOICE
SHALL INCLUDE:
•USE OF THE ACCESSORY IN THE PATIENT VICINITY
•EVIDENCE THAT THE SAFETY CERTIFICATION OF THE ACCESSORY HAS BEEN
PERFORMED IN ACCORDANCE TO THE APPROPRIATE IEC 601-1 AND/OR IEC
601-1-1 HARMONIZED NATIONAL STANDARD.
REPLACE FUSES ONLY WITH ONE OF THE FOLLOWING PARTS:
Aspect P/N 430-0006, 1.25 Amps, 250V, 5x20mm
Littelfuse 217 Series, 1.25 Amps, 250V, 5x20mm
Wickmann 193 Series, 1.25 Amps, 250V, 5x20mm
ALWAYS REPLACE BOTH FUSES TOGETHER, EVEN IF ONLY ONE HAS FAILED.
1.2 CAUTIONS
Caution: U.S. Federal law restricts this device to sale by or on the order of a physician.
Read the entire A-2000 Operating Manual carefully before using the monitor in a clinical
setting.
All repairs to the A-2000 Monitoring System should be made only by a qualified
Biomedical Engineering Technician or other authorized personnel.
Do not autoclave the Digital Signal Converter or Monitor. Autoclaving will seriously
damage both components.
Do not block fan output. Keep at least three 3 inches of unobstructed space between rear
of instrument and wall and other instruments. Do not allow other instruments to block
airflow. Do not block ventilation inlet holes on the underside of monitor.
Do not open Digital Signal Converter. The seal to prevent liquids from entering the Digital
Signal Converter may be damaged if opened. Service or repairs must be performed only
by qualified biomedical technicians.
Mixing of system configurations will increase sensor and hardware inventory
requirements and may create user and support issues.
Using accessories other than those specified may result in increased electromagnetic
emissions or decreased electromagnetic immunity of the BIS Monitoring System.
Each BIS sensor type has its own placement method. Be sure to carefully follow the
appropriate package directions.
The A-2000 has been designed to operate with a disposable BIS Sensor. The sensor is a
silver/silver chloride electrode array that utilizes Aspect's patented Zipprep™technology
and uses a proprietary connector. Use of other electrodes is not recommended.
Considerations when using Electro Convulsive Therapy (ECT) equipment during BIS™
monitoring: Place ECT electrodes as far as possible from the BIS sensor to minimize the
effect of interference. Certain ECT equipment may interfere with the proper function of the
BIS Monitoring System. Check for compatibility of equipment during patient setup.

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-4
Continuous impedance checking may need to be disabled if the 1 nanoampere 128 Hz
impedance check signal interferes with other equipment (e.g., evoked potential monitors).
Check the battery periodically, by operating an A-2000 that has been disconnected from
the wall socket and that has been charging the battery for at least 4 hours. After long
periods of storage (e.g., more than 1 month) it may be necessary to cycle (charge, then
discharge) the battery a few times to get full charge capacity. If the A-2000 fails to operate
reliably from the battery for 20 minutes, battery replacement is required.
The A-2000 contains an internal Nickel-Metal-Hydride battery. The battery must be
removed by a qualified service technician and disposed of or recycled in accordance with
the national laws of the country. Contact Aspect Medical Systems, Inc. or the local
distributor for servicing of battery.
Avoid liquid ingress to the PIC. Contact of fluids with the PIC sensor connectors can
interfere with PIC performance.
The A-2000 Monitor should not be used adjacent to or stacked with other equipment. If
adjacent or stacked use is necessary, the A-2000 monitor should be observed to verify
normal operation in the configuration in which it will be used.
The A-2000 system complies with the electromagnetic compatibility requirements of
EN60601-1-2. Operation of this device may affect or be affected by other equipment in the
vicinity due to electromagnetic interference (EMI). If this occurs:
•Increase separation between devices
•Re-orient device cabling
•Plug devices into separate outlet circuit branches
Consult Aspect Medical Systems Technical Support for assistance.
All work involving opening the instrument case must be performed in a static-safe
environment to prevent damage to electronic components and assemblies. This
environment includes the operator, work area and tools, and any other test or storage
items that might touch the DSC assemblies.
Use only the parts and tools specified. Use of any others may damage the instrument.
Handle PCBs only by board edges to avoid contamination (moisture, skin oils, etc.) on
PCB and component surfaces!
When connecting or disconnecting Digital Signal Converter, take care not to touch the
exposed contacts of either connector. Damage due to electrostatic discharge may result.
A-2000 is a trademark of Aspect Medical Systems, Inc.
Bispectral Index, BIS, the BIS logo, and Zipprep are trademarks of Aspect Medical Systems, Inc.
and are registered in the U.S.A., E.U. and other countries.

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-5
1.3 KEY TO SYMBOLS
Caution: Consult
Accompanying Documents Dangerous Voltage
J1
Attention, J1 RS-232 Serial
Port, Consult Accompanying
Documents
J2
Attention, J2 Printer Port, Consult
Accompanying Documents
Caution: Hot Surface Storage Temperature Limits
Type BF Equipment Type BF Equipment Defibrillator-
proof
Alternating Current (A/C)
Direct Current (D/C)
Battery Location
Reset Button
Monitor Power ON
Monitor Power OFF or Standby
Mode
Do not Reuse
Use by
YYYY-MM-DD or
YYYY-MM
Latex-free product PVC-free product
Manufacturer Date of Manufacture
EC REP
Authorized Representative in
the European Community Catalog Number
Batch Code Serial Number
Conformité Européenne (CE)
Marking of Conformity to
European Medical Device
Directive. CEXXXX represents
the Notified Body number
Classified by Underwriters
Laboratories Inc.®with respect to
electric shock, fire and mechanical
hazards only, in accordance with
UL 60601-1 and IEC60601-2-26
Recognized under the
Component Recognition
Program of Underwriters
Laboratories Inc.
Packaging Labeling:
Fragile, Do Not Get Wet, and This
Side Up
Audible Alarm Silenced Operating on Battery
Alternating Current
Fuse, Replace only with same
Type and Rating

SECTION I SAFETY PRECAUTIONS
____________________________________________________________________________
1-6
Equipotential Protective Earth (ground)
Recyclable
Crossed out wheelie bin indicates
separate treatment from general
waste at end of life *
Product marked with a
number contains certain toxic
or hazardous substances or
elements, and can be used
safely during its Environment-
Friendly Use Period (EFUP).
The product should be
recycled. The Environment-
Friendly Use Period is valid
only when the product is
operated under the conditions
defined in the product manual.
**
Product marked with the “e” does
not contain any toxic or hazardous
substances or elements, and is
green and environmental. The
product can be recycled. **
*Contact Aspect Medical Systems International B.V. for a Return Materials Authorization (RMA)
number. According to the WEEE Directive 2002/96/EC, all waste electrical and electronic
equipment (EEE) should be disposed of and collected separately and treated according to the
best available and environmentally friendly techniques.
EEE contains hazardous substances to the (human) environment but also EEE is a valuable
resource of new raw materials. Therefore it is important to collect WEEE separately from other
waste.
Aspect Medical products are subject to the Directive and we therefore urge you to dispose of the
equipment separately and make sure that it is treated at an electronics recycler. Please contact
your municipality or the nearest collection site and dispose of waste equipment there and make
sure the discarded equipment does not end-up in the ‘normal’ household waste.
** Refer to www.aspectmedical.com for Material Declaration Data Sheets.

SECTION II A-2000 SYSTEM OVERVIEW
____________________________________________________________________________
2-1
SECTION II
2 A-2000 SYSTEM OVERVIEW
2.1 INTRODUCING THE A-2000 BIS MONITORING SYSTEM
Aspect Medical Systems A-2000 BIS Monitoring System is intended to monitor the state of the
brain by data acquisition of EEG signals in the intensive care unit, operating room, and for clinical
research. The BIS, a processed EEG variable, may be used as an aid in monitoring the effects of
certain anesthetic agents.
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, 50/60Hz, 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.
2.1.1 Principal Components
The system is composed of a monitor and a digital signal converter, with a patient interface cable
(PIC), and BIS Sensor.
2.1.1.1 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 backward and forward in time. In the BIS
Log, they show the previous [←] or next [→] screen of data .
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. They are also used to increment and
decrement values. In the BIS Log, they are used to zoom time
out or in (increase or decrease reporting intervals).
The [SELECT] key is used to move between options within a
menu selection, to confirm an entry, and to answer "yes" to a
question.

SECTION II A-2000 SYSTEM OVERVIEW
____________________________________________________________________________
2-2
2.1.1.2 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.
2.1.2 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.
2.2 INSTRUMENT IDENTIFICATION
2.2.1 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.
2.2.2 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.
2.2.3 Software Revision Numbers
Software revision numbers are displayed in the Diagnostic Menu.
2.3 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 II A-2000 SYSTEM OVERVIEW
____________________________________________________________________________
2-3
Figure 2-1 The A-2000 BIS Monitoring System
BIS Monitor
Sensor
Monitor
Interface
Cable DSC
DSC Pigtail
Patient Interface
Cable (PIC)

SECTION II A-2000 SYSTEM OVERVIEW
____________________________________________________________________________
2-4
Figure 2-2 Rear View of Monitor
WARNING
REPLACE FUSES ONLY WITH ONE OF THE FOLLOWING PARTS:
Aspect P/N 430-0006, 1.25 Amps, 250V, 5x20mm
Littelfuse 217 Series, 1.25 Amps, 250V, 5x20mm
Wickmann 193 Series, 1.25 Amps, 250V, 5x20mm
ALWAYS REPLACE BOTH FUSES TOGETHER, EVEN IF ONLY ONE HAS
FAILED.
Fan
Clamp
Shoe
Fuse
Holde
r
Serial
Port
Printer
Port
AC Line
Connection
Potential
Equalization
Terminal

SECTION III PRINCIPLES OF OPERATION
_____________________________________________________________________________
3-1
SECTION III
3 PRINCIPLES OF OPERATION
INTRODUCTION
This section includes:
•How the A-2000 BIS Monitoring System works
•The architecture of the A-2000 monitor and DSC
•System Features
3.1 HOW THE A-2000 MONITORING SYSTEM WORKS
Sensors placed on the patient's head transmit EEG signals to the Digital Signal Converter. The
DSC amplifies and digitizes these signals, then sends them to the monitor. The monitor software
filters the data, analyzes it for artifact, and processes it using digital signal processing techniques.
The purpose of processing the EEG waveform data is to extract characteristic features from the
complex signal in order to provide easier pattern recognition of changes over time during the
recording.
The A-2000 BIS Monitoring System consists of:
•The BIS monitor with built-in battery backup and detachable power cord
•The Digital Signal Converter (DSC)
•Aspect’s BIS Sensor Patient Interface Cable (PIC) and BIS Sensor
3.2 SYSTEM ARCHITECTURE
Hardware is divided into three main components: the monitor, the digital signal converter (DSC)
and the Patient Interface Cable (PIC) with BIS Sensor. The A-2000 monitor contains the circuits
for monitor control, digitally processing the EEG data, computing the processed parameters, and
displaying the waveforms and processed parameters. The circuits to acquire and digitize the
EEG signals reside in the Digital Signal Converter (DSC). The PIC and Sensor are the patient
connection for EEG signal acquisition.
A block diagram depicting the monitor subassemblies appears in Figure 3-1. A signal flow
diagram appears in Figure 3-2.

SECTION III PRINCIPLES OF OPERATION
_____________________________________________________________________________
3-2
Figure 3-1 The A-2000 System Block Diagram
Power
Connector
J3
Power
Switch
SW1
Printer
Port
J27
Earth
Stud
J1
Serial
Port
J28
PREAMP
COMM
BOARD
DSC
J1
J1Patient
J2 J3 J4
J4 J2 J3
INTERCONNECT BOARD
J30 J29 J2 J20 J26 J16
J12J11J301 J200
J300
FAN
BATTERY
KEYBOARD
J2
J8 J1
DISPLAY
J13J
2
0
2
J
1
0
1
J
2
0
1
J
1
0
0
POWER SUPPLY BOARD MAIN
PROCESSOR
BOARD
MONITOR
These connectors are
internal to the board and
are mated as shown.