Respironics 920 Troubleshooting guide

English
Instruction and Service Manual
Models 920 and 920M
Hand Held Pulse Oximeters

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English
About the Manual
Boxes draw attention to contraindications, warnings, and
cautions.
The boxed messages are important. Be sure to read them.
The information in this manual has been carefully checked and is
believed to be accurate. In the interest of continued product
development, RESPIRONICS, INC. reserves the right to make
changes and improvements in this manual and the products it
describes at any time, without notice or obligation.
Caution: Federal Law (USA) restricts this device to sale by or
on the order of a physician.
Respironics Georgia
175 Chastain Meadows Court
Kennesaw, Georgia 30144-3724
USA
Customer Service Telephone: [phone] (USA and Canada)
Customer Service Fax: [phone] (USA and Canada)
www.respironics.com
Respironics Deutschland
Gewerbestrasse 17
82211 Herrsching
Germany
Telephone: [phone]
Fax: [phone]
Respironics Asia Pacific
3/F, Microtron Building
38 Hung To Road
Kwun Tong, Kowloon, Hong Kong
Telephone: [phone]
Fax: [phone]
References to “920” in this manual shall imply Models 920 and 920M.
References to “Respironics” in this manual shall imply Respironics, Inc.
is a registered trademark of Respironics, Inc.
Copyright © 1999 Respironics, Inc. All rights reserved.

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Table of Contents
I. Contraindications, Warnings, and Cautions......... 1
II. Unpacking Your Pulse Oximeter............................ 3
III. Introduction.............................................................. 4
A. Indications for Use.......................................................4
B. General........................................................................4
IV. Operating Instructions ............................................ 5
A. Batteries ......................................................................5
B. General........................................................................7
1. Connecting the Sensors.......................................7
2. Turning on the Pulse Oximeter.............................7
3. Verifying Operation...............................................9
4. Cleaning the Pulse Oximeter................................9
V. Features.................................................................. 10
A. Controls.....................................................................10
1. Power .................................................................10
2. Display Brightness..............................................10
3. Setup Mode........................................................11
a. Printer Settings .............................................11
b. Calendar Settings .........................................13
c. Clock Settings...............................................14
B. Displays.....................................................................15
1. SpO2Display.......................................................15
2. ♥(Pulse Rate) Display.......................................15
3. (Perfusion) Indicator..................................15
4. Flashing Display.................................................16
5. Dash in the SpO2Display ...................................16
C. Printer/Serial Output..................................................17
D. Memory Option (920M only) ......................................18
1. Recording Sessions ...........................................18
2. Memory Output Mode.........................................19
VI. Pulse Oximeter Sensors........................................ 21
A. General Sensor Description ......................................21
B. Finger Clip Sensors...................................................24
1. Adult Articulated Finger Clip Sensor ..................24
2. Pediatric Finger Clip Sensor...............................24
C. Flex Sensors..............................................................25
1. Adult Flex Sensor...............................................25
2. Infant Flex Sensor ..............................................26
3. Neonatal Flex Sensor.........................................26
D. Ear Clip and Reflectance Sensors.............................27
1. Ear Clip Sensor..................................................27
2. Reflectance Sensor............................................28
E. Adult and Pediatric Disposable Sensors ...................28

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F. Infant and Neonatal Disposable Sensors..................30
1. Infant Flexi-Form Sensor....................................30
2. Neonatal Flexi-Form Sensor ..............................31
G. Cleaning the Sensors................................................33
H. Sensor Compatibility .................................................33
VII. Theory of Operation ...............................................34
VIII.Specifications .........................................................36
IX. Service.....................................................................38
X. Warranty..................................................................39
XI. Accessories.............................................................40
XII. Troubleshooting Guide..........................................42
Tables
Table I: Printer, clock, and calendar mode
parameters.....................................................................11
Table II: 920P Printer modes........................................12
Table III: Printer/Sensor interface
assignments. .................................................................17
Table IV: 920M memory data format............................20
Table V: Reusable sensor reference. ..........................22
Table VI: Disposable sensor reference.......................23
Table VII: Sensor accessory reference. ......................23
Figures
Figure I: Replacing batteries in the 920..................... 6
Figure II: Connecting sensors to the 920................... 7
Figure III: Front view of the 920.................................. 8
Figure IV: Rear view of the 920................................... 8
Figure V: Flowchart for setting the printer mode. .. 12
Figure VI: Flowchart for setting the calendar.......... 13
Figure VII: Flowchart for setting the clock. ............. 14
Figure VIII: Adult Articulated Finger Clip Sensor.... 24
Figure IX: Pediatric Finger Clip Sensor. .................. 24
Figure X: Adult Flex Sensor...................................... 25
Figure XI: Flex Sensor with tape strain relief.......... 25
Figure XII: Infant Flex Sensor on big toe................. 26
Figure XIII: Neonatal Flex Sensor on foot................ 27
Figure XIV: Ear Clip Sensor....................................... 27
Figure XV: Finger Flexi-Form Sensor....................... 29
Figure XVI: Infant Flexi-Form Sensor....................... 31
Figure XVII: Neonatal Flexi-Form Sensor. ............... 32

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Glossary of Symbols
Symbol Definition of Symbol
ATTENTION
Consult ACCOMPANYING DOCUMENTS
Type BF Applied Part:
(Patient isolation from electrical shock).
Canadian Standards Association
UL Underwriters Laboratories
CE Marking indicating conformance to EC
directive No. 93/42/EEC concerning medical
devices.

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I. Contraindications, Warnings, and
Cautions
CONTRAINDICATIONS
•Do not operate in an explosive atmosphere.
•Do not operate the RESPIRONICS 920 in an MRI
environment.
•Do not use the 920 in a situation where alarms are
required. The 920 and 920M models have no audible
alarms.
WARNING
•The 920 is intended only as an adjunct in patient
assessment. It must be used in conjunction with clinical
signs and symptoms.
•Use only Respironics-manufactured sensors. These sensors
are manufactured to meet the calibration requirements for
Respironics pulse oximeters. Use of other manufacturer's
sensors may cause improper pulse oximeter performance.
•Check application site frequently to determine circulation,
positioning, and skin sensitivity of the patient. Each patient's
sensitivity to Respironics sensors may vary depending on
their medical status or the condition of their skin.
•Use of Respironics double-backed adhesive strips or the
Hydrogel tape strips should be discontinued if the patient
exhibits allergic reactions to the adhesive material.
•Do not stretch the adhesive tape while applying the sensors.
This may cause inaccurate readings or skin blisters.

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CAUTION
•Federal law (USA) restricts this device to sale by or on the
order of a physician.
•Read this manual carefully before use of the 920.
•Carefully read the instructional insert provided with the
sensor before use.
•The 920 is intended for spot-checking or continuous
monitoring by an attending health care professional.
Because the 920 has no audible alarms, international
labeling requirements dictate it be labeled “Not for
continuous monitoring.”
•The 920 must be able to measure the pulse properly to
obtain accurate SpO2measurement. Verify that nothing is
hindering the pulse measurement before relying on the SpO2
measurement.
•Fingernail polish may reduce light transmission and thereby
affect SpO2accuracy.
•The 920 may not work on all patients. If you are unable to
achieve stable readings, discontinue use.
•The 920 is sensitive and must be repaired by knowledgeable
and specially trained personnel only.
•The 920 may interpret motion artifact of sufficient amplitude
and regularity as good perfusion (green).
•The 920 is calibrated to determine the percentage of arterial
oxygen saturation of functional hemoglobin. Significant levels
of dysfunctional hemoglobin such as carboxyhemoglobin or
methemoglobin may affect the accuracy of the
measurement.
•Cardiogreen and other intravascular dyes, depending on the
concentration, may affect the accuracy of the SpO2
measurement.
•Do not use different types of batteries at the same time. Do
not mix fully charged and partially charged cells at the same
time. These actions may cause the batteries to leak.
•Do not immerse the 920 or Respironics sensors in liquid to
clean.
•Do not use caustic or abrasive cleaning agents.
•Ear Clip and Reflectance sensors are not recommended for
pediatric or neonatal use. The accuracy of the sensors has
not been established for pediatric or neonatal use.
•Do not remove any covers other than the battery cover when
battery replacement is necessary. There are no user
serviceable parts inside other than the replaceable batteries.
•Alkaline batteries may leak or explode if used or disposed of
improperly.

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II. Unpacking Your Pulse Oximeter
Contact the carrier immediately if the shipping carton for the 920 is
damaged. Carefully unpack the instrument and its accessories.
Confirm that the items listed below are packed with the 920 Hand
Held Pulse Oximeter. The 920/920M shipment includes:
•Model 920 or 920M Hand Held Pulse Oximeter
•Instruction and Service Manual for Models 920 and 920M
•Six AA batteries
•Model 936 Sensor (Adult Articulated Finger Clip)
If any item on this list is missing or damaged, do not use the pulse
oximeter. Contact your local distributor or, if you do not know your
local distributor, contact Respironics.

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III. Introduction
A. Indications for Use
The 920 Hand Held Pulse Oximeter is intended to be used for
monitoring oxygen saturation and pulse rate for adult, pediatric, and
neonatal patients in hospital, ambulatory, home, and EMS
environments. The 920 may be used for spot checking and/or
continuous monitoring when attended by a healthcare professional. The
variety of individual sensors available must be checked frequently to
ensure proper circulation and application.
B. General
The 920 Hand Held Pulse Oximeter is small and lightweight. The
920 has visual alarms for tracking patient status. It typically will
operate for 100 hours continuously between battery replacements.
The 920 requires no routine calibration or maintenance.
The 920 determines arterial oxyhemoglobin saturation (%SpO2) by
measuring the absorption of red and infrared light passed through
tissue. Changes in absorption caused by pulsation of blood in the
vascular bed are used to determine arterial saturation and pulse
rate.
Oxygen saturation and pulse rate are displayed on light emitting
diode (LED) digital displays. On each detected pulse, the perfusion
LED flashes. Patient perfusion signals are graded as good,
marginal or inadequate and are indicated as such by the LED
flashing green, yellow, or red. This simple method gives the user a
pulse-by-pulse visual indication of waveform signal quality without
requiring the user to perform complex waveform analysis during
critical patient care situations.
Sensor disconnect or malfunction is indicated by lack of good
perfusion flashes and/or a dash to the left of the SpO2value on the
LED display. Ultimately, if adequate perfusion pulses are not
received, the SpO2and Pulse Rate (♥) numerical values will be
replaced by dashes. When the batteries are low, the digital displays
will blink.
The 920 Pulse Oximeter may be used with all Respironics pulse
oximeter sensors (except fiber optic sensors) enabling proper
operation for nearly every patient.
NOTE: Respironics sensors do not contain natural rubber
latex.

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IV.Operating Instructions
A. Batteries
CAUTION •Do not remove any covers other than
the battery cover when battery
replacement is necessary. There are no
user serviceable parts inside other than
the replaceable batteries.
•Alkaline batteries may leak or explode if
used or disposed of improperly.
•Do not use different types of batteries at
the same time. In addition, do not mix
fully charged and partially charged cells
at the same time. These actions may
cause the batteries to leak.
The 920 Pulse Oximeter is powered by 6 AA Alkaline cells that will
typically provide 100 hours of continuous operation. The 920
indicates when the batteries are low by flashing the digital
displays once each second. When the displays begin flashing, the
batteries should be replaced as soon as possible. Replace the
batteries by removing the battery door on the bottom of the 920. Be
sure to follow the polarity markings on the rear label of the pulse
oximeter when installing new batteries. Refer to Figure I for an
illustration of battery replacement.
Rechargeable Nickel Cadmium batteries may be used in the 920 if
desired. Since NiCad batteries have less than half the capacity of
alkaline batteries, the batteries will have to be recharged more often
than every 100 hours.
NOTE: Reducing the LED display brightness can extend
battery life up to 100%! Refer to Section V (A. 2.).
NOTE: Replacing batteries erases the clock settings of the
920. The memory of the 920M will also be erased
when the batteries are replaced. These settings
should be reset after the batteries are replaced. To
do this, refer to Section V (A. 3.).
NOTE: Batteries should be removed if the 920 is going to
be stored for more than 30 days. Batteries may
leak if left in the device for a long period of time.

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Figure I: Replacing batteries in the 920.
IMPORTANT:
Insert these two
batteries first.
Battery
Door Battery
Orientation

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B.General
The 920 Hand Held Pulse Oximeter is portable and is intended for
attended patient monitoring by trained personnel. It displays
numerical values for oxygen saturation and pulse rate. Because the
920 Pulse Oximeter has no patient alarms, the user must frequently
observe the SpO2and Pulse Rate displays.
1. Connecting the Sensors
Connect the sensor to its 9-pin mating jack on the top of the 920 as
shown in Figure II. To select a sensor type, refer to Section VI (A). If
additional cable length is necessary, connect the Model 927 Patient
Cable between the sensor and the 920 Pulse Oximeter. Position the
appropriate sensor on the patient. Refer to Section VI for sensor
positioning information.
Figure II: Connecting sensors to the 920.
2. Turning on the Pulse Oximeter
Turn on the 920 Hand Held Pulse Oximeter by depressing the “”
button on the front of the pulse oximeter. Refer to Figure III.
When the 920 is powered on, the SpO2and ♥displays will cycle
through the following sequence before displaying valid data values:
•“888 888”
•time saved in memory in hours and minutes
•software revision number
•“--”

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Figure III: Front view of the 920.
Figure IV: Rear view of the 920.
Digital Display
Percent Oxygen
Saturation
Digital Display
Heart Rate
Perfusion Light
On Switch
Display Brightness
And Setup Mode
Off Switch
Serial Number
Battery
Orientation
Battery Door

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3. Verifying Operation
CAUTION •The 920 must be able to measure the
pulse properly to obtain accurate SpO2
measurement. Verify that nothing is
hindering the pulse measurement
before relying on the SpO2
measurement.
Verify that the sensor is properly positioned. Ensure the system is
sensing adequate perfusion by observing that the (perfusion)
indicator is blinking green, and the blinking is correlated to the pulse
rate for 10 seconds. Should the perfusion light be red or yellow or
flashing erratically, reposition the sensor or try a different sensor.
4. Cleaning the Pulse Oximeter
CAUTION •Do not immerse the 920 in liquid to
clean.
•Do not use caustic or abrasive
cleaning agents.
The 920 Pulse Oximeter may be cleaned with a mild detergent and
a soft cloth or with an isopropyl alcohol wipe. Allow enough time for
the 920 to dry thoroughly before reusing.

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V. Features
A. Controls
All functions of the 920 are controlled by switches found on the front of the
unit. Refer to Figure III for an illustration of these switches.
1. Power
Pressing the ON switch (“”) causes power to be applied to all
internal circuitry. Pressing the OFF switch (“∅”) causes power to be
removed from the displays and puts the pulse oximetry circuitry into
a low power standby mode.
In order to conserve battery life, the 920 will automatically power off
after 10 minutes of inactivity. Inactivity is indicated by dashes on the
displays and is caused by:
•no sensor connected to the pulse oximeter
•patient pulse too low
•sensor not attached to a patient
Each time a reading is displayed, the 10-minute timer is restarted.
The “” switch has additional clock and printer mode setting
functions when used in conjunction with the “ñ” switch. Refer to
Section 3 of this section for Setup Mode instructions.
2. Display Brightness
The arrow switch (“ñ”) causes the brightness of the digital displays to
change. When powered up, the digital display defaults to the maximum
brightness. Pressing the “ñ” will advance the brightness to the lowest
setting, and each subsequent press will advance the brightness through
8 different settings. The function is circular which means it will cycle
through the entire brightness range and then start at the beginning
again. The lower light brightness may be used to preserve battery life.
The higher light intensity may be used to view the displays from a
distance.
NOTE: Reducing the LED display brightness can
extend battery life up to 100%!
The “ñ” switch has additional clock mode setting functions when
used in conjunction with the “” switch. Refer to Section 3 of this
section for Setup Mode instructions.

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3. Setup Mode
Setup mode is used to control the internal time-of-day clock and the
external real-time printer (purchased separately). The setup mode is
initiated by holding the “ñ” switch when the unit is turned on by
pressing the “” switch. In setup mode, the “” switch and the “ñ”
switch are used to make the selections.
Advance to the next sequential mode by pressing the “” switch.
Each time the “ñ” switch is pressed, the number on the ♥display
will increment. It starts with the current value stored in memory for
the parameter designated in the SpO2display. When the correct
value appears in the ♥display, pressing the “” switch will advance
the SpO2display to the next sequential parameter as listed in Table
I. This process is continued until all parameters are set. The
settings can be easily checked, since the first value displayed for
each parameter represents the current setting. When the setting
sequence has been completed, the 920 exits the setup mode and
begins normal operation.
Range of ValuesSequence Appears in
SpO2Display From: To:
Printer “Prn”00 15
Year “y”00 99
Month “nn”00 12
Day “d”01 31
Hours “h”00 23
Minutes “nn”00 59
Table I: Printer, clock, and calendar mode parameters.
a. Printer Settings
NOTE: The 920P prints out real-time data only. Data
stored in the 920M can not be downloaded to
the 920P.
“Prn” will appear in the SpO2display indicating print setup mode.
There are 16 options for the printer mode: 00 through 15. Each printer
mode is explained in Table II. The modes determine how often data
is written out to the printer and the format of data written to the
printer. Refer to Figure V for a flowchart of setting the printer mode.
When the printer setting sequence has been completed, the 920
continues to the calendar settings (refer to section b of this section).

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Display
Press Press
Proceed to
calendar setup
Default
Setting
Press Press
SpO2
Display
Setup
Mode
Increment
printer
mode
Prn
0
y
Figure V: Flowchart for setting the printer mode.
Printer
ModeSeconds per data
point
Minimum
SpO2
printed?*
Touch
print
capability?**
00 10 No Yes
01 30 No Yes
02 120 No Yes
03 10 Yes Yes
04 30 Yes Yes
05 120 Yes Yes
15 --- No Yes
*For modes where the minimum SpO2data is written, there are two
lines of data written for each data output. The first line contains the
minimum value for SpO2since the last printout, and the second line
contains the current data values.
** The touch print mode enables the user to print out data at any time.
This is activated by pressing the “”switch.
Table II: 920P Printer modes.
NOTE: Printer modes 06 –14 are not used at this time.
They are reserved for future development.