Novametrix Medical Systems 515B User manual

Novametrix Medical Systems Inc. Wallingford, Connecticut, U.S.A. 06492.
Copyright 1995. All rights reserved. No part of this manual may be reproduced
without the written permission of Novametrix Medical Systems Inc. Printed in U.S.A.
Model 515B
and
Model 515C
Service Manual
Pulse Oximeter
This manual covers Model 515B (Cat. No. 6500-00) and Model 515C (Cat. No. 6550-00)
November 15, 1995
Catalog No. 6500-90-01/6550-90-01

Rev. 01 Model 515B/C Service Manual iii
R Revision History
19-May-95 Release at revision 00.
15-Nov-95 Updated, revision 01.

iv Model 515B/C Service Manual Rev. 01
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Rev. 01 Model 515B/C Service Manual v
G 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.
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 1995, 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.
Service Department
For factory repair service, call toll free
1-800-243-3444
In Connecticut, call Collect [phone]
Telex 956-054
Facsimile [phone]

vi Model 515B/C Service Manual Rev. 01
Service Policy
Novametrix Medical Systems Inc. will provide Warranty Service Support to its customers
within 48 hours of receiving a telephone request for technical support. This 48 hour period
begins once a service request is placed through the Factory Technical Support Department in
Wallingford, Connecticut. Novametrix provides factory direct technical support to its customers
through a technical support group located in Wallingford, Connecticut and company service
representatives located throughout the United States. All Technical Support for Novametrix
products is provided “Factory Direct”.
Novametrix provides 24 hour a day technical support accessibility via telephone numbers (800)
243-3444 or [phone]. After hours technical support requests (before 8:00 AM and after
5:00 PM Eastern Time) will be responded to promptly by the Technical Support On-Call staff.
It is suggested that any person calling in for technical support have the inoperative equipment
available for preliminary troubleshooting as well as product identification. Novametrix reserves
the right to repair or replace any product found to be defective during the warranty period.
Repair may be provided in the form of replacement exchange parts or accessories, on-site
technical repair assistance or complete system exchanges. Repairs provided due to product
abuse or misuse will be considered “non-warranty” and invoiced at the prevailing service rate.
Any replaced defective material is expected to be returned to Novametrix within 10 days of
being provided in order to avoid additional charges. Exchanged material should be returned
promptly and directlyto Novametrix using the return paperwork andshipping label(s) provided.
Transferring return materials to local sales or dealer representatives does not absolve return
responsibility.
Novametrix manufactures equipment that is generally “user serviceable” and can usually be
repaired with the replacement of a plug-in electro-mechanical assembly by the clinical end user.
When repair parts are provided, the recipient can call into Novametrix for on-line replacement
assistance and repair assurance. In the event a replacement part requires increased technical
capability, Technical Support may request Biomedical assistance, provide on-site technical
support or complete replacement equipment. If the customer requires the return of their original
product, the exchange material will be considered “loaner material” and exchanged again after
the customer equipment is repaired.
Novametrix promotes customer participation in warranty repairs should they become necessary.
This program allows for customer training and a smooth transition into self-maintenance after
warranty, which can provide substantial cost savings on repairs throughout the product’s life.
The Novametrix Technical Support Department can provide technical product support at a level
appropriate to most customers protocol and budget requirements. Please contact the Technical
Support Group at Novametrix for additional information.
Additional Novametrix Technical Support Programs
• Focus Series Technical Training Seminars
• Test Equipment and Test Kits
• Service Contract / Part Insurance Plans
• On-Site Technical Support
• 24 hr. telephone support
• “Demand Services”
Flat rate parts-exchange,
Flat rate return for repair
Time and Material,
Full warranty, discounted replacement sensors

Rev. 01 Model 515B/C Service Manual vii
C Contents
1 Description .................................................................................................... 1
1.1 Trademark Acknowledgments ...................................................................1
2 Patient Safety ................................................................................................ 3
2.1 Indications and Usage ...............................................................................3
2.2 Warnings ...................................................................................................4
2.3 Cautions ....................................................................................................5
3 Front and Rear Panel Illustrations .............................................................. 7
4 Summary of Operation ................................................................................. 9
4.1 Turning the monitor ON/OFF .....................................................................9
4.2 Displays .....................................................................................................9
4.3 Adjusting Alert Limits ................................................................................. 9
4.4 Adjusting Volume Levels .........................................................................10
4.5 Muting Alerts ............................................................................................10
4.6 Contrast ...................................................................................................10
5 Electronic Theory of Operation .................................................................11
5.1 2532/2725 Power Supply Board .............................................................. 11
5.1.1 AC Mains and Battery Operation Overview ..............................................................11
5.1.2 AC Mains Operation ..................................................................................................11
5.2 Main Board ..............................................................................................12
5.2.1 Power On/Off Control Circuitry ..................................................................................12
5.2.2 Power Supplies and Voltage References ..................................................................13
5.2.3 Sensor LED Drive Circuits ........................................................................................13
5.2.4 Sensor Photodiode Return Path ...............................................................................13
5.2.5 20-Bit Analog-to-Digital Convertor Self Calibration ...................................................14
5.2.6 20-Bit Analog-to-Digital Conversion ..........................................................................14
5.2.7 Sensor Status Decoding and Conversion .................................................................15
5.2.8 Front End Timing Signals ..........................................................................................15
5.2.9 Sensor Status Parameters ........................................................................................16
5.2.10 Serial I/O Controller ...................................................................................................17
5.2.11 Microprocessor and Memory .....................................................................................18
5.2.12 Decoding ...................................................................................................................18
5.2.13 Microprocessor Supervisor .......................................................................................19
5.2.14 System Output Ports .................................................................................................19
5.2.15 Displays .....................................................................................................................20
5.2.16 Audio Drive Circuitry .................................................................................................20
5.2.17 Keypanel and Configuration Header .........................................................................21
5.2.18 Graphics Display .......................................................................................................21

viii Model 515B/C Service Manual Rev. 01
6 Maintenance ................................................................................................23
6.1 Cleaning and Sterilization ........................................................................23
6.1.1 Monitor ......................................................................................................................23
6.1.2 SpO2Finger Sensor ..................................................................................................23
6.1.3 SpO2Y-Sensor .........................................................................................................23
6.1.4 Y-Strip Tapes and Foam Wraps ...............................................................................23
6.1.5 Ear Clips ...................................................................................................................23
6.2 Battery Maintenance ................................................................................24
6.3 Replacing AC Mains Fuses .....................................................................24
6.3.1 Assemblies with the earlier Power Entry Modules ....................................................25
6.3.2 Assemblies with the newer Power Entry Module ......................................................25
6.4 Changing AC Mains Voltage ...................................................................26
6.4.1 Assemblies with the earlier Power Entry Module ......................................................26
6.4.2 Assemblies with the newer Power Entry Module ......................................................27
6.5 Assembly Exchanges ..............................................................................29
6.5.1 Internal Assemblies ...................................................................................................29
6.5.2 Main Board/Keypanel Assembly ...............................................................................29
6.5.3 Power supply assembly ............................................................................................29
6.5.4 Replacing the internal battery ...................................................................................29
6.6 Changing System Software .....................................................................29
7 Troubleshooting ..........................................................................................31
8 Functional Test ...........................................................................................33
8.1 Equipment required .................................................................................33
8.2 Functional Test ........................................................................................34
9 Electronic Tests ..........................................................................................37
9.1 Assembly Tests .......................................................................................37
9.1.1 Equipment Required .................................................................................................37
9.1.2 Power Supply ............................................................................................................37
9.1.3 Main Board ................................................................................................................38
9.2 Accuracy Test ..........................................................................................40
9.2.1 Equipment Required .................................................................................................40
9.2.2 Test ...........................................................................................................................40
10 Specifications ..............................................................................................43
10.1 Pulse Oximeter ........................................................................................43
10.1.1 Principle of Operation ...............................................................................................43
10.1.2 SpO2(Oxygen Saturation) ........................................................................................43
10.1.3 Pulse Rate ................................................................................................................43
10.1.4 Sensors .....................................................................................................................43
10.1.5 Plethysmogram (Model 515C only) ...........................................................................43
10.2 General Specifications .............................................................................43
10.2.1 Alerts .........................................................................................................................43
10.2.2 Display ......................................................................................................................44
10.2.3 Physical .....................................................................................................................44
10.2.4 Electrical ...................................................................................................................44
11 Accesories ...................................................................................................45
12 Parts Lists ....................................................................................................49
12.1 Model 515C .............................................................................................49

Rev. 01 Model 515B/C Service Manual ix
12.2 Model 515B ..............................................................................................53
12.3 Common Assemblies to both Models 515B & 515C ................................59
13 Schematics and Assembly Drawings ........................................................63

x Model 515B/C Service Manual Rev. 01

Rev. 01 Model 515B/C Service Manual 1
1 Description
This manual is written for personnel who service and/or maintain the Novametrix Model 515B
or 515C Pulse Oximeter. The Model 515B/C provides reliable continuous measurement,
display, and alerts for oxygen saturation (SpO2) and pulse rate. The monitor can be powered
from its rechargeable internal battery or from the AC Mains.
The Model 515B/C measures oxygensaturation using sensors that contain red and infrared(660
and 940 nanometer) light sources, called LEDs. The light energy from each LED is beamed
through a sample cell—a pulsating vascular bed, the patient’s finger or toe for example. The
remaining light energy not absorbed by the sample cell reaches a light receptor in the sensor,
called a 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 oxygen saturation.
The Model 515B/C is calibrated to display “functional” saturation. This differs from the
“fractional” saturation value displayed by most co-oximeters. Functional saturation is defined
as:
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 in the measurement of functional saturation.
Pulse Rate is calculated by measuring the time interval between peaks of the infrared light
waveform. The inverse of this measurement is displayed as pulse rate.
The oxygen saturation and pulse rate values are updated once each second. Presence of a pulse
is indicated visibly by a bar graph display, a plethysmogram graphic display (Models 515C
only), and audibly by a “beep.”
The Model 515B/C must be used in conjunction with SuperBright™ Sensors. These sensors
have an 8700 series part number (e.g., 8776 or 8791).
1.1 Trademark Acknowledgments
SuperBright, Y-STRIP and Y-SENSOR are trademarks of Novametrix Medical Systems Inc.
Functional Saturation = HbO2
100 - (COHb + METHb)
HbO2 = Percentage of hemoglobin saturated with oxygen
COHb = Percentage of carboxyhemoglobin
METHb = Percentage of methemoglobin

1 Description Trademark Acknowledgments
2 Model 515B/C Service Manual Rev. 01
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Rev. 01 Model 515B/C Service Manual 3
2 Patient Safety
Pulse oximetry is a non-invasive method of monitoring the oxygen saturation of arterial blood.
Pulse oximeters display oxygen saturation of functional hemoglobin and therefore the accuracy
may be interfered with by carboxyhemoglobin or other dyshemoglobins present in significant
concentrations. Oxygen saturation monitoring is intended to be used in a variety of clinical
situations, including, but not limited to respiratory therapy, anesthesia, intensive care, and
emergency.
The Model 515B/C Pulse Oximeter has electrically isolated inputs. Patient leakage current
flowing from the instrument to ground is limited to less than 10 µA at 120 V, 60 Hz. Patient
isolation is greater than 10 MΩ, 2500 V rms at 60 Hz. For maximum patient and operator safety,
the following procedures are recommended;
• Failure of Operation: If the monitor fails to respond as described, do not use until the
situation has been corrected by qualified personnel.
• Keep the Model 515B/C and its accessories clean.
• Do not operate the Model 515B/C when it is wet due to spills or condensation.
• Do not operate the Model 515B/C if it appears to have been dropped or damaged.
• Connecttheline cordonlytoa groundedhospitalgradeoutlet.The Model 515B/Cshould
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.
2.1 Indications and Usage
The Model 515B/C is intended to be used for monitoring functional oxygen saturation and pulse
rate in circumstances where it is desirable to monitor patient oxygenation. The monitor is
designed to monitor all patients including adult, pediatric, and neonatal. The Model 515B/C is
not intended for any other purpose.
NOTE: Components of this product and its associated accessories which may have patient
contact are free of latex.

2 Patient Safety Warnings
4 Model 515B/C Service Manual Rev. 01
2.2 Warnings
•Explosion Hazard: Do NOT use the Model 515B/C in the presence of flammable
anesthetics. Use of this instrument in such an environment may present an explosion
hazard.
•Electrical ShockHazard: Always turn the oximeter off, and remove the AC power cord
beforecleaning it.Do NOTuse adamagedsensor or one withexposed electricalcontacts.
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 oximeter fails to respond as described, do not use it until
the situation has been corrected by qualified personnel.
•Data Validity: The Pulse Oximeter should NOT be used as a substitute for an ECG
monitor. The oximeter’s Pulse Rate display reflects thepulsatile flow found at the patient
extremity connected to the sensor. This rate can be affected by many factors and may
occasionally be “frozen.”
•Care should be exercised to assure continued peripheral perfusion distal to the SpO2
sensor site after application.
•Data Validity: Do NOT attach a 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.
•Data Validity: Inaccurate SpO2and/or Pulse Rate measurements can be caused by any
of the following:
• Incorrect application or use of a sensor
• Significant levels of dysfunctional hemoglobins 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.
•DoNotapply Y-Sensor tapes or wraps so tightly that circulation is restricted. Inspect site
often for adequate circulation - at least once every four hours. When applying sensors
take note of 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.
Warning
Indicates a potentially harmful condition
that can lead to personal injury.
!

Cautions Patient Safety 2
Rev. 01 Model 515B/C Service Manual 5
2.3 Cautions
• Do not operate the Model 515B/C when it is wet due to spills or condensation.
• Do not operate the Model 515B/C if it appears to have been dropped or damaged.
• Never sterilize or immerse the monitor in liquids.
• Do not sterilize or immerse sensors except as directed in this manual.
• Excessive tension should not be applied to the sensor cable.
• 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.
• Do not stretch the finger sensor open beyond the limit for which it was designed.
Overstretching the pulse oximeter finger sensor can damage the sensor and potentially
affect pulse oximeter readings. Overstretching can be prevented: avoid opening the
sensor by any means other thansqueezing the grips; DO NOT force the sensor onto large
objects such as a bedrail.
Caution
Indicates a condition that may lead to
equipment damage or malfunction.

2 Patient Safety Cautions
6 Model 515B/C Service Manual Rev. 01
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Rev. 01 Model 515B/C Service Manual 7
3 Front and Rear Panel Illustrations
POWER button - Press to turn the monitor
on or off.
AC indicator - Green when the monitor is
connected to AC power and rear panel
power entry module switch is set to “|”
(ON). Also indicates the battery is charging.
Audio key - Press to toggle two minute
silence, and reset alert conditions (when
active). Press and hold for audio disable.
Battery icon - Green when operating on bat-
tery with a charged battery, orange when
battery power is diminished, flashes red
when battery power is at a critical low.
Pulse Key - Sets pulse rate alert limits when
used with the keys. Press and hold
to set auto alert limits.
Finger probe icon -Flashes red when no
probe connected or probe off patient. Red
for any sensor errors.
SpO2key - Sets saturation alert limits when
used with the keys. Press and hold
to set auto alert limits.
Hand icon - Yellow when monitor is search-
ing for valid signal and data is being held.
Increase/decrease keys - Press to set pulse
and alert audio level. Sets alert limits when
used in conjunction with SpO2and Pulse
keys. Press and hold to control graphics dis-
play contrast on Models 515C (Model 515B
does not have graphics display option).
Audio disabled icon - Flashes yellow when
the audio has been disabled.
Two minute silence indictor - Illuminates
yellow when the audio has been muted for
two minutes.
Saturation and pulse rate displays - Satura-
tion and pulse rate values will appear. Status
messages will appear if necessary, see
“Troubleshooting” on page 31. Arrows indi-
cate alert status or that alerts are being set.
Signal bar - Pulses with respect to moni-
tored pulse rate. Amplitude corresponds to
signal strength.
ALERT BAR
SENSOR INPUT
WAVEFORM DISPLAY ON MODEL 515C ONLY

3 Front and Rear Panel Illustrations
8 Model 515B/C Service Manual Rev. 01
Ground stud - Use to connect monitor’s chassis to earth
ground.
Rear panel power switch - Set to “|” allows AC mains
to power monitor, set to “O” switches AC mains power
off.
Voltage select/fuse compartment - Sets mains operating
voltage and houses mains fuses.
Power cord entry - Plug power cord into this receptacle.
Use only hospital grade three wire plugs for connection
via supplied power cord.
Ground stud - Use to connect monitor’s chassis to earth
ground.
Rear panel power switch - Set to “|” allows AC mains
to power monitor, set to “O” switches AC mains power
off.
Voltage select/fuse compartment - Sets mains operating
voltage and houses mains fuses.
Power cord entry - Plug power cord into this receptacle.
Use only hospital grade three wire plugs for connection
via supplied power cord.
EARLIER REAR PANEL
NEWER REAR PANEL

Rev. 01 Model 515B/C Service Manual 9
4 Summary of Operation
This section gives a brief description of the operation of the Model 515B/C monitor. For more
detailed information refer to the Model 515B/C User’s Manual (Cat. No. 6500-23/6550-23).
4.1 Turning the monitor ON/OFF
The key controls powering the monitor on and off. To charge the battery from AC mains
ensure that the power cord is connected and plugged into a hospital grade three prong outlet. Set
the rear panel power switch to | (ON). Check that the front panel icon is green, this
indicates that AC mains power is connected to the monitor and charging the internal battery. The
monitor will operate on its internal battery power when the rear panel power switch is set to O
(OFF), or if the power cord is removed.
When operating on a fully charged battery the icon on the front panel will turn green. As
the battery charge diminishes and reaches a low level the icon will turn orange.When the battery
has reached a critical low the icon will flash red. If AC mains poweris not connected at this time
to power the unit and recharge the battery, the monitor will flash a red icon, emit an alarm
tone, then shut itself off.
4.2 Displays
When a sensor is connected to the monitor and detecting pulsatile data the SpO2and pulse rate
values will appear in their respective displays. The signal bar will pulse in accordance to the
pulse rate, and on Model 515C, the graphics display will show a plethysmogram (the waveform
will travel from left to right).
The and indicate conditions regarding sensor activity; poor signal, probe not
connected, etc. Refer to the User’s Manual for more detailed information (Cat. No. 6500-23/
6550-23).
4.3 Adjusting Alert Limits
The Model 515B/C can have its alert limits manually adjusted, or automatically adjusted1. To
manually set the alert limits press either for SpO2limits, or for pulse rate limits.
Pressing the appropriate key once will allow adjustment of the high limit using the up/down
arrow keys. Pressing the same button twice will allow adjustment of the lower alert limit. If the
key is pressed a third time the monitor will exit the alert limits setting mode and return to normal
operation and displays.
For example: Press once, use to adjust upper alert limit. Press again, use
to adjust lower alert limit. Press a third time to exit alert limits mode, or wait
for 10 seconds.2
1. For automatically set alert limits the monitor must first have acquired valid data on which to base the limits on for a spec-
ified amount of time.

4 Summary of Operation Adjusting Volume Levels
10 Model 515B/C Service Manual Rev. 01
To activate auto alert limits press and hold either the key for saturation, or the key for
pulse rate. The monitor will temporarily display the new upper, then lower limits on the
saturation or pulse rate display, depending upon which limits were set, then return to normal
operating mode.
4.4 Adjusting Volume Levels
Both pulse beep and alert volume can be separately adjusted. To adjust the pulse beep press
, “Pul” will appear in the SpO2display, use to adjust the volume level from 0
through 7. To adjust the alert volume press , “Alr” appears in the SpO2display, use
to adjust the alert volume level from 1 through 7.
NOTE: When the monitor is sounding an alert (with audible alerts enabled - not
illuminated), the keys will control the alert volume only.
4.5 Muting Alerts
The key controls two minute audio muting, audible alert disable, and alert acknowledge.
Pressing will activate the two minute audible alert mute. Press and hold until
illuminates to activate audible alert disable. Pressing again will cancel either the two
minute mute or the audio disable (which ever is active). Press to acknowledge and reset
alert conditions.
4.6 Contrast
Press and hold the key to vary the contrast of the graphics display (on Model 515C only).
The SpO2display will show “Con” to indicate that the monitor is in contrast adjust mode. Use
the keys to vary the contrast. The monitor will return to normal operating mode ten
seconds after the last key depression.
2. There is a ten second time-out counter that starts each time the SpO2or pulse key is pressed. When the counter times-out
the monitor will return to its normal operating mode.