Novametrix 520A Pulse Oximeter Service Manual

PRELIMINARY

OXYPLETH

®

Service Manual

Pulse Oximeter

Model 520A

June 5, 2001

Catalog Number 5693-90-01

Novametrix Medical Systems Inc. Wallingford, Connecticut, U.S.A. 06492.

Copyright

1992-2001. All rights reserved. No part of this manual may be reproduced without the written permission of Novametrix Medical Systems Inc.

Section

PRELIMINARY

Guarantee

Equipment manufactured or distributed by Novametrix Medical Systems Inc., is fully guaranteed, covering materials and workmanship, for a period of one year from the date of shipment, except for certain disposable products and products with stated guarantees other than one year. Novametrix reserves the right to perform guarantee service(s) at its factory, at an authorized repair station, or at the customer’s installation.

Novametrix’ obligations under this guarantee are limited to repairs, or at

Novametrix’ option, replacement of any defective parts of our equipment, except fuses, batteries, and calibration gasses, without charge, if said defects occur during normal service.

Claims for damages during shipment must be filed promptly with the transportation company. All correspondence concerning the equipment must specify both the model name and number, and the serial number as it appears on the equipment.

Improper use, mishandling, tampering with, or operation of the equipment without following specific operating instructions will void this guarantee and release

Novametrix from any further guarantee obligations.

Service Department

For factory repair service, call toll free

1-800-243-3444

In Connecticut, call Collect (203) 265-7701

Facsimile (203) 284-0753

World Wide Web: http://www.novametrix.com

Internet: [email protected]

Caution: Federal (U.S.A.) law restricts this device to sale, distribution, or use by or on the order of a licensed medical practitioner.

Copyright© 1992-2001 Novametrix Medical Systems Inc. This document contains information which is proprietary and the property of Novametrix Medical Systems

Inc., and may not be reproduced, stored in a retrieval system, translated, transcribed, or transmitted, in any form, or by any means, without prior explicit written permission from Novametrix Medical Systems Inc.

Novametrix and OXYPLETH are a registered trademarks. SuperBright is a trademark of Novametrix Medical Systems Inc.

The OXYPLETH® monitor and its sensors and accessories are covered by the following US patents: 5,190,038 5,398,680 5,448,991 5,820,550 5,999,834

5,891,026 6,073,038 6,149,481. Other patents pending

i

Model 520A Service Manual 5693-90-01

PRELIMINARY

Revision History

August 31, 1992 Release 00. This manual replaces all preliminary versions.

Based on Revision 2.0 CPU software.

June 5, 2001 Revision 01. R-N905

Declaration of Conformity with European Union Directives

The authorized representative for Novametrix Equipment is:

European Compliance Services Limited

Oakdene House

Oak Road

Watchfield

Swindon, Wilts SN6 8TD

UK

Manufacturing, Quality and Safety

Novametrix manufacturing facility is certified to ISO 9001 and EN46001 (MDD93/

42/EEC Annex II). Novametrix Medical Systems Inc. products bear the “CE 0086” mark. The product is certified by Underwriter’s Laboratories (UL) to bear the UL mark; and tested by TUV Rheinland to IEC601-1 / EN60601-1.

5-Jun-01 Model 520A Service Manual

ii

PRELIMINARY

C

Contents

Contents ............................................................................................... iii

List of Figures ..................................................................................... vii

List of Tables...................................................................................... viii

Introduction ........................................................................................... 1

Purpose ................................................................................................. 1

Technology Description ......................................................................... 1

Conventions Used In This Manual......................................................... 2

Acknowledgments ................................................................................. 2

Patient Safety ........................................................................................ 3

Warnings................................................................................................ 4

Cautions................................................................................................. 5

Front Panel ............................................................................................ 6

Rear & Top Panels ................................................................................ 7

Summary of Operation ......................................................................... 8

Menu Trees ............................................................................................ 9

Electronic Theory of Operation ......................................................... 15

2472 Power Supply Board ................................................................... 15

AC Mains and Battery Operation Overview ................................... 15

AC Mains Operation ...................................................................... 16

Battery Operation........................................................................... 16

2726 Power Supply Board ................................................................... 17

AC Mains and Battery Operation Overview ................................... 17

AC Mains Operation ...................................................................... 17

Battery Operation........................................................................... 18

2471 & 2775 Main Board ..................................................................... 19

Power On/Off Control Circuitry ...................................................... 19

Power Supplies.............................................................................. 20

Voltage References ....................................................................... 20

Preserving RAM and Real Time Clock Data.................................. 21

iii


Contents

PRELIMINARY

Low Battery Voltage Shutdown...................................................... 21

Timing Sequencer.......................................................................... 22

Data Sampling Controller............................................................... 22

Sensor LED Drive Circuits ............................................................. 23

Sensor Photodiode Return Path .................................................... 24

Calibrating the 20-Bit Analog-to-Digital Convertors ....................... 25

20-Bit Analog-to-Digital Conversion............................................... 26

Sensor Status Decoding and Conversion...................................... 26

Sensor Status Parameters............................................................. 27

Microprocessor .............................................................................. 28

Memory.......................................................................................... 28

Real Time Clock (RTC).................................................................. 29

Sound generator ............................................................................ 29

Keypanel Interface......................................................................... 30

Display Interface ............................................................................ 30

I/O Device Controller ..................................................................... 31

Watchdog Timer ............................................................................ 31

Serial I/O Controller ....................................................................... 32

RS232 Serial Communication........................................................ 33

Maintenance ........................................................................................ 35

General ................................................................................................ 35

Maintenance Schedules ...................................................................... 35

Cleaning and Sterilization .................................................................... 36

Model 520A Monitor....................................................................... 36

Finger Sensor ................................................................................ 36

Y-SENSOR™ and Y-STRIP™ Taping System.............................. 36

Battery Life and Maintenance .............................................................. 37

Mains Voltage Configuration ............................................................... 37

Fuse Replacement......................................................................... 37

Changing the Mains Voltage Setting ............................................. 38

AC Mains on older style assemblies .............................................. 39

Replacing the AC Mains Fuse(s) ................................................... 40

Changing the AC Mains Voltage.................................................... 40

Assembly Exchanges .......................................................................... 41

Changing System Software ................................................................. 44

Changing System Software on 2471 Main Board.......................... 44

Troubleshooting.................................................................................. 47

Functional Test ................................................................................... 51

Introduction .......................................................................................... 51

Monitor Functional Test ....................................................................... 51

Special Power Up Functions ............................................................... 53


iv

Section

Contents

PRELIMINARY

Accuracy Test ..................................................................................... 55

Introduction .......................................................................................... 55

Monitor Accuracy Test ......................................................................... 55

Calibration Tests................................................................................. 59

Introduction .......................................................................................... 59

Equipment Required and Test Setup .................................................. 59

Test Procedure .................................................................................... 60

Safety Testing...................................................................................... 63

Connecting to other Equipment ........................................................ 65

Connecting the Seiko DPU-414 Thermal Printer ................................. 65

Configuring the Seiko DPU-414 Printer ......................................... 65

Setting the DIP switches:............................................................... 65

Connecting the ThinkJet Printer .......................................................... 67

Connecting the Model 315 Printer ....................................................... 67

Connecting Seiko DPU-411 Thermal Printer ....................................... 68

Analog Output Module ......................................................................... 69

Analog Output Setup ........................................................................... 70

Specifications...................................................................................... 73

General ................................................................................................ 73

Oxygen Saturation (SpO2) Section ..................................................... 73

Pulse Rate Section .............................................................................. 73

General Specifications......................................................................... 74

Additional Features.............................................................................. 74

Accessories......................................................................................... 76

Model 520A ......................................................................................... 76

Parts Lists............................................................................................ 81

Family Tree.......................................................................................... 81

5693-01 MAIN ASSEMBLY ................................................................. 81

6538-01 REAR PANEL ASSY ............................................................. 82

5673-01 REAR PANEL ASSY ............................................................. 82

2726-01 POWER SUPPLY BD ASSY ................................................. 83

2472- 01 POWER SUPPLY BOARD ................................................... 84

5719-01 FRONT PANEL ASSY........................................................... 85

2473-01 ALERT BOARD ASSY .......................................................... 85

5720- 01 DISPLAY ASSY.................................................................... 85

5713-01 SPEAKER ASSY ................................................................... 85

5714-01 BATTERY HARNESS ASSY ................................................. 85

5728-01 CABLE ASSY ........................................................................ 86

5765-01 TOP COVER ASSY............................................................... 86

5766-01 BOTTOM COVER ASSY....................................................... 86

v


Contents

PRELIMINARY

2755-01 TONE GEN REPL BOARD ................................................... 87

2775-01 MAIN BOARD ASSY ............................................................. 87

2471-28 MAIN BD KIT (part of 2775-01) ............................................. 89

2471-01 MAIN BOARD ASSY ............................................................. 91

Schematic and Assembly Drawings ................................................. 93

Notes .................................................................................................... 95


vi

PRELIMINARY

F

List of Figures

Figure 1.

Front Panel Description ................................................................... 6

Figure 2.

Rear and Top Panel Descriptions .................................................... 7

Figure 3.

Figure 1. Front-End Timing............................................................ 23

Figure 4.

Power Entry Fuse Access Door Opening ...................................... 40

Figure 5.

Fuse Removal................................................................................ 40

Figure 6.

Power Entry Module Voltage Selector Drum Removal .................. 41

Figure 7.

Power Entry Module Voltage Selection Adjustment ...................... 41

Figure 8.

Removing the Top Cover............................................................... 42

Figure 9.

Monitor Assembly .......................................................................... 42

Figure 10. 520A Assembly with 2471 Main Board Removed.......................... 43

Figure 11. Changing the System Software EPROM ....................................... 45

Figure 12. Softkey Identification...................................................................... 54

Figure 13. Connecting the ThinkJet Printer .................................................... 67

Figure 14. Connecting the Model 315 Printer ................................................. 68

Figure 15. Configuration of Seiko Thermal Printer.......................................... 68

Figure 16. Connecting the Seiko Model DPU-411 Printer. ............................. 69

Figure 18. Analog Output Module Pinouts ...................................................... 70

Figure 17. Analog Output Module ................................................................... 70

Figure 19. Analog Output Setup ..................................................................... 71

vii


PRELIMINARY

T

List of Tables

Table 1.

Display Command/Data table. ....................................................... 30

Table 2.

CSI/O Decode Lines ...................................................................... 32

Table 3.

SpO2 Display tolerances for TB500B settings............................... 57

Table 4.

Analog Output Module Voltage Tolerances ................................... 71

Table 5.

Schematic and Assembly Drawings .............................................. 93


viii

Section

List of Tables

PRELIMINARY ix


5-Jun-01

PRELIMINARY

1

Introduction

Purpose

1.1

This manual has been prepared for technicians servicing the Novametrix Model

520A Pulse Oximeter monitor. It presents technical information relating to the monitor’s theory of operation, maintenance, calibration and repair. Refer to the

Pulse Oximeter Model 520A User’s Manual (Catalog Number 5693-23) for additional information.

Technology Description

1.2

Pulse oximetry is a non-invasive method of monitoring the oxygen saturation of arterial blood. Oxygen saturation monitoring is intended to be used in a variety of clinical situations including, respiratory therapy, anesthesia, the intensive care unit

(ICU) and neonatal (NICU) and pediatric (PICU) intensive care units.

The Model 520A Pulse Oximeter provides reliable continuous measurement, display, and alerts for oxygen saturation (SpO

2

) and pulse rate. The monitor can be powered from its rechargeable internal battery or from the AC Mains.

The Model 520A utilizes sensors containing two light emitting diodes (LEDs) and a photodiode. Each LED emits a specific wavelength of light (660 and 940 nanometers) through a pulsating vascular bed to the photodiode. Oxygen saturated blood absorbs different amounts of light at each wavelength as compared to unsaturated blood. Therefore, the amount of light absorbed by the blood in each pulse can be used to calculate saturation.

The Model 520A is calibrated to display “functional” saturation. This differs from the “fractional” saturation value displayed by most co-oximeters. Functional saturation is defined as:

Functional Saturation =

HbO

2

100 - (COHb + METHb)

HbO

2

= Fractional Hemoglobin

COHb = Carboxyhemoglobin

METHb = Methemoglobin

This can be considered to represent the amount of oxyhemoglobin as a percentage of the hemoglobin that can be oxygenated. Dysfunctional hemoglobins (COHb and

METHb) are not included.

Model 520A Service Manual

1

Section 1

Introduction

PRELIMINARY

Pulse Rate is calculated by measuring the time interval between detected peaks of the infrared light waveform. The inverse of this measurement is displayed as pulse rate.

The oxygen saturation and pulse rate values are displayed on monitor’s displays.

The displayed values are updated once each second. Presence of a pulse is shown as a waveform on the display and indicated audibly by a user selectable “beep”.

The Model 520A must be used in conjunction with SuperBright™ Sensors. These sensors have an 8700 series part number (e.g., 8776 or 8791). An

INCOMPATIBLE

PROBE

display message will indicate a non-SuperBright™ Sensor (e.g., 86xx series) is in use.

Conventions Used In This Manual

The following conventions will be used throughout this manual:

• Normal text will be shown in this type.

• Message Center alerts and displays will be shown in this type .

• The names of the front panel pushbuttons (keys) will be shown in this type.

1.3

Acknowledgments

1.4

SuperBright, Y-STRIP and Y-SENSOR are trademarks of Novametrix Medical

Systems Inc. SARAcap is a registered trademark of Allegheny International

Medical Technology, Inc. (PPG Biomedical Systems).

2


5-Jun-01

PRELIMINARY

2

Patient Safety

The OXYPLETH Pulse Oximeter Monitor, Model 520A, SpO

2

Input is electrically isolated. Patient leakage current flowing from the instrument to ground is limited to less than 10

µA at 120 VAC, 60 Hz. Patient isolation is greater than 10 MΩ, 2500

VAC rms at 60 Hz.

For maximum patient and operator safety, the following are recommended:

• Failure of Operation: If the monitor fails to respond as described, do not use it until the situation has been corrected by qualified personnel.

• Keep OXYPLETH and its accessories clean.

• Do not operate OXYPLETH when it is wet due to spills or condensation.

• Do not operate OXYPLETH if it appears to have been dropped or damaged.

• Connect the line cord only to a grounded hospital-grade outlet. OXYPLETH should be connected to the same electrical circuit as other equipment in use on the patient. Outlets on the same circuit can be identified by the hospital’s engineering department.

• Care should be exercised to assure continued peripheral perfusion distal to the SpO

2

sensor site after application.

• Components of this product and its associated accessories which may have patient contact are free of latex.


3

PRELIMINARY

!

3

Warnings

WARNING

Indicates a potentially harmful condition that can lead to personal injury

• Explosion Hazard: Do NOT use OXYPLETH in the presence of flammable anesthetics. Use of this instrument in such an environment may present an explosion hazard.

• Electrical Shock Hazard: Always turn OXYPLETH off and remove line cord before cleaning it. Do NOT use a damaged sensor or one with exposed electrical contacts. Refer servicing to qualified service personnel.



• Patient Safety: Extreme care should be exercised with neonates to assure continued circulation distal to the sensor site after application.

• Failure of Operation: If the monitor fails to respond as described, do not use it until the situation has been corrected by qualified personnel.

• Patient Safety: Care should be exercised to assure continued peripheral perfusion distal to the

SpO

2

sensor site after application.

• Data Validity: Inaccurate SpO

2

and/or Pulse Rate measurements can be caused by any of the following:

• Incorrect application or use of a sensor

• Significant levels of dysfunctional hemoglobin such as carboxyhemoglobin or methemoglobin

• Significant levels of indocyanine green, methylene blue, or other intravascular dyes

• Exposure to excessive illumination such as surgical lamps—especially ones with a xenon light source, or direct sunlight

• Excessive patient movement, venous pulsations, electrosurgical interference

• Data Validity: The Pulse Oximeter should not be used as a substitute for an ECG monitor. The oximeter’s Pulse Rate display reflects the pulsatile flow found at the patient extremity connected to the sensor. This rate can be affected by many factors and may occasionally be

“frozen.”

• Do NOT attach an SpO

2

sensor distal to a blood pressure cuff. Valid data

CANNOT

be processed when the cuff is inflated. Attach the sensor to the limb opposite to the site used for the blood pressure cuff.

• Do NOT apply Y-Sensor tapes or wraps so tightly that the circulation is restricted. Inspect site often for adequate circulation - at least once every four hours. When applying sensors take note of the patient’s physiological condition. For example, burn patients may exhibit more sensitivity to heat and pressure and therefore additional consideration such as more frequent site checks may be appropriate.

4


5-Jun-01

PRELIMINARY

4

Cautions

CAUTION

Indicates a condition that may lead to equipment damage or malfunction.



• Never sterilize or immerse the monitor in liquids.

• Do not sterilize or immerse sensors except as directed in this manual.

• Tension should not be applied to the sensor cable.

• Overstretching the pulse oximeter finger sensor can damage the sensor and potentially affect pulse oximeter readings. Do not stretch the finger sensor open beyond the limit for which it was designed. Overstretching can be prevented: avoid opening the sensor by any means other than squeezing the grips; Do NOT force the sensor onto large objects such as the bed rail.

• Do not store the monitor or sensors at temperatures less than 14

° F (-10° C) or greater than 131°

F (55

° C).

• Do not operate the monitor or sensors at temperatures less than 50

° F (10° C) or greater than

104

° F (40° C).

• Federal (U.S.A.) law restricts this device to sale, distribution, or use by or on the order of a licensed medical practitioner.


5

PRELIMINARY

5

Front Panel

3

1

13

2

17

15

14

12

7

8

9

1.

Saturation% Display Area;

SpO

2

and alert limit settings are displayed here.

2.

Pulse Rate Display Area;

Pulse Rate and alert limit settings are displayed here.

3.

Message Center; area where system messages are displayed.

The functions of the softkeys (#4) are annotated here.

4.

Softkeys # 1-5; Softkeys 1-5 (left to right) cause the action annotated in the lower half of the

Message Center to occur.

5.

Carrying Handle; monitor carrying handle molded into case

6.

Sensor Input Connector;

Connect SuperBright™ Sensors here. Press tab on sensor

connector to remove sensor. Do not twist connector.

7.

Two Minute Silence Indicator;

Illuminates (yellow) when the

AUDIO key is pressed. SpO

2

and

Pulse Rate alarms are silenced for two minutes.

11

4

18

10

16

8.

Audio key; Press and release

AUDIO to turn on/off the two minute silence function. Press and hold (approx. 3 seconds) AUDIO to enable the Audio Off feature

(unless disabled via Options

Menu). Press and release to disable Audio Off.

9.

Audio Off Indicator; Flashes

(yellow) as a warning that the audible alarms have been disabled.

10. Alert Indicator; Flashes (red) when an alert/alarm occurs.

Continues to flash until condition corrected and ALERT RESET is pressed.

11. Alert Reset key; Press ALERT

RESET to disable any active alert indicators. Alerts will reactivate if alert condition still exists.

12. AC Power Indicator; Illuminates

(green) when the monitor is connected to an AC (Mains) power source and the rear panel power switch is set to “|”.

13. Power key; Press POWER to turn the monitor off and on.

14. Low Battery Indicator;

Illuminates (red) when the monitor is powered from its internal battery and less than 30 minutes of battery power remain.

15. Red Alert Bar; Flashes (red) when an alert/alarm occurs (unless disabled via Options Menu).

Continues to flash until condition corrected and ALERT RESET is pressed (unless “unlatched” by the user via the Options Menu).

16. Front Feet; Rubber tipped front feet (2). Kickstand; Two position kickstand (not shown) lifts front of monitor for viewing from above.

17. Contrast; Press and hold for display contrast adjustment, release when desired contrast is obtained.

18. Event; Press to mark an event in trend memory.

Figure 1. Front Panel Description

5

6

6


PRELIMINARY

6

Rear & Top Panels

1 2 3 4 5 7 6

9

10

11

8

1.

Line Cord Clip; This clip can be set around the line cord strain relief so that the cord cannot be pulled out of the connector.

2.

Line Cord Connector; The AC

(Mains) line cord attaches to the monitor here.

3.

Fuse Compartment; The AC

(Mains) line fuse(s) are inside this compartment. Pry open with small screwdriver.

4.

AC Mains Voltage; The currently selected AC Mains input voltage is identified here.

5.

AC Mains Power Switch; With switch in “O” position, AC Mains voltage does not enter monitor.

With switch in “|” position, AC

Mains voltage allowed into monitor to power unit and/or charge internal battery.

6.

Rear Feet; Rubber tipped rear feet

(2).

7.

Serial Output Connector;

Serial (RS232) data output here for use with Tele-Sat™ telemetry system, optional analog output module, and other RS232 interfaces. A female 25pin “D” connector serves as the interface connector.

8.

Top Cover

9.

Carrying Handle; Monitor carrying handle molded into case.

10. Warning Label; Explosion and electrical shock warnings.

11. Patient Isolation Label; The

Model 520A is Type BF equipment.

Figure 2. Rear and Top Panel Descriptions


7

PRELIMINARY

7

Summary of

Operation

This section summarizes the operation of the Model 520A Pulse Oximeter. It is intended as a quick reference and refresher for persons who have thoroughly reviewed the Model 520A User’s Manual (PN: 5693-23). Persons unfamiliar with the Model 520A should thoroughly examine the User’s Manual before referencing the steps listed here.

1. If powering the monitor from the AC line voltage; Connect the line cord to the monitor and plug into a properly grounded 3-wire outlet. Set the rear panel power (Mains) switch to the | (on) position.

2. Press the front panel

POWER

key to turn the monitor on. Verify the Message

Center displays

Connect SPO2 Probe

after the self-tests are complete.

3. Use the Menu System to modify the operation of the monitor to best suit your application. The Menu System menus include:

•

ALRT

softkey - Use

SEL

to select SpO2 or Pulse limits, then use the

↑

or

↓

to set the limit to the desired value. Note that the monitor will maintain a spread of at least 5 digits between the upper and lower limit values.

•

TRND

softkey - enters Trend mode and draws trend memory on display.

•

MENU

then

AUDIO

softkeys - Select

Pulse

to turn on/off and control the volume of the audible beep with each detected pulse. Select

ALERT

to control alert volume.

•

MENU

then

AVG

- Select either 2 second or 8 second SpO2 averaging time.

•

MENU

then

LITE

softkeys - toggles backlight between bright and dim.

4. Verify that the SpO

2

and Pulse Rate alert limit settings are consistent with your monitoring application.

5. Connect a SuperBright™ (87xx series) sensor to the front panel input. Apply the sensor to the patient.

6. Check that within several seconds the patient’s SpO

2

and Pulse Rate are displayed on the monitor.

7. As necessary, refer to the appropriate sections within the User’s Manual for detailed operating instructions and explanations.

8


PRELIMINARY

8

Menu Trees

The

OXYPLETH

menus are described on the following pages.


9

5-Jun-01

PRELIMINARY

9

Electronic Theory of Operation

The electronic theory of operation of the Model 520A Pulse Oximeter monitor is detailed in the subsections below. Refer to Section 19, Schematic and Assembly

Drawings, on page 93 for further information.

2472 Power Supply Board

9.1

The 2472 Power Supply Board contains the circuitry needed to power the monitor from the AC Mains (line voltage). The power supply board also connects to the battery and contains the battery charging circuitry.

AC Mains and Battery Operation Overview

9.1.1

The Model 520A can be powered from its internal 12 volt battery or from the AC

Mains. The green (sine wave shaped) front panel indicator illuminates when the line cord is connected and the rear panel power switch is in the “|” (On) position.

This indicates that AC Mains power is reaching the power supply, that the battery is being charged, and that if the monitor is turned on, it is being powered from the line voltage.

If AC Mains power is removed by unplugging the line cord or setting the rear panel power switch to the “0” (Off) position, the monitor will operate for up to four hours from its internal 12 volt lead-acid battery. As the battery voltage runs low (

≈11.5

volts), the red (battery indicator) on the front panel illuminates. At this point, the

AC Mains should be reconnected to power the monitor and charge the battery.

If the monitor continues to be powered from a battery in a low voltage situation, at approximately 11 volts, a continuous alarm sounds for thirty seconds while the

Message Center displays

BATTERY EXHAUSTED CONNECT LINE CORD

. If this alarm/message is ignored, the monitor displays will shut down and the battery indicator will flash on and off about every 5 seconds. If AC power is now restored, the monitor will re-initialize (go through the power up and self-test routines) and resume normal operation. However, continued battery operation will eventually activate a hardware low voltage circuit (

≈8.5 volts) that shuts the monitor off to prevent damage to the battery. Once the unit is shut down with the hardware circuit,


15

Section 9

Electronic Theory of Operation

PRELIMINARY

the AC Mains must be connected and the front panel

POWER

key pressed before the monitor will turn back on.

AC Mains Operation

9.1.2

The AC Mains voltage enters the monitor at the rear panel Power Entry Module

(PEM). This device contains a built in RFI power line filter, a double-pole singlethrow switch that opens and closes both AC input lines, fuses, and an input voltage selection card.

The filtered, switched and fused output of the Power Entry Module is fed to the primary coils of the rear panel mounted system transformer, T301. The secondary output from T301 is rectified by D1 (bridge rectifier) and filtered by C1. The

(loaded) DC voltage at this point is approximately 20 volts.

The 20 DC volts is fed to the 2471 main board through fuse F301 to connector

E302, and is switched to the battery charging regulator IC1 (pin 5) through Q1.

Biasing for Q1 is accomplished by D2, R1 and R2 when AC power is applied. When running on battery power Q1 is biased off by R1, R2 and D3, this prevents the battery from trying to power the battery charger regulator and IC2 that informs the monitor of the loss of AC.

The output of switching regulator IC1 pin4 is rectified and filtered by D4, C4 and

L1 then fed to the battery through current sense resistor R3 and fuse F302 to J302 pin 1 (VBAT+). The battery float charge voltage is maintained at 13.2 volts except for fast charge which is regulated at 14.4 volts. The output is also monitored for over current conditions. These parameters are controlled by IC3 and associated circuitry. When the battery charge current exceeds 120mA of current IC3 pin 7 goes high which biases Q2 on, this in turn shorts out R12 which affects the feedback control (FB) to IC1 (pin 1). With R12 shorted out the control resistors R14 and R13 set the output voltage to 14.4 volts. When the charge current lowers IC3 pin 7 goes low which biases Q2 off, this puts R12 back into the feedback control which now consists of R12, R13 and R14 setting the voltage to 13.2 volts. When more than

600mA of current flows through R3, IC3 pin 1 shorts IC1 pin 2 to ground which shuts IC1 off until its next switching cycle, when the current reaches a safe level

IC3 pin 1 allows IC1 to remain on.

The voltage switched by Q1 is also fed to IC2 as VCH (Voltage Charge). The output of this 5 volt regulator provides the LINEST (Line Status) signal to the main board at E302 pin 3. With AC applied, LINEST is high. LINEST goes low when the AC

is disconnected. The LINEST line is also routed to the power on/off circuitry. See

Power On/Off Control Circuitry on page 19.

Battery Operation

9.1.3

Without AC power there will be no secondary voltage rectified by D1. Power for the monitor will be supplied from the battery at J302 pins 1 (VBAT+) and 2

16


2726 Power Supply Board

PRELIMINARY

(VBAT-). The battery power will conduct through D3 and F301 to VIN at E302 pin

1 to the 2471 main board. The arrangement of R1, R2 and D2 bias Q1 off in this condition which prevents power from reaching IC1, IC2 and IC3. The output of IC1 is also protected by D5 which is now reverse biased, the bridge D1 is also reverse biased and prevents T301 from discharging the battery. With no voltage at IC2 the

LINEST will be low which indicates to the main board that there is no AC power.

2726 Power Supply Board

9.2

The 2726 Power Supply Board contains the circuitry needed to power the monitor from the AC Mains (line voltage). The power supply board also connects to the battery and contains the battery charging circuitry.

AC Mains and Battery Operation Overview

9.2.1

The Model 520A can be powered from its internal 12 volt battery or from the AC

Mains. The green (sine wave icon) front panel indicator illuminates when the line cord is connected and the rear panel power switch is in the “|” (On) position. This indicates that AC Mains power is reaching the power supply, that the battery is being charged, and that if the monitor is turned on, it is being powered from the line voltage.

If AC Mains power is removed by unplugging the line cord or setting the rear panel power switch to the “0” (Off) position, the monitor will operate for up to four hours from its internal 12 volt lead-acid battery. As the battery voltage runs low (<11.5

volts), the red battery indicator on the front panel illuminates. At this point, the AC

Mains should be reconnected to power the monitor and charge the battery.

If the monitor continues to be powered from a battery in a low voltage situation, at approximately 11 volts, a continuous alarm sounds for thirty seconds while the

Message Center displays BATTERY EXHAUSTED CONNECT LINE CORD. If this alarm/message is ignored, the monitor displays will shut down and the battery indicator will flash on and off about every 5 seconds. If AC power is now restored, the monitor will re-initialize (go through the power up and self-test routines) and resume normal operation. However, continued battery operation will eventually activate a hardware low voltage circuit (<8.5 volts) that shuts the monitor off to prevent damage to the battery. Once the unit is shut down with the hardware circuit, the AC Mains must be connected and the front panel POWER key pressed before the monitor will turn back on.

AC Mains Operation

9.2.2

The AC Mains voltage enters the monitor at the rear panel Power Entry Module

(PEM). This device contains a built in RFI power line filter, a double-pole singlethrow switch that opens and closes both AC input lines, fuses, and an input voltage selection card.


17

Section 9


PRELIMINARY

The filtered, switched and fused output of the Power Entry Module is fed to the primary coils of the rear panel mounted system transformer, T301. The secondary output from T301 is rectified by D1 (bridge rectifier) and filtered by C1. The loaded

DC voltage at this point is approximately 20 volts.

The 20 DC volts is fed to the main board through fuse F301 to connector E302, and is switched to the battery charging regulator IC1 (pin 5) through Q1B. Biasing for

Q1B is accomplished by C2, R1, R2, C8 and Q1A when AC power is applied. When running on battery power Q1B is biased off by R2 and Q1A, this prevents the battery from trying to power the battery charger regulator and IC2 that informs the monitor of the loss of AC.

The output of switching regulator IC1 pin4 is rectified and filtered by D4, C4 and

L1 then fed to the battery through current sense resistor R3 and fuse F302 to

VBAT+ (J302 pin 1). The battery float charge voltage is maintained at 13.2 volts except for fast charge which is regulated at 14.4 volts. The output is also monitored for over current conditions. These parameters are controlled by IC3 and associated circuitry. When the battery charge current exceeds 120mA of current IC3 pin 7 goes high which biases Q2 on, this in turn shorts out R12 which affects the feedback control (FB) to IC1 (pin 1). With R12 shorted out the control resistors R14 and R13 set the output voltage to 14.4 volts. When the charge current lowers IC3 pin 7 goes low which biases Q2 off, this puts R12 back into the feedback control which now consists of R12, R13 and R14 setting the voltage to 13.2 volts. When more than

600mA of current flows through R3, IC3 pin 1 shorts IC1 pin 2 to ground which shuts IC1 off until its next switching cycle, when the current reaches a safe level

IC3 pin 1 allows IC1 to remain on.

The voltage rectified by D1, D2 and filtered by C2 is fed to IC2 as VCH (Voltage

Charge). The output of this 5 volt regulator provides the LINEST (Line Status) signal to the main board at E302 pin 3. With AC applied, LINEST is high. LINEST goes low when the AC is disconnected. The LINEST line is also routed to the power on/off circuitry.

Battery Operation

9.2.3

Without AC power there will be no secondary voltage rectified by D1. Power for the monitor will be supplied from the battery at J302 pins 1 (VBAT+) and 2

(VBAT-). The battery power will conduct through D3 and F301 to VIN at E302 pin

1 to the main board. R2 and Q1A bias Q1B off in this condition which prevents power from reaching IC1, IC2 and IC3. The output of IC1 is also protected by D5 which is now reverse biased, the bridge D1 is also reverse biased and prevents T301 from discharging the battery. With no voltage at IC2 the LINEST will be low which indicates to the main board that there is no AC power.

18


2471 & 2775 Main Board

PRELIMINARY

2471 & 2775 Main Board

9.3

The Main Board contains all the analog and digital circuitry that controls the sensor, external communication and front panel display. The isolated power supplies, microprocessor circuits and memory are all contained on this board. The earlier

2471 Main Board and newer 2775 Main Board are identical with exceptions noted in the text.

Power On/Off Control Circuitry

9.3.1

The Model 520A power on/off control circuitry consists of the VBACK supply

(regulated by IC12), IC10, IC11 and the

POWER

key. (See page 4 2471 schematic, page 4 on 2775 schematic.)

When the battery or AC Mains is first applied to the power supply board (via VIN

J102 pin 1), VBACK goes to +5 volts, provides power to IC10 and IC11, and through the C26 and RP4 (pins 3,4) network at IC10 pin 8, sets IC10 pin 2 to a logic

Low.

The ON/OFF line is brought Low each time the front panel

POWER

key is pressed.

This sends the output at IC11 pin10 High. This Low-to-High transition clocks the

(#1) D flip-flop portion of IC10. The /Q1 output at IC10 pin 2 goes High and with each successive press of the

POWER

key, this output toggles to the opposite level

(Low or High). A High turns the Model 520A on and a Low shuts it off.

While the /Q1 output at IC10 pin 2 is High, the MOSFET Q7 is turned on and pulls the gate of MOSFET Q8 to ground, thus causing Q8 to conduct as well. With Q8 conducting, the currently active monitor power source—either the AC Mains derived supply or the battery supply will flow through Q8 to the voltage input (pin

7) of the Pulse Width Modulator IC9. The output IC9 pin 6 will oscillate (at the frequency set by R13 and C15). This causes Q5 to switch on and off and provide a path to ground through the primary coils of T1 for the supply (Mains or battery) at

T1 pin 12. Current flowing in the primary is measured at IC9 pin 3 and the duty cycle of the pin 6 output will vary with the load on the transformer.

Current flow in the transformer primary induces current in the three secondary coils and creates the

± 12 volt analog supplies (+V12 and -V12), the VRAWI that powers the isolated RS232 circuitry, and the +5 volt VCC supply that power the remaining circuits in the monitor. The Model 520A turns on. The +V12 and -V12 supplies are rectified and filtered by D2, D4, C10, C11, C12 and C13. The +V12 is regulated by

IC7 and the -V12 by IC8. The VDD supply is rectified by D3, filtered by L1, C9 and C20 and fused at F1, and in addition, a feedback loop to IC9 contains VR1 which is factory adjusted to produce a +5.00 volt

± 0.05 volt VCC supply (measured under load).

Once the monitor powers up, a SYNC signal toggles Q9 on and off causing a timing pulse to be transmitted across C19 and C15 to the input at IC9 pin 4. This has the


19

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PRELIMINARY

effect of synchronizing the output of the pulse width modulator with the data sampling operations of the analog board and keeps power supply switching spikes from interfering with those operations.

Power Supplies

9.3.2

The secondary pins 7, 8, 9 of T1 form a center tap transformer, the voltage is rectified by D2 and D4 then filtered by C10, C11, C12 and C13. The dual 12 volt supplies, +V12 and -V12 which are generated from this voltage are regulated by

IC7 and IC8 respectively. The secondary winding of pins 5 and 6 of T1 are rectified by D3 and filtered by C9, L1 and C20, this voltage designated as VCC (+5 volts) acts as reference for IC9, supplies power for the opto isolator non-isolated side and powers other circuitry on the board.

The secondary winding consisting of pins 2 and 3 are rectified and filtered by D1 and C1. The rectified voltage at this point is approximately 7 volts DC and is regulated to 5 volts by IC2. This isolated supply powers the isolated portion of the opto-isolators and the RS232 driver chip IC1. The unregulated voltage VRAWI is sent to the rear panel connector J101.

The backup voltage (VBACK) is regulated by IC12 from the VIN supply.

Capacitors C22 and C27 serve as filters and D17 allows VCC to power VBACK circuitry when the monitor is on. At this point D18 is biased off so IC12 is idle.

When the monitor is turned off and VCC collapses D18 is then forward biased and

IC12 now supplies VBACK circuitry, D17 at this time is reverse biased and prevents power from reaching VCC.

The saturation sensor LEDs derive their power (LEDSRC) from the current regulator IC32. (See sheet 3 on 2471 schematic, page 2 on 2775 schematic.)

Resistor R31 limits the maximum current draw to 45 mA (nominal draw 35 mA).

Regulator output is filtered by C85 and L2. The charge stored on capacitor C1 supplies the 290-350 mA peak currents that can occur when the sensor LEDs are turned on. Diode D12 prevents the regulator output from exceeding +7.5 volts while the fuse, F2, provides current limit protection in the event of a regulator circuitry failure. The RP10 (pins 1,8 and 5,6) divider network provides the CPU (via IC33) with a means to monitor the LEDSRC status.

The +VA and -V12 supplies are regulated to +V5 (+5 volts) and -V5 (-5 volts) by

IC44 and IC43 respectively. These supplies are used by the 20 bit ADCs, the 8 bit

ADC and other circuits associated with them.

Voltage References

9.3.3

A +2.5 volt precision reference supply, generated by IC35 from the 12 volt +V12 supply, is used as a reference voltage for the ADC chips IC37 and IC34.

20


2471 & 2775 Main Board

PRELIMINARY

The +2.5 volt output from IC35 pin 6 is fed to the non-inverting input of amplifier

IC36 pin 3. Resistors R32 and R33 combine for a gain of 1.617 that provides a

+4.096 volt reference (approximately) supply, 4VREF, at IC31 pin 1.

The 4VREF is fed to IC30 pin 13 which is set up as a unity gain inverting buffer amplifier, therefore the output at IC30 pin 14 is -4 volts. This -4 volts is used by

IC29 as a reference voltage for VLED (Voltage LED) and CNTRST (Contrast) controls. (See sheet 4 on 2471 schematic, sheet 3 on 2775 schematic.)

Preserving RAM and Real Time Clock Data

9.3.4

The NAND gate output at IC11 pin11 will be Low when the monitor is on (IC10 pin 2 is High) and High when the monitor is off (IC10 pin 2 is Low). (See sheet 4 of 5 on schematic.) This PWRON* (Power On) signal is used to prevent corruption of RAM and clock data when the monitor is turned off. It does this by going High and therefore denying CPU access to the RAM and clock chips so that as the power supplies crash when the monitor is turned off, the CPU cannot send erroneous data to the chips.

Whenever the CPU is writing information to the RAM or Real Time Clock chips, the CPU momentarily sends the OFFDIS (Off Disable) line High. The High going level appears at IC11 pin 2. Since the monitor is powered on, IC11 pin1 will be

High. This means IC11 pin3 momentarily goes Low, Q6 starts to conduct and IC10 pin 4 goes High. In this reset condition the /Q1 output #1 flip-flop of IC10 (pin 2) will be held high even if the user presses the

POWER

key and clocks the flip-flop.

In effect, the CPU is not allowing the monitor to be turned off. The Low at IC11 pin3 will last for the duration of the RC time constant set by C21 and RP4 (pins 5,6).

These values were chosen to produce a time-out longer than the time necessary to complete the write to RAM or Real Time Clock operation. After the RC time-out,

IC10 pin 4 returns Low and a press of the

POWER

key will toggle the /Q1 output of

IC10 and the monitor will turn off. This is done to prevent corruption of RAM and

Real Time Clock data.

Low Battery Voltage Shutdown

9.3.5

The CPU monitors the battery voltage and provides the user with a low battery indicator ( ), messages and alarms. However, if these are ignored, a hardware circuit will take over and shut off the monitor before the battery is damaged.

The pulse width modulator IC9 requires at least 7.6 volts at pin 7, its voltage supply, in order to operate. This pin typically draws 10 mA of current. The resistance of the

R63 and Q8 combination is approximately 114 ohms. This equates to a voltage drop of approximately1.14 volts. Therefore if the battery voltage drops under 9.0 volts

(approximately), IC9 will not have sufficient voltage to operate and will shut down.

Shutdown of IC9 stops current flow through transformer T1 and the secondary supplies shut down, effectively turning off the monitor.


21

Section 9


PRELIMINARY

When IC9 shuts down, its VREF output at pin 8 is pulled Low. This forward biases

D6 and causes the NAND gate output at IC11 pin4 to go High. The #2 flip-flop of

IC10 is clocked, and the High at the D2 input (because /Q1 is High) is transferred to the Q2 output at pin 13. The High at pin 13 Sets the #1 flip-flop causing the /Q1 pin 2 output to go Low. This Low shuts off both MOSFETs Q7 and Q8, thereby blocking any supply voltage from IC9 pin 7. Normally, pressing the front panel

POWER

key would clock flip-flop #1 (at pin 3) and return the pin 2 output High— but the High output at pin 13 keeps the #1 flip-flop Set—and the

POWER

key has no effect.

If at this point the AC MAINS is reconnected, MOSFET Q8 continues to block current from IC9 pin 7 and the monitor remains off. Connecting the AC Mains does however send the LINEST signal High. This High Line Status signal is brought to

IC10 pin10 where it Resets the #2 flip-flop, sending IC10 pin 13 Low and removing the Set condition from flip-flop #1. Now, if the front panel

POWER

key is pressed, flip-flop #1 is clocked, IC11 pin11 goes High, MOSFETs Q7 and Q8 turn on, the supply to IC9 pin 7 is restored, the pulse width modulator restarts, energizes T1, and the monitor turns back on.

Timing Sequencer

9.3.6

A 14 stage divider, IC39, acts as a timing sequencer. (See sheet 3 on 2471 schematic, sheet 2 on 2775 schematic.) A 3.276 MHz crystal Y2, provides a Clock

Sequence (CLKSEQ) to IC39 pin 10. The IC39 pin 11 RESET input line resets

IC39 on monitor power up.

The IC39 pin 9 Q1,output provides a clock input signal to the tone generator board located at IC27. The IC39 pin 3 Q14 output provides a 5 ms interrupt (INT5MS) for

IC18. The Q4-Q11 outputs of IC39 become inputs to the Data Sampling Controller

IC42.

Data Sampling Controller

9.3.7

The IC39 Timing Sequencer’s Q4-Q11 outputs become inputs to IC42, a PEEL

(Programmable Electrically Erasable Logic) device. The PEEL uses the CLK and

D0-D6 inputs, and the SC1 and SC2 inputs, to control data sampling by providing sensor LED drive signals and demultiplexing for the signals returning from the saturation sensor.

The waveforms in Figure 3.(with the exception of CLK) are only valid when both

the SC1 and SC2 inputs are low. The System Calibration inputs (SC1 and SC2) generated by the microprocessor, are kept low, except that they are toggled high/

22


2471 & 2775 Main Board

PRELIMINARY

low, during a Probe Off Patient alert, and during a system power up self-test. See

Calibrating the 20-Bit Analog-to-Digital Convertors on page 25.

5-Jun-01

Figure 3. Figure 1. Front-End Timing

The data sampling sequence consists of: a. turn on the Red LED (RDLED*) and the Analog Sample line (ASAMP*) c. sample the Red LED return signal (RDSMP*) e. turn on the Infrared LED (IRLED*) and the Analog Sample line (ASAMP*) f. sample the Infrared LED return signal (ISMP*) h. turn off the Infrared LED, the Analog Sample line, and stop sampling i. repeat the process starting at step a.

The Analog Sample (ASAMP*) line is used to nullify the effects of any ambient

light signals returning from the sensor. See Sensor Photodiode Return Path on page

24.

The IC42 INSIG* and SIGND* outputs are used in conjunction with the SC1 and

SC2 inputs. See Calibrating the 20-Bit Analog-to-Digital Convertors on page 25.

The IC42 pin 14 external sequencer (SYNC) line is equivalent to the PEEL’s D1 input. It provides a “sync” pulse to the pulse width modulator on the power supply board in order to keep power supply switching spikes from interfering with data sampling operations.

Sensor LED Drive Circuits

9.3.8

The VLED line voltage is derived from IC30 pin 8 which is controlled by the

Digital to Analog Converter IC29. (See sheet 4 on 2471 schematic, sheet 3 on 2775 schematic.) When address line A0 is high (IC29 pin 6) and both WR* (IC29 pin 16) and DACCS* (IC29 pin 15) are low the D/A Converter is enabled. The data on lines


23

Section 9


PRELIMINARY

D0-D7 (IC30 pins 14-7) now control the output voltage of IC30 pin 8 (VLED) based on the VREFB voltage on IC29 pin 18.

When the RDLED* signal at IC42 pin 18 goes low (logic 0), Q14 turns off and the

Red LED signal (VLED from IC30 pin 8) at R37 is divided by R37 and R41, finally causing IC36 pin8 to go high. This positive output turns Q11 on and current flows from the LED source (LEDSRC), through the Red LED in the sensor (it turns on) returning as LED1SK (LED1 sink) across Q11 and the current limiting resistor R53 to ground. (See sheet 3 on 2471 schematic, sheet 2 on 2775 schematic.)

When RDLED* returns high (logic 1), Q14 is biased on, forcing IC36 pin8 to ground potential: Q11 is biased off, and as a result, the Red LED in the sensor is also off.

The Infrared LED drive circuit operates in the same manner as the Red LED drive discussed above. The IRLED* signal at IC42 pin 17 activates Q13 the LED2S signal causes a positive signal at IC36 pin 14, and current can flow from the

LEDSRC supply through the sensor’s Infrared LED, Q12, and the current limiting

R52 to ground.

Sensor Photodiode Return Path

9.3.9

Light, from the sensor’s Red or Infrared LED, shines through the pulsating vascular bed (the patient’s finger, toe, etc.) placed between the LEDs and the photodiode.

Some of this light emerges from the tissue and impinges on the photodiode, causing the photodiode to conduct current. IC40 pins 1-3 is set up as a differential amplifier that converts this input current to a voltage at the amplifier output. The sensors are wired such that photodiode current produces a positive voltage at IC40 pin 1

1

.

The voltage at IC40 pin 1 is presented to an analog switch IC41 pin 6. This switch is controlled at pin8 by INSIG* (Input Signal) from IC42, and will be closed (IC41 pins6 and7 connected) except if the monitor is in a Probe Off Patient condition or is undergoing its Self-Test at system power up. The switch IC41 pins 9-11, controlled from SIGND* (Signal Ground) at IC42 will be open (no connection between IC41 pins10 and 11) except as noted above for the switch at IC41 pins 6-

8. As a result, the IC40 pin 1 voltage passes undisturbed to the high pass filter consisting of R59 and C90.

As shown in Figure 3., the ASAMP* signal is active whenever either sensor LED

is turned on. This causes Q15 to turn off and the charge at C90 passes through the unity gain buffer to IC40 pin 7.

If the signal at IC40 pin 7 is the product of the Red LED being turned on, then

RDSMP* from IC42 pin 12 will go low and close the switch at IC41 pins 2-3, thereby presenting the signal to a sample and hold circuit consisting of R54 and

1. The Model 520A uses SuperBright™ sensors. If a non-SuperBright™ sensor is connected, IC40 pin 1 will go negative—a condition that causes an “Incompatible Probe” message to be displayed.

24


2471 & 2775 Main Board

PRELIMINARY

C100 (that maintains the signal until next sample pulse arrives), a gain stage, (IC38 pin 1), a filter/divider network (C87, R45 and R46), and finally, to the Red channel

Analog-to-Digital Convertor (ADC) IC34.

If the signal at IC40 pin 7 is the product of the Infrared LED being turned on, then

ISMP* from IC42 pin 13 will go low and close the switch at IC41 pins 14-15, thereby presenting the signal to a sample and hold circuit consisting of R55 and C96

(that maintains the signal until next sample pulse arrives), a gain stage, (IC38 pin

7), a filter/divider network (C88, R49 and R50), and finally, to the Infrared channel

Analog-to-Digital Convertor IC37.

Again referencing Figure 3., the ASAMP* line returns to a logic high when neither

LED is being driven, causing Q15 to turn on. With Q15 conducting, any charge at

C90 is discharged to ground and the next pulse will charge C90 from a known level.

If it were not for Q15, any charge remaining on C90 from the previous pulse or from ambient light reaching the photodiode would be added to the charge from a new pulse—creating measurement errors.

Calibrating the 20-Bit Analog-to-Digital Convertors

9.3.10

The 20-bit ADCs are calibrated as part of the system self-test which occurs each time the monitor is turned on. At power up, the microprocessor sets the CAL line high. The System Calibrations input SC1 is set high and SC2 is reset to a logic low.

The CS5503 ADC will not operate while the CAL line is high. On the falling edge of the CAL signal, the ADC will initiate a calibration cycle determined by the state of the SC1 and SC2 inputs.

The high at SC1 and the low at SC2 cause the Data Sampling Controller, IC42, to set INSIG* high and reset SIGND* to a logic low. The high INSIG* opens the switch at IC41 pin8 so that IC41 pins 6 and 7 are no longer connected— disconnecting the returning photodiode signal from the rest of the circuitry. The low

SIGND* signal closes the switch at IC41 pin9 and as a result, the input to the C90-

R59 high pass filter (and thus the entire ADC input circuitry) is brought to ground potential.

The CAL line (which went high at power up) is reset low and ADCs IC34 and IC37 begin their calibration cycles. Because the analog input circuitry is grounded via

SIGND*, only circuit offset voltages can be present at the (pin 9 AIN) input. The calibration cycle sets the ADC “zero” point to equal this voltage, thus compensating for any circuitry offsets. The ADC then sets its “full scale” point to equal the voltage at its VREF (pin 10) input. This completes the calibration cycle.

The ADC can now start sampling its input and converting it to a 20-bit digital word.

The processor resets SC1 to a logic low, causing IC41 pin9 to open and IC41 pin8

to close. The photodiode signal can now reach the ADCs. See Sensor Photodiode

Return Path on page 24.


25

Section 9


PRELIMINARY

20-Bit Analog-to-Digital Conversion

9.3.11

Data from the Red and Infrared channels is sampled by the 20-bit measurement

ADCs, IC34 and IC37 respectively. The analog input at pin 9 is converted to a digital representation with 20-bit resolution based on the input magnitude.

The CS5503 convertor continuously samples its input, converts the value to a digital word, puts the word in its output buffer (overwriting previous buffer contents), then repeats the process by again sampling its input. The frequency of the sample/convert/overwrite-buffer sequence is based on the 3.2768 MHz clock signal at the ADC pin 3 (CLKSEQ) input.

The microprocessor starts a read cycle of the Infrared channel by bringing IC37 pin

16 (Chip Select Channel 1) low. A Red channel read starts when IC34 pin 16 (Chip

Select Channel 2) is brought low.

On the falling edge of the ADC’s CS*, the output word’s MSB (most significant bit) appears at the pin-20 SDATA (Serial Data) output. The SDATA line connects directly to the microprocessor’s serial input (RXS) pin. The remaining bits (in descending order) are output from SDATA with subsequent falling edges of the

Serial Clock (SCLK) input at pin 19. The SDATA output automatically goes to a 3state (high impedance) condition after completing a word transmission, thus freeing the data line for other uses (i.e., the other ADC channel).

The Serial Clock speed is controlled through the digital board PEEL IC18. This clock rate is significantly slower than the ADC sampling rate. As a result, the ADC rewrites its output buffer with new information at a faster rate than the data can be read from the buffer. No conflict occurs, however, because while CS* is low

(during the read cycle), the ADC does not update its output buffer—the current word is not overwritten. After the processor receives the entire word, it allows the convertor’s CS* to return high, and the ADC resumes its sample/convert/overwritebuffer cycle.

Sensor Status Decoding and Conversion

9.3.12

The microprocessor monitors several sensor parameters in addition to the Red and

Infrared data channels. It monitors the status parameters, as well as the voltage of the monitor’s internal battery.

The 8-to-1 multiplexor, IC33, decodes the A0AUX-A2AUX input address lines and connects one of eight status parameter inputs (labeled channels 0-7 at IC33) to the multiplexor output at IC33 pin 3. Resistor R29 and diode D13 prevent negative voltages from reaching the input to the analog-to-digital convertor, IC31.

IC31 is an 8-bit analog-to-digital convertor with a serial data output. While the IC31

Chip Select (CS) input is high, the CLK input and DOUT output are in 3-state mode. When CS is brought low (under processor control), the most significant bit

(D7) of the PREVIOUS data conversion becomes available at the DOUT pin. The

26


2471 & 2775 Main Board

PRELIMINARY

remaining bits (D6-D0) are shifted out on subsequent falling edges of the CLK input. On the clock pulse following the one that shifts out the least significant bit

(D0), the CLK and DOUT lines are returned to 3-state and the ADC performs a new conversion based on the input it receives from the IC33 channel selected by the

A0AUX-A2AUX input address lines.

The ADC sample/convert/store-result cycle is based on internal chip timing and not the CLK input which (along with CS) only controls serial data output. Thus the CS line is free to return high once the ADC cycle begins.

Sensor Status Parameters

9.3.13

The sensor (and battery) status parameters input to the multiplexor IC33 are described below. Note that channel number refers not to the IC33 pin number, but to the signal label (e.g., channel I0 signal resides at IC33 pin 13).

Channel I0: ADCV12.

This is an extra input to the multiplexer IC33 pin 13. It is unused as of this writing.

Channel I1: Auxiliary Input.

This is an extra input to the multiplexer IC33 pin 14. It is unused as of this writing.

Channel I2: Photodiode DC Level.

Resistors R40, RP8 (pins 1, 2) and capacitor C97 form a voltage divider and low pass filter that provide a measure of the mean DC level at the output of the photodiode current-to-voltage amplifier IC40 pin 1. This channel (IC33 pin 15) is used in determining ambient light interference. If this line is examined while the sensor’s Red and Infrared LEDs are turned off, then any DC level at IC40 pin 1 must be the result of ambient light impinging on the photodiode. If the DC shift is in excess of limits set in the software, a Light Interference message appears on the monitor’s display.

Channel I3: Sensor LED Supply Voltage.

This channel, at IC33 pin 12, monitors the sensor LED supply voltage through a voltage divider consisting of RP10 (pins 5, 6) and RP8 (pins 1, 8). If a fault occurs that causes the LED supply fuse F2 to blow, or if the sensor wires are shorted, this channel reports the condition and the Message Center displays

PROBE FAILURE

.

Channel I4: Incompatible Probe Detection

The input at IC33 pin 1 provides the processor with an incompatible probe indicator

(words probe and sensor are interchangeable). The photodiode output voltage at

IC40 pin 1 will be positive if a SuperBright™ sensor is connected to the monitor.

This positive signal passes through the high pass filter of C73 and RP10 (pins 7, 8) to the amplifier inverting input IC36 pin 6, where it is summed with the -5 volt output from IC43. The resultant voltage at IC33 pin 1 will be approximately +2.81

volts with no photodiode input. This voltage drops as the (positive) photodiode signal at IC40 pin 1 increases. If the IC40 pin 1 signal goes negative, as would happen if a non-SuperBright™ 8600 series sensor were connected to the monitor,


27

Section 9


PRELIMINARY

the cumulative effect of the -5 volts and the negative photodiode signal passing through D14 and R34 would be to send the IC36 pin7 output to its positive rail (+12 volts). The processor recognizes this higher voltage and causes an

INCOMPATIBLE

PROBE

message to displayed in the Message Center.

Channel I5: Infrared LED Cathode Voltage.

A low pass filter consisting of RP10 (pins 3, 4), RP8 (pins 1, 7) and C89 provides a means to measure the cathode voltage of the sensor’s Infrared LED. If the channel at IC33 pin 5 is sampled the monitor can determine if the LED is open circuit (zero volts at IC33 pin 5) or operational (approximately 2.5 volts at IC33 pin 5). If not operational, display messages such as

PROBE I.R. LED FAILED

or

ERROR -

FAULTY PROBE

are generated.

Channel I6: Battery Supply Voltage

The monitor’s internal battery voltage is divided down by RP3 (pins 7, 8) and RP8

(pins 1, 5). The voltage at IC33 pin 2 is monitored and if its magnitude is less than a predetermined value (encoded in the software) the monitor lights and/or flashes its front panel battery indicator. This provides the user with a low battery warning.

Channel I7: Red LED Cathode Voltage.

A low pass filter consisting of RP10 (pins 1, 2), RP8 (pins 1, 8), and C92 provides a means to measure the cathode voltage of the sensor’s Red LED. If the channel at

IC33 pin 4 is sampled the monitor can determine if the LED is open circuit (zero volts at IC33 pin 4) or operational (approximately 2.5 volts at IC33 pin 4). If not operational, display messages such as

PROBE RED LED FAILED

or

ERROR -

FAULTY PROBE

are generated.

Microprocessor

9.3.14

A Hitachi HD64180RP microprocessor directs the actions of the Model 520A Pulse

Oximeter. (See sheet 2 on 2471 schematic, sheet 1 on 2775 schematic.) The processor, IC16, is operated at 6.144 MHz (half the12.288 MHz frequency of crystal Y1), has an 8-bit data bus and a 19-bit address bus (the 520A uses only 18bits). The microprocessor also provides two asynchronous serial communication channels, a clocked serial I/O port and various interrupt and control signals. The +5 volt VCC supply to the processor is first sent through inductor FB1, a ferrite bead, before powering the chip at IC16 pin 32.

Memory

9.3.15

The Model 520A system software is located at IC17, a 27C010 EPROM. The 32 K byte RAM, IC20, stores trend data, system power up settings (averaging times, serial output parameters, etc.), and provides an area for system (scratchpad) memory requirements. Since IC20 is powered from the VBACK supply, RAM memory is retained when the monitor is turned off and it becomes available again when the monitor is turned back on.

28


2471 & 2775 Main Board

PRELIMINARY

The ROM at IC17 is read when its Chip Enable line (IC17 pin 22) is brought low by the ROMCS* signal at IC25 pin 3, and the processor brings its Read line (IC16 pin 63) low—thereby activating the ROM Output Enable line at IC17 pin 24. Under these conditions, ROM data from the specified address bus location is made available to the data bus for use by the processor.

The RAM (IC20) is activated when its Chip Select line RAMCS* (IC20 pin 20) is brought low, via IC25 pin 8. When the ME* line at IC25 pin 5 is low, and the inverse of address line A17 at IC25 pin 4 is low, output pin 6 of IC25 will go low.

This in turn will drive IC25 pin 10 low, with PWRON* low at IC25 pin 9, IC25 pin

8 will be low (RAMCS*). If at that time, OE (IC20 pin 22) is low, a RAM Read occurs, whereas a RAM Write will occur if WE (IC20 pin 27) is low.

Real Time Clock (RTC)

9.3.16

A Real Time Clock provides the Model 520A the ability to time stamp collected

(printed) trend data. (See sheet 4 on 2471 schematic, sheet 3 on 2775 schematic.)

The 32.768 kHz crystal, Y3, provides the timing signals for the clock chip, IC24, which is powered from the VBACK supply so that the clock can continue to keep time when the monitor is turned off (provided the monitor’s 12 volt internal battery is connected and maintains at least a nominal charge).

The RTC is activated when its Chip Select line (CS0*) at IC24 pin 2 is brought low.

With the monitor on PWRON* will be low (IC25 pin 13), the RTC* line will be brought low by the processor through IC22 pin 14, these lines drive RTCCS (Real

Time Clock Chip Select IC25 pin 11) low. If at this time, the RD* (IC24 pin 8) input is low, a RTC Read occurs, whereas a RTC Write will occur if the WR* (IC24 pin

10) input is low. Addressing is handled by A0-A3 (pins 4-7) and data I/O through

D0-D3 (pins 14-11).

Sound generator

9.3.17

The programmable tone controller IC27 is replaced with the Tone Generator

Replacement board 2755-01, this is used to drive the monitor’s audio circuit. The tone generator is clocked by IC39 pin9 from the 1.638 MHz signal, Q1. The tone generator is enabled by the processor when IC22 pin12 is brought low. While CE* is low, WR* is brought low and data bus information including frequency (pitch) and attenuation (volume) is accepted by the tone generator. The Ready signal (IC27 pin 4) goes low while accepting data and the processor is put into a Wait state until

IC27 finishes its task; then Ready returns high and the processor continues its operations.

The AUDOUT output at IC27 pin 7 drives the audio amplifier IC26. The amplifier output is coupled through capacitors C55 and brought to J109 as the SNDOUT

(Sound Out) line. The speaker which is mounted in the chassis is connected to J109,

LS1 is not installed on the 2471 Main Board.


29

Section 9


PRELIMINARY

Keypanel Interface

9.3.18

The12 keys (switches) on the Model 520A front panel are connected to the 2471

Main Board through a ribbon cable at J104. Each key (except

POWER

) is connected to an 8-bit latch (either IC14 or IC15). When any of these keys is pressed, the corresponding latch input is brought low. The processor continually reads the status of these latch outputs, the RDKEY* enables IC14 when low and the RDKEY_2* line enables IC15 when brought low.

The

POWER

key ON/OFF signal is sent through J104 pin 15. The AC Line Status signal, LINEST, is generated by the power supply, and is high (+5 volts) when the monitor is connected to the AC Line (Mains) and the rear panel switch is set to “|”.

This +5 volt level is sent to LED D2 (the green indicator) on the keypanel via

J104 pin 16. The LINEST signal is also input to the latch at IC14 pin 8 so that the

CPU can detect if the unit is operating on AC line power (IC14 pin 8 high) or on battery power (IC14 pin 8 low). Diode D9 keeps current from backfeeding into

IC14 when the monitor is turned off but still connected to the AC line.

The 2MIN (D3), AUDIO OFF (D4), ALERT (D5), and LOW BAT (D1) LEDs are driven by the 8-bit latch IC13. When each of the corresponding signals is driven

high the appropriate LED on the keypanel is illuminated. See I/O Device Controller on page 31.

Display Interface

9.3.19

The display is connected to the 2471 Main Board at J107. It is controlled by the processor using the RD* (Read), WR* (Write), and DISPCS* (Display Chip Select) lines. Data bits D0-D7 are used as input/output lines and A0 is used in conjunction with the RD* and WR* lines to distinguish between read and write operations as listed below.

A0

RD*

Low

WR*

Low

High Status Read

Low Data Read

Command

Write

Data Write

Table 1. Display Command/Data table.

The CNTRST (Contrast) line is controlled by pressing the front panel key. When depressed and held the processor controls the digital to analog converter IC29, line

A0 is brought low along with WR* and DACCS*, the data on D0-D7 controls the voltage at IC30 pin 7 which can vary from 0-4 volts. The output of IC30 pin 7, along with 4VREF feeds a summing amplifier (IC30 pins 1, 2, 3). The output of the summing amplifier IC30 pin 3 controls the base of Q10 which in turn controls the contrast of the display through a variable negative voltage.

30


2471 & 2775 Main Board

PRELIMINARY

The backlight for the display is controlled by the DSPBR (Display Bright) line.

When DSPBR is high the gate of Q16 is biased off, current flows from Vcc through

R51 to IC45. This sets the backlight for low illumination. The illumination of the backlight is made greater when DSPBR is made low, this biases Q16 on which essentially shorts out R51 allowing more current to flow into IC45 creating a full backlight.

I/O Device Controller

9.3.20

The A/D Converter Chip Selects, serial A/D Chip Selects, Sensor Status Decoding and NEXT* line are all controlled by IC28 when selected by the OPORT line (IC21 pin 10). The OPORT line will go high when the L1* and WR* line both go low at

IC23 pins 13 and 12, this will send output pin IC23 pin 11 low which drives inverter

IC21 pin 10 high enabling IC28.

A 3 to 8 decoder is used to control the DACCS*, RTC*, DISPC*, AUD*, KEYS*,

L1*, L2*, 2KEYS* lines. when the IOE* line goes low and the LIR* line goes high being inverted by IC21 pin 2 and presented to IC22 pin 5 as a low enable line IC22 is enabled, Q0-Q7 will be driven low depending upon the A4, A5 and A6 lines on pins 1, 2, 3 respectively on IC22.

With the LPORT line high IC13 is enabled, this latches the data on lines D0-D7

(1D-8D pins 2-9) on its output pins 19-12 (1Q-8Q respectively), the outputs correspond to the following eight lines:

CAL-used by the A/D Convertors on power up to compensate for front end voltage offsets.

TML-Two Minute LED drives the LED on the front display.

AOL-Audio Out LED drives the LED on the front panel.

ARL-Alert LED drives the LED on the front panel.

KJL*-drives Q17 when high which in turn drives the Alert Bar LEDs via J105.

BTL-Battery Low LED on the front panel.

DSPBR-(not used on the 520A)

OFFDIS-sent to the Power On/Off section of the circuitry to prevent the monitor from being turned off while writing to RAM.

Watchdog Timer

9.3.21

The Watchdog Timer provides a system reset function in the event a hardware or software “glitch” occurs. The PEEL IC18 forms the heart of the Watchdog circuit.

(See sheet 2 on 2471 schematic, sheet 1 on 2775 schematic.)

At powerup and at specific intervals thereafter, the microprocessor outputs a logic high to IC18 pin 8, WDOG (Watchdog). The WDOG signal combines with other signals within the PEEL and as a result the Watchdog Clear (WDCLR) open drain output at IC18 pin 12 is continually brought low. This discharges the capacitor C46 before it can charge up (via RP2 pins 1 and 2) past the input threshold of IC21 pin 9.


31

Section 9


PRELIMINARY

If the WDOG pulse does not appear at regular intervals, as the result of a software or hardware problem, the RC charges up and IC21 pin 8 goes low producing a

Watchdog Time-out (WDTO*) input at IC18 pin 11. WDTO* combines with other signals within the PEEL and causes the open drain Master Reset (MR) output at

IC18 pin 13 to be brought low.

A low MR causes C45 to discharge, forcing IC21 pin6 high. This sends a reset pulse to the system. It also sets the Reset Input (RESIN) signal at IC18 pin 9 high which causes RESET* at IC18 pin 19 to activate low. The active RESET line causes the microprocessor (IC16 pin 7) and the display module to be reset. The monitor then performs its powerup self-test routines, and if the “glitch” has been cleared, the monitor resumes normal operation. If the problem still exists, a self-test or other error should be displayed.

Serial I/O Controller

9.3.22

Digital data from the three Analog-To-Digital Convertors is read by the CPU through its clocked serial data input (RXS) at IC16 pin 52. The PEEL IC18 acts as the Clocked Serial I/O (CSI/O) Controller.

Except during powerup or Watchdog Timer reset,IC39 pin 3 provides an interrupt to the CSI/O controller in the form of a 5 millisecond period square-wave input to

IC18 pin 7 (INT5MS).

On the rising edge of INT5MS, a CPU interrupt request is generated when IC18 pin

18 (CPUINIT*) goes low. The CPU responds by sending the clock input to CSI/O controller (CKS) at IC18 pin 6 low. (This CKS line is inactive high unless a serial receive operation is in progress.) The CPU also sets up the ADC decode lines AA1 and AA0 at IC18 pins 5 and 4, and as a result, one of the ADC chip select lines

(CSADC1*, CSADC2*, CSADC3*) is brought low, and the CPUINIT* line is disabled.

On the rising CKS signal a CLKS output pulse at IC18 pin 14 is sent as a serial clock input to the ADC selected by the decode lines. Decode results are shown below.

AA1 AA0 Decode

0

0

1

1

0

1

1

0

Red LED 20-bit ADC

Infrared LED 20-bit ADC

Sensor Status 8-bit ADC

Internal CSI/O signal (TEND)

Table 2. CSI/O Decode Lines

Successive CKS/CLKS pulses cause the ADC data to be shifted out of the ADC

(most significant bit first) along the serial data line (SDATA) to the CPU serial input (RXS) at IC16 pin 52.

32


2471 & 2775 Main Board

PRELIMINARY

After receiving the correct number of bits for the ADC being read, the CPU changes the AA1 and AA0 decode lines and exerts the Next line (NEXT*) at IC18 pin 9 low.

This restarts the serial data shifting out of the newly selected ADC.

After all three ADCs have been read, the CPU sets the AA1 and AA0 decode lines to exert the internal TEND signal and set the 8-bit ADC to the next channel (so that it has time to settle before the next read of the ADC). This re-enables the CPUINIT line. At this point the CSI/O controller is reset awaiting an INT5MS pulse to begin the cycle again.

RS232 Serial Communication

9.3.23

The Model 520A supports serial (RS232) communication with external devices via the monitor’s rear panel connector. Signals to and from the rear panel RS232 connector are electrically isolated from the rest of the Model 520A electronics by four opto-isolators (IC3-IC6). (See sheet 5 on 2471 schematic, sheet 4 on 2775 schematic.)

An isolated secondary coil from transformer T1 is rectified and filtered by D1 and

C1 before being input to the +5 volt regulator IC2. The regulated output of IC2 is sent to pin 25 of the 25-pin D connector on the rear panel in order to power the optional Analog Module or Telemetry transmitter. The supply also powers IC1.

The Dual RS232 Transmitter/Receiver, IC1, uses a single +5 volt supply (pin 16).

The two Receive (Rx) inputs can accept

±30 volt levels, while the two Transmit

(Tx) lines output

±9 volt levels. The four level translators within the chip turn the

RS232 level signals to 5 volt TTL/CMOS compatible levels.

Two signals lines TX0 and TX1 transmit data from the CPU across the optoisolators ICs 3 and 4 to IC1. Here the signals are level shifted to the standard

±9 volt levels and sent to the rear panel connector.

When the CPU brings the TX0 signal at R62 Low, the LED portion of IC3 becomes forward biased and illuminates and causes the transistor portion of the device to conduct. Therefore, when TX0 is Low, IC1 pin 11 is Low and when TX0 is High,

IC1 pin 11 is also High. All four opto-isolators work in the same way. IC1 level shifts its input at pin 11 and outputs RS232 standard

±9 volt levels at the TX signal at J101 pin 3. This transmit signal is used to output data to RS232 devices including the Hewlett-Packard ThinkJet Printer and the Novametrix Model 315 Printer.

The CPU TX1 signal crosses the isolation barrier at IC4. The 0-5 volt opto-isolator output at IC4 pin 5 is used to bring data to the Optional 9622-01 Analog Module.

The IC4 pin 5 output is also brought to IC1 pin 10. The level shifted output at IC1 pin 7 is unused (except for factory test use).

The Receive (RX) line at J101 pin 2 and the Clear To Send (CTS) line at J101 pin

6 are input signals to the Model 520A. They are level shifted by IC1 and sent across the isolation barrier by ICs5 and 6 respectively.


33

Section 9


PRELIMINARY

The transmit signal TX1, is dedicated to communication with the Optional Analog

Module (Catalog Number 9622-01) which when connected to the rear panel connector, provides analog representations of the SpO

2

and Pulse Rate values, a plethysmogram signal, and a pass through port for the RS232 connector.

The transmit output TX0 from the CPU and the Receive (RX0) and Clear To Send

(CTS*) inputs to the CPU are connected to the rear panel RS232 connector.

34


5-Jun-01

PRELIMINARY

10

Maintenance

General

10.1

This section presents recommended maintenance schedules for the Model 520A and information on general maintenance, such as battery and fuse replacement, disassembly and assembly instructions, and system software updates.

Maintenance Schedules

10.2

The electronic circuits within the Novametrix Model 520A Pulse Oximeter monitor do not require scheduled calibration or service. However, in order to maximize battery life, the monitor’s internal battery should be exercised monthly. Novametrix recommends the following maintenance schedules.

1

• Cleaning and Sterilization:

Perform as required. See Cleaning and Sterilization on page 36.

• Battery Life and Maintenance:

See Battery Life and Maintenance on page 37.

• Functional Test:

The test may also be used as a “spot check” to verify system operation if reports of malfunctions are received. The test verifies overall functional integrity of the monitor and sensors. Section 12, Functional Test, on page 51

• Accuracy Test:

This test, which requires the use of the Model TB500B Sensor Simulator, verifies the performance accuracy of the Model 520A. If the monitor does not pass the accuracy test, the Calibration and Adjustment test should be performed.

See Section 13, Accuracy Test, on page 55.

• Calibration Tests:

These tests contain information on calibrating the electronic circuits within the

Model 520A and should only be performed if the monitor fails to pass the

Functional and/or Accuracy Tests. Only qualified service personnel should attempt to perform the Calibration and Adjustment Test. See Section 14,

Calibration Tests, on page 59.

1. At the customer’s request, Novametrix will provide repair and calibration services under the terms of a Service Contract. Contact the Novametrix Service Department for contract details.


35

Section 10

Maintenance

PRELIMINARY

Cleaning and Sterilization

10.3

Model 520A Monitor

10.3.1

• Turn the monitor off and unplug from the AC (Mains) line before cleaning.

• The monitor can be cleaned and disinfected with solutions such as a 70% isopropyl alcohol, 2% glutheralhyde, or 10% bleach solution. Then wipe down with a water-dampened clean cloth to rinse. Dry before use.

• Do not immerse the monitor.

• Do not attempt to sterilize the monitor.

Finger Sensor

10.3.2

• The sensor can be cleaned and disinfected with solutions such as a 70% isopropyl alcohol, 2% glutheralhyde, or 10% bleach solution. Then wipe down with a water-dampened clean cloth to rinse. Dry before use.

• Make certain that the finger sensor windows are clean and dry before reuse.

• Do not immerse the finger sensor.

• Do not attempt to sterilize the finger sensor.

• After cleaning the finger sensor, verify that the sensor is physically intact, with no broken or frayed wires or damaged parts. Make certain that the connectors are clean and dry, with no signs of contamination or corrosion. Do not use a broken or damaged sensor or one with wet, contaminated or corroded connectors.

Y-SENSOR™ and Y-STRIP™ Taping System

10.3.3

• Do not immerse connector on the Y-Sensor.

• The Y-Sensor may be immersed—up to, but not including, the connector, in a

2% glutheralhyde solution, or 10% bleach solution. Refer to manufacturer’s instructions and standard hospital protocols to determine recommended times for disinfection and sterilization.

• Rinse thoroughly with water and dry before use (do not rinse the connector).

• Do not attempt to sterilize Y-Sensor except as stated above.

• After cleaning or sterilizing the Y-Sensor, verify that the sensor is physically intact, with no broken or frayed wires or damaged parts. Make certain that the connectors are clean and dry, with no signs of contamination or corrosion. Do not use a broken or damaged sensor or one with wet, contaminated, or corroded connectors.

• Treat Y-Strip Tapes and foam wraps in accordance with hospital protocol for single-patient use items.

36


Battery Life and Maintenance

PRELIMINARY

Battery Life and Maintenance

10.4

The monitor was shipped from the factory with a fully charged battery. Since the monitor draws some battery power even while turned off, it is recommended that the monitor be operated on line power for the first 24 hours to allow ample time for the battery to fully recharge.

The monitor may be operated on line power while the battery is recharging.

Approximately 16 hours are required to fully recharge a discharged battery.

During prolonged periods of storage or shipment, the battery may discharge enough to prevent the unit from turning on while operated from battery power. If this occurs, plug in the line cord, set the switch on the rear panel to the “|” On position, ensure that the green indicator on the front panel is illuminated, and allow the monitor to charge for 24 hours before switching it on.

Mains Voltage Configuration

10.5

The rear panel power entry module indicates the mains voltage setting for the monitor. Check that the voltage is correct before attaching the AC line cord and powering the monitor. The Model 2001 can be set to operate from 100-120 VAC

50/60Hz or 200-240VAC 50/60Hz.

Instructions for fuse replacement and changing the mains voltage setting follow.

CAUTION:

Replace fuses with same type and rating. Verify proper fuse value for mains voltage setting (see table below)

.

Fuse Replacement

10.5.1

1. Check that the monitor is OFF.

2. Set the rear panel power entry module switch to OFF (“O”). Remove the AC line cord from the power entry module.

3. Using a flat blade screwdriver, pry the fuse access door open to expose the fuse housing. Note the orientation of the fuse housing (this determines the mains operating voltage).

Mains Voltage Fuses (Slo Blo)

100-120 VAC 0.5 A 250V

200-240 VAC 250mA 250V


37

Section 10

Maintenance

PRELIMINARY

Power entry module

Fuse access door

4. Pry the fuse housing out from the power entry module.

Fuse housing

Fuse housing

OR

NOTE: 5 mm X 20 mm fuses are installed toward the “back” of the fuse housing as shown

3AG type 5 X 20mm type

5. Replace the blown fuse(s) with the proper type and rating.

6. Reinstall the fuse housing. When positioning the housing into the power entry module make sure that it is oriented correctly. Press the fuse housing back into the power entry module.

7. Close the fuse access door and verify that the proper mains operating voltage is displayed.

Line operating voltage

Changing the Mains Voltage Setting

10.5.2

1. Check that the monitor is OFF.

2. Set the rear panel power entry module switch to OFF (“O”). Remove the line cord from the power entry module.

CAUTION:

Replace fuses with same type and rating. Verify proper fuse value for mains voltage setting (see table below)

.

Mains Voltage Fuses (Slo Blo)

100-120 VAC 0.5 A 250V

38


PRELIMINARY

Mains Voltage Configuration

200-240 VAC 250mA 250V

3. Using a flat blade screwdriver, pry the fuse access door open to expose the fuse housing. Pry the fuse housing out from the power entry module.

Fuse access door

Fuse housing

4. Install the proper type and rating fuse for the mains voltage setting required.

5. Position the housing into the power entry module so that the desired voltage is furthest away from the switch (see below).

Set for 100-120V operation

Set for 200-240V Operation

6. Close the fuse access door and verify that the proper mains operating voltage is displayed.

Line operating voltage

AC Mains on older style assemblies

10.5.3

The Model 520A will operate on line voltages of 100, 120, 220 or 240 VAC

± 10% at 50/60 Hz. At 100/120 VAC,two 0.5 Amp, 250 Volt, Slo-Blo (time delay) AC

Mains fuses are required, while Two T 250 mA, 250 Volt fuses are required when operating at 220 or 240 VAC. For continued protection against fire hazard, replace only with fuse(s) of the same type and rating. The rear panel Power Entry Module

(PEM) houses the AC Mains fuses and is where the input voltage is selected. It also houses the AC Mains Power switch: set to “|”, AC Mains power is presented to the internal circuitry; set to the “0” position, power does not pass through the PEM.


39

Section 10

Maintenance

PRELIMINARY

Replacing the AC Mains Fuse(s)

10.5.4

1. Turn off the Model 520A. Set the rear panel AC Mains power switch to “0” and disconnect the line cord from the monitor.

2. Place a screwdriver into the Fuse Access Slot and pry open the Fuse Access

Door.

Line Cord Receptacle

Power Switch

O

Voltage Select Indicator Fuse Acces Slot

Figure 4. Power Entry Fuse Access Door Opening

3. With the Fuse Access Door open pull the fuse(s) out by pulling on the point of the arrow indicator, the fuse holder assembly will slide out.

Fuse Holder Assembly

O

Fuse Holder Assembly

Figure 5. Fuse Removal

4. After replacing the fuse(s), snap the fuseholder assemblies into the PEM and shut the Fuse Access Door.

Changing the AC Mains Voltage

10.5.5

1. Turn off the Model 520A. Set the rear panel AC Mains power switch to “0” and disconnect the line cord from the monitor.

2. Place a screwdriver into the Fuse Access Slot and pry open the Fuse Access

Door.

40


PRELIMINARY

Assembly Exchanges

3. Using needle-nosed pliers, pull the Voltage Selector Drum from the PEM.

Note the orientation of the drum; the proper voltage should face out.

Voltage Selector Drum

O

Figure 6. Power Entry Module Voltage Selector Drum Removal

4. Set the Voltage Selector Drum so that the printed side of the correct voltage faces you. The voltage selections are pictured below.

O

OR

Figure 7. Power Entry Module Voltage Selection Adjustment

5. Snap the Voltage Selector Drum back into the PEM. Be sure that the Voltage

Setting Indicator shows the proper voltage. Close the Fuse Access Door.

Assembly Exchanges

10.6

Disassembly should be performed by qualified personnel. Follow proper grounding procedures to avoid damage to internal components from static discharge.


41

Section 10

Maintenance

PRELIMINARY

1. Turn the Model 520A Off. Disconnect the line cord and sensor. Remove the four cover screws from the bottom cover. Holding both case halves together, flip the monitor right-side up.

Remove Line Cord

Remove these

(4) four screws.

Figure 8. Removing the Top Cover

2. Lift the top cover from the monitor. Use a gentle rocking motion to lift first one side and then the other side a little at a time. Set the Red Alert Bar lens aside with the cover for safe keeping.

P109 Speaker

P102 Power Supply

2471 Main Board

P105 Alert Bar

42


P104 Keyboard

P106 Backlight P103 Display

P108 Sensor

Figure 9. Monitor Assembly

3. Unplug P102 The Power Supply connector from the 2471 Main Board, disconnect P109 (Speaker), P108 (Sensor), P104 (Keypanel), P106

(Backlight), P105 (Alert Bar), and P103 (Display). Unscrew 2471 Main

5693-90-01

PRELIMINARY

Assembly Exchanges

Board from the rear panel. Remove the front Bezel assembly then slide the

2471 Main Board out, the 2472 Power Supply Board and Battery should be exposed.

4. The separate sections of the monitor can now be removed.

2472 Power Supply Board

Battery Connection to Power

Supply P302

Battery

5-Jun-01

SpO2 Input Assy

Figure 10. 520A Assembly with 2471 Main Board Removed

5. IMPORTANT. The battery is connected to the Power Supply Board through connector J302. Before attempting to apply power to the monitor ensure all connections are properly made, then connect the AC mains and turn the PEM switch to “|”, ensure that the on the front panel illuminates before powering up.

6. Remove/replace the various assemblies as needed. IMPORTANT: The monitor will be damaged if power is applied to it while cables or assemblies are improperly connected.

7. After the monitor is fully assembled perform safety checks. Reconnect the line cord to the AC Mains and to the monitor. Set the AC Mains switch to the

“|” (On) position. Verify the indicator illuminates. Turn the monitor on.

8. Measure the AC leakage current from the monitor’s chassis to earth ground with the monitor grounded, ungrounded, and ungrounded reverse polarity.

When operating from 100/120 VAC, no leakage current may be greater than

25

µA. If operating at 220/240 VAC, no leakage current may be greater than

50

µA.

9. With the monitor grounded, measure from the AC line to the SaO

2

Input connector pins. When operating from 100/120 VAC, no leakage current may be greater than 25

µA. If operating at 220/240 VAC, no leakage current may be greater than 50

µA.


43

Section 10

Maintenance

PRELIMINARY

Changing System Software

10.7

The system software is contained in EPROM IC17 on the 2775 Main Board. New software releases are made available from time-to-time. These new releases may add features or be maintenance upgrades. To install a new EPROM:

1. Follow the steps listed in Assembly Exchanges on page 41 to open the

monitor. Be sure to disconnect J102 from the 2775 Main Board to ensure that there is no power on the board while changing the system software.

2. Use a PLCC extraction tool to carefully pry the EPROM IC17 from the socket.

3. Install the update EPROM into the socket. Align the EPROM so that IC17 pin-1 is inserted into pin 1 of the socket.

Changing System Software on 2471 Main Board

10.7.1

The system software is contained in EPROM IC17 on the 2471 Main Board. New software releases are made available from time-to-time. These new releases may add features or be maintenance upgrades. To install a new EPROM:

1. Follow the steps listed in Assembly Exchanges on page 41 to open the

monitor. Be sure to disconnect J102 from the 2471 Main Board to ensure that there is no power on the board while changing the system software.

44


PRELIMINARY

Changing System Software

2. Use a small flat-blade screwdriver (or IC extraction tool) to pry the EPROM

IC17 from the socket—be careful not to bend the pins.

IC17 System Software

Pin 1 orientation

Figure 11. Changing the System Software EPROM

3. Install the new EPROM into the socket. Align the EPROM so that IC17 pin-

1 is inserted into pin 1 of the socket.

4. Reverse the above steps to reinstall the assembly into the monitor.


45

Section 10

Maintenance

PRELIMINARY

[This page intentionally blank]

46


5-Jun-01

PRELIMINARY

11

Troubleshooting

Fault, alert and error messages that can appear on the Model 520A Message Center display are described below.

Paragraphs marked with a “

☞

” are intended for qualified service personnel only.

Message Center Display

AUDIO OFF DISABLED

BAD SIGNAL TIMEOUT

BATTERY EXHAUSTED

CONNECT LINE CORD

CAN’T I.D. PROBE

CONNECT SP02 PROBE

PROBE FAULTY

EVENT MARKED

Possible Explanation

Displayed if user tries to enable Audio Off mode (by pressing and holding the AUDIO key) while the “Allow Audio

Off” portion of the Options Menu is set to “No”.

Monitor not receiving valid signals from sensor. May be caused by excessive motion, cardiac arrhythmia or other situations leading to poor signal. Check patient status, reposition sensor.

Monitor is running on battery power and the battery power has been depleted. Connect line cord to AC Mains power source and set the rear panel switch to “|”.

☞ Monitor’s rear panel fuse has blown, monitor switched over to battery power and has depleted battery life.

Sensor is placed on too thick of a site. Reposition the sensor on a thinner (less opaque) section of tissue.

A non-SuperBright™ sensor is connected, use only 87xx series sensors.

Sensor is faulty. Remove sensor from use and contact qualified service personnel.

Sensor is disconnected from the monitor.


☞ Both sensor LEDs have failed or the cable connections are open or shorted.

Sensor faulty. Remove sensor from use and contact qualified service personnel.

☞ This error traps intermittant faults such as Probe Red

LED or Infrared LED failures caused by frayed or broken wires in the sensor cable. Whereas PROBE RED or I.R

LED FAILED is displayed for as long as the error lasts,

Faulty Probe is displayed if those errors cease without the user replacing the faulty sensor.

An event was successfully entered into trend memory.


47

Section 11

Troubleshooting

PRELIMINARY

Message Center Display Possible Explanation

INCOMPATIBLE PROBE

INSUF. LIGHT **



Insufficient Light, where ** is time in seconds (after 99 seconds display shows “--”). Sensor placed on a site too thick

(or opaque) for adequate light transmission. Reposition the sensor.


LIGHT INTERF.**

LOW SIGNAL **

MONITOR ERROR

MONITOR PERFORMING

SELF TEST.

Light Interference, where ** is the time in seconds (after 99 seconds display shows “--”) ambient light sources (sunlight, warming lights, etc.) are interfering with sensor light sources. Shield the sensor from ambient light sources.

Low Signal Strength, where ** is the time in seconds (after

99 seconds display shows “--”) that the pulse strength as detected by sensor is too weak for proper monitor operation.

Reposition sensor.

Monitor faulty. Record error message (appearing on bottom line of display) and contact qualified service personnel.

☞ “RAM SELF TEST FAILED” - Ram failed the power up self-test.

☞ “ROM SELF TEST FAILED” - Calculated EPROM checksum not does not equal stored value. Bad EPROM.

☞ “BAD STACK POINTER” - Stack pointer base not at top of stack.

☞ “CORRUPT SYSTEM MMU” - The CPU MMU pointing to an illegal address map. Digital Bd fault.

☞ STACK OVERFLOW” - Stack pointer exceeded allocated stack size.

☞ “DISP BUFFER OVERFLOW” - Display buffer queue exceeded its allocated size.

☞ “HARDWARE ERROR 1” - (1)Main Bd PEEL is defective, (2) Main Bd 20-bit ADCs exceeded acceptable calibration thresholds.

☞ “XXms INT.TIMEOUT” where XX is 10 or 25. The interrupt has interrupted itself.

☞ “ERROR UNDEFINED” - Failed in an unknown state.

Monitor is performing its power up system diagnostic tests.

Parameters Reset

To Factory Default

Displayed when monitor is turned on while pressing the

ALERT RESET key. Monitor now using factory default settings.

48


PRELIMINARY

Message Center Display

PROBE FAULTY RD

PROBE FAULTY IR

PROBE OFF PATIENT

PULSE-HIGH

PULSE-LOW

PULSE OUT OF RANGE

Revision 2.0

APR/28/92

SpO2-HIGH

SpO2-LOW

Possible Explanation


☞ Sensor Red LED has failed or the cable connections are open or shorted.


☞ Sensor Red LED has failed or the cable connections are open or shorted.

Sensor disconnected from patient, improperly applied, or placed on an area too translucent for proper sensor operation.

Reposition sensor.

Selected pulse rate high alert limit has been violated.

Selected pulse rate low alert limit has been violated.

Pulse rate is less than 30 bpm or is greater than 250 bpm.

Monitor software revision level. Displayed when monitor is turned on while pressing AUDIO key.

Selected saturation high alert limit has been violated.

Selected saturation low alert limit has been violated.


49

Section 11

Troubleshooting

PRELIMINARY


50


5-Jun-01

PRELIMINARY

12

Functional Test

Introduction

12.1

The test verifies overall functional integrity

1

of the monitor and sensors. If the monitor or sensors do not pass these tests, remove from use and contact the

Novametrix Service Department for repair/replacement assistance.

This procedure assumes the technician performs each step as indicated - leaving the monitor in a known state prior to performing the next step. If steps are omitted or performed out of order, be sure that the monitor is set to the correct state beofre continuing.

Monitor Functional Test

12.2.1

12.2.2

12.2.3

12.2.4

12.2.5

12.2

Equipment Required:

Model 520A to be tested

AC Mains Line Cord (supplied with monitor)

Finger Sensor (Cat. No. 8776) or Y-Sensor™ (Cat. No. 8791)

Visually inspect the monitor and line cord. Verify there is no external damage. Shake the unit to check that there is no loose hardware inside.

Inspect the sensor(s). Verify mechanical integrity.

Check the rear panel power entry module. Verify that it is set to the proper voltage.

Set the AC Mains switch to the “0” (Off) position. Connect the line cord to the monitor and to the AC Mains.

12.2.6

12.2.7

12.2.8

Verify the (AC Mains) indicator is not illuminated.

Set the AC Mains switch to the “|” (On) position. Verify the indicator illuminates.

Depress and hold the

ALERT RESET

key. Press the front panel

POWER

key then release both keys. The monitor will;

• Briefly illuminate all displays and indicators

2

• Produce an audible “beep” indicating the audio is operational

1. See Section 13,

Accuracy Test

, on page 55 for tests that check the accuracy of the monitor.

2. The AC indicator will illuminate only when the monitor is connected to line power and the rear panel Power switch is On (|).


51

Section 12

Functional Test

PRELIMINARY

12.2.9

12.2.10

12.2.11

12.2.12

12.2.13

12.2.14

12.2.15

12.2.16

12.2.17

12.2.18

• Briefly display

Parameters Reset To Factory Default

.

3

• Briefly display

MONITOR PERFORMING SELF TEST.

4

• The message center will display

ERASE STORED TRENDS ?

for approximately 10 seconds.

Verify the Message Center flashes

CONNECT SPO2 PROBE

while no sensor is connected to the monitor.

Press the

ALRT

key to display the

SET ALERT LIMITS

menu.

Press the

↓

(down arrow) key several times and verify the Saturation display upper alert limit decreases each time the key is pressed.

Press the

RUN

key. Note the displayed Saturation alert limit settings. Turn the monitor off and back on again. After the self-test is complete, verify the monitor “remembered” the alert limit values.

Press the

Menu

key and then the

AUDIO

key.

Press the

ALERT

key to display the

SET ALERT VOLUME

menu.

Press and hold the

↓

key and verify the volume of the tone decreases as the volume display decreases to 01. Press the

↑

key to return to maximum (07) volume. Press

RUN

.

Press

MENU

then press

LITE

, verify the backlight toggles between dim and bright with each depression.

Press

RUN

.

Press the

Menu

key and then the

AUDIO

key.

Press the

PULSE

key to display the

SET AUDIO FEATURES

menu.

Press the

↑ key to set the value to 01 then press

RUN

.

Do not apply the sensor to yourself. If using a Y-Sensor, fold the sensor heads so that the windows face (or even touch) each other. Connect the sensor to the monitor. Verify the Message Center flashes

PROBE OFF

PATIENT

and no alarm sounds.

If using a Finger sensor, apply it to your index finger, and if using a Y-

Sensor, tape the sensor to your index finger. Verify that after several seconds, reasonable Pulse Rate and Saturation (>95%) values are displayed.

Check that the Message Center displays a Pulse Activity Bar and that a tone sounds with each pulse beat. (Note that the pitch of the tone will vary with the Saturation display value.)

Remove the sensor from your finger. Verify the Saturation and Pulse Rate displays blank out, an alarm sounds and

PROBE OFF PATIENT

is displayed. (If using a Y-Sensor, you may have to fold the heads so that the windows face each other in order to make the alarm and message activate.)

3. This message is only displayed if the ALERT RESET key is depressed at power up.

4. If “Monitor Error” appears, turn the monitor off and back on. If the message reappears, contact qualified service personnel. See Section 11,

Troubleshooting

, on page 47.

52


Special Power Up Functions

PRELIMINARY

12.2.19

12.2.20

12.2.21

12.2.22

12.2.23

12.2.24

12.2.25

12.2.26

Press and release the

AUDIO

key. The (Two Minute Silence) indicator should illuminate and the alarm should be silenced. After two minutes the indicator turns off and the alarm sounds again (providing the alarm condition still exists).

With the alarm sounding, press and hold the

AUDIO

key until the (Audio Off) indicator illuminates. Verify that the alarm is silenced.

Press and release the

AUDIO

key. Verify the indicator shuts off and the alarm sounds.

With the

PROBE OFF PATIENT

alarm still sounding, press the

ALERT RE-

SET

key. Verify the message and alert indicators continue to flash but the alarm is silenced.

Set the AC Mains switch to the “0” (Off) position. Verify the unit operates from battery power (provided the battery is substantially charged). Place the AC Mains switch back to the “|” position.

Press the

POWER

key to turn the monitor off and disconnect the sensor.

Depress and hold the

ALERT RESET

key. Press the front panel

POWER

key then release both keys. The monitor will power up with the factory default settings in place. After the self-test is complete, turn the monitor off.

This completes the Functional Test. If the monitor and sensor performed as described above, they are functionally operational. If the monitor is to be returned to clinical use, be sure to let the user know that the monitor is now using its default settings—as these may differ from the user’s “normal” settings.

Special Power Up Functions

12.3

Each of the Model 520A front panel pushbutton keys is linked to a special “hidden” power up function. To initiate the special function, start with the monitor off and press a front panel key. While still holding that key, press the

POWER

key to turn the monitor on.

AUDIO

= Software (EPROM) Revision Level

Turn the monitor on while holding the

AUDIO

key and the monitor’s software revision level is displayed in the message center for as long as the

AUDIO

is pressed. Release the key and the monitor continues with its normal power up sequence.

ALERT RESET

= Return to factory default settings

Turn the monitor on while holding the

ALERT RESET

key and the monitor resets all its control settings (including alert limits, averaging times, etc.) to the factory default values. A

Parameters Reset To Factory Default

message is briefly displayed and the monitor continues with its


53

Section 12

Functional Test

PRELIMINARY

normal power up sequence. Note that the system date and time are not affected by this action.

Softkey #1 Softkey #2

Figure 12. Softkey Identification

Softkey #1

= EPROM Checksum Test, Production Test Mode

Turn the monitor on while holding

Softkey #1

(the leftmost softkey) and the monitor calculates and displays the checksum value of the EPROM containing the system software. Press and hold

Softkey #3

while the checksum is displayed and the monitor enters Production Test Mode.

Softkey #2

=Extended Display and Watchdog Test

Turn the monitor on while holding

Softkey #2

(second from left) and all front panel indicators and display segments illuminate for several seconds. The watchdog now resets the monitor which should then execute its normal power up sequence. Note that the indicator will illuminate only if the monitor is being powered from the AC Mains.

54


5-Jun-01

PRELIMINARY

13

Accuracy Test

Introduction

13.1

The Accuracy Test verifies the performance accuracy of the Model 520A Pulse

Oximeter monitor. If the monitor does not pass the accuracy test, the monitor should be recalibrated. Refer to Section 14, Calibration Tests, on page 59, or contact the

Novametrix Service Department for repair/replacement assistance.

The test requires the use of the Model TB500B Sensor Simulator.

1

This is the same device used by the factory technicians to calibrate the monitor prior to shipping. The

TB500B is an updated version of the TB500A Test Box. Owners of TB500A should contact the Novametrix Service Department for details on upgrading to the

TB500B. Note that the TB500A, used in conjunction with the Cat. No. 5453-00

Adapter Cable, may be substituted for the TB500B in most parts of this test.

Monitor Accuracy Test

13.2.1

13.2.2

13.2.3

13.2

Equipment Required:



TB500B Sensor Simulator (Cat. No. 5530-00)

Press and release the front panel

POWER

key. The monitor will;

• Briefly illuminate all displays and indicators

2

• Produce an audible “beep” indicating the audio is operational

• Briefly display

MONITOR PERFORMING SELF TEST.

3

• Display the Message Center flashes

ERASE STORED TRENDS?

for ten seconds then displays

CONNECT SPO2 PROBE

while no sensor is connected to the monitor.

Press the

Menu

key and then press

AVG

.

The

SELECT SPO2 AVERAGING

menu should be displayed. Press

2s

and then press

RUN

to return to the Main Menu. This sets the SpO

2

averaging to 2-seconds for the quickest response to changing TB500B settings.

1. Available through the Novametrix Service Department.

2. The AC indicator will illuminate only when the monitor is connected to line power and the rear panel Power switch is On (|).

3. If “Monitor Error” appears, turn the monitor off and back on. If the message reappears, contact qualified service personnel. Refer to Section 11,

Troubleshooting

, on page 47.


55

Section 13

Accuracy Test

PRELIMINARY

13.2.4

13.2.5

13.2.6

13.2.7

13.2.8

13.2.9

13.2.10

13.2.11

13.2.12

13.2.13

Set the TB500B to these settings;

Power - On, Sensor Type

4

- 87xx, Signal Attenuation - 3, Saturation - 92.

Connect the TB500B to the Model 520A SpO

2

Input Connector.

Verify a Pulse Activity Bar appears in the Message Center.

Verify SpO

2

and Pulse Rate values appear after several “pulses”.

Set the Signal Attenuation to 1. Verify the Saturation and Pulse Rate displays blank out, an alarm sounds and

PROBE OFF PATIENT

is displayed. Set the Signal Attenuation to 3 and verify the displays and

Pulse Activity Bar return.

Set the Saturation to 0. Verify that after a short delay,

LOW SIGNAL appears in the Message Center. Set the Saturation to 100 and verify the displays and Pulse Activity Bar return.

Press and hold the TB500B RED push-button. Verify the monitor alarms and displays

PROBE FAULTY RD

. Release the button.

Press and hold the TB500B INFRARED push-button. Verify the monitor alarms and displays

PROBE FAULTY IR

. Release the button. Verify the displays and Pulse Activity Bar return.

Press and hold both the TB500B RED and INFRARED push-buttons.

Verify the displays blank out and

CONNECT SPO2 PROBE

is displayed.

Release the buttons. Verify the displays and Pulse Activity Bar return.

Disconnect the TB500B from the monitor. Set the Sensor Type switch to

86xx.

5

Reconnect the simulator to the monitor. Verify the message

INSUFFICIENT LIGHT

is replaced in approximately 10 seconds by

CAN’T I.D. PROBE

, which is itself replaced later by

PROBE FAULTY

.

Disconnect the TB500B from the monitor, return the Sensor Type switch to 87xx and then plug it back in. Verify the displays and Pulse Activity Bar return.

Press and hold the

AUDIO

key until the (Audio Off) indicator illuminates. This will keep the monitor silent for the remainder of the test.

Verify the displayed SpO

2

value is within the tolerances stated below for each setting of the Signal Attenuation and Saturation switches. Verify a

Pulse Rate of 60 bpm

± 1bpm for all switch settings. (Note that alert

4. The 5453-00 Adapter Cable is used instead of the Sensor Type switch for the TB500A.

5. If using a TB500A, disconnect the Adapter Cable and plug the TB500A directly into the Model

520A. The Message Center should display “INCOMPATIBLE PROBE”. Install the Adapter Cable between the TB500A and the Model 520A and move on to the next step.

56


Monitor Accuracy Test

PRELIMINARY

13.2.14

13.2.15

messages will be generated and displayed as the saturation value violates the alert limit settings.)

TB500B 520A 520A SpO

2

SAT ATTEN SpO

2

100

92

82

72

62

100

92

82

72

3

3

3

3

3

7

7

7

7

99

± 1

92

± 2

82

± 2

72

± 2

62

± 2

99

± 1

92

± 4

82

± 4

72

± 4

62 7 N/A

(w/ TB500A)

99

± 1

92

± 2

84

± 2

77

± 2

69

± 2

99

± 1

92

± 4

84

± 4

77

± 4

N/A

Table 3. SpO2 Display tolerances for TB500B settings

Press the

Menu

key and then press

AVG

. Press the appropriate key to return the averaging to its pretest value.

Press

RUN

to return to the Main Menu.

This completes the Monitor Accuracy Test. If the monitor does not meet the above listed specifications, refer to Section 14, Calibration Tests, on page 59, or contact the Novametrix Service Department for recalibration, repair, or replacement information.


57

Section 13

Accuracy Test

PRELIMINARY


58


5-Jun-01

PRELIMINARY

14

Calibration Tests

Introduction

14.1

The Calibration Tests verify the calibration and operation of the electronic circuits within the Model 520A Pulse Oximeter. These tests do NOT need to be performed on a regular (preventative maintenance) basis. Perform these tests only if the monitor fails to operate as expected and/or fails the Functional Test on page 51 and/ or the Accuracy Test on page 55. Calibration Tests should be performed only by qualified service personnel. The Model 520A contains static sensitive devices.

Follow proper grounding procedures when handling the internal components to avoid damage from static discharge.

The test requires the use of the Model TB500B

1

Sensor Simulator Test Box. This is the same device used by the factory technicians to calibrate the monitor prior to shipping. The TB500B is an updated version of the TB500A

2

Test Box.

If the monitor does not pass the Calibration Tests, remove it from use and contact the Novametrix Service Department for repair/replacement assistance.

This procedure assumes the technician performs each step as indicated—leaving the monitor in a known state prior to performing the next step. If steps are omitted or performed out of order, be sure that the monitor is set to the correct state before continuing.

Equipment Required and Test Setup

14.2.1

14.2.2

14.2



TB500B Sensor Simulator (Cat. No. 5530-00) or TB500A Sensor Simulator and Adapter Cable 5453-00.

RS232 test fixture, PN: 5479-01

Saturation test jack, PN: 5942-00

Digital Voltmeter

Small Flat-blade screwdriver

With the Model 520A Off. Disconnect any line cord and sensor from the monitor.

1. Available through the Novametrix Service Department.

2. The TB500A, used in conjunction with the Cat. No. 5453-00 Adapter Cable, may be substituted for the TB500B in most parts of this test.


59

Section 14

Calibration Tests

PRELIMINARY

14.2.3

14.2.4

Flip the monitor over to expose the bottom cover and remove the four cover screws. Holding both the top and bottom halves together, flip the monitor over again and set it on its bottom cover.

Lift the top cover from the monitor and set it aside. Set the Red Alert Bar lens aside with the cover for safe keeping.

Test Procedure

14.3

Unless otherwise specified all measurements are with respect to isolated ground.

Use the top of R4 (end closest to IC2) as ground reference.

14.3.1

Attach a line cord and place the mains switch to the “|” position. Verify that the green LED on the front panel illuminates. The monitor may power up when the Mains switch is set to“|”, if this occurs turn the monitor off with the front panel button.

14.3.2

14.3.3

14.3.4

14.3.5

Measure the voltage at J102 pin 2 and verify 13.2 VDC ± 0.4 volts.

This voltage is dependent on a fully charged battery installed. If an installed battery is less than fully charged, the measured voltage will not match the expected voltage.

Simultaneously press the leftmost softkey and the power button.

While

Calculating Checksum

is displayed, press and hold the third softkey from the right until

Novametrix Inc Production Test appears.

Measure the voltage at TP1. Verify 5.000V ± 50mV. Adjust VR1 if necessary.

Verify the following voltages:

Location

IC40 pin 4

IC40 pin 8

IC20 pin 28

IC37 pin 14

IC37 pin 7

IC37 pin 10

IC36 pin 1

IC30 pin 14

Signal Name

-VA

+VA

VBACK

+V5

-V5

VREF

4VREF

-4VREF

Voltage

-12.00V ± 500mV

12.00V ± 500mV

4.75V ± 250mV

5.00V ± 250mV

-5.00V ± 250mV

2.500V ± 5mV

4.045V ± 50mV

-4.045V ± 100mV

60


Test Procedure

PRELIMINARY

14.3.6

Short out capacitor C90 by installing a jumper wire from R59 to R56.

Back of Unit

2471 / 2775 Bd

Component Side

Front of Unit

5-Jun-01

14.3.7

14.3.8

14.3.9

14.3.10

Connect the RS232 test fixture to J101 and the saturation test jack to the saturation input connector.

Run monitor test 1. Press the Test softkey,

Automatic Test

will appear.

Press the Test softkey again to initiate the test, follow the prompts in each test and verify each test passes.

Note: A series of auto tests will be performed, if any failures are encountered the monitor will default to MONITOR TEST 2. Of the list below only the tests with * next to them are performed in the auto test. Upon completion of the auto test the monitor will default to MONITOR TEST

2. The following is a list of the monitor tests available;

Test# Description

1

2*

Auto Test

RAM Test

3*

4*

5*

6*

ROM Test

Real Time Clock Test

Audio Volume Test

Audio Frequency Test

7*

8

RS232 Loopback Test

Keyboard Test

9 Mains Test

10* 20 Bit ADC Test

11* 8 Bit ADC Test

12 Display ADC Channels Test

13 515A-> PC Interface Test

Disconnect the jumper wire, the RS232 test fixture, and the saturation test jack.

Connect the TB500B to the saturation input connector. Set the saturation to 0 and the attenuation to 5.


61

Section 14

Calibration Tests

PRELIMINARY

14.3.11

Using the Next softkey increment to monitor test 12 (Display ADC channels). Press the Test softkey,

Display ADC channels

will appear.

Press the Test softkey to initiate the test. Press the Prev softkey. Verify the

LED pwr=20. Press the Prev softkey until

IR Adc=xxxxx

appears, verify the value displayed is within the limits specified below. Press the Prev softkey again,

RED Adc=xxxxx

will appear. Verify the value displayed is within the limits specified. Press the exit softkey and set the TB500B saturation to 100 and attenuation to 3.

14.3.12

14.3.13

14.3.14

14.3.15

RED ADC

IR ADC

Power the monitor down.

5B32-88CB hex

3324-4CB7 hex

Power up the monitor by pressing the power button. Verify a

Monitor performing self test

message is displayed then is immediately followed by the main monitoring screen.

Press the Menu softkey followed by the Avg and 2s softkey then press

Run.

Set the TB500B to the settings in the chart. Verify the saturation values are within the specified tolerance:

TB500B Settings Board Parameters

Saturation

100

82

Attenuation

3

3

Saturation

98 - 100

80 - 84

Pulse Rate

60 ± 1

60 ± 1

62

72

92

3

7

7

60 - 64

68 - 76

88 - 96

60 ± 1

60 ± 1

60 ± 1

14.3.16

14.3.17

14.3.18

14.3.19

Note: Verify a visual (alert bar flashing) and audible alert condition occurs when the saturation is set to 82. Press and hold the audio alert key. Verify the audio off LED turns on and the audible alert is silenced.

Change the TB500B power switch to OFF. Verify an

Insufficient

Light

error message is displayed.

Change the TB500B power switch to ON. Verify the error message clears and a saturation and pulse value are displayed.

Set the TB500B Signal Attenuation to “1”. Verify a

Probe Off

Patient

message is displayed.

Set the TB500B Signal Attenuation to “3”. Verify the error message clears and a saturation and pulse value are displayed.

62


Safety Testing

PRELIMINARY

14.3.20

14.3.21

14.3.22

14.3.23

14.3.24

14.3.25

14.3.26

14.3.27

14.3.28

Set the TB500B Saturation to “0”. Verify a

Low Signal Strength message is displayed.

Set the TB500B Saturation to “100”. Verify the error message clears and a saturation and pulse value are displayed.

Press the TB500B Red Open button. Verify a

Probe Faulty

message is displayed.

Release the Red Open button. Verify the error message clears and a saturation and pulse value are displayed.

Press the TB500B Infrared Open button. Verify a

Probe Faulty message is displayed.

Release the Infrared Open button. Verify the error message clears and a saturation and pulse value are displayed.

Disconnect the TB500B from the saturation input connector. Verify a

Connect SPO2 Probe message is displayed.

Set the current time / date. Press and hold the Menu softkey. Press the

Next softkey until

Monitor Options 2

appears. Press the Clock softkey. Use the appropriate softkeys to set the correct Time, Mins, Day,

Month and Year.

Set the mains switch from“|” to “O”, verify the green LED on the front panel goes out. Verify that the monitor continues to function on battery power without interruption. Power down the monitor by pressing the power button.

Safety Testing

14.4.1

14.4.2

14.4.3

14.4.4

14.4

Apply 1.5 KV for 60 seconds between the shorted hot and neutral leads of the power cord and chassis ground.

Apply 4 KV for 60 seconds between the shorted hot and neutral leads of the power cord and shorted saturation test jack.

Apply 1.5 KV for 60 seconds between the shorted saturation test jack and the chassis.

Measure the leakage from chassis gnd. to ref. gnd. with the monitor;

-grounded

-ungrounded

-polarities reversed ungrounded

With the monitor grounded measure the leakage from shorted probe to

120VAC 60Hz


63

Section 14

Calibration Tests

PRELIMINARY


64


5-Jun-01

PRELIMINARY

15

Connecting to other Equipment

The Model 520A Pulse Oximeter communicates with external equipment via its rear panel (25 pin D style female) connector. The monitor can be connected to

RS232 compatible (digital) equipment. If the optional Analog Output Module is connected, the monitor can output to analog devices such as strip chart recorders.

Refer to the Model 520A Pulse Oximeter User’s Manual (Catalog No. 5693-23) for further information on the RS232 and analog outputs listed below.

Connecting the Seiko DPU-414 Thermal Printer

15.1

To connect a Seiko DPU-414 Thermal Printer (PN: 9140-00) to the OXYPLETH:

1. Connect the 9085-00 interface cable to the monitor‘s RS232 connector and to the printer’s serial input connector—the 9 pin D connector.

2. Connect the AC adapter and turn the printer on.

Configuring the Seiko DPU-414 Printer

15.1.1

The Seiko DPU-414 Thermal Printer (Cat. No. 9140-00) must be configured to communicate with the OXYPLETH. When properly configured, the Seiko printer will retain the settings, even when turned off.

1. Slide the printer’s power switch to OFF “O”.

2. Press and hold the ON LINE button, then slide the power switch ON “|”.

Release the ON LINE button after the list of current settings starts printing out.

Setting the DIP switches:

1. The printout of the current settings is followed by the prompt:

15.1.2

“Continue? : Push On-line SW”

“Write? : Push Paper feed SW”

To change the DIP switch settings, push the ON LINE button (to leave the

DIP switch settings unchanged, push the FEED button).


65

Section 15

Connecting to other Equipment

PRELIMINARY

2. “DIP SW-1” will print. Enter the new settings for switches 1-8.

“ON” is set by pushing the ON LINE button once

“OFF” is set by pushing the FEED button once

The printer will confirm each selection. Repeat for DIP SW 2 and 3.

The DIP switch settings for the Model 520A are as follows:

[ DIP SW settings mode ]

Dip SW-1

1 (OFF) : Input = Serial

2 (ON ) : Printing Speed = High

3 (ON ) : Auto Loading = ON

4 (OFF) : Auto LF = OFF

5 (ON ) : Setting Command = Enable

6 (OFF) : Printing

7 (ON ) : Density

8 (ON ) : = 100 %

Dip SW-2

1 (ON ) : Printing Columns = 40

2 (ON ) : User Font Back-up = ON

3 (ON ) : Character Select = Normal

4 (ON ) : Zero = Normal

5 (ON ) : International

6 (ON ) : Character

7 (ON ) : Set

8 (OFF) : = U.S.A.

Dip SW-3

1 (ON ) : Data Length = 8 bits

2 (ON ) : Data Parity = No

3 (ON ) : Parity Condition = Odd

4 (ON ) : Busy Control = H/W Busy

5 (OFF) : Baud

6 (ON ) : Rate

7 (ON ) : Select

8 (ON ) : = 9600 bps

Continue ? : Push ‘On-line SW’

Write ? : Push ‘Paper feed SW’

CAUTION:

DIP SW Set Mode cannot be cancelled once it is initiated. Answer “ON” or

“OFF” for every setting.

Note: More information about DIP switch settings can be found in the Seiko “DPU-

414 Thermal Printer Operation Manual.”

3. When the printer finishes writing the new settings to memory, “DIP SW setting complete!!” is printed out and the printer returns to ON LINE mode.

CAUTION:

Never turn the printer off while it is writing the new settings to memory.

Wait until “DIP SW setting complete!!” is printed, then the printer power may be turned off.

66


Connecting the ThinkJet Printer

PRELIMINARY

Connecting the ThinkJet Printer

15.2

To connect the Hewlett-Packard ThinkJet Printer to the Model 520A:

1. The Hewlett-Packard ThinkJet must be a Model 2225D (RS-232C interface).

2. Set the dip switches on the rear panel of the ThinkJet.

Mode switches = 1, 2, 5, 6 up (on) and 3, 4, 7, 8 down (off).

RS-232C switches = 1 up (on) and 2, 3, 4, 5 down (off).

DIP SWITCHES

MODE RS-232C

1 2 3 4 5 6 7 8 1 2 3 4 5

MODEL 520A REAR PANEL

MODEL 2225D ThinkJet PRINTER

AC POWER

POWER SWITCH

5331-00 CABLE

RS232-C INTERFACE

CONNECTOR

Figure 13. Connecting the ThinkJet Printer

3. Connect the interface cable, PN:5331-00, to the Model 520A RS232C connector and to the ThinkJet. (If Model 520A has an Analog Module attached, connect to the module’s RS232C connector.)

4. Connect the printer’s AC input and turn the printer on.

5. Select

T-Jet

(ThinkJet) from the

Ser.

(Serial) portion of the Model 520A

Options Menu.

6. Refer to the ThinkJet Owner’s Manual for further printer details.

Connecting the Model 315 Printer

To connect the Model 315 Printer to the Model 520A:

1. Set the dip switches on the Model 315 rear panel.

The settings are; 1-5 up (off), 6-7 down (on), and 8 up (off).

15.3


67

Section 15


PRELIMINARY

2. Connect the printer interface cable, PN:4913-00, to the RS232C connector

1 on the Model 520A. Connect the other end of the cable to the Model 315.

DIP SWITCHES

MODEL 520A REAR PANEL

1 2 3 4 5 6 7 8

MODEL 315 REAR PANEL

RS232-C INTERFACE

CONNECTOR

4913-00 CABLE

AC ADAPTER

POWER SWITCH

Figure 14. Connecting the Model 315 Printer

3. Connect the printer’s AC adapter (if desired).

4. Turn the printer on first, then turn the Model 520A on.

5. Select

315

from the

Ser.

(Serial) portion of the Model 520A Options Menu.

6. Refer to the Model 315 documentation for further printer details.

Connecting Seiko DPU-411 Thermal Printer

15.4

To connect the SIEKO Model DPU-411 Thermal Printer to the Model 520A:

1. Set the DIP switches located on the bottom of the DPU-411.

First bank of eight switches; 1,2 down (off), 3,4 up (on), 5,6 down (off), 7,8 up (on).

Second bank of six switches; 1-3 up (on), 4-6 down (off).

68


Seiko DPU-411 bottom view

Figure 15. Configuration of Seiko Thermal Printer.

5693-90-01

PRELIMINARY

Analog Output Module

2. Connect the printer interface cable, PN:5861-00, to the RS232C connector on the Model 520A. Connect the 25 pin connector at the other end to the 25 pin

D connector on the rear panel of the DPU-411 (upper connector).

Plug the cable DC power plug into the rear jack of the Model DPU-411.

Seiko Model DPU-411

Model 520A

INTERFACE CABLE PN:5861-00

DC POWER PLUG

(part of 5861-00 cable)

Figure 16. Connecting the Seiko Model DPU-411 Printer.

3. Turn the printer on first, then turn the Model 520A on.

4. Select

Seiko

from the

Ser.

(Serial) portion of the Model 520A Monitor

Options 2 Menu.

5. Refer to the Seiko Model DPU-411 documentation for further printer details.

Analog Output Module

15.5

The optional Analog Output Module (Catalog Number 9622-01), provides the necessary analog output voltages for use with analog instruments such as strip chart recorders. (The Model 520A does not directly support analog devices.)

The Analog Output Module attaches to the connector on the rear panel of the Model

520A and provides analog output voltages, via a 9-pin connector, and RS232C pass through, via a 25-pin connector, so that both analog and serial devices can be used simultaneously.

Two screws, supplied with the module, are passed through the module and screw into the pre-tapped holes in the rear panel of the Model 520A to secure the Analog


69

Section 15


PRELIMINARY

SAT

5

9

Figure 17. Analog Output Module

Output Module in place. The pinouts of the 9-pin analog and 25-pin RS232C connector are shown below.

GNDI

PR

1

6

Pin 1

Pin 2-3

Pin 4-5

Pin 8-9

Pulse Rate, 4mV/bpm, 0-1V

GNDI (Interface ground)

Saturation, 10mV/%, 0-1V

Plethysmogram, 0-1V

(Auto Gain Control)

PLETH CTS

GNDI

TX

RX

13

25

VDI

GNDI

DTR

1

14

Pin 2

Pin 3

Pin 6

Pin 7

Pin 20

Pin 21-22

Pin 24-25

RX (Receive In)

TX (Transmit Out)

CTS (Clear To Send (input))


DTR (Data Transmit Ready

(output))


VDI (Interface +5 volts)

Figure 18. Analog Output Module Pinouts

Analog Output Setup

15.6

A

CALIBRATE RECORDER

menu within the Model 520A software allows the user to easily calibrate analog recorders to the voltage levels produced by the Analog

Output Module. To access this feature:

1. With the monitor in normal running mode press and hold the

MENU

key until

SPO2 SETUP OPTIONS

appears on the display. Press the

NEXT

key until

70


PRELIMINARY

Analog Output Setup

MONITOR OPTIONS 2

appears on the display. Select

REC

for

CALIBRATE

RECORDER

menu.

5-Jun-01

Press and hold for 5 seconds while in normal running mode

Figure 19. Analog Output Setup

2. The Recorder Outputs menu will be displayed.

CALIBRATE RECORDER

RUN

ZERO

HALF FULL PREV

• RUN

- return to Monitoring Mode

• ZERO

- set analog outputs to 0 volts

(0% = 0 volts, 0 bpm = 0 volts, pleth = 0 volts)

• HALF

- set analog output voltages to half scale

(50% = 0.50 volts, 125 bpm = 0.50 volts, pleth = 0.50 volts)

• FULL

- set analog output voltages to full scale

(100% = 1.00 volt, 250 bpm =1.00 volts, pleth =1.00 volts)

• PREV

- returns to

MONITOR OPTIONS 2

menu.

3. Press the

ZERO

key and adjust the analog baselines on the recorder. Press the

FULL

key and adjust the recorder full scale deflection. Press the

HALF

key and check that the recorder registers at half scale.

Signal

Pulse Rate

Saturation

Plethysmogram

Analog

Connector

Pin #

1

4 + 5

8 + 9

Min-Max Voltages

(Referenced to Pins 2 + 3)

ZERO HALF FULL

0.000-0.012 0.477-0.520 0.955-1.030

0.000-0.012 0.477-0.520 0.955-1.030

0.000-0.012 0.477-0.520 0.955-1.030

Table 4. Analog Output Module Voltage Tolerances

Note: Earlier versions of the Analog Output Module have a 2.5 volt maximum scale for the Plethysmogram and Pulse Rate (1.25 volt half scale).


71

Section 15


PRELIMINARY

4. When the recorder is properly adjusted, press the

RUN

key. The monitor will return to Monitoring Mode and automatically begin outputting analog data to the Analog Output Module.

Note: This setup procedure does not have to be performed each time the monitor is turned on—the monitor will always automatically output analog information via the Analog Output Module, this procedure simply helps to calibrate the recorder to the Model 520A signals.

72


5-Jun-01

PRELIMINARY

16

Specifications

General

16.1

Specifications for the Novametrix OXYPLETH Pulse Oximeter, Model 520A, are listed for informational purposes only, and are subject to change without notice.

Oxygen Saturation (SpO

2

) Section

• Range, 0-100%

• Accuracy, 80-100%

± 2%, 0-79% unspecified

(Approximately 68% of the observations are within the accuracy claim.)

16.2

• Display Resolution, 1%

• Averaging Time, menu selectable times of 2 and 8 seconds

• Audible SpO

2

Trend Feature

Pitch of (user selectable) Pulse Rate “beep” tracks the SpO

2

value (i.e., decreasing SpO

2

values are signalled by lower pitched “beeps”).

• Settling Time

Display settles to within 1% of the final reading less than 15 seconds after the sensor is properly applied.

• Alerts

Continuously displayed. Menu selectable high and low limits (100-50). Visible alarm is immediate. Audible alarm occurs after 10 seconds of continuous violation of the set limit, or immediately. Limit values are retained in memory when monitor is turned off, or the monitor can be set to use its default settings each time it is turned on.

Pulse Rate Section

16.3

• Range, 30-250 beats per minute (bpm)

• Accuracy

, ± 1% of full scale

(Approximately 68% of the observations are within the accuracy claim.)

• Display Resolution, 1 bpm

• Averaging Time, fixed at 8 seconds

• Settling Time

Display settles to within 1% of the final reading less than 15 seconds after the sensor is properly applied.


73

Section 16

Specifications

PRELIMINARY

• Alerts

Continuously displayed. Menu selectable high and low limits (249-30 or Off).

Visible alarm is immediate. Audible alarm occurs after 10 seconds of continuous violation of the set limit or immediately. Limit values are retained in memory when monitor is turned off, or the monitor can be set to use its default settings each time it is turned on.

General Specifications

16.4

• Operating Environment

50-104

° F (10-40 °C), 0-90% relative humidity (non-condensing)

• Weight, 7 lbs 5 oz. (3.32 kg)

• Dimensions

Height, 3.3 inches (8.38 cm) Width, 9 inches (22.86 cm) Depth, 8 inches (20.32

cm)

• Power, 100-120/200-240 VAC, 50/60 Hz

• Fuse Rating

U.S.A.: 0.5 A, 250 V, Slo-Blo (x2) European: T 250 mA/250 V (x2)

• Battery

Type, lead-acid gel-cell Battery Life, 3 hours

(Note: Excessive alerting reduces battery life.) When 15 minutes of battery life remain, the (low battery) indicator illuminates. When the battery becomes exhausted, the monitor display shuts down. Connect to AC power to recharge battery. Recharge Time, battery fully recharged in 12-15 hours max.

Additional Features

16.5

• 2 Minute Silence

When

AUDIO

key is pressed, deactivates audible alerts for two minutes.

Indicated by illuminated (2 Min LED).

• Audio Off

Feature user selectable. If enabled, press and hold

AUDIO

key for 3 seconds, and audible alarms will not activate.

Indicated by flashing (OFF LED).

• Battery Backed Trend Memory

Trend memory print of any 30 minutes, 2 hours, 8 hours 12 hours or 24 hours when used with the Seiko DPU-414, Seiko DPU-411, Hewlett-Packard

ThinkJet, or Model 315 Printer.

• Analog (Recorder) Output Module—Optional

Provides analog output for strip chart applications at the following levels;

Oxygen Saturation value, 10mV/% (100% = 1 V)

Pulse Rate value, 4mV/bpm (250 bpm = 1 V)

Plethysmograph pulse waveform, 0-1V max (AGC)

74


PRELIMINARY

• Serial (RS232) Data Output

Provides RS232 data interface compatible with;

Seiko DPU-414 Thermal Printer

Seiko DPU-411 Thermal Printer

Hewlett-Packard ThinkJet Printer

Novametrix Model 315 Printer

Novametrix Model 1260 Capnograph

Novametrix Model 1010 Telemetry Central Station

SARACAP

 monitor

RS232 computer interface

NOVACARD Memory Module

NOVACOM1 Interface

• Internal Real Time Clock

• Alert Bar

Additional Features


75

PRELIMINARY

17

Accessories

Model 520A

Catalog No.

Description

SuperBright™ SpO

2

SENSORS

8793-00

OxySnap™ Y-Sensor™

(use with OxySnap™ Extension Cable), 90 day warranty

8744-00

OxySnap™ Finger Sensor

(use with OxySnap™ Extension Cable), 1 yr. warranty

8853-00

OxySnap™ Extension Cable

(use with OxySnap™ sensors), 8 feet, 1 yr. warranty

8898-00

OxySnap™ Extension Cable

(use with OxySnap™ sensors), 12 feet, 1 yr. warranty

8776-00

SuperBright™ Finger Sensor

(10 ft sensor cable), 1 yr. warranty

8791-00

SuperBright™ Y-Sensor™

(10 ft sensor cable), 90 day warranty

9768-00

Finger Sensor

(use with DB-9 Sensors), 6 feet, 1 yr. warranty

9168-00

Finger Sensor

(use with DB-9 Sensors), 3 feet, 1 yr. warranty

9769-00

Y-Sensor™

(use with DB-9 Sensors), 6 feet, 90 day warranty

9169-00

Y-Sensor™

(use with DB-9 Sensors), 3 feet, 90 day warranty

SENSOR MANAGEMENT PLANS

Select a Finger Sensor or Y-Sensor™ Management Plan for each SuperBright™ Pulse Oximeter.

The plan you select determines the length of coverage—36 or 60 months.

How the Plans Work: Included in each Plan are TWO sensors—one for immediate use, the other one for back-up. If a sensor becomes inoperative, place the backup sensor into use and return the inoperative sensor in the convenient prepaid mailer. A replacement sensor will be shipped within two business days of receipt of the inoperative sensor. This simple return/replacement method will be used for the entire warranty period, thereby, guaranteeing your costs and virtually eliminating sensor tracking hassles.

Warranty: For each Pulse Oximeter a plan is purchased for, the warranty on the monitor is also extended to the length of the Plan (a pre-contract inspection may be required). Replacement sensors provided under terms of the Plan shall carry the remaining Plan warranty—replacements do not extend the warranty.

8791-36 Y-36 Plan The Plan length is 36 months. Includes 9 boxes of any Y-Strip Taping Systems

17.1

76


Model 520A

PRELIMINARY

Catalog No.

Description

8791-60 Y-60 Plan The Plan length is 60 months. Includes 15 boxes of any Y-Strip Taping Systems

8776-36 Finger-36 Plan The Plan length is 36 months

8776-60 Finger-60 Plan The Plan length is 60 months

Y-SENSOR™ APPLICATORS

8828-00 20mm Wrap Style Taping System (100 per box)

Use on neonatal foot and hand, or on pediatric toe or finger, color coded blue

8829-00 25mm Wrap Style Taping System (100 per box)

Use on neonatal foot and hand, color coded green

8831-00 20mm Finger Style Taping System (100 per box)

Use on pediatric finger or on small adult finger, color coded blue

8832-00 25mm Finger Style Taping System (100 per box)

Use on adult finger, color coded green

6929-00 Adhesive Foam Wraps, Large (25 per box)

6968-00 Adhesive Foam Wraps, Small (25 per box)

8836-00 Non-Adhesive Foam Wraps, Large (25 per box)

8943-00 Non-Adhesive Foam Wraps, Small (25 per box)

6131-50 Ear Clips (5 per box)

6131-25 Ear Clips (25 per box)

8700-00 Adhesive Dots (200 per box)

OUTPUT OPTIONS—ANALOG, DIGITAL & PRINTER

5963-00 Analog Output Module, for Model 2001

9622-01 Analog Output Module, for OXYPLETH

®

, includes RS232 pass-thru

6045-00 Cable, for 5963-00 Analog Output Module (open ended, 6 ft)

5333-00 Cable, for 9622-00 Analog Output Module (open ended, 6 ft)

2736-00 Analog/RS232 Output Option Kit for Model 515B (if ordered at time of purchase)

6659-00 Cable, for 2736-00 Analog Output Option Kit (open ended, 6 ft)


77

Section 17

Accessories

PRELIMINARY

Catalog No.

Description

5334-00 Cable,

Serial Output to Personal Computer

(PC with 25-pin connector)

5335-00 Cable,

Serial Output to Personal Computer

(PC with 9-pin connector)

5726-00 Cable,

Analog Output Module (9622-01) to Aequitron 9500 Series

Monitor

9140-00 Thermal Printer, Seiko DPU-414 (with battery pack)

400052 AC Adapter, for Seiko DPU-414 Printer, 120

VAC

300017 Printer Paper, for Seiko DPU-411/414 Printer (2 rolls per box)

9085-00 Printer Cable, for Seiko DPU-414 Printer, 9-to-25 pin (Models 515B/520A/

860/1265/7100/2001)

PULSE OXIMETRY ACCESSORIES

420034 Model 515B/C Inservice Video, VHS video tape (NTSC format)

420016

OXYPLETH

®

Model 520A Inservice Video, VHS video tape (NTSC format)

7106-10 Transport Pouch, for Models 515/520A/860/1265/7100/2001

7104-10 Side Accessory Pouch, (included with monitor)

600026 Power Cord, (included with monitor)

4941-00 Saturation Sensor Extension Cable (4 feet)





6455-00 Single Patient Use Pediatric/Adult Sensor (10 per box)

6455-25 Single Patient Use Pediatric/Adult Sensor (25 per box)

6480-00 Single Patient Use Neonatal/Pediatric Sensor

(10 per box)

6480-25 Single Patient Use Neonatal/Pediatric Sensor

(25 per box)

8933-00 Sensor Extension Cable, for use with Single Patient Use Sensors (DB-9 connectors)

8936-00 Sensor Jumper Cable, for use with Single Patient Use Sensors

(DB9 to OxySnap™ connector)

EXTENDED WARRANTY

Normal warranty: Monitor—1 year

9400-81

Model 2001 warranty extended an additional 1 year(s) at time of purchase

5693-81

OXYPLETH

®

warranty extended an additional 1 year(s) at time of purchase

6500-81

Model 515B warranty extended an additional 1 year(s) at time of purchase

6550-81

Model 515C warranty extended an additional 1 year(s) at time of purchase

BIOMEDICAL EQUIPMENT & TRAINING

78


Model 520A

PRELIMINARY

Catalog No.

Description

Service Test Kits include items and materials qualified service personnel may require to determine the functional integrity and/or accuracy of the system.

5777-00 Test Kit, Pulse Oximeter

9999-96 “focus” Technical Training Seminar (1 day course)

For class schedules call: 1-800-243-3444 Ext. 2565

MOUNTING SYSTEMS

ROLLSTAND

140098 Rollstand, includes base, casters, tilt swivel head, post, poll, handle, utility basket. Requires either 140095 or

140101 Mounting Plate Kit.

ROLLSTAND AND MOUNTING ACCESSORIES

140095 Adapter Plate Kit, for 515B/C, 520A, 2001, 1265/7100, 860, and CO

2

SMO Plus!

®

140099

Laptop Tray with Adapter Plate

140030

Wall Mount

140031 Wall Mount (less Wall Channel)

140032

Pivot Block Mount

140036 Countertop Mount (5 inch Base)

140100

Swivel C-Clamp Hanger

140067

Clamping Block

140068 Counterweight, for Rollstand

140070 Pole Mount Bracket, (for 2” pole), for Models 515B/C, 520A, 2001, 1265/7100, 860, and CO

2

SMO Plus!

®

140093 Mounting Plate Upgrade Kit, contains Mounting Plate Only

140094 Pole Mount, (for 3/4” - 2” dia. pole), for Models 515B/C, 520A, 2001, 1265/7100, 860, and CO

2

SMO Plus!

®

140097 6” Utility Basket, for Rollstand


79

Section 17

Accessories

PRELIMINARY


80


PRELIMINARY

18

Parts Lists

Family Tree

18.1

The Model 520A diagram below shows the individual assemblies of the finished product— the 5693-00 Final Assembly.

5765 TOP COVER ASSY

2471/2775 MAIN BD ASSY

5-Jun-01

5673/6538 REAR PANEL ASS

2473 ALERT BD ASSY

5720 DISPLAY ASSY

5714 BATTERY HARNESS ASSY

5713 SPEAKER ASSY

5766 BOTTOM COVER ASSY

5719 FRONT PANEL ASSY

5728 SPO2 INPUT ASSY

5693-01 MAIN ASSEMBLY

013

005

007

014

140002

5713-01

5719-01

161067

Description

CARD GUIDE, 2.5” L

SPEAKER ASSY

FRONT PANEL ASSY

TAPE, CL CELL

Qty

1

0

2

1

18.2


81

Section 18

Parts Lists

PRELIMINARY

016

006

015

018

009

001

010

008

001

012

017

003

002

5766-01

5728-01

2471-01

9621-16

286220

6538-01

5664-10

286205

5714-01

284200

400024

5765-01

2775-01

Description

BOTTOM COVER ASSY

CABLE ASSY, SPO2 IN

MAIN BOARD ASSY,

LENS, ALERT

SCREW, 6-32 X 3/16

REAR PANEL ASSY

CHASSIS, MODEL 520A

6-32 x 3/4 S.B.H.

BATTERY HARNESS ASSY

#4-40 x 1/4 SLOTTED

BATTERY, 12VDC, 2.3A

TOP COVER ASSY

MAIN BOARD ASSY

6538-01 REAR PANEL ASSY

017

022

013

011

014

004

012

023

021

020

008

016

015

002

024

006

001

007

018

019

003

6538-17

285001

285005

5812-10

4109-10

161092

9090-01

2726-01

280188

5820-01

210149

285013

285000

608033

216059

161008

515023

286219

6549-01

281501

281500

Description

REAR PANEL SUBASSY

LOCK WASHER, NO. 6

FLAT WASHER, NO. 8

SPACER, SUPPORT

SUPPORT BRACKET, PC

ADHESIVE, 262

POWER CABLE ASSY

POWER SUPPLY BD ASSY

STANDOFF, 3/8 DIA

GROUND WIRE ASSY

POWER ENTRY MODULE,

NYL WASH, #4 NATURAL

LOCK WASHER, NO. 4

WIRE CLIP & BUSHING

CONNECTOR, PLUG

ADHESIVE, 242

FUSE, 1/2A, 250V

SCREW, 6-32 X 1 1/4

GROUND WIRE ASSY

NUT, HEX, NO. 6-32

NUT, HEX, NO. 4-40

5673-01 REAR PANEL ASSY

016

007

002

019

022

285001

5812-10

4109-10

5819-01

285046

Description

LOCK WASHER, NO. 6

SPACER, SUPPORT

SUPPORT BRACKET

GROUND WIRE ASSY

WASHER, FLAT, NO. 6

82


Qty

0

2

1

1

0

Qty

0

1

0

1

1

1

1

1

1

0

1

1

1

Qty

1

0

0

1

1

0

0

1

1

0

2

0

0

1

1

1

0

0

2

1

0

18.3

18.4

5693-90-01

2726-01 POWER SUPPLY BD ASSY

PRELIMINARY

018

004

012

001

014

011

023

008

021

005

006

013

020

003

017

015

5673-32

5743-10

280188

5820-01

5229-11

285013

285000

216059

161008

9308-11

515023

286219

5673-10

281501

2472-01

281500

Description

REAR FACEPLATE

POWER ENTRY MODULE

STANDOFF, 3/8 DIA

GROUND WIRE ASSY

WIRE CLIP MOD

NYL WASH, #4 NATURAL

LOCK WASHER, NO. 4

CONNECTOR, PLUG

ADHESIVE, 242

BUSHING MOD, LINECORD

FUSE, 1/2A, 250V

SCREW, 6-32 X 1 1/4

REAR PANEL

NUT, HEX, NO. 6-32

POWER SUPPLY BOARD

NUT, HEX, NO. 4-40

2726-01 POWER SUPPLY BD ASSY

Item Nbr

486805

2725-02

515085

474141

2726-04

600034

474181

474166

474216

485543

211213

481552

154072

211505

474145

481530

474214

474137

481549

152096

484529

180014

474165

152081

474162

5918-10

470026

474215

Seq

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

Description

CONNECTOR, 5 PIN

RESISTOR, 215 OHM

DIODE, KBU4G, 4 AMP

RESISTOR, 332K OHM

RESISTOR, 1M OHM

DIODE, MBRS14OT3

CAPACITOR, 220UF

VOLTAGE REGULATOR

INDUCTOR, 2SUH

RESISTOR, 10K OHM

CAPACITOR, 6BOOUF

RESISTOR, 61.9K OHM

XFMR, MAINS, PWR SPL

RESISTOR, 150 OHM

RESISTOR, 2.21K OHM

IC, LM393M, DUAL VOL

RAE, POWER SUPPLY BD

FUSE W FUSEHOLDER

RESISTOR, 249K OHM

TEST PROCEDURE, PWR

RIBBON CABLE ASSY

RESISTOR, 4.3 OHM

RESISTOR, lOOK OHM

RESISTOR, 4.99K OHM

TRANSISTOR, MOSFET

CONNECTOR, 2 PIN

DIODE, MBRS34OT3

CAPACITOR, .1UF

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

3

1

1

4

1

4

0

1

Qty

1

18.5

Qty

0

1

0

1

0

2

2

1

0

0

0

1

1

1

1

0


83

Section 18

Parts Lists

PRELIMINARY

Seq

000

000

000

000

000

000

000

000

000

000

000

000

000

Item Nbr

474151

484559

515083

2726-17

154079

474218

280114

152029

485532

474211

481561

474341

481563

Description

RESISTOR, 37.4K OHM

VOLT RGLR, LT1O76CT

FUSE W FUSEHOLDER

POWER SUPPLY BOARD

CAP, 1OUF, 2EV, 20%,

RESISTOR, 47.5K OHM

SNAP RIVET, .118

CAPACITOR, 220UF 20%

TRANSISTOR, 2N7002T1

RESISTOR, 49.9K OHM

DIODE, ULTRAFAST, 3A

RESISTOR, 4.3 OHM

DIODE, SCHOTTKY, 5A

022

019

038

031

026

042

021

018

043

030

039

033

004

017

023

012

037

041

034

028

035

014

027

032

040

020

044

024

016

036

001

481541

5918-10

470026

472058

472005

600034

474181

486716

472049

472016

485527

481022

472146

515503

472030

472185

484529

180014

472140

152081

485517

515035

481542

472065

211505

484539

2472-02

481530

515046

472022

161049

2472- 01 POWER SUPPLY BOARD

Description

RESISTOR, 200K OHM

CONNECTOR, 5 PIN

VOLTAGE REGULATOR

FAB, POWER SUPPLY BD

DIODE, KBU4G, 4 AMP

FUSE, 2A, 250V

RESISTOR, 4.99K OHM

ADHESIVE, HOT MELT

RESISTOR, 61.9K OHM

VOLTAGE REGULATOR

INDUCTOR, 25UH, .25

RESISTOR, 332K OHM

CAPACITOR, 6800UF

TRANSISTOR, VN1OKM

FUSE, 1/2A, 250V

DIODE, UF5400

DIODE, 100V, 1A

XFMR, MAINS, PWR SPL

RESISTOR, 150 OHM

RESISTOR, lOOK OHM

RESISTOR, 249 OHM

RIBBON CABLE ASSY

RESISTOR, 4.3 OHM

LM393N DUAL COMPARATOR

RESISTOR, 49.9K OHM

RESISTOR, 2.21K OHM

MOSFET, IRF9523

DIODE, ZENER, BZY88C

RESISTOR, 47.5K OHM

FUSE HOLDER, FOR 5MM

RESISTOR, 10K OHM

84


Qty

1

1

1

1

1

2

1

0

1

1

1

1

1

Qty

1

4

1

1

1

1

1

1

1

1

1

1

3

1

1

1

2

1

1

1

1

1

1

1

0

1

1

1

1

1

1

18.6

5693-90-01

PRELIMINARY

015

013

011

025

029

211213

154016

152029

472109

472270

Description

CONNECTOR, 2 PIN

CAPACITOR, .1UF

CAPACITOR, 220UF

RESISTOR, 37.4K OHM

RESISTOR, 1.2M OHM

5719-01 FRONT PANEL ASSY

002

008

007

004

009

006

003

001

010

280033

5720-01

2473-01

285000

5676-27

284200

280187

6278-10

284204

Description

SPACER *4 X 1/8

DISPLAY ASSY

ALERT BOARD ASSY

LOCK WASHER, NO. 4

MEMBRANE KEYPANEL

*4-40 X 1/4 SLOTTED

STANDOFF, .187 DIA

SHIELD, VFD

*4-40 X 1/2 SLOTTED

2473-01 ALERT BOARD ASSY

006

005

007

001

482565

470024

600038

2473-02

Description

LED, CLEAR, ROUND

RESISTOR, 100 OHM

RIBBON CABLE ASSY

FAB, ALERT BOARD

5720- 01 DISPLAY ASSY

001

002

482573

600033

Description

LCD MODULE, DOT MATRIX

RIBBON CABLE ASSY

5713-01 SPEAKER ASSY

001

002

005

004

003

130010

211225

5855-10

608003

605060

Description

SPEAKER, 8 OHM 15%,

CONNECTOR, 2 PIN

FOAM LINER

TUBING, HEAT SHRINK

WIRE, 26AWG, PVC INS

5714-01 BATTERY HARNESS ASSY

004 605163

Description

WIRE, 22AWG, BLACK

5719-01 FRONT PANEL ASSY

Qty

1

5

1

1

1

18.7

Qty

0

1

1

0

0

1

0

0

1

18.8

Qty

4

2

1

1

18.9

Qty

1

1

18.10

Qty

1

1

1

0

0

Qty

0

18.11


85

Section 18

Parts Lists

PRELIMINARY

001

002

005

003

211215

216068

608001

605162

Description

CONNECTOR, 2 PIN

TERMINAL LUG, RECEPT

CABLE TIE

WIRE, 22AWG, RED

5728-01 CABLE ASSY

Item Nbr

211704

605063

608005

210098

605059

280108

5606-16

608001

605061

180009

605065

605064

161060

211630

605060

608011

161110

9779-33

Seq

012

002

005

009

014

010

003

013

004

011

015

006

008

007

001

016

002

017

Description

CONNECTOR, RCPT


TUBING, HEAT SHRINK

CONTACT, FEMALE


SNAP RIVET

DRESS BEZEL, SAO2 IN

CABLE TIE

WIRE, 2EAWG, PVC INS

FERRITE SLEEVE



EPOXY, 2 PART (5/7)

CONNECTOR, 6 PIN


TUBING, HEAT SHRINK

EPOXY, 2 PART (1/1)

ASSY PROC, EPOXY MIX

5765-01 TOP COVER ASSY

Seq

005

001

002

004

003

Item Nbr

5862-10

5765-13

5827-32

5823-32

5828-32

Description

SHIELD, MYLAR

TOP COVER

WARNING LABEL

LABEL, INSTRUCTIONS

LABEL, ISOLATION

5766-01 BOTTOM COVER ASSY

003

015

011

012

016

010

009

005

161007

284261

4727-10

5826-10

5766-13

284264

161064

5405-10

Description

ADHESIVE

SCREW, 4-40 X 5/8 L

KICKSTAND, BEDRAIL

FOOT PAD

BOTTOM COVER

SCREW, 4-40 X 1/4 L

TAPE, 3/4 X 60 YDS

SHIELD, BATTERY

86


Qty

0

1

1

0

1

4

0

0

Qty

1

1

1

1

1

Qty

1

0

0

0

Qty

1

0

0

0

1

0

0

0

0

0

0

0

1

0

0

1

0

0

18.12

18.13

18.14

5693-90-01

2755-01 TONE GEN REPL BOARD

PRELIMINARY

007

008

013

002

006

5760-16

5761-16

5849-10

5409-32

315052

Description

LEFT FOOT, WHITE

RIGHT FOOT, WHITE

BRACKET, SUPPORT

LABEL, WARNING, POLE

LABEL, EARTHING SYMB

2755-01 TONE GEN REPL BOARD

003

016

019

011

013

011

010

002

014

001

017

012

022

018

023

020

474224

211814

154104

2755-03

9074-07

474235

474270

211815

486358

474241

486825

474300

474228

2755-02

474240

474197

Description

IC, NC7SZ32MS, 2-IN

RESISTOR, 150K OHM

IC, LMC7101BIM5X

RESISTOR, 402K OHM

RESISTOR, 1.21K OHM

FAB, TONE GENERATOR

RESISTOR, lOOK OHM

RESISTOR, 49.9K OHM

RESISTOR, 100 OHM

CONNECTOR, 8 PIN

CAPACITOR, .O1UF

SCHEM, TONE GEN REPL

IC, TONE GENERATOR

RESISTOR, 24.9K OHM

RESISTOR, 200K OHM

CONN, 8 PIN, HDR

2775-01 MAIN BOARD ASSY

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

472011

474089

474131

211306

180033

472255

154065

152040

472007

154081

472121

483017

474032

472041

472063

472200

487064

154058

Description

RESISTOR, 3.74K OHM

TRANSISTOR, BC214C

RESISTOR, 10 OHM

RESISTOR, 20K OHM

RESISTOR, 162K OHM

RESISTOR, 5.6 OHM

IC, CNY17-III, PHOTO

CAPACITOR, .022UF

RESISTOR, 1K OHM

RESISTOR PACK, lOOK

RESISTOR PACK, 10K

CONNECTOR, 3 PIN

EMI FILTER, 22PF

RESISTOR, 1 OHM

CAP, .1UF, 63V

CAPACITOR, 2.2UF

RESISTOR, 475 OHM

CAPACITOR, 100PF

Qty

2

2

1

1

13

Qty

1

2

1

2

4

0

1

2

3

1

1

1

1

1

1

1

18.15

18.16

Qty

5

3

1

2

6

5

1

1

5

2

4

1

1

1

1

2

1

4


87

Section 18

Parts Lists

PRELIMINARY

472227

285000

474134

486299

472170

474132

472276

470016

472268

5833-01

472003

472146

152072

472246

472198

474098

472021

210144

153003

472193

481541

475034

483002

472058

154060

481501

472274

472105

470109

481534

2471-28

154016

216029

152045

153052

152073

280023

153021

472195

180011

153027

472030

474133

474086

472034

153063

152075

474138

000

000

000

000

000

000

000

000

000

000

000

000

000

009

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

007

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

Description

RESISTOR, 4.75K OHM

JUMPER, 2 POSITION

CAPACITOR, .O1UF

RESISTOR, 23.7K OHM

DIODE, bOy, 1A

POTENTIOMETER, 2K OHM

2N3906 PNP SILICON

RESISTOR, lOOK OHM

CAPACITOR, .22UF,

DIODE, 1N4148, SIGNAL

RESISTOR, 26.7 OHM

RESISTOR, 3.92K OHM

RESISTOR, 470K OHM

DIODE, BAT82, SCHOTT

MAIN BD KIT

RESISTOR, 47 OHM

LOCK WASHER, NO. 4

RESISTOR PACK, 41K

IC, CS5SO3JP, 20-BIT

RESISTOR, 22.1K OHM

RESISTOR PACK, 41K

RESISTOR, 6.49K OHM

RESISTOR, 22 OHM

RESISTOR, 8.66K OHM

GROUND WIRE ASSY

RESISTOR, 100 OHM

RESISTOR, 47.5K OHM

CAPACITOR, 1OUF

RESISTOR, 66.5K OHM

RESISTOR, 3.3 OHM

RESISTOR PACK, lOOK

CAPACITOR, 220PF

RESISTOR, 10K OHM

RESISTOR PACK, 10 OH

RESISTOR PACK, 10K

RESISTOR, 12.1K OHM

CAPACITOR, 220PF

CAPACITOR, 47UF, 25V

RESISTOR, 100 OHM,

CAPACITOR, .1UF

TEST POINT, SPRING

CAPACITOR, 1OUF 16V

CAPACITOR, .022UF

CAPACITOR, 100UF

SPACER HEX #4-40

CAPACITOR, .47UF

RESISTOR, 41.2K OHM

FERRITE BEAD, 22 AWG

88


Qty

1

4

1

2

2

1

1

1

2

1

1

2

1

2

2

0

2

1

2

1

9

1

7

1

1

1

1

4

1

1

1

1

4

4

0

1

6

1

59

2

2

4

1

2

1

1

1

7

5693-90-01

2471-28 MAIN BD KIT (part of 2775-01)

PRELIMINARY

000

000

000

006

000

000

002

000

010

010

000

000

000

001

000

008

000

153051

474135

481031

2755-01

472037

284217

180067

215080

481050

2775-02

212136

5715A-07

211237

486845

161039

5712-10

5711-10

Description

CAPACITOR, .22UF,

RES PACK, 100 OHM

DIODE, ZENER, BZX79-

TONE GEN REPL BOARD

RESISTOR, 13.7K OHM

SCREW, 4-40 X 3/16

FERRITE BEAD, 600 uH

SOCKET, 32 PIN, PLCC

ESD SUPPRESSOR

FAB, MAIN BD

CONN, 10 PIN, HDR

PROGRAM, SPO2, 520A

CONNECTOR, 2 PIN

IC, 2.SV OR 3.OV V R

FOAM TAPE, 1/32THK

TRANSFORMER, MAIN BD


000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

000

001

000

000

000

485528

486651

471400

153006

486298

486680

9715-07

9716-07

154076

481542

215060

484533

484523

484529

487061

486300

487069

486712

152086

180012

484535

486295

484534

486625

211414

152085

515511

2471-28 MAIN BD KIT (part of 2775-01)

Description

FERRITE BEAD

VOLTAGE REGULATOR, L

IC, MM74HC4OS1N

VOLTAGE REGULATOR

MC74HC32N I.C. QUAD

CONNECTOR, 4 PIN

CAPACITOR, 1500UF

FUSEHOLDER, VERT

VOLTAGE RGLTR

VOLTAGE REGULATOR

VOLTAGE REGULATOR

IC, TBA82OM, MONOLIT

IC, TLC549IP, 8-BIT

IC, LT1O19CN8-2.5

TLO74CN QUAD F FET

CAPACITOR, 1000UF

MOSFET, N-CH

MM74HC138 I.C.

RESISTOR, lOOM OHM

CAPACITOR, 47PF, 63V

IC, MM74HC4O2ON

IC, MM74HC573AN

PROGRAM, PEEL ASSY

PROGRAM, PEEL ASSY

CAPACITOR, .O1UF

DIODE, UF5400

SOCKET, IC, 32 PLN

Qty

1

1

1

4

1

4

1

1

2

1

1

2

2

1

1

1

1

1

1

2

2

3

1

1

1

1

1

18.17

Qty

1

0

1

1

1

0

1

1

1

2

1

2

0

15

1

1

1


89

Section 18

Parts Lists

PRELIMINARY

211412

484014

486276

180004

215031

211213

211629

470111

153012

212501

486675

486685

486256

485529

154057

485527

230006

152084

230018

486268

486305

153013

153013

210097

230016

486600

484531

486285

515071

180010

153012

153046

486606

152066

485520

212529

484515

215055

515072

487065

400035

210051

180011

487053

486717

000

000

000

000

000

000

000

000

000

000

000

000

03A

000

000

000

000

000

000

003

000

000

000

000

000

000

000

000

000

002

02A

000

000

000

000

004

004

000

000

000

000

000

000

000

000

Description

CRYSTAL,3.2768MHZ

CAPACITOR, 470UF

CRYSTAL, 12.288MHZ

IC, DG444DJ, SPST

IC, MSM6242BRS, CMOS

CAPACITOR, 33PF

CAPACITOR, 33PF

CONNECTOR, 16 PIN

CRYSTAL, 32.768K HZ

IC, CD4O13B

VOLTAGE REGULATOR

IC, HD64180R1P6

FUSE, 1/1OA, 125V

INDUCTOR, 18UH

CAPACITOR, 22PF

CAPACITOR, 22PF

CONNECTOR, 20 PIN

MM74HC14N, IC,CMOS

IC, DUAL 8-BIT

IC, K6TO8O8C1D-DB7O

TRANSISTOR, VNO61OL

CAPACITOR, 470pF

MOSFET, 1RF9523

CONNECTOR, 4 PIN

NPN TRANSISTOR ZTX1O

IC, LT1O81CN

CHOKE, 100UH, 10%

SOCKET, 20 PIN, DIP

CONNECTOR, 2 PIN

CONNECTOR, 6 PIN

RESISTOR, .33 OHM

CAPACITOR, 4700PF

CD4O93BE

CAPACITOR, 220uF

TRANSISTOR, BS2SO

CONNECTOR, 20 PIN

LM317LZ REGULATOR

SOCKET, IC

FUSE, 1A, 125V

IC, UC3843N, CURRENT

IN\JERTER, DC TO AC

CONNECTOR, 25 PIN

FERRITE BEAD, 22 AWG

IC, AD712JN, DUAL BI

LF353N

90


Qty

1

3

2

2

1

1

1

1

1

1

1

7

2

1

6

1

1

4

1

1

1

1

1

1

3

1

1

1

1

2

1

1

1

1

1

2

2

1

1

1

1

1

2

1

1

5693-90-01

PRELIMINARY

152

092

080

066

090

096

063

155

001

020

070

094

056

002

058

004

149

032

150

011

057

083

009

085

064

073

130

151

067

153

082

062

086

081

077

078

138

055

088

003

117

069

079

093

008

075

2471-01 MAIN BOARD ASSY

Description

RESISTOR, 3.74K OHM

TRANSISTOR, BC214C

RESISTOR, 10 OHM

RESISTOR, 20K OHM

RESISTOR, 162K OHM

RESISTOR, 5.6 OHM

IC, CNY17-III, PHOTO

CAPACITOR, .022UF

RESISTOR, 1K OHM

RESISTOR PACK, lOOK

PROGRAM, EPROM ASSY

RESISTOR PACK, 10K

RESISTOR, 1 OHM

CAP, .1UF, 63V

IC, SN76496AN

CAPACITOR, 2.2UF

RESISTOR, 475 OHM

SCHEMATIC, MAIN BD

RESISTOR, 4.75K OHM

PROGRAM, SPO2, 520A

FAB, MAIN BOARD

CAPACITOR, .O1UF

RESISTOR, 23.7K OHM

DIODE, bOy, 1A

POTENTIOMETER, 2K

2N3906 PNP SILICON

RESISTOR, lOOK OHM

CAPACITOR, 15OPF

CAPACITOR, .22UF

DIODE, 1N4148, SIGNAL

RESISTOR, 26.7 OHM

RESISTOR, 3.92K OHM

RESISTOR, 59K OHM

DIODE, BAT82, SCHOTT

MAIN BD KIT

RESISTOR, 47 OHM

RESISTOR PACK, 41K


IC, CSS5O3JP, 20-BIT

RESISTOR, 22.1K OHM

RESISTOR PACK, 41K

RESISTOR, 6.49K OHM

RESISTOR, 22 OHM

RESISTOR, 8.66K OHM

GROUND WIRE ASSY

RESISTOR, 100 OHM

475034

483002

472058

153062

154060

481501

472274

472105

472007

2471-03

472021

5715-07

2471-02

153003

472193

481541

472011

474089

6344-07

474131

472255

154065

486255

152040

472121

483017

474032

472041

472063

472200

487064

154058

472272

481534

2471-28

472227

474134

5712-10

486299

472170

474132

472276

470016

472268

5833-01

472003

2471-01 MAIN BOARD ASSY

Qty

1

2

1

10

7

3

1

1

1

4

1

1

1

1

6

0

1

3

2

5

0

1

5

2

4

1

1

1

1

2

1

4

1

1

2

2

1

4

2

1

1

1

1

2

1

2

18.18


91

Section 18

Parts Lists

PRELIMINARY

216029

152045

153052

152073

153021

472195

153051

474135

481031

2755-01

472037

472146

152072

472246

472198

6266-57

474098

153027

472030

474133

474086

5711-10

472034

153038

152075

154016

024

071

027

089

142

012

144

015

091

154

061

060

025

016

028

059

087

145

003

068

014

076

072

010

084

148

Description

RESISTOR, 47.5K OHM

CAPACITOR, 1OUF

RESISTOR, 66.5K OHM

RESISTOR, 3.3 OHM

PROGRAM, DISK ASSY

RESISTOR PACK, lOOK

CAPACITOR, 220PF

RESISTOR, 10K OHM

RESISTOR PACK, 10 OHM

RESISTOR PACK, 10K


RESISTOR, 12.1K OHM

CAPACITOR, .OO1UF

CAPACITOR, 47UF, 25V

CAPACITOR, .1UF

TEST POINT

CAPACITOR, 1OUF 16v

CAPACITOR, .022UF

CAPACITOR, 100UF

CAPACITOR, .47UF

RESISTOR, 41.2K OHM

CAPACITOR, .22UF

RES PACK, 100 OHM

DIODE, ZENER

TONE GEN REPL BOARD

RESISTOR, 13.7K OHM

Qty

1

1

1

4

1

4

2

6

1

1

2

1

1

2

59

1

0

6

1

4

1

1

0

1

1

2

92


5-Jun-01

PRELIMINARY

19

Schematic and

Assembly

Drawings

Drawing Description

5693-09 Overall Wiring Diagram

2726-01 PSU Board Assy

2726-03 PSU Board Schematic

2472-01 PSU Board Assy

2472-03 PSU Board Schematic

5693-01 Oximeter Unit Assy

2471-01 Main Board Assy

2471-03 Main Board Schematic

2775-01 Main Board Assy

2775-03 Main Board Schematic

2755-01 Tone Generator Replacement Bd

2755-03 Tone Generator Replacement Bd

5728-01 Cable Assy, SpO2 Input

2473-03 Alert Lamp Board

5676-27 Keypanel Schematic

5693-00 Main Assy, Model 520A

Optional Analog Module

9622-01 Analog/RS232 Module

2289-01 Analog/RS232 Bd. Assy

2289-03 Analaog/RS232 Bd. Schematic

Table 5. Schematic and Assembly Drawings


93

Novametrix 520A Pulse Oximeter Service Manual

Assistant Bot

OXYPLETH

Service Manual

Pulse Oximeter

Model 520A

Guarantee

Revision History

Declaration of Conformity with European Union Directives

Manufacturing, Quality and Safety

Contents

List of Figures

List of Tables

Introduction

Purpose

Technology Description

Conventions Used In This Manual

Acknowledgments

Patient Safety

!

Warnings

Cautions

Front Panel

Rear & Top Panels

Summary of

Operation

Menu Trees

Electronic Theory of Operation

2472 Power Supply Board

AC Mains and Battery Operation Overview

AC Mains Operation

Battery Operation

2726 Power Supply Board

AC Mains and Battery Operation Overview

AC Mains Operation

Battery Operation

2471 & 2775 Main Board

Power On/Off Control Circuitry

Power Supplies

Voltage References

Preserving RAM and Real Time Clock Data

Low Battery Voltage Shutdown

Timing Sequencer

Data Sampling Controller

Sensor LED Drive Circuits

Sensor Photodiode Return Path

Calibrating the 20-Bit Analog-to-Digital Convertors

20-Bit Analog-to-Digital Conversion

Sensor Status Decoding and Conversion

Sensor Status Parameters

Microprocessor

Memory

Real Time Clock (RTC)

Sound generator

Keypanel Interface

Display Interface

I/O Device Controller

Watchdog Timer

Serial I/O Controller

RS232 Serial Communication

Maintenance

General

Maintenance Schedules

Cleaning and Sterilization

Model 520A Monitor

Finger Sensor

Y-SENSOR™ and Y-STRIP™ Taping System

Battery Life and Maintenance

Mains Voltage Configuration

Fuse Replacement

Changing the Mains Voltage Setting

AC Mains on older style assemblies

Replacing the AC Mains Fuse(s)

Changing the AC Mains Voltage

Assembly Exchanges

Changing System Software

Changing System Software on 2471 Main Board

Troubleshooting

Functional Test

Introduction