Mindray PM-60 User manual

Pulse Oximeter
Service Manual

I
Preface
Manual Purpose
This manual provides detailed information about the assembling, dissembling, testing and
troubleshooting of the equipment to support effective troubleshooting and repair. It is not
intended to be a comprehensive, in-depth explanation of the product architecture or technical
implementation. Observance of the manual is a prerequisite for proper equipment
maintenance and prevents equipment damage and personnel injury.
This manual is based on the maximum configuration; therefore, some contents may not apply
to your pulse oximeter. If you have any question, please contact our Customer Service
Department.
Intended Audience
This manual is for biomedical engineers, authorized technicians or service representatives
responsible for troubleshooting, repairing and maintaining the pulse oximeter.
Revision History
This manual has a revision number. This revision number changes whenever the manual is
updated due to software or technical specification change. Contents of this manual are subject
to change without prior notice.
Revision number: 1.0
Release time: August 2007
Password
Maintenance password: 321

II
FOR YOUR NOTES

1
Contents
1 Safety................................................................................................................................. 1-1
1.1 Safety Information ..........................................................................................................1-1
1.1.1 Dangers .............................................................................................................. 1-2
1.1.2 Warnings............................................................................................................. 1-2
1.1.3 Cautions ............................................................................................................. 1-2
1.1.4 Notes .................................................................................................................. 1-2
1.2 Equipment Symbols........................................................................................................ 1-3
2 Theory of Operation ........................................................................................................ 2-1
2.1 Introduction..................................................................................................................... 2-1
2.2 System Connections........................................................................................................ 2-1
2.2.1 Mounting the Pulse Oximeter ............................................................................ 2-1
2.2.2 Connectors for Peripheral Devices..................................................................... 2-2
2.3 Main Unit........................................................................................................................ 2-3
2.3.1 Main Control Unit.............................................................................................. 2-3
2.3.2 Power Supply..................................................................................................... 2-6
2.3.3 Main Board Interfaces........................................................................................ 2-9
2.3.4 SpO2Module.................................................................................................... 2-10
2.3.5 Charger stand ....................................................................................................2-11
3 Testing and Maintenance................................................................................................. 3-1
3.1 Introduction..................................................................................................................... 3-1
3.1.1 Test Report ......................................................................................................... 3-2
3.1.2 Recommended Frequency.................................................................................. 3-2
3.2 Visual Test....................................................................................................................... 3-3
3.3 Power On Test................................................................................................................. 3-3
3.4 Performance Tests...........................................................................................................3-4
3.4.1 SpO2Test............................................................................................................ 3-4
3.4.2 SpO2Test in Motion Mode................................................................................. 3-4
3.5 Electrical Safety Tests.....................................................................................................3-5
3.5.1 Enclosure Leakage Current Test......................................................................... 3-6
3.5.2 Patient Leakage Current Test ............................................................................. 3-6
3.6 Output Interface Test.......................................................................................................3-7
3.6.1 RS232 Port test................................................................................................... 3-7
3.6.2 Infrared Output Test ........................................................................................... 3-7
3.7 Program Upgrade............................................................................................................ 3-8
4 Troubleshooting................................................................................................................ 4-1
4.1 Introduction..................................................................................................................... 4-1

2
4.2 Part Replacement ............................................................................................................4-1
4.3 Software Version Check .................................................................................................. 4-2
4.4 Technical Alarm Check ................................................................................................... 4-2
4.5 Troubleshooting Guide.................................................................................................... 4-3
4.5.1 Power On/Off Failures ....................................................................................... 4-3
4.5.2 Display Failures ................................................................................................. 4-3
4.5.3 Alarm Problems.................................................................................................. 4-4
4.5.4 Button Failure..................................................................................................... 4-4
4.5.5 Interface Failures................................................................................................ 4-4
4.5.6 Power Supply Failures ....................................................................................... 4-5
4.5.7 Software Upgrade Problems............................................................................... 4-5
5 Repair and Disassembly .................................................................................................. 5-1
5.1 Tools................................................................................................................................ 5-1
5.2 Preparations for Disassembly.......................................................................................... 5-1
5.3 Disassembly Guide ......................................................................................................... 5-2
5.3.1 Removing the Covers......................................................................................... 5-2
5.3.2 Removing the Main Board ................................................................................. 5-4
5.3.3 Removing the Speaker and SpO2Communication Cable Socket....................... 5-4
5.3.4 Removing the LCD Screen ................................................................................ 5-5
5.3.5 Remove the Screen Mount ................................................................................. 5-6
6 Parts .................................................................................................................................. 6-1
6.1 Introduction..................................................................................................................... 6-1
6.2 Main Unit ........................................................................................................................ 6-2
6.3 Front Panel Assembly ..................................................................................................... 6-3
6.4 Main Board Assembly..................................................................................................... 6-4
6.5 Battery Adjusting Bracket Assembly .............................................................................. 6-5
6.6 Rear Cover Assembly...................................................................................................... 6-6
6.7 Replacement Parts...........................................................................................................6-7

1-1
1 Safety
1.1 Safety Information
DANGER
zIndicates an imminent hazard that, if not avoided, will result in death or serious
injury.
WARNING
zIndicates a potential hazard or unsafe practice that, if not avoided, could result in
death or serious injury.
CAUTION
zIndicates a potential hazard or unsafe practice that, if not avoided, could result in
death or serious injury.
NOTE
zProvides maintenance tips or other useful information.

1-2
1.1.1 Dangers
There are no dangers that refer to the maintenance in general. Specific “Danger” statements
may be given in the respective sections of this manual.
1.1.2 Warnings
WARNING
zAll installation operations, expansions, changes, modifications and repairs of this
product should be conducted by authorized personnel only.
zAlways disconnect the equipment with the charger stand and remove the batteries
before disassembling the equipment.
zDispose of the packaging material according to local waste control regulations and
your hospital’s waste disposal protocols. Keep the packaging material out of
children’s reach.
1.1.3 Cautions
CAUTION
zMake sure that no electromagnetic radiation interferes with the performance of the
equipment when preparing to carry out performance tests. Mobile phone, X-ray
equipment and MRI devices are possible sources of interference as they may emit
higher levels of electromagnetic radiation.
zBefore connecting the charger stand to the AC mains, check that the voltage and
frequency ratings of the AC mains meet the specifications indicated on the
equipment’s label or in this manual.
zProtect the equipment from damage caused by drop, impact, strong vibration or
other mechanical force during servicing.
1.1.4 Notes
NOTE
zRefer to Operation Manual for detailed operation and other information.

1-3
1.2 Equipment Symbols
Direct Current (DC)
Attention: Consult this manual before maintenance.
Auxiliary output connector
Audio pause
Battery door locked/unlocked
Power supply connector
Left/Right button
Power button
Up button
Down button
Date of manufacture
Serial number
Safety Class II equipment
Type BF applied part, defibrillation protected
The following definition of the WEEE label applies to EU member states
only.
This symbol indicates that this product should not be treated as household
waste. By ensuring that this product is disposed of correctly, you will help
prevent bringing potential negative consequences to the environment and
human health. For more detailed information with regard to returning and
recycling this product, please consult the distributor from whom you
purchased it.
* For system products, this label may be attached to the main unit only.

1-4
FOR YOUR NOTES

2-1
2 Theory of Operation
2.1 Introduction
This pulse oximeter is designed to monitor or measure the oxygen saturation and pulse rate of
single adult, pediatric and neonatal patient.
The pulse oximeter also:
Presents audible and visual alarms in case of patient or equipment problems.
Enables the real-time displaying, reviewing, storing and exporting of SpO2and PR
values.
Supports Pitch Tone, which means the pitch of pulse tone rises as the oxygen saturation
level increases and falls as the oxygen saturation level decreases.
Operates on either alkaline batteries or a lithium-ion battery.
Offers wired or wireless communication with a personal computer.
2.2 System Connections
2.2.1 Mounting the Pulse Oximeter
The pulse oximeter can be mounted on a wall bracket or on a trolley support. The wall
bracket or trolley support can be ordered optionally. Each type of mounting bracket is
delivered with a complete set of mounting hardware and instructions for use. To install the
pulse oximeter, refer to the instrutions for installation.
CAUTION
zUse mounting brackets we supply or approve. If other compatible mounting
bracket is used, be sure it can be safely applied to the pulse oximeter.
zThe mounting bracket should be installed by our qualified service personnel, or
mechanical engineers who have adequate knowledge on it.
zIf other mounting solution is used, the installation personnel and the customer
should verify if it can be safely applied to the pulse oximeter, and the customer
assume the responsibility for any risk resulting from that.

2-2
2.2.2 Connectors for Peripheral Devices
The connectors for peripheral devices are located at the top, right side and bottom of the
pulse oximeter as shown in the figure.
Multifunctional connector
It is a DB 9 connector which is used to connector a SpO2 sensor (including reusable
sensor, disposable sensor and veterinary sensor) to measure the oxygen saturation or
connect a personal computer through a PC communication cable to export trend data.
Infrared port
It is a port through which a personal computer is communicated using a infrared adapter
to export data in real time without affecting patient monitoring.
Power supply connector
It is a female power socket which is used to connect the charger stand’s male power
plug . To avoid being mixed with other power supply adapters, it has nonstandard size.

2-3
2.3 Main Unit
The pulse oximeter consists of main board, SpO2board, display, speaker, batteries and
charger stand. The main board is composed of a main control unit and a power module.
The following diagram shows the structure of the main unit.
2.3.1 Main Control Unit
The main control unit provides the system with resources and support. It controls the LCD
screen, alarm LED, speaker, button operation and data storage. It also implements
communication with the SpO2board, power module and external interfaces.
The functional block diagram of the main control unit is shown below:

2-4
2.3.1.1 Power Supply
The power module provides the main control unit with 3.1 V, 2.5 V and 0.9 V power supple.
Label Voltage Applicable parts
DVDD 3.1 V Alarm LEDs, Flash memory, infrared light-emitting IC,
PC communication cable, LCD boost up circuit,
prestage audio optional amplifier.
VDDE 2.5 V DSP peripheral voltage, SDRAM, LCD logic, infrared
logic, buttons and resetting.
VDDINT 0.9 V DSP kernel voltage

2-5
2.3.1.2 Core Control Unit
The Core control unit consists of CPU, SDRAM and Flash memory.
The CPU is ADI’s DSP BF531. Its kernel running frequency is up to 400 MHz and external
frequency up to 133MHz. The kernel voltage is 0.8 V and the current consumed at 50 MHz is
as low as 26mA. The oscillating frequency of the CPU clock is 11.0592 MHz and its
expected frequency is 55MHz, which can be implemented through internal PLL frequency
multiplication. The SDRAM provides space for program running and the Flash memory
provides space for storing program, data, lingual library and configuration information. The
BF531 starts directly from the Flash memory.
2.3.1.3 Man-machine Interfaces
The functions of the buttons are listed below:
Button In measurement mode In menu mode
Audio Pause
button
Pauses audible alarms. Pauses audible alarms.
Up button Increases the beat
volume.
Moves the cursor upwards or
increases the value of selected
menu item by one.
Down button Decreases the beat
volume.
Moves the cursor downwards
or decreases the value of selected
menu item by one.
Left button Enters the main menu Enters a submenu or confirm
the selection.
Right button Locks/Unlocks buttons. Returns to the previous menu
or exits the current menu.
LCD screen
It is a 2.4” standard QVGA (320×240) TFT LCD with a 36-pin connector. The LCD is
connected with the BF531 through a bus. 4 LEDs in series are used to backlight the
LCD. The maximum current is 15mA and driving voltage 13.2V. The main control
board provides DC power supply for the LCD and the backlight board.
Alarm lamp
The alarm lamp gives visual alarm signals which meet applicable requirements. It
consists of 4 LEDs in parallel. The alarm LEDs receive electrical signal sent by the main
board and convert it into optical signal which is then sent to the panel through a light
conducting bar. The alarm LEDs light up in red and yellow.

2-6
Audible indicators
Audio files including alarm tone, button tone and pulse tone are burned in a serial flash
memory in advance. To give out a sound, the CPU reads audio data from the flash
memory and controls the puse-width modulation (PWM) to give out a audible signal.
The pulse oximeter supports pitch tone and multi-level volume. The speaker is
connected with the main board and the audible signal is provided by the main board.
2.3.1.4 Communication Interfaces
RS232 port
The RS232 port implements communication through the CPU’s UART module and the
RS232 drive chip. The RS232 drive chip which is integrated in the PC communication
cable is electrostatically protected. The CPU’s UART module has an external drive IC
to enforce driving and ensure protection.
Infrared port
The BF 531’s UART supports infrared transmission. The transmitted and received
signals are connected directly to the infrared IC.
2.3.2 Power Supply
The power module provides hardware for power supply management. It detects the level
required by all hardware, the priority of power supply type as well as the power supply status.
It is also controls the power indicating lamp and real-time clock, manages battery charging
and communicates with the main control unit.
The block diagram of the power module is shown below:

2-7
2.3.2.1 Input
The pulse oximeter runs on a chargeable lithium-ion battery or three alkaline AA size
batteries.
Lithium-ion battery: voltage 3.7V, capacity 1800mAh;
Alkaline AA size batteries: three batteries in series, the total voltage 4.5V.
Connect the pulse oximeter to the charger stand and then connect the AC mains. The battery
will be charged automatically if a lithium-ion battery is used. However, if alkaline batteries
are used, the batteries will not be charged.
2.3.2.2 Output
1. SpO2 circuit
3.3V 20mA (Peak 120mA)
±2.5V 10mA
2. Main control circuit
3.1V 5mA (Peak 150mA)
2.5V 50mA (Peak 150mA)
0.9V 20mA (Peak 50mA)
3. LCD backlight and speaker are directly run by the power supply.
2.3.2.3 Power Supply Management
1. Shutdown delay
When the battery voltage is too low, an alarm message “Battery Too Low” is presented
and the pulse oximeter will shut down automatically in maximum 10 minutes.
2. Run time
In the case that SpO2is monitored continuously, audio indicators are off and backlight
brightness is set to minimum, the run time of alkaline batteries is 36 hours and
lithium-ion battery 24 hours, using a new, fully charged battery at ambient temperature
25℃.
3. The power supply efficiency is not less than 80 percent.

2-8
2.3.2.4 Charging the Lithium-ion Battery
The pulse oximeter is configured with a lithium-ion battery charging circuit which can detect
battery charging status and provide protection against overtime, overcurrent as well as
overtemperature charging. It automatically charges the battery in circle and enters into the
sleeping mode when the battery is fully charged. The system identifies battery type through
BC pole to avoid charging the alkaline batteries. The charge time to 90% capacity is less than
2 hours and to 100% capacity less than 3.5 hours.
2.3.2.5 Man-machine Interfaces
Button
To avoid pressing the Power button by accident, you have to press and hold it for 2
seconds when you need to turn off the pulse oximeter. However, to turn on the pulse
oximeter, just press it momentarily.
LED indicator
The Power Indicating lamp is a LED that lights green and yellow. It is located on the
main board. The status of the LED is specified as follows:
Green: when the pulse oximeter is plugged in the charger stand, and the AC
mains is connected, or when the battery is fully charged if a lithium
battery is used.
Yellow: when a lithium ion battery is used and is being charged.
Off: When the AC mains is not connected.

2-9
2.3.3 Main Board Interfaces
The main board implements connection and communication with other parts and peripheral
devices. The interfaces located on the main board are listed below:
No. Description What to connect
J1 LCD connector LCD screen
J2 SpO2board connector SpO2board, providing power supply and
communicating the SpO2board
J3 SpO2sensor connector SpO2board, connecting the SpO2sensor to the
SpO2board
J4 Multifunctional
connector SpO2sensor or personal computer
J5 DSP simulator
connector DSP simulator
J6 Speaker connector Speaker
J7 DC connector Charger stand
J8 Battery positive pole
connector Battery positive pole
J9 Common earthing
connector Charger stand or battery negative pole
J10 BC connector
Lithium-ion battery BC pole, detecting battery
type
J11 NTC connector
Lithium-ion battery NTC pole, detecting battery
temperature
J12 Power supply program
downloading connector Power supply MCU programmer

2-10
2.3.4 SpO2Module
The SpO2module measures oxygen saturation and pulse rate and offers Pleth wave and
perfusion strength. It also offers motion and poor perfusion proof, detects status and fault,
and communicates with the main control unit.
The SpO2module block diagram is shown below: