Smiths Medical 1818R Operation And Service Manual

BCI PulseOx
Handheld
Manual

Get an original copy of the BCI PulseOx Handheld Manual for
manufacturer information about service, available
accessories and how to use and maintain your device.

Oximeter

Operation and Service Manual

Catalog Number 1818R

Version 7, February 2005

© 2005 Smiths Medical family of companies. All rights reserved.

Table of Contents

Oximeter Operation and Service Manual i

Table of Contents

Chapter 1: Introduction................................................................ 1-1

About This Manual..........................................................................1-1

Proprietary Notice................................................................... .........1-1

Warranty..........................................................................................1-1

Limited Warranty......................................................................1-1

Disclaimer of Warranties ..........................................................1-2

Conditions of Warranty.............................................................1-2

Limitation of Remedies.............................................................1-2

Warranty Procedure.........................................................................1-3

CE Notice.........................................................................................1-3

Warnings, Cautions, and Notes .......................................................1-5

Chapter 2: General Description ................................................... 2-1

Intended Use....................................................................................2-1

Features............................................................................................2-1

Description.......................................................................................2-2

Theory of Operation .................................................................... ....2-4

Chapter 3: Using the Oximeter....................................................3-1

Install the Batteries....... .... ..... ..........................................................3-1

Installing or Replacing the Batteries......................................... 3-2

Care and Handling of Sensor ....................................................3-3

Choose the Sensor............................................................................3-4

Attach the Sensor to the Patient.......................................................3-5

Clean or Disinfect the Sensors..................................................3-5

Finger Sensor for Adult or Pediatric Finger..............................3-5

Attach the Sensor to the Oximeter............................................3-6

Measuring the Patient’s % SpO2 and Pulse Rate............................3-6

Patient Numbers and Spot Check Data............................................3-8

Manually Incrementing the Patient Number.............................3-8

Clearing All Spot Check Data...................................................3-8

Low Battery Indicator......................................................................3-8

Turning Off the Oximeter................................................................3-9

Checking the Oximeter’s Performance............................................3-9

Table of Contents

ii Oximeter Operation and Service Manual

Chapter 4: Printer and Computer Interface.................................. 4-1

Computer Interface Description...................................................... 4-1

Equipment Required........................................................................4-1

Interface Instructions.......................................................................4-1

Spot Check Printouts........................................................ .... ..... .... ..4-3

Collecting Spot Check Data......................................................4-3

Manually Incrementing the Patient Number.............................4-3

Clearing All Spot Check Data ..................................................4-3

About the Oximeter’s Batteries and Spot Check Data .............4-3

Printing Spot Check Data .........................................................4-4

Chapter 5: Operator’s Maintenance............................................. 5-1

Batteries...........................................................................................5-1

Disposal of batteries and rechargeable batteries....................... 5-1

Sensors ............................................................................................5-1

Reusable Sensors......................................................................5-1

Disposable Sensors........................................................ ...........5-2

Cleaning the Oximeter’s Surfaces ...................................................5-2

Long Term Storage..........................................................................5-2

Chapter 6: Operator’s Troubleshooting Chart ............................. 6-1

EMI Interference.............................................................................6-3

Chapter 7: Optional Supplies and Accessories............................ 7-1

Ordering Information ......................................................................7-2

Chapter 8: Specifications............................................................. 8-1

Equipment Classification ................................................................8-1

Displays, Indicators, & Keys...........................................................8-1

SpO2................................................................................................8-1

Pulse Rate.................................................. ......................................8-2

Auxiliary Printer Output..................................................................8-2

Power Requirements ............................................................ ...........8-2

Battery Life .....................................................................................8-2

Dimensions......................................................................................8-2

Environmental Specifications .........................................................8-2

Table of Contents

Oximeter Operation and Service Manual iii

Chapter 9: Service Maintenance and Repair................................ 9-1

General Description.........................................................................9-1

Power Supply and ON/OFF Circuitry .............................................9-1

Digital Section.................................................................................9-1

Analog Section..........................................................................9-3

LED Controller..........................................................................9-4

Signal Dictionary ......................................................................9-4

Test Equipment and Tools Required...............................................9-6

Connecting a DC Power Supply......................................................9-6

Voltage Test Points..........................................................................9-7

Waveform Test Points .....................................................................9-9

Appendix: Assembly Drawings, Schematics & Parts Lists.............1

This page is intentionally left blank.

Chapter 1: Introduction

Oximeter Operation and Service Manual 1-1

Chapter 1: Introduction

About This Manual

The operator’s instru ct ions provide installation, operation, and mainte­nance instructions. It is intended for health-care professionals trained in
monitoring respiratory and cardiovascular activity.

The service maintenance and repair section contains circuit descriptions,
voltage and waveform test points, detailed parts lists, and circuit diagrams.
It is intended for persons trained in service, maintenance, and repair of
modern medical equipment. Thorough knowledge of this equipment’s
operation is required before attempting to repair this equipment.

Proprietary Notice

Information contained in this document is copyrighted by Smiths Medical
PM, Inc. and may not be duplicated in full or part by any person without
prior written approval of Smiths Medical PM, Inc. Its purpose is to provide
the user with adequately detailed documentation to efficiently install, oper­ate, maintain and order spare parts for the device supplied. Every effort has
been made to keep the information contained in this document current and
accurate as of the date of publication or revision. However, no guarantee is
given or implied that the document is error free or that it is accurate regard­ing any specification.

Warranty

Limited Warranty

Seller warrants to the original purchaser that the Product, not including
accessories, shall be free from defects in materials and workmanship under
normal use, if used in accordance with its labeling for two years from the
date of shipment to the original purchaser.

Seller warrants to the original purchaser that the reusable oximeter sensors
supplied as accessories, shall be free from defects in materials and work­manship under normal use, if used in accordance with its labeling for one
year from the date of shipment to the original purchaser (USA only).

Chapter 1: Introduction

1-2 Oximeter Operation and Service Manual

Disclaimer of Warranties

THE FOREGOING EXPRESS WARRANTY, AS CONDITIONED AND
LIMITED, IS IN LIEU OF AND EXCLUDES ALL OTHER WARRAN­TIES WHETHER EXPRESS OR IMPLIED, BY OPERATION OF LAW
OR OTHERWISE, INCLUDING BUT NOT LIMITED TO, ANY
IMPLIED WARRANTIES OF MERCHANT ABILITY OR FITNESS FOR
A PARTICULAR PURPOSE.

Seller disclaims responsibility for the suitability of the Product for any par­ticular medical treatment or for any medical complications resulting from
the use of the Product. This disclaimer is dictated by the many elements
which are beyond Seller’s control, such as diagnosis of patient, conditions
under which the Product may be used, handling of the Product after it
leaves Seller’s possession, execution of recommended instructions for use
and others.

Conditions of Warranty

This warranty is void if the Product has been altered, misused, damaged by
neglect or accident, not properly maintained or recharged, or repaired by
persons not authorized by Seller. Misuse includes, but is not limited to, use
not in compliance with the labeling or use with accessories not manufac­tured by Seller. This warranty does not cover normal wear and tear and
maintenance items.

Limitation of Remedies

The original purchaser’s exclusive remedy shall be, at Seller’s sole option,
the repair or replacement of the Product. THIS IS THE EXCLUSIVE

REMEDY. In no event will Seller’s liability arising out of any cause
whatsoever (whether such cause is based in contract, negligence, strict
liability, tort or otherwise) exceed the price of the Product and in no
event shall Seller be responsible for consequential, incidental or special
damages of any kind or nature whatsoever, including but not limited
to, lost business, revenues and profits.

Chapter 1: Introduction

Oximeter Operation and Service Manual 1-3

Warranty Procedure

To obtain warranty service in the USA, you must request a Customer Ser­vice Report (CSR) number from Technical Service. Reference the CSR
number when returning your Product, freight and insurance prepaid, to:
Smiths Medical PM, Inc., N7 W22025 Johnson Drive, Waukesha, WI
53186-1856. Telephone: [phone]. Facsimile: 262-542-3325. Seller
will not be responsible for unauthorized returns or for loss or damage to the
Product during the return shipment. The repaired or replaced Product will
be shipped, freight prepaid, to Purchaser.

To obtain warranty service outside the USA, contact your local distributor.
Keep all original packing material, including foam inserts. If you need to

ship the device, use only the original packaging material, including inserts.
Box and inserts should be in original condition. If original shipping mate­rial in good condition is not available, it should be purchased from Smiths
Medical PM, Inc.

Damages occurred in transit in other than original shipping containers are
the responsibility of the shipper. All costs incurred returning devices for
repair are the responsibility of the shipper.

CE Notice

Marking by the symbol C

0473

indicates compliance of this device to the

Medical Device Directive 93/42/EEC.
Authorized Representative (as defined by the Medical Device Directive ):

Smiths Medical International Ltd.
Colonial Way, Watford, Herts,
UK, WD24 4LG

Phone: [phone]
Fax: [phone]

Chapter 1: Introduction

1-4 Oximeter Operation and Service Manual

Definition of Symbols

SYMBOL DEFINITION

2

Attention, consult accompanying documents.

r

Type BF equipment

7

Refer servicing to qualified service personnel.

REF

Catalog Number

SN

Serial number

R

On

Q

Off

y

Date of Manufacture

1

Non AP Device

C

Use by

Chapter 1: Introduction

Oximeter Operation and Service Manual 1-5

Warnings, Cautions, and Notes

2

WARNING! Federal law (USA) restricts this device to sale
by, or on the order of, a physician.

2

WARNING! This device is not intended for continuous
patient monitoring. This device is intended to measure the
patient’s %SpO

2

and pulse rate values. There are no audi-

ble or visible alarms.

2

WARNING! This device must be used in conjunction with
clinical signs and symptoms. This device is only int ended
to be an adjunct in patient assessment.

2

WARNING! Do not use this device in the presence of flam­mable anesthetics.

2

WARNING! Do not use this device in the presence of mag­netic resonance imaging (MR or MRI) equipment.

2

WARNING! Prolonged use or the patient’s condition may
require changing the sensor site periodic ally. Change sen­sor site and check skin integrity, circulatory status, and
correct alignment at least every 4 hours.

2

WARNING! When connecting this monitor to any instru­ment, verify proper operation before clinical use. Refer to
the instrument’s user manual for full instructions. Acces­sory equipment connected to the monitor’s data interface
must be certified according to the respective IEC stan­dards, i.e., IEC 950 for data processing equipment or IEC
601-1 for electromedical equipment. All combinations of
equipment must be in compliance with IEC 601-1-1 sys­tems requirements. Anyone connecting additional equip­ment to the signal input port or signal output port
configures a medical system, and, therefore, is responsi­ble that the system complies with the requirements of the
system standard IEC 601-1-1.

Chapter 1: Introduction

1-6 Oximeter Operation and Service Manual

2

WARNING! IEC 950 approved equipment must be placed
outside of the “patient environment.” The patient environ­ment is defined as an area 1.5 m (4.92 feet) from the
patient.

2

WARNING! When attaching sensors with Microfoam®1
tape, do not stretch the tape or attach the tape too tightly.
Tape applied too tightly may cause inaccurate readings
and blisters on the patient’s skin (lack of skin respiration,
not heat, causes the blisters).

CAUTION! Observe proper battery polarity (direction)
when replacing batteries.

CAUTION! Do not autoclave, ethylene oxide sterilize, or
immerse the sensors in liquid. Evidence that liquid has
been allowed to enter the monitor voids the warranty.

CAUTION! This device is intended for use by persons
trained in professional health care. The operator must be
thoroughly familiar with the information in this manual
before using the device. (Notice: This device is not
approved for home use by a non-health care profes­sional.)

CAUTION! Connect only the printer adapter specifically
intended for use with this device (see Optional Supplies
and Accessories).

NOTE! Operation of this device may be adv ersely af fected
in the presence of strong electromagnetic sources, such
as electrosurgery equipment.

1. Microfoam is a registered trademark of the 3M Company.

Figure 1-1: Patient Environment

Chapter 1: Introduction

Oximeter Operation and Service Manual 1-7

NOTE! Operation of this device may be adv ersely affect ed
in the presence of computed tomograph (CT) equipment.

NOTE! Use only SpO

2

sensors supplied with, or specifi-

cally intended for use with, this device.
NOTE! SpO

2

measurements may be adversely affected in

the presence of high ambient light. Shield the sensor area
(with a surgical towel, for example) if necessary.

NOTE! Dyes introduced into the bloodstream, such as
methylene blue, indocyanine green, indigo carmine,
patent blue V (PBV), and fluorescein, may ad versely affe ct
the accuracy of the SpO

2

reading.

NOTE! Any condition that restricts blood flow, such as
use of a blood pressure cuff or extremes in systemic vas ­cular resistance, may cause an inability to determine
accurate pulse rate and SpO

2

readings.

NOTE! Remove fingernail polish or false fingernails be fore
applying SpO

2

sensors. Fingernail polish or false finger-

nails may cause inaccurate SpO

2

readings.

NOTE! The presence of dyshemoglobins, such as carbox­yhemoglobin (with CO-poisoning) or methemoglobin (with
sulfonamide therapy) may advers ely affect the accuracy
of the SpO

2

measurement.

NOTE! Hazards arising from software errors have been
minimized. Hazard analysis was performed to meet
EN1441: 1997.

NOTE! Optical cross-talk can occur when two or more
sensors are placed in close proximity. It can be eliminated
by covering each site with opaque material.

This page is intentionally left blank.

Chapter 2: General Description

Oximeter Operation and Service Manual 2-1

Chapter 2: General Description

Intended Use

The oximeter provides fast, reliable SpO2 and pulse rate measurements. It
can be used in the hospital or clinical environment, and during emergency

air or land transport. The oximeter will operate accurately over an ambient
temperature range of 32 to 131° F (0 to 55° C). The oximeter works with

all BCI

®

oximetry sensors providing SpO2 and pulse rate on all patients

from neonate to adult.

Features

• Provides fast, reliable SpO2 and pulse rate measurements on any

patient, from neonates to adults.

• Ideally suited for use in intensive care units, in outpatient clinics,

in emergency rooms, or during emergency air or land transport.

• Portable and lightweight. Weighs only 9 ounces (255 grams) with-

out the batteries.

• Ergonomically designed to fit comfortably in the palm of your

hand.

• Uses three standard alkaline batteries (type LR 14) or three

rechargeable (type KR27/50) NiCad “C” cell batteries.

• Battery life is approximately twenty-four (24) hours in continuous

mode or eighty (80) hours in spot check mode.

• Bright, easy-to-read LED displays indicate SpO

2

and pulse rate

measurements.

• An eight-segment LED bar graph indicates pulse strength.

• Automatically turns off after patient’s finger is removed from the

sensor.

• Low battery indicator lights when about two hours of battery use

remains.

• Optionally connects to an external printer or computer, providing

spot check printouts of SpO

2

and pulse rate readings.

• Collects up to seventeen (17) hours of spot check data for up to

ninety-nine (99) patients for printout later.

Chapter 2: General Description

2-2 Oximeter Operation and Service Manual

Description

PATIENT CABLE/SENSOR

The sensor connects here. If you need the extra length of the patient cable,
attach the sensor to the patient cable, then attach the patient cable to the
oximeter’s PATIENT CABLE/SENSOR connector. The serial printer or PC
communication cable is also connected here.

% SpO

2

DISPLAY

The % SpO

2

value is shown here. Dashes ( -- ) indicate the oximeter is

unable to calculate the SpO

2

value.

PULSE RATE DISPLAY

The pulse rate value is shown in beats per minute (BPM). Dashes ( --- )
indicate the oximeter is unable to calculate the pulse rate value. Flashing
255 indicates the pulse rate value is greater than 255.

Figure 2-1: Oximeter Controls

Patient Cable/Sensor

% SpO

2

Display

Pulse Rate Display
Pulse Strength Bar Graph

R and Q Keys

Low Battery Indicator

Batteries and
Access Door

Chapter 2: General Description

Oximeter Operation and Service Manual 2-3

PULSE STRENGTH BARGRAPH

The eight-segment bar graph “sweeps” with the patient’s pulse beat, indi­cating pulse strength. The bar graph is logarithmically scaled to indicate a
wide range of pulse strengths.

R and Q KEYS

Press “R” to turn on the oximeter. Press “Q” to turn off the oximeter.
While the oximeter is on, momentarily pressing the “R” key increments the

patient number. While the oximeter is on, pressing and holding the “R” key
for about six seconds clears all the spot check data and resets the patient
number to P1.

The oximeter turns off automatically two minutes after the sensor is
removed from the patient or after the sensor is disconnected from the
oximeter. This feature extends the battery use time.

LOW BATTERY INDICATOR

When about two hours of battery use time remains, the left-most bar graph
segment lights. The oximeter will continue to operate normally until the
batteries no longer have sufficient power to operate the oximeter. At that
point, the oximeter automatically turns off.

BATTERIE S AND ACCESS DOOR

The oximeter’s three “C” cell batteries are accessed through this door on
the backside of the oximeter. See Installing or Replacing the Batteries for
details on installing or replacing the batteries.

Chapter 2: General Description

2-4 Oximeter Operation and Service Manual

Theory of Operation

The oximeter determines SpO2 and pulse rate by passing two wavelengths
of light, one red and one infrared, through body tissue to a photodetector.

During measurement, the signal strength resulting from each light source
depends on the color and thickness of the body tissue, the sensor place­ment, the intensity of the light sources, and the absorption of the arterial
and venous blood (including the time varying effects of the pulse) in the
body tissues.

The oximeter processes these signals, separating the time invariant parame­ters (tissue thickness, skin color , light intensity , and venous blood) from the
time variant parameters (arterial volume and SpO

2

) to identify the pulse

rate and calculate oxygen saturation. Oxygen saturation calculations can be
performed because oxygen saturated blood predictably absorbs less red
light than oxygen depleted blood.

Figure 2-2: Oximetry Theory of Operation

Low intensity red and infrared LED light sources

Detector

Chapter 3: Using the Oximeter

Oximeter Operation and Service Manual 3-1

Chapter 3: Using the Oximeter

Unpack the Oximeter

Carefully remove the oximeter and its accessories from the shipping car­ton. Save the packing materials in case the oximeter must be shipped or
stored.

Compare the packing list with the supplies and equipment you received to
make sure you have everything you’ll need.

Install the Batteries

The oximeter uses three standard “C” cell batteries (type LR 14). You can
use disposable alkaline batteries or rechargeable (type KR27/50) batteries.

If you use disposable batteries, be sure to dispose of them in compliance
with your institution’s guidelines and local ordinances.

If you use rechargeable batteries, it’s best to have two sets of batteries on
hand. That way, you can use one set of batteries in the oximeter while the
other set of batteries is recharging.

NOTE! If you’ve collected spot check data for printing,
make sure you print the spot check data before removing
and replacing the oximeter’s batteries. Removing the bat­teries erases spot check data from the oximeter’s memory.

Chapter 3: Using the Oximeter

3-2 Oximeter Operation and Service Manual

Installing or Replacing the Batteries

1. Turn over the oximeter so its back is
facing you.

2. Push on the thumb grip and slide the
door open.

3. If you are replacing the batteries,
remove the old batteries from the
battery compartment.

If the old batteries are disposable, be
sure to dispose of them in compli­ance with your institution’s guide­lines and local ordinances.

If the old batteries are rechargeable,
be sure to charge them right away so
they’ll be ready to use again as s oon
as possible.

4. Install three batteries in the oximeter
battery compartment. Make sure the
batteries are installed in the proper
direction.

5. Slide the battery door closed, push­ing firmly until it snaps into place.

NOTE! It is easiest to install
the batteries in the sequenc e
shown in figure 3-2.

Figure 3-1: Open
the Battery Door

Figure 3-2: Install
the Batteries

Chapter 3: Using the Oximeter

Oximeter Operation and Service Manual 3-3

Care and Handling of Sensor

Hold the connector rather than the cable when connecting or disconnecting
the finger sensor to the oximeter as shown in figure 3-3.

Do not use excessive force, unnecessary twisting, or kinking when con­necting, disconnecting, storing, or when using the sensor.

When placing the sensor on the patient, allow the cable to lay across the
palm of the hand and parallel to the arm of the patient as shown in figure
3-4.

Upon completion of patient monitoring, detach the sensor and loosely coil
finger sensor cable. Do not wrap the finger sensor cable around the oxime­ter.

2

WARNING! Misuse or improper handling of the sensor and
cable could result in damaging the sensor. This may cause
inaccurate readings.

Figure 3-3: Connect the Finger Sensor

Figure 3-4: Position
the Sensor Cable

Chapter 3: Using the Oximeter

3-4 Oximeter Operation and Service Manual

Choose the Sensor

Choose the appropriate sensor from the following chart. Refer to the sensor
insert for application instructions.

Patient Site Description

Adult

>45 Kg

Finger 3044: Sensor, Reusab le, Adult

3444: Sensor, Reusable, Comfort Clip

®

1310: D.O.T. Reusable Oximetry Sensors

Finger or Toe 3043: Sensor, Universal “Y”

1300: Sensor, Disposable, Adult, Finger

Ear 3078: Sensor, Ear

Pediatric

15-45 Kg

Finger 3044: Sensor, Reusab le, Adult

3444: Sensor, Reusable, Comfort Clip

®

3178: Sensor, Reusable, Pediatric

Finger or Toe 3043: Sensor, Universal “Y”

1301: Sensor, Disposable, Pediatric, Finger

Ear 3078: Sensor, Ear

Infant

3-15 Kg

Hand or Foot
Toe
Finger or Toe

3043: Sensor, Universal “Y”
3025: Sensor, Wrap, Infant
1303: Sensor, Disposable, Infant

Neonate

<3 Kg

Hand or Foot
Foot

1302: Sensor, Disposable, Neonate
3026: Sensor, Wrap, Neonate

Chapter 3: Using the Oximeter

Oximeter Operation and Service Manual 3-5

Attach the Sensor to the Patient

Clean or Disinfect the Sensors

Clean or disinfect the reusable sensors before attaching a new patient.

Clean the sensor with a soft cloth moistened in water or a mild soap solu­tion. To disinfect the sensor, wipe the sensor with isopropyl alcohol.

Finger Sensor for Adult or Pediatric Finger

Attach the finger sensor to
the patient as shown. Be
sure to fully insert the
patient’s finger into the sen­sor. For patients with long
fingernails, use the universal
“Y” sensor.

2

WARNING! Prolonged use or the patient’s condition may
require changing the sensor site periodically. Change sen­sor site and check skin integrity, circulatory status, and
correct alignment at least every 4 hours.

2

W ARNING! When at t aching s ensors with Microfoam® tape,
do not stretch the tape or attach the tape too tightly. Tape
applied too tightly may cau se in acc urat e rea din gs a nd blis­ters on the pat ient’s skin (lack of skin respiration, not heat,
causes the blisters).

2

WARNING! Do not autoclave, ethylene oxide sterilize, or
immerse the sensors in liquid.

2

CAUTION! Unplug the sensor from the monitor before
cleaning or disinfecting.

Figure 3-5: Attach the Finger Sensor

Chapter 3: Using the Oximeter

3-6 Oximeter Operation and Service Manual

Attach the Sensor to the Oximeter

• Attach the sensor connector to the oximeter’s PATIENT CABLE/

SENSOR connector.

• If you need the extra length of the patient cable, attach the sensor

to the patient cable, then attach the patient cable to the oximeter’s
PATIENT CABLE/SENSOR connector.

Measuring the Patient’s % SpO2 and Pulse Rate

To begin measuring the patient’s SpO2 and pulse rate, press the “R” key.
When turned on, the oximeter goes through this power-up sequence:

• The pulse strength bar graph segments light one at a time.

• The oximeter's software revision is momentarily displayed.

• The patient number for spot check printouts is momentarily dis-

played. The format for the patient number display is “P” followed
by the number. For example, P14 means the patient number is 14.

Figure 3-6: Attach the
Sensor to the Oximeter

Chapter 3: Using the Oximeter

Oximeter Operation and Service Manual 3-7

After a few seconds the % SpO2 value, pulse rate, and pulse strength bar
graph should be shown. If not, see Operator’s Troubleshooting Chart for

help.

The SpO

2

display shows the patient’s blood oxygen saturation, calculated

as a percentage. The pulse rate display shows the patient’s pulse rate in
beats per minute (BPM). The pulse strength bar graph shows the patient’s
pulse strength; the bar graph is scaled logarithmically to indicate a wide
range of pulse strengths.

Figure 3-7: SpO2 Pulse Rate and Pulse Strength Bar Graph

% SpO

2

Value Displayed

Pulse Rate Value Displayed
Pulse Strength Bar Graph

Sweeping with Patient’s
Pulse

Press On

Low Battery Indicator

Chapter 3: Using the Oximeter

3-8 Oximeter Operation and Service Manual

Patient Numbers and Spot Check Data

Whenever the oximeter is on, it stores one SpO2 and pulse rate reading
every thirty (30) seconds. The stored readings are called spot check data.

The oximeter remembers spot check data for up to ninety-nine (99) patients
and seventeen (17) hours of run-time. The spot check data then can be
printed at any time on the optional printer.

Spot check data is saved for each patient number. When you turn on the
oximeter, the patient number is automatically incremented and displayed
during the power-up sequence if valid spot check data was collected from
the previous patient. When the patient number is incremented, then spot
check data is saved for the new patient number. If no valid spot check data
was collected from the previous patient, the patient number is displayed
only and is not incremented. The oximeter remembers all the spot check
data and all the patient numbers for up to ninety-nine (99) patients and sev­enteen (17) hours of run-time.

Manually Incrementing the Patient Number

Press the “R” key while the oximeter is on to manually increment the
patient number . The new patient number is momentarily displayed and spot
check data for the new patient is automatically saved.

Clearing All Spot Check Data

Press and hold the “R” key for about six seconds while the oximeter is on to
clear all spot check data and reset the patient number to

P1. While you are

holding the “R” key, the message

[{r flashes on the display to notify you

that the spot check data for all patients is about to be cleared. When the
spot check data is cleared, the display shows

P1.

See Spot Check Printouts for more information on printing spot check data.

Low Battery Indicator

When about two hours of battery use time remains, the left-most bar graph
segment lights. The oximeter will continue to operate normally until the
batteries no longer have sufficient power to operate the oximeter. At that
point, the oximeter automatically turns off.

Chapter 3: Using the Oximeter

Oximeter Operation and Service Manual 3-9

Turning Off the Oximeter

Press the “Q” key to turn off the oximeter.
The oximeter turns off automatically two minutes after the sensor is

removed from the patient or after the sensor is disconnected from the
oximeter. This feature extends the battery use time.

Checking the Oximeter’s Performance

Pulse oximeters do not require user calibration. To check the function of
the device, an optional Oximeter/ECG Patient Simulator is available as an

accessory (BCI

®

Cat# 1606HH). The simulator attaches to the oximeter in

place of the sensor or patient cable. It provides a known SpO

2

and pulse

rate signal to the oximeter, allowing the oximeter's performance to be
checked.

Follow the instructions included with the Oximeter/ECG Patient Simulator.

NOTE! At power up, when the sensor is disconnected and
patient data is stored, the oximeter will turn off automati­cally two minutes after the oximeter executes its print
patient routine.

This page is intentionally left blank.

Chapter 4: Printer and Computer Interface

Oximeter Operation and Service Manual 4-1

Chapter 4: Printer and Computer Interface

Computer Interface Description

The oximeter can transfer stored data to a PC. Information Data Log and
Spot Checks will be displayed/saved to a file in the format as shown in the
Spot Check Printouts section of this manual.

Equipment Required

1. Hand Held Oximeter

2. 3350 Printer Cable

3. 3339 PC Adapter Cable

4. Communication settings:

Interface Instructions

1. Disconnect the sensor from the oximeter.

2. Connect the printer adapter cable (part #3350) to the sensor connector

on the unit.

3. Connect 9-pin connector of PC adapter cable (part #3350) to the

printer adapter cable (part #3339). Be sure to connect the 3339 to the
end of the 3350 cable marked as “printer.”

Baud rate 9600
Data bits 8
Stop bits 1
Parity none
I/O Port: Serial RS-232C
Data Type: ASCII
Data Format: 9600 baud, 1 start bit, 8 data

bits, 1 stop bit, no parity

I/O Connector: Standard DB-9

Chapter 4: Printer and Computer Interface

4-2 Oximeter Operation and Service Manual

4. Using the PC adapter cable (part #3339), connect the 9-pin connector
of the PC adapter cable to the COM port on the PC as shown in figure
4-1.

2

WARNING! When connecting this monitor to any instru­ment, verify proper operation before clinical use. Refer to
the instrument’s user manual for full instructions. Acces­sory equipment connected to the monitor’s data interface
must be certified according to the respective IEC stan­dards, i.e., IEC 950 for data processing equipment or IEC
601-1 for electromedical equipment. All combinations of
equipment must be in compliance with IEC 601-1-1 sys­tems requirements. Anyone connecting additional equip­ment to the signal input port or signal output port
configures a medical system, and, theref ore, is responsible
that the system complies with the requirements of the sys­tem standard IEC 601-1-1.

Figure 4-1: Connect the Oximeter to a PC

Connect to
Oximeter

Cable (catalog # 3350)

Cable (catalog # 3339)

Printer Adapter
db-9 Connector

PC Adapter
db-9 Connector

Connect to IBM
Compatible PC
or Printer

Chapter 4: Printer and Computer Interface

Oximeter Operation and Service Manual 4-3

Spot Check Printouts

Collecting Spot Check Data

Whenever the oximeter is on, it stores one SpO

2

and pulse rate reading

every thirty (30) seconds. The stored readings are called spot check data.
The oximeter remembers spot check data for up to ninety-nine (99) patients
and seventeen (17) hours of run-time. The spot check data then can be
printed at any time on the optional printer .

Spot check data is saved for each patient number. When you turn on the
oximeter, the patient number is automatically incremented and displayed
during the power-up sequence if valid spot check data was collected from
the previous patient. When the patient number is incremented, then spot
check data is saved for the new patient number . If no valid spot check data
was collected from the previous patient, the patient number is displayed
only and is not incremented. The oximeter remembers all the spot check
data and all the patient numbers for up to ninety-nine (99) patients and sev­enteen (17) hours of run-time.

Manually Incrementing the Patient Number

Press the “R” key while the oximeter is on to manually increment the
patient number . The new patient number is momentarily displayed and spot
check data for the new patient is automatically saved.

Clearing All Spot Check Data

Press and hold the “R” key for about six seconds while the oximeter is on to
clear all spot check data and reset the patient number to

P1. While you are

holding the “R” key, the message

[{r flashes on the display to notify you

that the spot check data for all patients is about to be cleared. When the
spot check data is cleared, the display shows

P1.

About the Oximeter’s Batteries and Spot Check Data

NOTE! If you’ve collected spot check data for printing, make
sure you print the spot check data before removing and
replacing the oximeter’s batteries. Removing the batteries
erases spot check data from the oximeter’s memory.

Chapter 4: Printer and Computer Interface

4-4 Oximeter Operation and Service Manual

Printing Spot Check Data

1. Set up the oximeter and the
printer as previously described.

2. Disconnect the SpO

2

sensor

from the oximeter.

3. Turn on the printer.

4. Turn on the oximeter. The
oximeter prints the spot check
data for each patient, from
patients 1-99, as shown in the
sample printout.

5. If there is no spot check data at
all, the message **** is printed.

6. The oximeter does not automati­cally turn itself off when print­ing spot check data.

7. If no valid data is collected for a
patient number, **** is printed.

8. If valid data is collected for a
patient number for less than one
minute, only the last measure­ment is printed.

9. If data is collected for a patient number for more than one minute, the
relative time since the first measurement is shown for that patient.

10. Dashes indicate invalid or unavailable data (for example, the patient’s
finger was removed from the SpO

2

sensor).

Figure 4-2: Print Spot Check Data

Chapter 5: Operator’s Maintenance

Oximeter Operation and Service Manual 5-1

Chapter 5: Operator’s Maintenance

Batteries

When about two hours of battery use time remains, the left-most bar graph
segment lights. The oximeter will continue to operate normally until the
batteries no longer have sufficient power to operate the oximeter. At that
point, the oximeter automatically turns off.

Replace weak or dead batteries with new disposable batteries or freshly
charged NiCad batteries. See Installing or Replacing the Batteries for
instructions.

Disposal of batteries and rechargeable batteries

Batteries and rechargeable batteries

• do not throw into fire - risk of explosion.

• do not force open - danger of corrosion.

• do not recharge normal batteries.

• Batteries and rechargeable batteries must be treated as special
waste.

• dispose of in accordance with local waste disposal regulations.

For information contact the local environmental protection offices or
licensed waste disposal contractors.

Sensors

Reusable Sensors

Clean the reusable sensor’s surfaces with a soft cloth moistened in a mild
soap solution. If disinfection is required, wipe the reusable sensor’s sur­faces with a soft cloth moistened in isopropyl alcohol. Do not allow liquid
to enter any of the sensor’s openings.

2

WARNING! Prolonged use or the patient’s condition may
require changing the sensor site periodically. Change sen­sor site and check skin integrity, circulatory status, and
correct alignment at least every 4 hours.

CAUTION! Do not autoclave, ethylene oxide sterilize, or
immerse the sensors in liquid.

Chapter 5: Operator’s Maintenance

5-2 Oximeter Operation and Service Manual

Disposable Sensors

Disposable sensors are for single-patient use only. Disposable sensors can
be repositioned on the same patient as long as the correct SpO

2

and pulse

rate values are shown after repositioning. Disposable sensors cannot be
cleaned or repaired; discard them if they become soiled or no longer work.

Cleaning the Oximeter’s Surfaces

Clean the oximeter’s surfaces with a soft cloth moistened in a mild soap
solution. If disinfection is required, wipe the oximeter’s surfaces with a
soft cloth moistened in isopropyl alcohol. Do not allow any liquid to enter
any of the oximeter’s openings.

Long Term Storage

Remove the batteries from the oximeter before long term storage, or if the
oximeter won't be used for 6 months or more. This protects the oximeter
from damage due to batteries leaking acid.

Store the oximeter in its original shipping carton and packing materials to
help protect the oximeter from damage during storage.

CAUTION! Do not autoclave, ethylene oxide sterilize, or
immerse the oximeter in liquid.

Chapter 6: Operator’s Troubleshooting Chart

Oximeter Operation and Service Manual 6-1

Chapter 6: Operator’s Troubleshooting Chart

Problem Possible Cause Corrective Action

No pulse shown on
the bar graph.

Patient cable or sen­sor is disconnected
from the oximeter.
Sensor is incorrectly
positioned on the
patient.
Poor patient perfu­sion.
Defective sensor or
patient cable.

Check sensor connections to the
patient cable and to the oximeter.

Reposition the sensor.

Reposition the sensor.

Try a new sensor or contact your
authorized repair center for help.

Pulse rate is erratic,
intermittent, or
incorrect.

Sensor incorrectly
positioned.

Patient motion

Reposition the sensor.

SpO

2

value is

erratic, intermittent,
or incorrect.

Poor patient perfu­sion.

Patient motion.

Reposition the sensor

Patient must remain still to obtain
an accurate measurement.

The oximeter doesn't
turn on.

Batteries weak.

Batteries not
installed or batteries
incorrectly installed.

Replace the batteries.

Ensure the batteries are installed
correctly.

Chapter 6: Operator’s Troubleshooting Chart

6-2 Oximeter Operation and Service Manual

The oximeter turns
off unexpectedly.

The oximeter turns
itself off automati­cally two minutes
after the sensor is
removed from the
patient or after the
sensor is discon­nected from the
oximeter. This fea­ture extends the bat­tery use time.

Batteries are weak or
dead.

None.

Replace the batteries.

No printout on
optional printer.

Printer power not
connected or printer
power switch is Off.

Connect the printers power source
and turn on the printer.

Printer interface
assembly not
securely connected.

Push on both ends of the printer
interface assembly to ensure all
the connections are tight.

Printer interface
malfunction.

Contact your authorized repair
center for help.

No trends in mem­ory.

Collect trend data.

Sensor must be dis­connected for spot
check output.

Disconnect sensor.

E00 ROM Error

7 Refer servicing to qualified

service personnel. Contact Smiths
Medical PM, Inc. Service

E01 RAM Error

7 Refer servicing to qualified

service personnel. Contact Smiths
Medical PM, Inc. Service

Chapter 6: Operator’s Troubleshooting Chart

Oximeter Operation and Service Manual 6-3

EMI Interference

The monitor is designed for use in environments in which the signal can be
obscured by electromagnetic interference. During such interference, mea­surements may seem inappropriate or the monitor may not seem to operate
correctly.

The monitor generates, uses, and can radiate radio frequency energy and, if
not installed and used in accordance with these instructions, may cause
harmful interference with other devices in the vicinity. Disruption may be
evidenced by erratic readings. Cessation of operation, or other incorrect
function. If this occurs, the site of use should be surveyed to determine the
source of this disruption, and actions taken to eliminate the source:

• Turn equipment in the vicinity off and on to isolate the offending
equipment.

• Reorient or relocate the other receiving device.

• Increase the separation between the interfering equipment and this
equipment.

If assistance is required, contact Smiths Medical PM, Inc. Service Depart­ment or you local representative.

2

CAUTION! This device has been tested and found to com­ply with the limits for medical devices to the IEC 601-1­2:1993, EN 60601-1-2:1994, Medical Device Directive 93/42/
EEC. These limits are designed to provide reasonable pro­tection against harmful interference in a typical medical
installation. However, because of the proliferation of radio­frequency transmitting equipment and other sources of
electrical noise in the heath-care and home envir onments
(for example, cellular phone, mobile two-way radios, elec­trical appliances), it is possible that high levels of such
interference due to close proximity or strength of a so urce,
may result in disruption of performance of this device.

This page is intentionally left blank.

Chapter 7: Optional Supplies and Accessories

Oximeter Operation and Service Manual 7-1

Chapter 7: Optional Supplies and Accessories

Cat. No Description Quantity

1300 Sensor, Oximetry, Disposable, Adult Finger 10/box
1301 Sensor, Oximetry, Disposable, Pediatric,

Finger, 15-45 Kg

10/box

1302 Sensor, Oximetry, Disposable, Neonate,

< 3 Kg

10/box

1303 Sensor, Oximetry, Disposable, Infant,

3-15 Kg

10/box

1310 D.O.T. Reusab le Oximetry Sensors 3/box
1311 D.O.T. Sensor Replacement Tape 24/pkg
1606HH Simulator & Cable, Oximeter, 5 ft. each
1818R Manual, Operation (English and Spanish)

and Service (English)

each

3025 Sensor, Oximetry, Wrap, Infant, 3-15 Kg each
3026 Sensor, Oximetry, Wrap, Neonate, < 3 Kg each
3043 Sensor, Oximetry, Universal “Y” each
3044 Sensor, Oximetry, Finger each
3049 Strips, Adhesive 40/pkg
3078 Sensor, Oximetry, Ear each
3134 Tap e, Attachment, Neonatal 50/pkg
3135 Tap e, Attachment, Infant 50/pkg
3136 Tape, Attachment, Neonatal 100/pkg
3137 Tape, Attachment, Infant 100/pkg
3138 Posey Wrap, Attachment, Universal "Y" 10/pkg
3178 Sensor, Oximetry, Pediatric Finger each
3311 Cable, Patient, 5 ft. each
3315 Case, Carrying each
3318 Protective Boot with Strap each
3339 PC Adapter Cable each
3444

Sensor, Oximetry, Finger, Comfort Clip

®

each

3350 Cable, printer interface each

Chapter 7: Optional Supplies and Accessories

7-2 Oximeter Operation and Service Manual

Ordering Information

For ordering information, contact your local distributor or the Smiths Med­ical PM, Inc. customer service department.

Smiths Medical PM, Inc.

N7 W22025 Johnson Drive

Waukesha, WI 53186 USA

Phone: [phone]

Fax: [phone]

Email Address: [e-mail]

Chapter 8: Specifications

Oximeter Operation and Service Manual 8-1

Chapter 8: Specifications

Equipment Classification

Displays, Indicators, & Keys

SpO

2

Type of Protection Against Electric shock: Internally Powered
Mode of operation: Continuous
Degree of Protection Against ingress of Liquids: IPX1, drip proof
Degree of Mobility: Portable
Degree of Protection Against Electric Shock: Type BF
Safety Requirements: EN60601-1; 1990

SpO

2

: LED numeric display, 0.46 inches (11.68 mm) high

Pulse Rate: LED numeric display, 0.38 inches (9.65 mm) high
Pulse Strength: Logarithmically scaled 8-segment LED bar graph
Keys: R & Q keys

Range: 0-99%
Accuracy: ±2% at 70-99%
Averaging: 8 pulse beat average
Display Response The display is to functional saturation. The pulse

strength bar graph is not proportional to pulse vol­ume.

Display Update
Rate

1 Hz (SpO

2

); 60 Hz (pulse strength)

Calibration Factory calibrated over range 70% to 100% SpO

2

using human blood samples to functional saturation.
Test methods available upon request. No in-service
calibration required.

Sensors Red 660nm, 2mW (typical)

Infrared 905nm, 2-2.4mW (typical)

Chapter 8: Specifications

8-2 Oximeter Operation and Service Manual

Pulse Rate

Auxiliary Printer Output

Data saved every thirty (30) seconds can be printed (spot check).

Power Requirements

Uses three standard alkaline (type LR 14) or nickel-cadmium “C” cell bat­teries (type KR27/50).

Battery Life

Approximately 24 hours in continuous mode or 80 hours in spot check
mode.

Dimensions

Environmental Specifications

Range: 30-254 BPM
Accuracy: ±2% at 30-254 BPM
Averaging: 8 second average
Display Update Rate 1 Hz

Width: 3.25 inches (82.6 mm)
Height: 6.3 inches (160 mm)
Depth: 1.25 inches (31.75 mm)
Weigh t: 9 ounces (255 grams) without the batteries

Operating Temp.: 0-55° C (32-131° F)
Storage Temp.: -34-70° C (-29-158° F)
Relative Humidity: 10-95% (storage), non-condensing

15-95% (operating), non-condensing

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-1

Chapter 9: Service Maintenance and Repair

The service maintenance and repair section contains circuit descriptions,
voltage test points, and waveform test points. The Appendix contains
detailed parts lists and circuit diagrams. It is intended for persons trained in
service, maintenance, and repair of modern medical equipment. Thorough
knowledge of this equipment’s operation is required before attempting to
repair this equipment.

General Description

The oximeter contains one circuit board. This board contains all power
supply, microprocessor, date acquisition, and display circuitry.

Power Supply and ON/OFF Circuitry

The power supply is built around a switch mode regulator IC U10. It is
configured as a fly-back regulator to convert input voltage in the range of

2.7-4.5 VDC into +5VDC output voltage. Negative voltage used by the
analog section is generated as a “by-product” of the main +5VDC supply.
Charge pump C55-D4-C69 is used to convert pulsatile voltage on the out­put LX of U10 into negative voltage in the range of –4VDC to –6VDC.
The V-RAM voltage used by the on-off circuitry and RAM is generated
either from the battery, or from VCC when unit is on. V-RAM is taken
straight from the battery due to the maximum voltage being 4.5V. V-RAM
may approach +3VDC as the battery power gets depleted, however, this
voltage is high enough to retain trend data in RAM. Capacitor C70 is used
to maintain V-RAM when batteries are being replaced. It can keep infor­mation in RAM for more than 1.5 minutes.

On/Off circuitry is built around U7A-U7B flip-flop, which directly con­trols regulator IC U10.

Digital Section

Microprocessor U11 is Hitachi HD64180. Its address and data buses are
connected to the One Time Programmable Read Only Memory (OTP
ROM) U12 and Random Access Memory (RAM) U24. Memory Address
Decoder is implemented using U17A demultiplexer chip.

Chapter 9: Service Maintenance and Repair

9-2 Oximeter Operation and Service Manual

Memory address map is shown in the following table:

Display Select Signal DSP-LD is used to latch displayed data into U22 and
U23 LED drivers.

Address decoder for Input/Output Interface devices is implemented using
U17B demultiplexer chip.

The I/O address space is divided according to the following table:

Watch dog timer U18 is used to reset microprocessor in case of ESD and at
power up. Its internal comparator is used to compare battery voltage offset
by Vr voltage coming from digitally co ntrolled potentiometer with internal
U18 voltage reference. The output of the comparator (signal BATT) is used
to detect battery voltage. The following battery states are distinguished by
this measurement system:

RS-232 communication interface is built around Q3, Q5, and Q6. It con­verts CMOS voltage levels into RS-232 bipolar voltage levels. Inverter
U16C is used to disable communication interface circuitry when oximetry
probe is plugged in to reduce power consumption and eliminate cross-talk
between communication and probe reading.

Device Address Space

OTP ROM 0..FFFF
RAM 10000..1FFFF
Display Select Signal 20000..2FFFF

I/O Address Space Device

0..3F Used by Z180 for internal registers

40..7F Input port

80..BF Output port

Battery Voltage Condition

2.7V Dead battery level-units shuts itself
off

3.0V Low battery level-signal to user

4.5V Ok battery level

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-3

Internal timer 1 of U11 is used as a tone generator to drive piezo speaker
through connector J5.

Analog Section

Analog to Digital Converter (ADC) U6 is a 12 bit, successive approxima­tion sampling ADC. The ADC+IN signal input comes from TP22. VREF is
used here as a pseudo ground. The ADC is configured as a differential
input converter with the –IN input connected to VREF. This allows the +IN
signal to range from 2.5V to 5V. The ADC transfers data with a 3 wire
serial interface. ADCLK synchronizes the data transfer with each bit being
transmitted on the falling ADCCLK edge and captured on the rising
ADCLK edge. /ADCS must beheld low when the ADC transmits data.

LED Drive circuitry is used to turn on and off the oximetry probe LED’s,
precisely controlling the current through them. The second half of the vari­able potentiometer U5 is used to generate voltage between 0 and 2.5VDC.
U5 is controlled, serially, by the processor. Operational amplifier U2B
together with transistor Q7 create a constant current sink. The current is
proportional to the voltage generated by variable potentiometer. The H­bridge Q8-Q9 is used to activate either LED, red or infrared, inside the
oximeter probe. The following table describes the states of the H-bridge:

In this table, 1 indicates logic 1, 0 indicates logic 0, and x indicates either
logic 0 or 1.

The “Open circuit” state is used to check for a possible probe cable fault. In
case of probe cable fault, one of the LED wires can short to the ground
shield causing high current through the probe LED. To prevent this, before
turning any LED on, the processor checks the cable by “floating” the H­bridge. If the cable is shorted CON3 and CON2 connections are pulled low ,
and comparator U9A generates /PRB_FAULT signal, which causes the
processor to shut down the LED excitation cycle and generate the appropri­ate message.

RED-DRV IR-DRV FET-ON Function

101Red LED is on
011Infrared LED is

on

X X 0 “Open circuit”

state

Chapter 9: Service Maintenance and Repair

9-4 Oximeter Operation and Service Manual

The differential photo amplifier formed by U1 and U3A, converts the pho­todetector’s current output to a voltage at T10 (VAMB). Amplifier U3B
offsets the signal at T10 allowing a wider signal range. Comparator U9B is
used to inform the microprocessor if U3A is saturated by an excess of
ambient light. VAMB is passed through blocking capacitor C77 to remove
the signal’s DC component. The signal is then buffered and amplified by
U27A. Gain is defined by the first channel of digital potentiometer U5. The
output of U27A is routed to the integrator-filter-of fset circuitry U27B, con­trolled by analog switch S53. The output of the integrator is then routed to
the ADC for measurement.

LED Controller

LED controller is built around U22 and U23 buffers. Data is latched into
buffers by DSP-LD signal. Signal/DSP-EN is used to disable LED’s at
power up to limit initial surge current.

Signal Dictionary

This section lists, in alphabetical order, the signal names used on the sche­matics. The signal’s origin, destination, and purpose are described.

Signal Description

ADCLK
ADOUT
/ADCS

3 wire serial interface for analog to digital converter U6.

/AMB­FAULT

Signal informing processor about excess of ambient light.

ANA+5 Filtered VCC. ANA+5 powers the analog circuitry.
ANA-5 ANA-5 po wers the analog circuitry.
BASE Keeps integrator U27B fro saturating during data acquisitions.
BATT Signal from watchdog timer U18 to inform processor of low bat-

tery condition.

CAP­GND

Signal used to short blocking capacitor C77 to ground.

CTS0 Serial Port Clear To Send handshake signal from external RS-232

communication device.

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-5

CON2,
CON3

Probe LED’s driving signals.

/DSP­EN

Enable display drivers signal.

DSP-LD Signal used to load data into display drivers.
FET-ON Used to control MOSFET H-bridge Q8 and Q9, which powers

probe LED’s.
INTGAT Signals used to enable integrator U27B.
IR-DRV Used to control MOSFET H-bridge Q8 and Q9, which powers

probe LED’s.
/NMI Non-Maskable Interrupt that signals watch dog timer time-out.
PON Power on signal.
CLK Clocks data into digital potentiometer chip U5.
POT-LD POT-LD is used to select digital potentiometer chip U5.
SDI Serial Data Input to digital potentiometer chip U5.
PRB-

DET

PRB-DET is used to inform processor if probe is plugged in.

/PRB­FAULT

Signal used to inform processor about probe cable problem.

QUIET Signal used to shut down power down supply during data acquisi-

tion.
RX External RS-232 receive (CTS0) line.
RED-

DRV

Used to control MOSFET H-bridge Q8 and Q9, which powers

probe LED’s.
RESET System reset signal generated by the watch dog tim e r U18 .
RST-

INT

Resets integrator U27B by shorti n g cap acit o r C50.

SHT­DWN

Output of the microprocessor to turn unit off.

TX External RS-232 transmit line.
/TEN Signal which enables RS-232 driver. Is connected to PRB-DET

signal.

Chapter 9: Service Maintenance and Repair

9-6 Oximeter Operation and Service Manual

Test Equipment and Tools Required

To diagnose and repair the full extent of possible malfunctions on the
oximeter and display board, you will need the following test equipment
and tools:

• DMM volts/ohms/amps, with MΩ input impedance or greater.

• Oscilloscope, 50 MHz, with 10 MΩ input impedance or greater.

• Variable output DC power supply, 0-5 VDC at 200 mA or greater.

• Small Phillips screwdriver

• Small flat blade screwdriver

• Needle nose pliers

• Diagonal cutters

• Clip leads

• Low-power microscope or magnifying glass

• Soldering iron and solder

• Solder wick or solder remover

Connecting a DC Power Supply

To verify so me of the voltage measurements that follow, you’ll need to
connect a variable output DC power supply in place of the three “C” cell
batteries. You must be careful to observe the polarity of J9 when doing this.
Follow these steps to connect a DC power supply in place of the “C” cell
batteries:

TXA0 Asynchronous serial communication transmit signal to RS-232.
VAMB VAMB is the output of the front-nd differential amplifier.
V-BT Battery voltage
VR Output voltage from the digitally controlled potentiometer.
VREF 2.5VDC reference to voltage.
V-RAM Voltage used to maintain trend information in RAM.
VCC,

VDD

5VDC used for digital output supply voltage.

/WDT Watch dog timer strobe

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-7

1. Remove the three “C” cell batteries.

2. Connect the DC power supply’s “+” output to J9-1.

3. Connect the DC power supply’s “-” or “ground” output to J9-2.

Voltage Test Points

Unless otherwise noted, all voltages are measured with respect to ground at
P1-2.

CAUTION! Be sure to observe the polarity of the battery
connections. Failure to observe the polarit y may cause fus e
F1 to blow.

Location Condition Nominal and Range

T19

Oximeter on. 5 VDC, ± 0.1 VDC
ANA+5 (T18) Same as T19. Same as T19.
FLTR+5 Same as TP14. Same as T19.
ANA-5 Same as TP15. Same as TP15.
FLTR-5 (T16) Same as TP15. -4.8 VDC to –6.2 VDC
V-REF (T17) Oximeter on. 2.5 VDC
V-RAM Oximeter on.

Oximeter off.

T19 minus 0.7 VDC.

V_BT minus 0.7 VDC.

U11-71 Oximeter on. 3.072 MHz, 50% duty

cycle.

Low battery LED. When battery voltage

drops to 3.00 VDC.

Low battery LED first
turns on at 3.00 VDC,
±0.2 VDC.

Low battery shut off. Oximeter on, battery

voltage slowly drop-

ping.

Oximeter shuts off
when battery voltage
drops to 2.7 VDC, ± 0.2
VDC.

Chapter 9: Service Maintenance and Repair

9-8 Oximeter Operation and Service Manual

Automatic shut off. Turn on oximeter and

place finger in sensor.
Remove finger from
sensor.

Remove sensor from
oximeter. Turn on
oximeter.

Oximeter should turn
off 2 minutes (± 5 sec­onds) after finger is
removed from sensor.

Oximeter should turn
off in 2 minutes (± 5
seconds).

Current draw through

J9-1 (total battery cur­rent).

Oximeter on, sensor
attached to oximeter, no
finger in the sensor,
with battery voltage at

3.5 VDC, ±0.2 VDC.

110 mA, ± 15 mA

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-9

Waveform Test Points

The following oscilloscope screens show typical waveforms from the sen­sor detector’s amplifier and data acquisition circuits. Unless otherwise
noted:

• The waveforms are measured with respect to ground at J9-2.

• The oscilloscope is triggered on T2, falling edge.

• The waveforms are measured with the finger sensor attached to the
oximeter, but no finger inserted in the sensor.

Connect CH1 probe to T10, T21, T22, T24. Verify the signal shown in the
respective figures.

Measurement at T2
2V/DIV

0.4mS/Div

0V

Chapter 9: Service Maintenance and Repair

9-10 Oximeter Operation and Service Manual

Measurement at T22
2V/DIV

0.4mS/Div

0V

Measurement at T24
2V/DIV

0.4mS/Div

0V

Chapter 9: Service Maintenance and Repair

Oximeter Operation and Service Manual 9-11

Remove all scope connections from the oximeter board.
Functional Testing
Disconnect the oximetry test fixture. Turn oximeter board off and then on

again. Connect Finger probe to oximeter board and put your finger in the
probe. Verify SpO

2

and Pulse Rate readings are displayed.

Verify that the pulse tone is heard when the pulse strength bar lights up.
Remove finger from finger probe. Verify “dashes.”

Measurement at T24
2V/DIV

0.4mS/Div

0V

0V

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Appendix

Oximeter Operation and Service Manual Appendix-1

Appendix

Assembly Drawings, Schematics & Parts Lists

Number Description Item

Number
of pages

71000A23 F/ASM OXIMETER REDESIGN

BOM

A-1 1

71000A23 F/ASM OXIMETER REDESIGN A-2 1
71264B1 PWB ASM MAIN BOARD

REDESIGN

A-3 1

71264B1 PWB ASM MAIN BOARD

REDESIGN PARTS LIST

A-4 3

71264S1 MAIN BOARD REDESIGN

SCHEMATIC

A-5 5

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Smiths Medical PM, Inc.

Patient Monitoring and Ventilation

m

Authorized Representative (as defined by the Medical Device Directive ):

Smiths Medical International Ltd.
Colonial Way, Watford, Herts,
UK, WD24 4LG

Phone: [phone]
Fax: [phone]