S5 Patient Side Module, E-PSM, E-PSMP Technical Reference Manual Slot July 2004

Table of contents

Table of contents Introduction 1

Specifications 1.1 1.2

1.3

2

2.2

2.3

3.3 3.4

8

Measurement principle... 8 2.1.1 NIBP... 8 2.1.2 ECG... 8 2.1.3 Pulse oximetry... 8 2.1.4 Temperature... 11 2.1.5 Invasive blood pressure...11 2.1.6 Respiration...11 Main components...12 2.2.1 E-PSMP/E-PSM...12 2.2.2 NIBP board...13 2.2.3 ECG board in 12-lead measurement...15 2.2.4 ECG filtering... 17 2.2.5 STP board...19 Connectors and signals...24 2.3.1 Module bus connector (on the NIBP board)...24 2.3.2 Front panel connectors...25

Service procedures 3.1 3.2

3

General specifications... 3 Typical performance... 3 1.2.1 NIBP... 3 1.2.2 ECG... 3 1.2.3 Pulse oximetry... 4 1.2.4 Temperature... 4 1.2.5 Invasive blood pressure... 5 1.2.6 Respiration... 5 Technical specifications... 5 1.3.1 NIBP... 5 1.3.2 ECG... 6 1.3.3 Pulse oximetry... 6 1.3.4 Temperature... 6 1.3.5 Invasive blood pressure... 6 1.3.6 Respiration... 7

Functional description 2.1

3

1

27

General service information...27 Service check...27 3.2.1 Recommended tools...27 3.2.2 Recommended parts...28 Disassembly and reassembly...36 Adjustments and calibrations...36 3.4.1 NIBP calibrations...36 3.4.2 Temperature calibration...38

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4

Invasive pressure calibration...38

Troubleshooting 4.1

4.2 4.3

40

Troubleshooting charts...40 4.1.1 NIBP...40 4.1.2 NIBP error code explanation...42 4.1.3 ECG...43 4.1.4 Impedance respiration...43 4.1.5 Pulse oximetry (SpO2)...44 4.1.6 Temperature...44 4.1.7 Invasive blood pressure...45 Troubleshooting flowcharts... 47 4.2.1 Module troubleshooting for NIBP parameter... 47 4.2.2 Module troubleshooting for parameters ESTPR...48 E-PSMP disassembly and reassembly...49 4.3.1 Before disassembly...49 4.3.2 Tools needed...49 4.3.3 To disassemble the module...49 4.3.4 To replace the NIBP filter:...56

Appendix A: Service check form

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A-1

S/5 Patient Side Module, E-PSM, E-PSMP

Introduction This Technical Reference Manual Slot provides information for the maintenance and service of the S/5 Patient Side Modules E-PSMP and E-PSM. Later in this manual modules may be referred to w/o the system name S/5 for simplicity. Please also refer to Part I sections of this manual for information regarding system specific information e.g. related documentation, conventions used, symbols on equipment, safety precautions, system description, system installation, interfacing, functional check and planned maintenance. The E-PSMP and E-PSM modules provide general hemodynamic parameters.

Figure 1

S/5 PSM Module, E-PSMP

Table 1

Options of S/5 hemodynamic modules

Parameter

E-PSMP

E-PSM

Two invasive blood pressures

x

Impedance respiration

x

x

ECG

x

x

Pulse oximetry

x

x

Two temperatures

x

x

NIBP

x

x

Intended purpose (Indications for use) The Datex-Ohmeda S/5 Patient Side Module (model family E-PSMP) and accessories are indicated for monitoring of hemodynamic parameters of all hospital patients. The hemodynamic parameters of the module comprise ECG including ST-segment and arrhythmia, Impedance respiration, NIBP, Temperature, SpO2 (including monitoring during conditions of clinical patient motion), and invasive blood pressure.

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Impedance respiration measurement is indicated for patients aged 3 and up. The NIBP measurement is indicated for patients who weigh 5kg (11 lb.) and up. This device is indicated for use by qualified medical personnel only.

Monitor software compatibility Datex-Ohmeda S/5 Patient Side Module, E-PSM(P) is designed for use with Datex-Ohmeda S/5 FM monitors using software: L-FICU03(A) or later.

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1

Specifications

1.1

General specifications Module size WxDxH Module weight Power consumption Operation temperature

1.2

Typical performance

1.2.1

NIBP

51 x 132 (171 w/ tab) x 140 mm 2 x 52 (67 w/ tab) x 5,5 in 0.6 kg /1.4 lb. 2.3 W typical (NIBP pump off) 7.5 W typical (NIBP pump on) 10 to 40°C / 50 to 104°F

NOTE: Non-invasive blood pressure measurement is intended for patients weighing over 5 kg (11 lb.) Oscillometric measurement principle. Measurement range adult 25 to 260 mmHg child 25 to 195 mmHg infant 15 to 145 mmHg Pulse rate range accepted 30 to 250 bpm Measurement interval from 1 min. to 1h, 2h, Typical measuring time adult 23 s infant 20 s Initial inflation pressure adult 170 ±10 mmHg child 150 ±10 mmHg infant 120 ±10 mmHg Venous stasis adult 40 ±5 mmHg / 2 min. child 40 5 mmHg / 2 min. infant 30 ±5 mmHg / 1 min. Cuff widths see User’s Guide

1.2.2

ECG Lead selection, 12-lead ECG Lead selection, other modules Sweep speeds

I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, V6 I, II, III, aVR, aVL, aVF, V 12.5, 25, 50 mm/sec.

Display filter Diagnostic, 12-lead ECG Diagnostic, other modules Monitoring ST filter

0.05 to 150 Hz 0.05 to 100 Hz 0.5 to 30 Hz (-3 dB, with 50 Hz reject filter) 0.5 to 40 Hz (-3 dB, with 60 Hz reject filter) 0.05 to 30 Hz (-3 dB, with 50 Hz reject filter) 0.05 to 40 Hz (-3 dB, with 60 Hz reject filter)

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Heart rate from ECG Range Accuracy Resolution Update interval Averaging time

30 to 250 bpm ±5 bpm or ±5%, whichever is greater 1 bpm 5s 10 s

ST levels (in main software) ST level range Resolution Averaging

-9 to +9 mm (-0.9 to +0.9 mV) 0.1 mm (0.01 mV) calculated from 8 QRS

Pacemaker pulse detection Detection level 2 to 700 mV Pulse duration 0.5 to 2 ms The monitor is specified for both of the methods A and B in ANSI/AAMI EC13 4.1.4.2.

Direct ECG and Synchronization for specifications see section “Specifications” in the Frame Unit Technical Reference Slot

1.2.3

Pulse oximetry Measurement range Calibration range Accuracy1

0 to 100% 70 to 100 & 100 to 70%, ±2 digits ±3 digits during clinical patient motion 69 to 0%, unspecified Display resolution 1 digit = 1% of SpO2 Display averaging time Slow, Normal, beat-to-beat Pulse beep pitch varies with SpO2 level The monitor is calibrated against functional oxygen saturation SpO2 func.

Pulse rate from Pleth Measurement range Accuracy Resolution Display averaging Adjustable pulse beep volume.

30 to 250 bpm 30 to 100, ±5 bpm, 100 to 250, ±5% 1 bpm 10 s

Pleth waveform Scales 2, 5, 10, 20, 50 mod%, Auto Start up scale is 20 mod% if AUTO is not selected to be the default setting.

1.2.4

Temperature Measurement range Measurement accuracy

10 to 45 °C (50 to 113 °F) ±0.1 °C (25 to 45.0 °C) ±0.2 °C (10 to 24.9 °C)

1. Accuracy is based on deep hypoxia studies with volunteered subjects during motion and non-motion conditions over a wide range of arterial blood oxygen saturation as compared to arterial blood CO-Oximetry.

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Display resolution Temperature test Probe type Single use sensors

1.2.5

0.1 °C (0.1 °F) automatic (every 10 min.) compatible with YSI 400 and 700 series ±0.2 °C (25 to 45.0 °C) ±0.3 °C (10 to 24.9 °C)

Invasive blood pressure Measurement range Measurement accuracy Zero adjustment range Calibration range Scales Sweep speed

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

Digital display Range Resolution

-40 to 320 mmHg ±1 mmHg

Waveform display Range

-30 to 300 mmHg

Pulse rate from arterial pressure Measurement range Resolution Accuracy

1.2.6

30 to 250 bpm 1 bpm ±5 bpm or ±5% whichever is greater

Respiration NOTE: The respiration measurement is intended for patients over three years old Measurement range 4 to 120 bpm Accuracy ±5 bpm or ±5% Resolution 1 bpm Averaging time 30 s Update interval 10 s

Respiration waveform Sweep Speeds

1.3

Technical specifications

1.3.1

NIBP

6.25 mm/s and 0.625 mm/s

Deflation rate, PR dep. 3 to 8 mmHg/s Inflation time 20 to 185 mmHg, 1 to 5 s Automatic software control, max. inflation pressure adult 280 ±10 mmHg child 200 ±10 mmHg infant 145 ±5 mmHg

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Over pressure limit, stops measurement after 2 seconds adult 320 mmHg child 220 mmHg infant 160 mmHg The safety circuit limits the maximum cuff pressure to 320 mmHg in adult/child mode or 160 mmHg in infant mode. Independent timing circuit limits pressurizing (>15 mmHg) time to 3 minutes maximum in adult/child mode, and 90 seconds at (>5mmHg) in infant mode. Zeroing to ambient pressure is done automatically. Inflation pressure is adjusted according to the previous systolic pressure, typically 40 mmHg above. If the systolic pressure is not found, inflation pressure is increased typically 50 mmHg. Max. measurement time adult 120 s child 120 s infant 75 s Pressure transducer accuracy is better than ±3 mmHg or ±2% whichever is greater. Max. error ±4 mmHg. Protection against electrical shock Type BF defibrillation proof

1.3.2

ECG Defibrillation protection Recovery time Input impedance CMRR System noise Allowable offset Gain range Pacemaker pulse detection Protection against electrical shock

1.3.3

Type CF defibrillator proof

Pulse oximetry Protection against electrical shock

1.3.4

5000 V, 360 J 2s >2.5 MW (10 Hz) >100 dB (ST) <30 mV (p-p, RTI) ±800 mVDC 0.2 to 5.0 cm/mV 2 to 700 mV, 0.5 to 2 ms pulses

Type CF defibrillation proof

Temperature Measurement accuracy Protection against electrical shock

±0.1 °C (25.0 to 45.0 °C) ±0.2 °C (10.0 to 24.9 °C) Type CF defibrillation proof

NOTE: The accuracy of the measurement may be different from the specified, depending on transducer/probe used. Please refer to the transducer/probe specification.

1.3.5

Invasive blood pressure Digital display averaging Digital displays Art and P1 are averaged over 5 seconds and updated at 5 seconds intervals. All other pressures have respiration artifact rejection.

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Accuracy Transducer and input sensitivity Filter Zero set accuracy Calibration resolution Zero time Protection against electrical shock

±5% or ±2 mmHg, whichever is greater 5 mV/V/mmHg, 5 VDC, 20 mA max current 0 to 4 - 22 Hz adjustable ±1 mmHg ±1 mmHg less than 15 s Type CF defibrillation proof

NOTE: The accuracy of the measurement may be different from the specified, depending on transducer/probe used. Please refer to the transducer/probe specification.

1.3.6

Respiration Excitation frequency, 12-lead ECG Breath detection detection: 0.2, 0.4, 0.6, 0.8, 1.0 Input dynamic range Input impedance range Respiration Rate Lead off detection

31.25 kHz automatic, range 0.3 to 6 Ω manually adjustable minimum 0.2 to 6 Ω 100 to 5000 Ω min. 4 bpm max. 120 bpm >3 MΩ

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2

Functional description

2.1

Measurement principle

2.1.1

NIBP NIBP (Non-Invasive Blood Pressure) is an indirect method for measuring blood pressure. The NIBP measurement is performed according to the oscillometric measuring principle. The cuff is inflated with a pressure slightly higher than the presumed systolic pressure, and deflated at a speed based on the patient’s pulse, collecting data from the oscillations caused by the pulsating artery. Based on these oscillations, values for systolic, mean, and diastolic pressures are calculated. The following parts are necessary for the NIBP measurement:

• • • 2.1.2

E-PSPMP/E-PSM module twin hose (adult or infant model) blood pressure cuffs (various sizes)

ECG Electrocardiography analyzes the electrical activity of the heart by measuring the electrical potential produced with electrodes placed on the surface of the body. ECG reflects:

• • • •

electrical activity of the heart normal/abnormal function of the heart effects of anesthesia on heart function effects of surgery on heart function

See the “User's Guide” or the “User’s Reference Manual” for electrodes positions and other information.

2.1.3

Pulse oximetry A pulse oximeter measures the light absorption of blood at two wavelengths, one in the near infrared (about 940 nm) and the other in the red region (about 660 nm) of the light spectrum. These wavelengths are emitted by LEDs in the SpO2 probe, the light is transmitted through peripheral tissue and is finally detected by a PIN-diode opposite the LEDs in the probe. The pulse oximeter derives the oxygen saturation (SpO2) using an empirically determined relationship between the relative absorption at the two wavelengths and the arterial oxygen saturation SaO2. In order to measure the arterial saturation accurately, pulse oximeters use the component of light absorption giving variations synchronous with heart beat as primary information on the arterial saturation. A general limitation of pulse oximetry is that due to the use of only two wavelengths only two hemoglobin species can be discriminated by the measurement. The modern pulse oximeters are empirically calibrated either against fractional saturation SaO2frac;

SaO2frac =

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HbO2 HbO2 + Hb + Dyshemoglobin

Formula 1

S/5 Patient Side Module, E-PSM, E-PSMP

or against functional saturation SaO2func;

SaO2func =

HbO2 HbO2 + Hb

Formula 2 Functional saturation is more insensitive to changes of carboxyhemoglobin and methemoglobin concentrations in blood. The oxygen saturation percentage SpO2 measured by the Datex-Ohmeda module is calibrated against functional saturation SaO2func. The advantage of this method is that the accuracy of SpO2 measurement relative to SaO2func can be maintained even at rather high concentrations of carboxyhemoglobin in blood. Independent of the calibration method, pulse oximeters are not able to correctly measure oxygen content of the arterial blood at elevated carboxyhemoglobin or methemoglobin levels.

Plethysmographic pulse wave The plethysmographic waveform is derived from the IR signal and reflects the blood pulsation at the measuring site. Thus the amplitude of the waveform represents the perfusion.

Pulse rate The pulse rate calculation is done by peak detection of the plethysmographic pulse wave. The signals are filtered to reduce noise and checked to separate artifacts.

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Intensity of transmitted light

Imax (DC-component)

Imax Imin

AC-component

Variable absorption due to pulse added volume of arterial blood

Transmitted light

Arterial blood Venous blood

No pulsation

Pulsatile blood

absorption of light vsd

Tissue Time

Incident light

Figure 2

Absorption of infrared light in the finger

SpO2 sensor connector

RED

Detector

Figure 3 10 Document No. M1024662-2

Pulse oximetry probe parts layout and schematic diagram

PSM_absorption_of_infrared.vsd

IRED

Emitter

S/5 Patient Side Module, E-PSM, E-PSMP

The standard probe is a finger clamp probe which contains the light source LEDs in one half and the photodiode detector in the other half. Different kinds of probes are available from Datex-Ohmeda.

2.1.4

Temperature The temperature is measured by a probe whose resistance varies when the temperature changes, called NTC (Negative Temperature Coefficient) 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 through the resistor and measuring the voltage that is generated across it. In Datex-Ohmeda modules the two methods are combined in the form of a voltage divider. The NTCresistor 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.

2.1.5

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.

2.1.6

Respiration Impedance respiration is measured across the thorax between ECG electrodes. The respiration signal is made by supplying current between the electrodes and by measuring the differential current from the electrodes. The signal measured is the impedance change caused by breathing. From these impedance changes, respiration rate is calculated, and the respiration waveform is displayed on the screen.

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2.2

Main components

2.2.1

E-PSMP/E-PSM

1 2 3

1. Module keys 2. NIBP connector 3. InvBP connector in E-PSMP only 4. Temperature connector 5. SpO2 connector 6. ECG and impedance respiration connector 7. Tab for removing the module

7

4 5 6

Figure 4

Front panel of E-PSMP

The E-PSMP and E-PSM modules contain three main PC boards, the STP board, the ECG board, and the NIBP board. Each of these boards contain a processor and software in the processor flash memory. The boards produce their own supply voltages from the Vmod 13.8-16 V line that is available via the module bus connector. One exception, the NIBP board provides +5V for the ECG and STP board nonisolated side components. The NIBP board provides also the synchronization signal for the ECG and STP board power supplies. There are two small boards, the STP input and the ECG input board attached to the front panel of the module. The front panel has five connectors and four keys. The connectors are: one for temperature measurement, one for invasive blood pressure measurement, one for ECG, one for NIBP, and one for SpO2 measurement. The NIBP connector includes two plungers for NIBP hose identification. The keys are for NIBP Auto On/Off, NIBP Start/Cancel, P1 zero, and P2 zero.

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2.2.2

NIBP board

P a t ie n t a n d N I B P c u f f

N IB P c u ff h o s e

N IB P c o n n e c to r w ith N IB P h o s e id e n t if ic a t io n

N I B P p n e u m a t ic s ( m a n if o ld )

D r iv e r s f o r p u m p & v a lv e s

P re s s u re s e n s o rs

M a in C P U

N V m e m o ry f o r c o n t in u e d p a t ie n t d a t a

N V m e m o ry

S a fe ty C P U

P o w e r s u p p ly RS 485 c o m m u n i c a t io n

+5 V and s y n c h r o n iz a tio n s ig n a l fo r E C G - a n d S T P -b o a rd s

M o d u le b u s c o n n e c t o r

Figure 5

PSM_NIBP_blockdiag.vsd

N IB P c o n tro l keys

Pum p

NIBP board functional block diagram

Signal processing Two signals from the pressure transducers are amplified and sent to the A/D converter. After the converter, digitized signals are sent to the microprocessor for data processing. The NIBP board is controlled with a H8/3052 microprocessor at 16 MHz oscillator frequency.

Memory NIBP program memory (processor flash memory) size is 512k x 8. The processor has 4 kBytes RAM and there is also an external RAM memory the size of which is 128k x 8. Variable values of the NIBP measurement are stored into the external RAM. The EEPROM size is 512 x 8 and it is used to store the calibration values for the pressure transducers, the pulse valve constants gained during measurements, the PC board identification, and module serial number.

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Software control Software controls valves and pump. In addition to the individual on/off signals for each component there is a common power switch for the valves and the pump that can be used at pump/valve failures. In addition to external RS485 reset line the microprocessor system is equipped with its own power-up reset. See the section in the ECG board’s description: “RS485 communication”

Safety circuit The NIBP board is equipped with an independent safety circuit to disconnect supply voltages from the pump and the valves if the cuff has been pressurized longer than the preset maximum measurement time, or if the pressure of the cuff is inflated over the specified pressure limit. The maximum measurement time values and pressure limits for different measurement modes have been specified in the technical specification section of this manual.

Pneumatics

The module has the following pneumatics parts: 1. Intake air filter; for preventing dust and other parts to enter the air pump and the valves. 2. Air pump: for pumping the measuring pressure of the cuff. 3. (Pulse) Valve; for producing a linear pressure fall (bleeding) in order to measure the blood pressure of the patient. Note that in the service menu also names Valve and Set valve have been used for this valve. 4. Safety valve; The safety valve has been intended to be used for deflating the cuff in single fault case, i.e. to prevent too long measurement time or too high inflation pressure of the cuff. Note that there has been used also Exh2 valve to designate the Safety valve in service menu. 5. Main pressure sensor: for measuring the pressure of the blood pressure cuff and the pressure fluctuations caused by arterial wall movement. 6. Safety pressure sensor: for detection of cuff loose, cuff occlusion situations etc. and recognizing the pressure sensor fault. 7. Cuff connector: for connection and hose identification.

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Safety pressure sensor

S1 Plunger

Proportional valve Air pump

Cuff connector

S2

Main pressure sensor

Pump valve Intake air filter

Figure 6

PSM_NIBP_pneum_diagr.vsd

Plunger

NIBP pneumatics diagram

Power supply section of the NIBP board All connections are established via 5-pin connector (female). The module needs +15 V (dirty) power supply to operate. The supply voltage Vmod 13.8- 16 V is generated in the power supply section of the S/5 FM monitor. The other voltages needed for the operation of the NIBP measurement are made on the NIBP board. The NIBP power supply synchronizes the ECG and STP isolation power and supplies the non-isolated 5 V to ECG and STP board.

2.2.3

ECG board in 12-lead measurement The 12-lead ECG measurement consists of the functions, which are shown, in Figure 7 on page 16. All functions are located in the ECG board except the ECG input unit.

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PATIENT AND ECG ELECTRODES ECG CABLE - ECG LEAD SET - ECG TRUNK CABLE ECG INPUT UNIT - ECG CONNECTOR - INPUT PROTECTION RESISTORS INPUT PROTECTION DIODES FOR ECG & RESPIRATION MEASUREMENT

INPUT FILTERING FOR ECG & RESPIRATION MEASUREMENTS

RESPIRATION MEASUREMENT AMPLIFIERS

RESPIRATION MEASUREMENT CURRENT SUPPLY

ECG PREAMPLIFIERS & RLD CIRCUIT

LEADS OFF & PACER & DEFIBRILLATION DETECTION

BASELINE RESTORATION

ECG CPU

NV MEMORY RS 485 COMMUNICATION ISOLATION

POWER SUPPLY ISOLATION

MODULE BUS CONNECTOR

ECG BLOCK DIAGRAM

Figure 7

12-lead ECG measurement block diagram

ECG input unit The ECG input unit consists of the front panel connector and the ECG input connector board with the high voltage protection resistors. The connector for the 12-lead ECG cable is a green 11-pin rectangle shaped connector.

Input protection and filtering The input protection is implemented with high voltage protection resistors in the ECG input unit and with protection diodes in the ECG board. The input filtering for ECG measurement is done with passive RC filtering.

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ECG preamplifiers The buffer amplifiers are used for each lead. The “Leads off” detection is implemented by measuring the output level of the input buffer amplifiers with A/D converter of CPU. The ECG signals are measured using differential amplifiers.

ECG amplifiers and baseline restoration The function of the ECG amplifiers and baseline restoration is to amplify the signal and to restore the baseline of the signal in the middle of the display after the change of the signal level e.g. after the change of the DC offset voltage.

Pacer detection Pacer detection has been made by using four slew rate detector circuits. The pacer detection amplifiers have been realized at the front of the slew rate detectors independently from the ECG measuring channels.

Respiration impedance supply The 31.25 kHz sine wave generator is used as the respiration measurement signal supply. Analog switches are used for connecting the sine wave to the ECG leads to be measured.

Respiration impedance amplifiers Buffer amplifiers are used in respiration measurement. Analog switches are used for selecting the measurement leads. There are also additional amplifiers for increasing the respiration signal gain. When ECG measurement is 5/12-lead, the respiration measurement is always done between R and F, independently on the ECG lead selection. When ECG measurement is 3-lead, then the respiration measurement is happened at the same lead as the ECG measurement (I, II or III).

ECG CPU The CPU is a 16 bit H8/3052 single-chip microcomputer. It contains 128 kbytes of flash memory and 4 kbytes of RAM. The clock frequency is 16 MHz.

RS485 communication The communication to the CPU board of the monitor uses RS485 protocol. The RS485 driver circuits are optically isolated from the processor of the module.

Power supply The ECG board has a driver controlled half bridge switching power supply with 5 kV isolation. The supply voltages have been regulated with linear regulators.

2.2.4

ECG filtering The S/5 monitors have three ECG filtering modes: MONITORING 0.5 to 30 Hz (with 50 Hz reject filter) 0.5 to 40 Hz (with 60 Hz reject filter) DIAGNOSTIC 12-lead ECG 0.05 to 150 Hz ST FILTER 0.05 to 30 Hz (with 50 Hz reject filter) 0.05 to 40 Hz (with 60 Hz reject filter) The purpose of filtering is to reduce high frequency noise and low frequency (e.g. respiratory) movement artifacts.

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