Datex-Ohmeda S/5 M-PT Use and care manual

Datex-Ohmeda Pressure Modules
S/5TM Pressure Temp Module, M-PT (Rev. 02)
S/5TM Pressure Module, M-P (Rev. 04)
Technical Reference Manual Slot
All specifications are subject to change without notice.
Document No. 800 1013-1
June 2001
Datex-Ohmeda Inc.
3030 Ohmeda Drive
53707–7550 MADISON, WIS
USA
Tel. [phone], Fax [phone]
www.us.datex-ohmeda.com
Datex-Ohmeda Division,
Instrumentarium Corp.
P.O. Box 900, FIN-00031
DATEX-OHMEDA, FINLAND
Tel. [phone] Fax [phone]
www.datex-ohmeda.com
Instrumentarium Corp. All rights reserved.

Table of contents
Document No. 800 1013-1
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TABLE OF CONTENTS
Pressure Module, M-P, Pressure Temp Module, M-PT
TABLE OF CONTENTS i
TABLE OF FIGURES ii
Introduction 1
1 Specifications 2
1.1 General specifications ..............................................................................................................................2
1.2 Typical performance .................................................................................................................................2
1.2.1 InvBP...............................................................................................................................................2
1.2.2 Temperature.....................................................................................................................................2
1.2.3 Signal output ...................................................................................................................................2
1.3 Technical specifications............................................................................................................................3
1.3.1 InvBP...............................................................................................................................................3
1.3.2 Temperature.....................................................................................................................................3
1.3.3 Signal output ...................................................................................................................................3
2 Functional Description 4
2.1 Measurement principle .............................................................................................................................4
2.1.1 Invasive blood pressure ....................................................................................................................4
2.1.2 Temperature.....................................................................................................................................4
2.2 Main components.....................................................................................................................................4
2.2.1 PT board ..........................................................................................................................................6
2.3 Connectors and signals...........................................................................................................................10
2.3.1 Module bus connector....................................................................................................................10
2.3.2 Front panel connectors ...................................................................................................................11
2.3.3 Other connectors............................................................................................................................11
3 Service Procedures 13
3.1 General service information.....................................................................................................................13
3.2 Service check .........................................................................................................................................13
3.2.1 Recommended tools ......................................................................................................................13
3.3 Disassembly and reassembly..................................................................................................................18
3.4 Adjustments and calibrations..................................................................................................................19
3.4.1 Invasive pressure calibration...........................................................................................................19
3.4.2 Temperature calibration..................................................................................................................19
4 Troubleshooting 21
4.1 Troubleshooting chart .............................................................................................................................21
4.1.1 Invasive blood pressure ..................................................................................................................21
4.1.2 Temperature...................................................................................................................................22
Troubleshooting flowchart ..............................................................................................................................23
5ServiceMenu 24
5.1 P/PT menu .............................................................................................................................................25
5.2 P/PT calibration menu ............................................................................................................................26
6 Spare Parts 28

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6.1 Spare parts list .......................................................................................................................................28
6.1.1 Pressure Module, M-P, Rev. 00.......................................................................................................28
6.1.2 Pressure Module, M-P, Rev. 01.......................................................................................................29
6.1.3 Pressure Module, M-P, Rev. 02.......................................................................................................29
6.1.4 Pressure Module, M-P, Rev. 03.......................................................................................................29
6.1.5 Pressure Module, M-P, Rev. 04.......................................................................................................29
6.1.6 Pressure Temp Module, M-PT, Rev. 00 ............................................................................................30
6.1.7 Pressure Temp Module, M-PT, Rev. 01 ............................................................................................31
6.1.8 Pressure Temp Module, M-PT, Rev. 02 ............................................................................................31
6.1.9 Front panel stickers for AS/3 modules (square buttons)...................................................................31
6.1.10 Front panel stickers for S/5 modules (round buttons) ..................................................................31
7 Earlier Revisions 33
APPENDIX A 35
Service check form A-1
TABLE OF FIGURES
Figure 1 Datex-Ohmeda M-PT and M-P Module................................................................................................... 1
Figure 2 Front panel of M-P and M-PT Module..................................................................................................... 5
Figure 3 PT board block diagram ........................................................................................................................ 6
Figure 4 Pressure transducer principle of operation............................................................................................. 7
Figure 5 Temperature measurement principle..................................................................................................... 8
Figure 6 Serial communication and opto isolation section................................................................................... 8
Figure 7 Module bus connector (X1) .................................................................................................................10
Figure 8 Troubleshooting flowchart...................................................................................................................23

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INTRODUCTION
This section provides information for the maintenance and service of the Pressure Module, M-P,
and Pressure Temp Module, M-PT. The M-P and M-PT modules are single width plug-in modules
designed for use with the S/5 monitors. Both modules provide invasive pressure measurement.
Additionally, the M-PT-module provides temperature measurement. The M-PT module also has a
connector for direct ECG and pressure signal output.
NOTE: Do not use identical modules in the same monitoring system. The modules M-P and M-PT
are considered as identical modules.
Figure 1 Datex-Ohmeda M-PT and M-P Module

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1SPECIFICATIONS
1.1 General specifications
Module size, W ×D ×H 37 ×180 ×112 mm / 1.5 ×7.1 ×4.4 in
Module weight 0.35 kg / 0.8 lbs
Power consumption Approximately 3.5 W
1.2 Typical performance
1.2.1 InvBP
Measurement range -40...+320 mmHg
Accuracy ±5 % or ±2 mmHg, whichever is greater
Zero adjustment range ±150 mmHg
Calibration range ±20 %
Scales Upper limit is adjustable between 10 and 300 mmHg in steps of
10. Lower limit is 10 % of selected upper limit below zero.
Sweep speed 12.5, 25, 50 mm/s
DIGITAL DISPLAY
Range -40...+320 mmHg
Resolution ±1 mmHg
WAVEFORM DISPLAY
Range -30...+300 mmHg
HEART RATE FROM ARTERIAL PRESSURE
Measurement range 30...250 bpm
Resolution 1 bpm
Accuracy ±5 bpm or ±5 %, whichever is greater
1.2.2 Temperature
Measurement range 10...45 °C (50...113 °F)
Display resolution 0.1 °C (0.1 °F)
Temperature test Automatic (every 10 min.)
YSI 400 probe compatible
1.2.3 Signal output
ECG out 1 V/mV
Pressure P3 out 1 V/100 mmHg, (0...300 mmHg)

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1.3 Technical specifications
1.3.1 InvBP
Accuracy ±5 % or ±2 mmHg, whichever is greater
Transducer and input sensitivity 5 µV/V/mmHg, 5 VDC, 20 mA max current
Nonlinearity <1 %, 0 to 200 mmHg
<2 %, -40 to 0 and 200 to 320 mmHg
Filter 0...4 - 22 Hz adjustable
Zero set accuracy ±1 mmHg
Calibration resolution ±1 mmHg
Zero time less than 15 sec
Protection against electrical shock Type CF defibrillation proof
DIGITAL DISPLAY AVERAGING
Art and P1 digital displays are averaged over 5 seconds and updated at 5 seconds intervals. All
other pressures have respiration artifact rejection.
NOTE: The accuracy of the measurement may be different from that specified, depending on the
transducer/probe being used. Please check the transducer/probe specification.
1.3.2 Temperature
Measurement accuracy ±0.1 °C (25.0...45.0 °C)
±0.2 °C (10.0...24.9 °C)
Protection against electrical shock Type CF
NOTE: The accuracy of the measurement may be different from the specified, depending on
transducer/probe used. Please check the transducer/probe specification.
1.3.3 Signal output
Max. delay: ECG1 15 ms
Pressure P3 25 ms (0...300 mmHg)
Pressure offset error max. 10 mmHg

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2FUNCTIONAL DESCRIPTION
2.1 Measurement principle
2.1.1 Invasive blood pressure
To measure invasive blood pressure, a catheter is inserted into an artery or vein. The invasive
pressure setup, consisting of connecting tubing, pressure transducer, an intravenous bag of normal
saline all connected together by stopcocks, is attached to the catheter. The transducer is placed at
the same level with the heart, and is electrically zeroed.
The transducer is a piezo-resistive device that converts the pressure signal to a voltage. The monitor
interprets the voltage signal so that pressure data and pressure waveforms can be displayed.
2.1.2 Temperature
The temperature is measured by a probe whose resistance varies when the temperature changes,
called Negative Temperature Coefficient (NTC) resistor.
The resistance can be measured by two complementary methods:
•Applying a constant voltage across the resistor and measuring the current that flows through
it.
•Applying a constant current to flow through the resistor and measuring the voltage that is
generated across it.
In S/5 module the two methods are combined in a form of a voltage divider. The NTC-resistor is
connected in series with a normal resistor and a constant voltage is applied across them. The
temperature dependent voltage can be detected at the junction of the resistors, thus producing the
temperature signal from the patient. The signal is amplified by analog amplifiers and further
processed by digital electronics.
2.2 Main components
The M-PT module consists of the following main parts:
•PT board
•Two connectors for YSI 400 series temperature probes; temperature channels T3 and T4.
•Nicolay-type connector for an invasive blood pressure sensor; invasive blood pressure
channel P3.
•Key for pressure zeroing.
•DIN-type connector for two direct ECG output signals and pressure 3.
NOTE: These output-signals are non-floating
The M-P module consists of the following main parts:
•PT board
•Nicolay-type connector for an invasive blood pressure sensor; invasive blood pressure
channel P3.

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•Key for pressure zeroing.
Communication between the module and the central unit is established through RS485 serial
interface.
The power supply voltages to the module are generated in the power supply section of the
monitor’s Central Unit. All electrical connections between the module and the Central Unit are
established via 25-pin D-type connector on the backside of the module.
P3
Zero
P3
Zero
P3
Signal
Out
T3
T4
P3
Figure 2 Front panel of M-P and M-PT Module

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2.2.1 PT board
RS485 driver
for data
RS485 driver
for module
reset
Power-up
reset
Power,
non-isolated
section
ECG OUT
PRESSURE OUT
Patient Isolation
Opto
Isolation
Isolation
transformer
Power,
isolated
section
Module bus connector, D25
Microprocessor
section
A
/D converter
INV.pressure
measuring
unit
Temperature
measuring
unit
Keyboard
to output connector
to pressure
sensor
to temperature
sensors
non-volatile
memory
Figure 3 PT board block diagram
ECG and pressure signal prosessing
The PT-module has the Signal Out connector, for output of analog ECG and pressure signals.
The analog ECG-output signals are made by detecting the pulse-width modulated (PWM) ECG
signal of the module bus. The module detects the presence of the pacemaker pulses by following
the ECG module. Every time the pacer pulse has been detected, the microprocessor of the M-PT
module generates a 2.5 ms pacer pulse which is added to the analog ECG signal.
The PRESSURE OUT signal is generated from the P3 invasive pressure signal of the M-PT module.

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The P3 signal is transmitted as a pulse width modulated (PWM) signal over the patient isolation.
The analog signal is generated by low-pass filtering the PWM signal.
Microprocessor unit
The microprocessor uses the Intel 80C196KC-16 which includes three A/D converters and a UART.
There are external memories, an 8-bit data bus, a 16 MHz oscillator, an open collector reset, and a
watchdog timer. The internal UART communicates and transfers data between the module and the
CPU board in the monitor.
High speed I/O is used to obtain pulse control sequence necessary for pulse oximetry
measurement. It receives its timing clock from the oscillator.
Invasive blood pressure measurement unit
An isolated +5 V supply is connected to the input of the pressure transducer bridge circuit. From
the bridge circuit output a differential voltage, which depends on blood pressure and input supply
voltage, is calculated using the following formula:
Uout = Uin ×Pressure ×5 V
where Uin = 5 V
Uout = 25 V ×Pressure [mmHg]
Pressure amplification is performed by the instrumentation amplifier. The gain of the amplifier is
set so that the level of the signal transferred to the A/D converter stays within the measurement
range even when there are circumstantial offsets or offsets caused by the pressure transducer. The
input filter before the amplifier attenuates high frequency disturbances.
Input
Filter
Instrumentation
amplifier
to AD converter
Pressure
transducer
Vin
Vout G
Figure 4 Pressure transducer principle of operation
Temperature measurement unit
Value of NTC-resistor in the probe depends on patient’s temperature. It is measured with the
following principle.
The temperature signal(s) is produced by voltage dividers, part of which is the patient probe (YSI
400-series thermistor). The output is amplified by the calibrated amplifier(s) whose offset voltage
makes its output spread on both sides of zero. Wider output range (measurement range) means
better resolution.

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NTC
to AD
converter
+5Vreference
offset
A1
0 °C => 7K357
15 °C => 3K541
25 °C => 2K253
38 °C => 1K301
45 °C => 984R1
Figure 5 Temperature measurement principle
Serial communication
Serial communication between the module and the Central Unit is done by RS485 type bus whose
buffers get their supply voltage (+5 VDC) from the Central Unit and in the isolation section get the
supply voltage (+5 V) from the isolated power supply.
The communication drivers are controlled by a reset signal such that when the reset is active the
drivers do not transfer data.
Reset is also RS485 type and additionally, there is an auxiliary logic power reset, which keeps the
reset active for about 500 ms despite the state of reset in the module bus. A time constant
determines the power-up reset time. There are components to prevent the module from sending
data during reset. The data transmission rate is 500 kbps.
RS485
Driver
RS485
Driver
Reset
Data
NDa
t a
Reset in
NReset in
Send data
Receive data
send / r eceive
Receive da t a
Send
da t a
send
/ r eceive
Reset
to modul
e
p
r
o
sess
o
r
to
ce
nt
ra
l unit
(modul
e
bu
s
)
Opto isol a t i on
Patient Isolation
Figure 6 Serial communication and opto isolation section
Isolated section
There are two opto isolators, one for data and one for the reset signal. Signals are processed on
logical high-low levels even though the output of the opto isolators in the isolation section are
analog signals.

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The reset line is an open collector type with a pull-up resistor so that the microprocessor is able to
use its internal watchdog function.
Power supply section
Isolated supply voltage of the module is developed from +15 Vdirty voltage from the Central Unit.
Power supply is a switched-mode circuit, where FET transistor switch is controlled by an oscillator
using bipolar timer. The frequency of the oscillator is about 30 kHz and pulse ratio 50 %.
Controlling of the FET switch is slowed to suppress spurious interference.
A special pulse transformer is used in the circuit. The transformer secondary circuit uses normal
linear regulators except for +5 V which uses a low drop type linear regulator.

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2.3 Connectors and signals
2.3.1 Module bus connector
13
1
14
25
Figure 7 Module bus connector (X1)
Pin No I/O Signal
1 I RESET_RS485*
2 I -15 VDC*
3 I +15 VDIRTY*
4 I +15 Vin*
5 I/O NDATA_RS485*
6 I/O DATA_RS485*
7 Ground*
8 I NRESET_RS485*
9 I CTSB
10 O RTSB
11 I RXDB
12 O TXDB
13 Ground*
14 I +32 VDIRTY
15 I GroundDIRTY*
16 I CTSC
17 O RTSC
18 I RXDC
19 O TXDC
20 ON/STANDBY
21 O PWM_ECG*
22 RXDD_RS232
23 TXDD_RS232
24 I +5 VDCin*
25 I +5 VDC*
* Used in the M-PT module

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2.3.2 Front panel connectors
Pressure connector (P3)
Pin No Signal
1 Pressure 3 +
2 Pressure 3 -
3 Polarization - (ground)
4 Polarization +
5 Not connected
6 Not connected
7 Not connected
8 Not connected
9 Ground
10 Cable detection
Signal out connector (Sync. out)
Pin No Signal
1 ECG out, 1 V/ 1 mV
2 Pressure out, 1 V/ 100 mmHg
3 ECG out, 1 V/ 1 mV
4 Ground
NOTE: The ECG out signal is not available with modules M-ESTP rev. 01, M-EST rev. 00 and M-ETP
rev. 00.
2.3.3 Other connectors
Keyboard connector (X3)
Pin No Signal Notes
1 N/C Not connected
2 COSWITCH Not used
3 PSWITCH for zeroing of P3
4 fGND Floating GND
5 fGND Floating GND
X3
1 5
6
8
9
0
1
2
4
5
7
3
1
2
3
4

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Pressure sensor connector (X4)
Pin No
board
Pin No
fr.panel
Signal Notes
1 0 PCABEL 5V if cable not connected
2 4 PCURRENT Pulsed supply to sensor
3 3,9 P3- Signal from the sensor
4 1 P3+ Signal from the sensor
5 2 fGND Floating GND
X4
1 5
When the board is used in the M-PT module, there are the following connectors connected on the
board in addition to X1 and X4.
Signal out connector (X5)
Pin No
board
Pin No
fr.panel
Signal Notes
1 - ECG OUT ECG to (e.g.) IABP
2 - N/C Not connected
3 4 GND +5VDCin GND
4 1 ECG OUT ECG to (e.g.) defib.
5 - N/C Not connected
6 3 ECG OUT ECG to (e.g.) IABP
7 2 P OUT P3 to (e.g.) IABP
8 GND GND +5VDCin GND
X5
1 8
Connector for temperature probes (X8)
Pin No Signal Notes
1T3-
2T4-
3 fGND Floating GND
4 CON Low if PT
5 fGND Floating GND
6 GND Floating GND
X8
1 6

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3SERVICE PROCEDURES
3.1 General service information
Field service of the M-P and M-PT modules is limited to replacing faulty circuit boards or
mechanical parts. The circuit boards should be returned to Datex-Ohmeda for repair.
Datex-Ohmeda is always available for service advice. Please provide the unit serial number, full
type designation, and a detailed description of the fault.
CAUTION Only trained personnel with appropriate equipment should perform the tests and
repairs outlined in this section. Unauthorized service may void warranty of the unit.
3.2 Service check
These instructions include complete procedures for a service check. The service check is
recommended to be performed after any service repair. However, the service check procedures can
also be used for determining possible failures.
The procedures should be performed in ascending order.
The instructions include a check form (Appendix A) which should be filled in when performing the
procedures.
The mark ?in the instructions means that the check list should be signed after performing the
procedure.
The procedures are designed for monitors with S/5 monitor software of revision 01. However, most
of the procedures also apply to monitors, which contain some other monitor software
type/revision.
3.2.1 Recommended tools
Tool Order No. Notes
M-NE(12)STPR/M-ESTPR/M-ESTP Not M-ESTP Rev. 01, M-EST Rev. 00 or M-ETP
Rev. 00
Patient simulator
Pressure manometer
Temperature test set 884515
InvBP transducer
Oscilloscope
Screwdriver

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All modules
•Detach the module box by removing the two screws from the back of the module. Be careful
with the loose latch and spring locking pin.
1. Check internal parts:
•screws are tightened properly
•cables are connected properly
•all socket mounted IC’s are inserted properly
•EMC covers are attached properly
•there are no loose objects inside the module
?
2. Check external parts:
•the front cover and the front panel sticker are intact
•all connectors are intact and are attached properly
•the module box, latch and spring locking pin are intact
?
•Reattach the module box and check that the latch is moving properly.
•Switch the monitor on and wait until the monitoring screen appears.
Configure the monitor screen so that all the needed parameters are shown, for example as
follows:
Monitor Setup - Screen 1 Setup - Waveform Fields - Field 1 - ECG1
Field 2 - P1
Field 3 - P3
Field 4 - P5
Digit Fields
Field 4 - T3+T4
3. Plug in the module. Check that it goes in smoothly and locks up properly.
?
•Preset InvBP measurement settings:
Invasive Pressures - P1 ‘Art’ Setup - Label - Art
P3 Setup - Label – PA

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4. Enter the service menu:
Monitor Setup - Install/Service (password 16-4-34) - Service - (password 26-23-8)
Take down the information regarding module software by selecting SCROLL VERS and turning
the ComWheel.
?
5. Enter the P/PT service menu (according to the tested module):
Parameters - P/PT
Check that the “Timeouts”, “Bad checksums” and “Bad c-s by mod” values are not increasing
faster than by 50 per second. Check also that the module memories have passed the internal
memory test, i.e. the “RAM”, “ROM” and “EEPROM” show all OK.
?
Invasive blood pressure measurement
6. Check the front panel membrane key.
Press the key at least for one second. Check that the pressed key is identified, i.e. the text for
“Button” changes from OFF to ON in the service menu.
?
7. Check that the “Cable” and “Probe” show OFF.
Plug a cable with an invasive blood pressure transducer into the front panel connector P3.
Check that the “Cable” and “Probe” show ON and the pressure
8. waveform field appears onto the monitor screen..
NOTE: Test both invasive blood pressure channels with M-PP.
?
9. Calibrate the InvBP channel according to the instructions in the Technical Reference
Manual.
?
10. Check that the module configuration is correct with P and PT modules.
The configuration in use is shown beside the text “Configuration” in the service menu and it
can be either BP or PT.
Change the configuration in the CALIBRATIONS -menu, if necessary.
?
11. Check the InvBP channels with a patient simulator

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The settings and checks with a Dynatech Nevada medSim 300 Patient Simulator are:
SENSITIVITY switch position: 5 µV/V/mmHg
ECG - BASE - BPM - 60
BP - 2 - WAVE -
ATM
connect a cable from the channel BP3 to the connector P3.
Ccheck that appropriate InvBP waveform is shown and the InvBP value is approximately
25/10 (±2 mmHg).
?
Modules with temperature measurement
11. Check that the “Cable” and “Probe” show OFF for the channels T3 and T4 when no probes are
connected.
Connect a temperature test plug into the connector T3. Check that the “Cable” and “Probe”
for T3 show ON and the corresponding temperature value appears onto the screen.
Perform the same check also for the channel T4.
?
12. Check the temperature calibrations using temperature test plugs.
If the deviation on a temperature reading on the screen is more then 0.1 °C, calibrate the
temperature channels according to the instructions in the Technical Reference Manual.
?
13. Activate the temperature test by selecting TEMP TEST from the menu and pressing the
ComWheel twice. When the message “Performing temp test” disappears from the digit field
for T3+T4, check that no error messages appear and “Temp error” shows OFF for both
channels in the menu.
?