S5 Pressure Temp Module Technical Reference Manual Slot June 2001

Table of contents

TABLE OF CONTENTS Pressure Module, M-P, Pressure Temp Module, M-PT TABLE OF CONTENTS

i

TABLE OF FIGURES

ii

Introduction

1

1

2

Specifications

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

5

Service Menu

24

5.1 P/PT menu ...25 5.2 P/PT calibration menu ...26

6

Spare Parts

28 i Document No. 800 1013-1

Datex-Ohmeda S/5 monitors 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

ii Document No. 8001013-1

Pressure Module, M-P and Pressure Temp Module, M-PT

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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1

SPECIFICATIONS

1.1 General specifications Module size, W × D × H Module weight Power consumption

37 × 180 × 112 mm / 1.5 × 7.1 × 4.4 in 0.35 kg / 0.8 lbs Approximately 3.5 W

1.2 Typical performance 1.2.1 InvBP Measurement range Accuracy Zero adjustment range Calibration range Scales Sweep speed

-40...+320 mmHg ±5 % or ±2 mmHg, whichever is greater ±150 mmHg ±20 % Upper limit is adjustable between 10 and 300 mmHg in steps of 10. Lower limit is 10 % of selected upper limit below zero. 12.5, 25, 50 mm/s

DIGITAL DISPLAY Range Resolution

-40...+320 mmHg ±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 Display resolution Temperature test

10...45 °C (50...113 °F) 0.1 °C (0.1 °F) Automatic (every 10 min.)

YSI 400 probe compatible

1.2.3 Signal output ECG out Pressure P3 out

2 Document No. 8001013-1

1 V/mV 1 V/100 mmHg, (0...300 mmHg)

Pressure Module, M-P and Pressure Temp Module, M-PT

1.3 Technical specifications 1.3.1 InvBP Accuracy Transducer and input sensitivity Nonlinearity Filter Zero set accuracy Calibration resolution Zero time

±5 % or ±2 mmHg, whichever is greater 5 µV/V/mmHg, 5 VDC, 20 mA max current <1 %, 0 to 200 mmHg <2 %, -40 to 0 and 200 to 320 mmHg 0...4 - 22 Hz adjustable ±1 mmHg ±1 mmHg 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: Pressure offset error

ECG1 15 ms Pressure P3 25 ms (0...300 mmHg) max. 10 mmHg

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2

FUNCTIONAL 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. 4 Document No. 8001013-1

Pressure Module, M-P and Pressure Temp Module, M-PT 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.

Zero P3

Zero P3 T3

P3

T4 Signal Out

P3

Figure 2

Front panel of M-P and M-PT Module

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2.2.1 PT board Module bus connector, D25

RS485 driver for data

RS485 driver for module reset

Power-up reset

Power, non-isolated section

ECG OUT PRESSURE OUT to output connector

Opto Isolation

Patient Isolation

Microprocessor section

non-volatile memory

Power, isolated section

A/D converter

INV.pressure measuring

Figure 3

Isolation transformer

unit

Temperature measuring unit

to pressure sensor

to temperature sensors

Keyboard

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. 6 Document No. 8001013-1

Pressure Module, M-P and Pressure Temp Module, M-PT 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. Pressure transducer

Vin

Instrumentation amplifier Vout

Input Filter

G to AD converter

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. 7 Document No. 800 1013-1

Datex-Ohmeda S/5 monitors

0 °C => 7K357 15 °C => 3K541 25 °C => 2K253 38 °C => 1K301 45 °C => 984R1

+5Vreference

A1 to AD converter

NTC offset

Figure 5

Temperature measurement principle

Serial communication

Send data

Receive data Send data send/receive Reset

Figure 6

RS485 Driver NData

Opto isolation

send/receive

Reset

RS485 Driver

Reset in NReset in

to central unit (module bus)

Data

Receive data

Patient Isolation

to module prosessor

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.

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.

8 Document No. 8001013-1

Pressure Module, M-P and Pressure Temp Module, M-PT 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

1

13 25

14

Figure 7

Module bus connector (X1)

Pin No

I/O

Signal

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

I I I I I/O I/O

RESET_RS485* -15 VDC* +15 VDIRTY* +15 Vin* NDATA_RS485* DATA_RS485* Ground* NRESET_RS485* CTSB RTSB RXDB TXDB Ground* +32 VDIRTY GroundDIRTY* CTSC RTSC RXDC TXDC ON/STANDBY PWM_ECG* RXDD_RS232 TXDD_RS232 +5 VDCin* +5 VDC*

I I O I O I I I O I O O

I I

* Used in the M-PT module

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Pressure Module, M-P and Pressure Temp Module, M-PT

2.3.2 Front panel connectors Pressure connector (P3) 3 6 1 2

4

7

5

8

9

0

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 2 1

3 4

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

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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

1

T3

-

2

T4

-

3

fGND

Floating GND

4

CON

Low if PT

5

fGND

Floating GND

6

GND

Floating GND

12 Document No. 8001013-1

X8 1

6

Pressure Module, M-P and Pressure Temp Module, M-PT

3

SERVICE 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.

M-NE(12)STPR/M-ESTPR/M-ESTP

Notes 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

Digit Fields

Field 2 - P1 Field 3 - P3 Field 4 - P5 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 15 Document No. 800 1013-1

Datex-Ohmeda S/5 monitors The settings and checks with a Dynatech Nevada medSim 300 Patient Simulator are: SENSITIVITY switch position: 5 µV/V/mmHg ECG - BASE - BPM - 60 ATM

BP - 2 - WAVE -

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.

?

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Pressure Module, M-P and Pressure Temp Module, M-PT

Modules with signal output connector •

Preset InvBP and ECG measurement settings:

Invasive Pressures - P3 Setup - Label - Art ECG - ECG1 LEAD -I Connect a patient simulator to the connector P3 and to the connector ECG on the used M-NE(12)STPR/M-ESTPR/M-ESTP. The settings and checks with a Dynatech Nevada medSim 300 Patient Simulator are: SENSITIVITY switch position: 5 µV/V/mmHg BP - 1 - WAVE - ART ECG - BASE - BPM - 160 PACE - WAVE - NSR Use the channel BP1 for the connector P3. 14. Connect an oscilloscope between the signal out connector pins 1 (ECG out) and 4 (Ground).

2 1

3 4

Check that an analog signal which corresponds with the ECG waveform on the screen comes out. The output signal’s ratio to the actual ECG signal should be around 1V/1mV. Check that a similar output signal is coming out also from the pin 3 (ECG out).

? 15.

Connect the oscilloscope between the signal out connector pins 2 (Pressure out) and 4 (Ground). Check that an analog signal which corresponds with the InvBP waveform on the screen comes out. The output signal’s ratio to the actual InvBP signal should be around 1V/100mmHg.

?

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