Rigel Vital Signs Rev 1.2 USA

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Innovating Together

An introduction to

measuring and simulating

Vital Signs

rigelmedical.com Innovating Together

We’ve picked your brains to develop the

world’s most advanced vital signs simulator.

Your ideas have had us thinking. Some of you wondered why the

functions of an ECG patient simulator, NIBP and SPO2 simulator

couldn’t be combined into one compact tester?

So we put our heads together and used our unrivalled expertise

to create the hand-held Rigel UNI-SIM. To see the result, or to

contribute your own ideas, call us on 813-886-2775,

email us at enquiry@rigelmedical.com or visit rigelmedical.com

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Contents

Foreword 2

1 Introduction 2

1.1 Visual inspection 3

1.2 Who should verify the correct operation? 3

2 Physiology of the Respiratory System 4

3 Blood Pressure 5

3.1 Measuring blood pressure 6

3.2 Testing your NIBP monitor 7

3.3 Test setup 7

3.3.1 System pressure leak test: 7

3.3.2 System overpressure valve test 8

3.3.3 Static pressure or linearity test 9

3.3.4 Dynamic pressure 9

3.4 Considerations 9

4 Invasive Blood Pressure 11

4.1 Testing IBP function 11

4.2 Test setup 11

4.2.1 Static pressure or linearity test 12

(verify alarm testing)

4.2.2 Dynamic pressure 12

5 Pulse Oxymetry 13

5.1 Artifacts 14

5.2 Testing your SPO2 monitor – 15

pulse oximeter

5.3 Test setup 16

5.3.1 Testing monitor accuracy 16

5.3.2 Alarms and time response test 17

5.3.3 Sensitivity test 17

5.3.4 Testing the SPO2 probe 17

6 Electrocardiographs (ECG) 18

6.1 Einthoven Triangle 19

6.2 Precordial leads 20

6.3 Unipolar vs. bipolar leads 21

6.4 Color coding 21

6.5 The ECG machine 22

6.6 Testing ECG monitor 22

6.6.1 Linearity of heart rate measurement 23

6.6.2 QRS beep 23

6.6.3 Alarms (high and low) 23

6.6.4 Arrhythmias recognition (Asystolic) 23

6.6.5 Sensitivity test (Gain) 23

6.6.6 Zero offset 23

6.6.7 Frequency response 24

6.6.8 Printer calibration (amplitude, timing) 24

7 Respiration 24

7.1 Testing respiration function 26

7.1.1 Linearity of respiration measurement 26

7.1.2 Sleep apnea 26

7.1.3 Testing apnea alarms 26

8 Temperature 27

8.1 Testing temperature function 27

on multiparametric monitors

8.1.1 Linearity of temperature measurement 27

8.1.2 Testing temperature alarms 28

9 Record Keeping 28

Conclusion 29

Considerations and Recommendations: 29

Appendix A 30

IEC 60601-1 collateral standards

Appendix B 31

IEC 60601-2 particular standards

Appendix C 34

YSI 400 & 700 resistance reference table

Appendix D 35

Example documentation template

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Introduction

For decades, considerable work has been

carried out across many industries; to reduce the

risk of injury and occupational death to members

of the general public. In addition, to aid the

process of treating members of the general

public, the health sector has evolved, offering an

ever increasing portfolio of treatments,

monitoring and diagnostic tools.

Risks due to injuries or fatalities during medical

treatment or examination are reduced through

the introduction of industry practises (i.e.

disinfection), guidelines (i.e. best practise),

standards (i.e. design criteria, quality processes)

and regulations (i.e. mandatory criteria).

To ensure the safety of patients, operators and

the members of public, all medical electronic

devices must meet the design criteria of the

internationally published IEC 60601 standard (or

local equivalent where applicable). First

published in the 1970’s, the IEC 60601 standard

(then referred to as IEC 601) describes the

design criteria of medical electronic equipment

(ME Equipment) in areas such as:

■Electrical safety

■Functional accuracy

■Mechanical safety

■Radiation safety

■Operator safety and errors (labelling,

unambiguous instructions)

■Safety of software

■Risk assessment and preventative actions

IEC 60601-1-X (X representing a specific

standard number between 1 - 12) is the primary

standard and has eleven (sub) standards directly

relating to the safety of medical equipment. IEC

60601-2-X (X representing a specific standard

number between 1—65). This part of the standard

is specific to various types of medical equipment

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Foreword

This booklet is written as a guideline for people involved in testing medical, electrical equipment. All

reasonable care has been taken to ensure that the information, reference figures and data are accurate

and have been taken from the latest versions of various standards, guidance notes and recognized

“best practises” to establish the recommended testing requirements. Rigel Medical, their agents and

distributors, accept no responsibility for any error or omissions within this booklet or for any misinter-

pretations by the user. For clarification on any part of this booklet please contact Rigel Medical before

operating any test instrument.

No part of this publication shall be deemed to form, or be part of any contract for training or equipment

unless specifically referred to as an inclusion within such contract.

Rigel Medical assumes that the readers of this booklet are electronically and technically competent and

therefore does not accept any liability arising form accidents or fatalities directly or indirectly from the

tests described in this booklet.

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and provides additional information to the four

basic standards.

Appendix A and B provide an overview of the IEC

60601-1-X and IEC 60601-2-X standards.

This booklet describes the common aspects of

vital signs monitoring and performance testing of

those vital signs.

The main vital signs described are:

■Blood pressure

(Invasive or non invasive methods)

■Temperature

■Electro cardiogram (ECG )

■Respiration

■Blood oxygen saturation (SpO2)

To ensure the correct treatment, diagnoses or

monitoring of patients, it is of critical importance

that the vital signs monitor is able to provide

accurate data across all available vital signs. Such

accuracy is verified on a regular basis, based on

risk assessment, manufacturer recommendations

and stages of the monitor’s life cycle.

Performances tests (also referred to as quality or

functional tests) are typically executed using

calibrated simulators across a number of

applications and are all part of an acceptance

test, preventative maintenance cycle or repair.

A typical test cycle for a vital signs monitor might

include:

■Visual inspection

■Self tests (where applicable)

■Electrical safety testing

(ground bonding, leakage currents)

■Integrity of the device under test

(i.e. leak test, over pressure test)

■Parameter accuracy (temperature, pressure,

SpO2, time etc….)

■Check alarms (pitch, frequency, volume)

■Physiological simulations (Dynamic Patient

Simulation)

1.1 Visual Inspection

The process of visual inspection is not clearly

defined by any standard, however visual

inspections form a critical part of the general

safety and performance inspections during the

functional life of medical equipment.

Visual inspections are a relatively easy procedure

to ensure that the medical equipment in use, still

conforms to the specifications as released by the

manufacturer and has not suffered from any

external damage and / or contamination.

These can include the following inspections:

■Housing - Enclosure; look for damage, cracks etc.

■Contamination; look for obstruction of moving

parts, connector pins, etc.

■Cabling (supply, Applied Parts etc); Look for

cuts, wrong connections, etc.

■Fuse rating; check correct values after

replacement

■Markings and Labelling; check the integrity of

safety markings

■Integrity of mechanical parts; check for any

obstructions

1.2 Who should verify the correct operation?

The correct function and operation of medical

equipment is equally as important as the function

it performs. An incorrect reading or missed

condition might have considerable consequences

for the patient therefore; the person carrying out

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the maintenance must be technically competent,

appropriately trained and aware of the various

parameters being verified.

It is the responsibility of the medical equipment

manufacturer to provide verification procedures

to ensure optimum performance is being

achieved. The person or organization carrying

out the maintenance must make themselves

aware of the required procedures and operation

of the medical equipment. When in doubt,

contact the manufacturer.

2 Physiology of the respiratory system

All vital signs are related to the operation and

functioning of the respiratory system. While the

Electro Cardiogram (see chapter 6) shows the

electrical activity of the human heart pumping the

oxygenated blood (see chapter 5) around the

arteries, blood pressure (see chapter 3 & 4) is

generated. Respiration (see chapter 7) rates

might show any obstruction (apnea) in the

airways thus affecting the oxygen absorption in

the lungs. The core body temperature, together

with blood pressure being the most commonly

measured vital signs, is maintained through good

blood circulation (see chapter 8).

The human heart is central to the respiratory

system and can be seen as the main engine

within. The heart circulates blood through the

body and lungs (the carburetor of the body

attaching oxygen to the hemoglobin protein in

the red blood cells) in order to ensure oxygen is

able to reach the (brain) tissues and organs in

order to sustain life.

Figure 1: A simplified representation of the

circulatory system

To establish a single circulation cycle, blood flows

through the heart twice, passing through the left

and right side of the heart respectively. Acting as

two “pumps”, the heart circulates oxygenated

blood (red circuit, systemic circulation) from the

lungs through the left side of the heart, while

deoxygenated blood from the tissues flows

through the right side of the heart to the lungs in

order to re-oxygenate the blood cells (blue

circuit, pulmonary circulation).

The two ventricles (chambers) provide the blood

from the heart while blood is entering the heart in

the two atria (chambers). Valves in and between

the different chambers ensure the chambers can

fill up with blood during the diastolic phase (the

heart muscle relaxes) and pressures can build-up

in the ventricles to provide the required condition

to allow circulation from a high pressure (systolic

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phase) to the lower pressure areas. A complete

cycle of events is referred to as the cardiac cycle,

a single heart beat and involves;

1. Atrial systole,

2. Ventricular systole and

3. Complete cardiac diastole.

Cardiac muscles are electrically stimulated and the

cardiac cycle is triggered by Sinoatrial Node (S.A.

Node), then synchronized through timing (delays)

(Atrioventricular A.V. Node and bundle of His) which

ensures coordinated contraction and relaxation of

the different heart muscles to allow the individual

chambers to fill-up and empty. While the heart is

self-exciting and able to maintain it’s own pace (S.A.

Node), the heart rate can be altered due

tometabolic demands (e.g. exercise, emotion,

anxiety).

During the cardiac diastolic phase, the heart

relaxes and blood is able to fill the two atria. As the

atria fill up to around 70%, the pressure in the atria

releases the valves to the ventricles (tricuspid and

mitral valve). The remaining 30% of blood volume

in the atria is pumped out as the atria contract

(atrial systole) at the start of the heart beat. The

ventricles contract (ventricle systole) resulting in

the blood flowing out of the heart through the main

heart valves (aortic and pulmonary valves) into the

pulmonary and systemic circulation.

The number of circulations per minute (or beats per

minute) can vary due to age, as a result of exercise,

hormone levels (ie caused by anxiety or stress) and

physical condition (related to cardiac output).

The greater the need for oxygen by the body, the

greater the need for oxyhemoglobin. A human

heart has a certain capacity to circulate blood

(cardiac output) therefore; oneway to increase

blood supply is to increase heart rate. In general;

■The smaller the cardiac output, the higher the

heart rate.

■The greater the cardiac output, the lower the

heart rate.

This is evident in infants and children, having a

relatively small cardiac output, thus higher heart

rate. Their resting heart rate can be between

100—150 bpm. In comparison, a trained athlete has

been able to increase their cardiac output through

build up of exercise. The resting heart rate can be

as low as 40 bpm or even lower. Cardiac output is

not classed as a vital sign and therefore not

considered further in this booklet.

3 Blood pressure

The most common vital sign parameter being

monitored or measured is the (arterial) blood

pressure. During the cardiac cycle, the ventricles

contract (systole) and the blood pressure is at its

highest (systolic) and during complete cardiac

diastole, the blood pressure is at its lowest

(diastolic) which enables the blood to circulate

through the body through the systemic and

pulmonary circulation. The blood flow and pressure

change with each stage of the cardiac cycle and are

reported in millimeters of mercury (mmHg).

This is represented in figure 2.

In a healthy patient, the average values for the

different pressure variations are:

■Systolic pressure 120 mmHg

■Diastolic pressure 80 mmHg

■Mean arterial pressure 90—93 mmHg

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Figure 2: ECG waveform vs aortic pressure

and plethymograph

It is not uncommon to have deviations from these

values which can be the result of for example;

emotions, anxiety, drug-use, cardiac conditions,

life style, fitness, age and diet.

■Hypotension Blood pressure being

abnormally lower

than average

■Hypertension Blood pressure being

abnormally higher

than average

3.1 Measuring blood pressure

Blood pressure can be measured both

noninvasively (NIBP) and invasively (IBP) and is

associated with the pressure in the arterial blood

vessels. While the invasive method (see 4) is

more accurate, the non-invasive method (NIBP)

is the most common. While invasive procedures

require highly skilled people, the non-invasive

method is relatively simple and can be done by

both skilled and unskilled people. NIBP monitors

range from domestic use to comprehensive multi

parameter monitors used in healthcare facilities.

The principles of measuring NIBP can vary from:

■Palpation method (feeling) —an indication of

the minimum (systolic) blood pressure obtained

through the touch/feel sensation at determined

positions (radial, femoral, carotid) of the body.

Palpation is often used in emergency and trauma

cases where rapid detection of a present blood

pressure is required or rapid loss of blood pressure

is expected.

■Auscultatory method (listening) – as blood flow

is interrupted (blocked by external cuff) and released

(deflation of the cuff), sounds can be associated with

the systolic and diastolic pressures. When a cuff is

positioned around the upper arm and inflated to the

point the artery is blocked (no blood flow), the cuff is

then deflated. The pressure at which blood flow

regains is the systolic pressure and is accompanied

by a specific beating sound (referred to as first

korotkoff sound) caused by turbulent blood flow in

the artery. The pressure at which the sound stops

(fifth korotkoff sound) is referred to as the diastolic

pressure. Observation is done by listening through a

stethoscope (or can be automated through

microphone electronic pick-up), positioned directly

on the elbow artery and the use of a calibrated

manometer. (The mean arterial pressure is

calculated from the systolic and diastolic pressures.

There is no agreed standard but the formula below

is often referred to:

■Mean BP = 1⁄3* (systolic + 2 x diastolic)

■Oscillometric method (measuring) – Unlike

the auscultatory method, the oscillometric method

measures the mean arterial pressure and calculates

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SPO2

Ventricular pressure

Aortic pressure SystolicpressureSystolicpressure

Diastolic pressure

Dicrotic notch

QS

PT

R

QS

PT

R

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the systolic and diastolic pressures from pressure

variations in the cuff when inflated (blocking the

blood flow) and then deflated (blood flow regains).

While the auscultatory method often relies on

human interpretation (listening), the oscillometric

method is done through automation and the use of

electronic pressure sensors. Due to the use of

electronic pressure transducers, regular calibrations

are required and often advised by the manufacturer.

3.2 Testing your NIBP monitor

As explained above, oscillometric NIBP monitors

require regular performance verifications to

ensure the correct operation. Common issues

relating to the accuracy of the NIBP monitor are:

■A leak in the cuff or pressure system,

resulting in a lower blood pressure reading.

■Acoustic variance of the cuff due to incorrect

cuff volume, variety in materials used and

positioning or applying cuff on patient.

■Incorrect operation of the overpressure valve

caused by a leak or complete malfunction.

■Deviation in accuracy of the electronic

pressure transducer caused by wear and tear

of electronic components.

■Changes in atmospheric pressure including

pressure variations caused by closing

doors/windows.

A number of tests are provided to determine the

correct operation of the NIBP monitors. These

are:

■Pressure leak test (see 3.3.1)

■Over pressure valve test (see 3.3.2)

■Static pressure & linearity test (see 3.3.3)

■Dynamic pressure (see 3.3.4)

3.3 Test setup

In the example below, the Rigel BP-SIM or UNI-

SIM is used to reflect the NIBP simulator. Ensure

the correct cuff size and positioning to reduce

acoustic errors. An additional 500cc cylinder may

also be used to provide a consistent reading.

In order for the NIBP simulator to measure the

pressure in the cuff and simulate into the NIBP

monitor any pressure variations associated with

the oscillometric method, the simulator must be

inserted in (one of) the pressure tubes to the cuff

as shown in the figure below.

Figure 3: Test setup: Connecting the NIBP

simulator

3.3.1System pressure leak test

The purpose of the pressure leak test is to verify

and ensure the integrity of pressure system

including the tubing and cuff. The leak test

measures the pressure drop over time and must

fall within acceptable values as documented by

the supplier or manufacturer of the monitor and

or cuffs. Often, the pressure drop is documented

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SYS 120 mmHg

DIA 80 mmHg

HR 70 bpm

UNI-SiM

NIBP Monitor Cuff

as mmHg / min from a certain start pressure e.g.

200 mmHg. Refer to the service or maintenance

instructions provided with the monitor as it may

have to be set in service or calibration mode.

For example: a manufacturer could specify a

system leak test for a duration of three minutes

where the expected total pressure drop must not

exceed 15 mmHg. This is equal to 5 mmHg per

minute.

Some NIBP simulators like the Rigel UNI-SIM

have a built-in pump to generate the required

pressure levels. Inflate the pressure into the

system and monitor the pressure drop and time.

Figure 4 shows a sample screenshot from the

Rigel UNI-SIM while performing the leak test.

Figure 4: NIBP leak test on the Rigel UNI-SIM

Once the selected pressure is stabilized, the

timer starts and the UNI-SIM will show real-time

system pressure over time.

3.3.2 System overpressure valve test

When dealing with pressure systems, it is

important to ensure the system is able to vent

when pressures reach a value exceeding the

safety of the patient or operator and the correct

functioning of the monitor itself.

The purpose of the overpressure test is to

determine whether the internal safety valve(s) are

functioning correctly and release the internal

pressure when it reaches the maximum allowable

system pressure set by the monitor’s

manufacturer. Refer to the service or maintenance

instructions provided with the monitor as it may

have to be set in service or calibration mode.

For example: a manufacturer could specify the

set-point of 300 mmHg as the maximum

allowable system pressure for an adult setting

and 150 mmHg for a pediatric setting (+/-10%).

Some NIBP simulators like the Rigel UNI-SIM

have a built-in pump to generate the required

pressure levels. Inflate the pressure into the

system until the monitor releases the

overpressure valve, resulting in an almost

instantaneous pressure drop. The inclusion of the

original cuff or air reservoir of 500cc during this

test is advised to provide consistency with the

normal operation of the monitor. Figure 5 shows

an example screen shot from the Rigel UNI-SIM

displaying the set-point at which the pressure

drop (valve release) occurred.

Figure 5: NIBP pop-off test on the Rigel UNI-SIM

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In the example above, the test demonstrates that

the valve was released at 331 mmHg.

3.3.3 Static pressure or linearity test

The static pressure tests are useful for verifying

the performance of the pressure transducer and

verifying the integrity of tubing systems internal,

external and cuff). In addition, the static pressure

test can be used to test the accuracy over a

range of pressures. Refer to the service or

maintenance instructions provided with the

monitor as it may have to be set in service or

calibration mode.

For example: A manufacturer could ask to perform

a linearity test on the following static pressures:

250mmHg, 200mmHg, 150mmHg, 100mmHg,

50mmHg and 0mmHg. The reading values

should be at +/-3mmHg from expected value.

Some NIBP simulators like the Rigel UNI-SIM have

a built-in pump to generate the required pressure

levels. Inflate the pressure into the system (monitor

with or without the cuff) and compare the reading

from the monitor with that of the calibrated

manometer (UNI-SIM). The inclusion of the original

cuff or air reservoir of 500cc during this test is

advised to provide consistency with the normal

operation of the monitor.

3.3.4 Dynamic pressure

Static testing is useful for verifying the

performance of the pressure transducer but it

does not prove the accuracy of the monitor under

dynamic pressures. The performances of the

computing algorithms that enable calculation of

systolic, diastolic and mean blood pressures are

tested in real conditions.

Figure 6: Dynamic pressure simulation

settings on the Rigel UNI-SIM

Patient simulations —It maybe necessary to

perform verifications using different patient

settings for example; a low (hypotension), normal

and high (hypertension) blood pressure;

■Patient A : 80/40 Heart rate 80

■Patient B : 120/80 Heart rate 80

■Patient C : 180/140 Heart rate 80

Testing alarms – Most monitors are equipped

with both audible and visual alarms. It is

important to verify these alarms are working

correctly. Refer to the monitor’s manual to

understand the different alarm conditions.

The simulator can be used to introduce certain

conditions and arrhythmias that will trigger an

alarm, subject to monitor and simulator features.

Figure 6 shows an example screenshot from the

Rigel UNI-SIM displaying the various dynamic

pressure simulation settings available.

3.4 Considerations

There are some physiological variations from one

patient to another. Different patients have

different arterial pulse shapes, arterial

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compliance, flesh rigidity and other factors which

simply make the BP cuff respond differently. The

oscillometric signal is complex and changes not

only in size but in shape in relation to the cuff

pressure.

Manufacturers of automated NIBP monitors are

using different methods and aspects to

determine the systolic and diastolic pressures.

These methods and aspects can include:

■Measuring the pulse size

■Measuring the average pulse size

■Determining the peak of the pulse size

envelope

■Measuring the average cuff pressure at a set

point

■Extracting data during cuff inflation or deflation

All different methods and aspects will result in

different readings on the same patient. As such,

a single NIBP simulator will read different on a

range of different makes of NIBP monitors.

During a dynamic simulation, the NIBP monitor

will inflate the cuff to a level above the expected

systolic pressure. The NIBP simulator, such as

the Rigel UNI-SIM is connected to the pressure

system, and is able to measure the pressure

drop in the cuff introduced by the monitor.

When the system (cuff) pressure is above the

systolic pressure, blood flow is unable to flow

past the cuff. The pressure variations

(oscillations) created by the simulator in the cuff

are minimal and is the result of simulating the

pulsating arterial blood against the cuff.

As the pressure in the cuff drops, the simulator will

simulate greater oscillations in the cuff, simulating

that blood flow is able to resume further along the

artery (along the length of the cuff).

When blood flow in the artery has been

established across the full length of the cuff, the

systolic pressure has been achieved although the

monitor is not able to establish this at this time as

the oscillations in the cuff continue to increase

until the cuff pressure is equal to the mean arterial

pressure.

When the pressure drops below the mean arterial

pressure, the oscillations from the simulator

decrease again (simulating a reduced pressure on

the artery). When the simulated oscillations reach

a minimum, the monitor stops the deflation

process and determines the systolic and diastolic

pressures from the measured mean arterial blood

pressure and or any of the aspects detailed above

depending on the manufacturer.

An example of the shape of the oscillometric

wave form captured by the NIBP monitor is

provided in figure 7.

The deviation in NIBP simulation values

compared to the values displayed on the monitor,

varies between manufacturers of NIBP monitors

and of NIBP simulators. Depending on shape of

the simulated oscillometric waveform, each type

of monitor might give a different interpretation of

the systolic and diastolic values. Consistency in

deviations is one way of ensuring that the monitor

function hasn’t deteriorated though accurate

simulation of the manufacturer’s oscillometric

waveform will allow the verification of whether the

correct components are being used (i.e.

compatible or recommended cuffs and tubing),

determine the accuracy of the calibration and

accurately simulate alarm conditions.

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To improve the accuracy of simulation, it is

essential that the NIBP simulator can simulate

manufacturer specific curves so the calculated

data is taken from identical parts of the envelop.

The Rigel UNI-SIM has the ability to create or

upload manufacturer specific envelopes to

ensure repeatable and accurate simulations.

4 Invasive blood pressure

Arterial pressure can be monitored both

invasively (IBP) and non-invasively (NIBP) as

discussed in the previous chapter however, it

must also be noted that the automated NIBP

method can only provide an indirect and non-real

time arterial pressure as it calculates pressures

based on a typically 30 second cycle.

When a greater accuracy or a real time arterial

pressure is required e.g. when a patient’s blood

pressure is expected to vary greatly during

surgical procedures, it’s most common to use

the invasive method.

During an invasive blood pressure measurement,

a liquid filled catheter is placed in the artery

(radial, brachial, femoral or axillary). The arterial

pressure is directly transferred to the liquid inside

the catheter and tubing to the pressure

transducer (non-invasive but external from the

monitor). The pressure transducer converts the

pressure to an electronic signal which is then

connected to the monitor for further processing

such as determining systolic and diastolic

pressures.

4.1 Testing IBP function

A number of tests are provided to determine the

correct operation of the IBP monitors. These are:

■Static pressure & linearity test (see 4.2.1)

■Dynamic pressure (see 4.2.2)

4.2 Test setup

The external pressure transducer produces a milli

Volt (mV) signal. The IBP simulator will produce

corresponding mV signals on the signal and

excitation connections to the IBP monitor to

simulate the external pressure transducer.

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Figure 7: Oscillometric wave form

There are several types of connections

depending on the monitor make and the

sensitivity of the pressure transducer

(mV/mmHg) will also vary by model. It is advised

that the correct connections are made and

tested prior to the simulations to avoid errors in

the simulations.

In this example we connect the Rigel UNI-SIM to

the IBP monitor and simulate dynamic pressure

values.

Figure 8: Test setup: Connecting the IBP

simulator

4.2.1 Static pressure or linearity test

(verify alarm testing)

The static pressure tests are useful for verifying

the performance of the pressure transducer. A

linearity test can be done similar to that during

the NIBP simulations, in order to verify the

accuracy of the IBP monitor over a pressure

range.

Start by setting the transducer sensitivity,

typically 5µV/V/mmHg. Zero the system by

simulating a zero pressure with the simulator and

set up the zero value on the monitor (refer to the

service or maintenance manual for instructions).

Once the zero is established, a number of

different pressure values can be simulated.

Forexample: A manufacturer could ask to perform

a linearity test on the following static pressures:

250mmHg, 200mmHg, 150mmHg, 100mmHg,

50mmHg and 0mmHg. The reading values

should be within +/-3mmHg from expected

value.

Record whether the alarm on the monitor occurs

at the set value(s) and whether the alarm(s) is at

the correct pitch and frequency (refer to the

instruction manual).

4.2.2 Dynamic pressure

The accuracy of the pressure transducer can

also be verified using a dynamic pressure

simulation. The performance of the computing

algorithms that enable calculation of systolic,

diastolic and mean blood pressures are tested in

real conditions.

Patient simulations —It may be necessary to

perform verifications using different patient

settings for example; a low (hypotension), normal

and high (hypertension) blood pressure;

■Patient A : 80/40 heart rate 80

■Patient B : 120/80 heart rate 80

■Patient C : 180/140 heart rate 80

Testing alarms – Most monitors are equipped

with both audible and visual alarms. It is

12

SYS 120 mmHg

DIA 80 mmHg

HR 70 bpm

UNI-SiM

IBP Monitor

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important to verify these alarms are working

correctly. Refer to the monitor’s manual to

understand the different alarm conditions.

5 Pulse oxymetry

If we consider the heart as the engine of the

respiratory system (see chapter 2) and the lungs

as the carburetor, oxygenated blood can be

considered the fuel whereby the level of oxygen

can be directly related to the potential capacity in

the blood (or octane level in fuel 95—98% being a

typical value).

Oxygen is absorbed by the blood as it passes

through the lungs, as oxygen sticks to the

hemoglobin protein in the red blood cells. The

quantity of oxygen absorbed (oxyhemoglobin) is a

sign of the respiratory system’s vitality

(performance), hence it is one of the most

common monitored vital signs. Displayed in

percentage oxyhemoglobin (SaO2, a direct

measurement) in relation to hemoglobin, pulse

oximeters can provide a real-time indication of the

total oxygen saturation (SpO2) in the blood.

To establish an indication of the oxygen saturation,

the pulse oximeter relies on the different light

absorption characteristics of oxyhemoglobin and

hemoglobin at different spectrums of light. Using a

red (650—700 nm) and infrared (850—950 nm)

spectrum light source, a pulse oximeter can

determine the oxygen concentration by measuring

the difference between the red and infrared light

being absorbed by the arterial blood.

To do so, a finger probe (or ear probe) is placed

on the finger. A red and infrared spectrum LED is

driven by the monitor at consecutive intervals of

typically 0.2 ms (5kHz). On the opposite side of

the finger probe, a broadband receiver converts

the unabsorbed red and infrared light signals into

electrical signals. Other types of probes (i.e. foot

probes) or techniques are available such as a

reflective method used on the forehead. These

however, are not part of this booklet although the

principles are similar.

Figure 9: The finger probe pulse oximeter

The red light is absorbed more in relation to infrared

light when passing through hemoglobin (Hb, de-

oxygenated blood cells) whilst infrared light is

absorbed more by oxyhemoglobin (HbO2,

oxygenated blood cells). The ratio at which the light

is being received can therefore provide an

indication of the level of oxygen concentration:

In principle, this translates to:

■Less infrared than red light being received:

higher concentration of oxyhemoglobin (HbO2)

■Less red than infrared light being received:

lower concentration of oxyhemoglobin (Hb)

A simplified representation of the absorption

properties of hemoglobin and oxyhemoglobin is

provided in figure 10. Note that this is not suitable

for clinical use.

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SPO2

Red LED

Infrared LED

PhotoDetector

Figure 10: Absorption properties of

hemoglobin and oxyhemoglobin.

The red line shows the fully oxygenated

hemoglobin (HbO2 - 100% SpO2) while the blue

line shows the fully deoxygenated hemoglobin

(Hb - 0% SpO2). At around 800nm wavelength

the absorption is equal for both HbO2 and Hb,

this is referred to as the isosbestic point (803nm)

Typical ratio values are:

■100% SpO2 R/IR approximate ratio of 0.5

■82% SpO2 R/IR approximate ratio of 1.0

■0% SpO2 R/IR approximate ratio of 2.0

Different manufacturers use different wavelengths

(within the described spectrum) and have different

absorption look-up tables. This is referred to as

the R-curves for each manufacturer.

5.1 Artifacts

It is important to realize that light is passing

through different types of tissue (skin, muscle,

bone), cells and vessels (arterial and venous).

Therefore, to determine the amount of arterial

oxyhemoglobin, the monitor will look at the

“pulsating” light absorption waveform, the so

called plethysmograph (see figure 11).

Figure 11: An example plethysmograph vs

ECG waveform

As the heart pumps the blood through the lungs,

the level of oxyhemoglobin is “restored” (typically

5% of oxygen in lungs) at every systolic cycle after

which it will be absorbed at the capillaries

(typically around 40%) until the next systolic cycle.

At the peak of the plethysmograph, the monitor

measures the total light absorption (arterial and

other cells, tissues, venous vessels) while at the

troughs, the monitor measures all but the arterial

absorption (all remaining cells and tissues). By

subtracting peak from the trough, the monitor is

able to determine the arterial oxyhemoglobin, the

value for SpO2. See figure 12.

14

Dicrotic notch

QS

PT P

R

10.0

1.0

0.1

0.01

600 640 680 720 760 800 840 600 920

Methemoglobin

Oxyhemoglobin

Reduced hemoglobin

Wavelength (nm)

Extinction Coefficient

960 1000

15

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The monitor will therefore only respond to peak

values in a pulsating plethysmograph.

The measurement process within pulse oximetry

can be affected by motion and low perfusion

(peak to trough value less than 5%). Motion

introduces varying levels of oxyhemoglobin which

might introduce incorrect readings (heart rate and

SpO2 %) where as low perfusion can introduce

higher inaccuracy due to noise signal ratio.

External light sources may also introduce errors

when they contain red and infrared spectrum

light. These light sources could introduce a stable

amount of light (DC or non pulsating) or a

pulsating amount (AC) at frequencies of 50, 60Hz

or their harmonics.

Monitors must therefore be able to differentiate

between a normal plethysmograph and one with

artifacts.

Modern technologies in pulse oximeters are able

to differentiate and provide accurate readings

during low perfusion, motion and light artifacts

however, it is suggested that the performance

under such conditions is verified on a regular

basis. Recent developments in pulse oximetry

see the use of additional light spectrums to obtain

more detailed information on the exact content of

the arterial blood including methemoglobin

(MetHb) and carboxyhemoglobin (COHb).

5.2 Testing your SPO2 monitor – Pulse oximeter

Most pulse oximeters on the market are capable

of measuring under extreme conditions (artifacts,

low perfusion). In order to establish the correct

operation under these conditions, it is important

to verify both the performance of the monitor as

well as the SpO2 probe and its connection

cables.

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Figure 12: Light absorption in the

red spectrum

Transmitter RED 660nm Transmitter RED 660nm

INCIDENT LIGHT

Reciever Sp02 = 80% Reciever Sp02 = 100%

absorption due tobone,

skin and other tissues

and pigment

absorption due to MetHb

absorption due to COHb

Hb02: DC absorption

Hb: DC absorption

remaining light

Light Signal Max is normally called IDC

Light Signal Min is normally called IDC + AC

Light Signal

Max

Light Signal

Max

Light Signal

Max

All parts of the SpO2 probe (LED’s, broad band

detector, lens and cabling) are subject to wear

and tear and when faulty (or in poor quality) might

introduce inconsistent and inaccurate

performance with potentially serious implications

on the treatment of well-being of patients.

For this reason, we include both the monitor and

the SpO2 probe when discussing the testing

procedures for pulse oximetry.

Common issues relating to the accuracy of the

SpO2 monitor are:

■Faulty (near faulty) LED’s (red and infrared)

■Non-OEM probes (white label)

■Contaminated lens / probe window

■Damaged wiring or extension cable

■Inaccurate calibration of SpO2 monitor

■Testing of audible alarms

■Display of plethysmograph

A number of tests are provided to determine the

correct operation of the SpO2 monitors. These are:

■Testing monitor accuracy (see 5.3.1)

■Testing alarms and response time (see 5.3.2)

■Testing under low perfusion (see 5.3.3)

■Testing probe quality (see 5.3.4)

5.3 Test setup

In the example below, the Rigel SP-SIM or UNI-

SIM is used to represent the SpO2 simulator.

Ensure the correct adaptor module is provided

during the test as connector shape and pin-out

configuration differ between different makes of

SpO2 probes and monitors.

Figure 13: Test setup: Connecting the

SPO2 simulator (opto-electronic method)

5.3.1 Testing monitor accuracy

The purpose of this test is to verify the performance

of the monitor measurement circuits and SpO2

probe characteristics by simply displaying the

SpO2% value and heart rate on the monitor.

To simulate the heart rate, the UNI-SIM simulates

the (pulsating) plethysmograph at rates of 30 to

300 beats per minute (bpm). Simulated saturation

levels can be set between 50 and 100%. In order

to verify a range of possible measurements, some

simulations can be performed across a number of

critical values (see alarm testing) as example:

normal, low and critical.

In addition, artifacts (light, motion and

arrhythmia’s) can be introduced to test the

performance of SpO2 monitors either for

evaluation, acceptance and as part of preventative

maintenance.

Note that the precision of pulse oximeters can

vary greatly between brands but typically does

not exceed +/-2%.

16

SPO2 98%

HR 70 bpm

UNI-SiM

SpO2 Monitor

SPO2

SpO2 Probe

Probe

Interface

17

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5.3.2 Alarms and time response test

Use the different values of SpO2 simulation to

trigger audible alarms. Alarms of medical devices

are specified by the IEC 60601 standard and

must be documented by the manufacturer, such

as pitch, frequency and strength. Consult the

monitor’s service or instruction manual for details

on the types of alarms available.

In addition, the SpO2 value is updated at set

intervals e.g. every 15 seconds. The set

response time can be verified using the

chronometer function in the UNI-SIM. The

response time and alarm function can be

combined in a single test setup i.e. by setting the

SpO2 value to 94% with a target of 85%. Wait for

the SpO2 monitor to display the 94% SpO2.

Activate the chronometer function on the UNI-

SIM. This will change the simulation to 85%

SpO2 and starts the timer. When the monitor

reaches the alarm (i.e. when set to 85% SpO2),

press the capture button on the UNI-SIM to

display the time taken to alarm.

Record whether the alarm on the monitor occurs

at the set value(s) and whether the alarm(s) is at

the correct pitch and frequency (refer to the

instruction manual).

5.3.3 Sensitivity test

To determine whether the SpO2 monitor is able to

measure accurately under different pulse

volumes, e.g. as a result of different types of

patients (normal adult, obese, pediatric, skin color

variation), the UNI-SIM can be used to simulate a

variety of pulse volumes and skin colors.

Using the SpO2 simulator, the pulse volume can be

reduced until the monitor displays “no SpO2

signal”. The value before this point highlights the

minimum sensitivity of the monitor. It is important to

realize that the quality of the probe can affect the

outcome of this test as non-original probes might

have poorer quality components and have less

sensitivity compared to the original probes (OEM).

Record the sensitivity value over time to monitor

the performance of the oximeter.

5.3.4 Testing the SPO2 probe

The SpO2 sensor is often the weakest link in the

chain of SpO2 measurement. Probes are

considered consumables as they suffer

significant wear and tear thus are easily

replaceable.To test the functionality of the probe

it is important to realize the different parts that

make up the probe and connections:

1. Red LED

2. Infrared LED

3. Broadband detector

4. Lens

5. Cabling

6. Connector

7. Extension cable (where applicable)

The quality or function of the LED’s will

deteriorate over time. To test the accuracy, the

UNI-SIM is able to simulate through the red and

infrared circuit individually. This will allow for

comparison between the two circuits as the

reading on the monitor should be within 1% of

each other. When one of the LED’s has

deteriorated, the readings will differentiate by

more than 2% of SpO2 value. Replace the probe

and repeat the test again to ensure the new

probe is as expected.

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Other forms of problems associated with the

quality of the SpO2 LED’s are a deterioration of

the perfusion sensitivity (see 5.3.3). This could be

due to quality of the LED’s, broadband detector

or the lens (contamination or cuts).

When testing the probe, always ensure that the

cable and extension leads are flexed during the

tests so that open or short circuits cause an

alarm or a “no reading” on the monitor.

Suggestion: Always record the findings on each

type of SpO2 probe to build-up an expected

performance reference list (perfusion, Delta R / IR

reading). This will help in identifying poor or (near)

faulty SpO2 probes in the future.

Consideration: Some simulators on the market

might make use of an optical finger, capturing the

signals from the SpO2 probe and changing the

characteristics before converting them back to

red and infrared signals. The advantage would be

the elimination of probe adaptor boxes however,

the disadvantages are significant; Red – Infrared

light / blood absorption characteristics have a

strong and direct link with the wave length used

(LED spectrum). An optical finger may use

different wave length or single LED compared to

the manufacturer (OEM). This could result in

inaccurate readings. Probe placement will also

affect the result and as such can be influenced

thus not able to form an accurate reference value.

6 Electrocardiographs (ECG)

The heart, central in the respiratory system,

converts bio-electric pulses to a bio- mechanical

operation (blood flow). The function of the heart

is monitored by measuring the electrical activity

(milli-volt signals) generated in the heart and is

referred to as Electrocardiography.

The most common ECG tracing of a cardiac cycle

(heart beat) is represented below and consists of

a P wave, the QRS complex and a T wave. The

typical duration of the electrical activity is usually

around 400-600 ms. The ECG trace represents

the change in voltage across different parts of the

body (limbs) because of depolarization

(contracting or systole) and repolarisation

(relaxing or diastole) in the heart muscles. The

baseline voltage of the ECG is referred to as the

isoelectric line.

Figure 14: An example of an ECG trace

1. The P wave is generated during the atrial

depolarization.

2. Following this, the right and left ventricles are

depolarized, generating the QRS complex.

3. During the T wave, the ventricles re-polarize.

4. During the latter part of the T wave, the

human heart is most vulnerable against

disturbance or fibrillation.

18

Q

S

PT

R

PR QT

100-200 300-400

400-600

QRS

isoelectric line

appr. 1-2mV

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6.1 Einthoven Triangle

As a result of the body’s natural impedance, the

electrical activity results in different potentials

across the body. One of the most referred to

means of measuring the electrical potentials is by

positioning electrodes (limb leads) on the patient in

a triangular shape, the einthoven triangle, placed

on the left leg (LL), right arm (RA) and left arm (LA).

These limbs can also be referred to as:

Left leg (LL) = Left foot or foot (F)

Right arm (RA) = Right (R)

Left arm (LA) = Left (L)

Right leg (RL) = Neutral (N)

This is represented in the diagram below:

Figure 15: The Einthoven triangle

Whereby you can calculate that Lead I + Lead III

= Lead 2 (Kirchhoff’s law)

(ΦLA-ΦRA)+(ΦLL-ΦLA)=ΦLL-ΦRA

The ECG waveform, (PQRST) can now be

determined at various locations of the body, to

specifically highlight anomalies in a specific part

of the waveform. These can be directly related to

the performance of the atrium and ventricle

muscles.

Figure 16: A typical waveform (Lead I) and

the derived shapes (Lead II and III)

Using vectors, Lead I, II and III can be separated

into Augmented limb leads whereby the potential

is measured from one (positive) of the three

positions on the Einthoven triangle and the

combined other two (negative) as shown in figure

17 on the following page.

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RL

NF

_+

++

__

l

l

Potential

V1= ΦLA-ΦRA

V2= ΦLL-ΦRA

V3= ΦLL-ΦLA

(-) negative

RA

RA

LA

(+) positive

LA

LL

LL

Lead

I

II

III

Figure 17: Augmented limb leads

6.2 Precordial leads

When a more detailed electrocardiogram is

required, additional leads, the precordial leads,

are placed on the chest. The different lead

configurations will allow diagnosis of numerous

heart conditions by studying relative amplitudes,

heart rates and uniformity across the different

leads.

The precordial leads (V1,V2,V3,V4,V5 and V6)

are placed in close proximity to the heart to

ensure sufficient signal strength and accuracy.

Placements of the leads are in accordance with

figure 18 below.

Figure 18: Precordial lead placement

For figure 18 use IEC Code 1 for lead

identification, not those shown, including the

chest leads which should be C1 – C6 not ‘Y’.

20

R

N

L

C1C2

C3

C4C5C6

F

RL

F

RL

F

RL

F

aVL

aVR

aVF

5 KΩ

5 KΩ

5 KΩ

5 KΩ5 KΩ

5 KΩ

-

R (RA) + F (LL)

L(LA) + (RA)

L(LA) + F(LL)

+

L (LA)

F(LL)

R(RA)

Lead

aVL

aVF

aVR

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Figure 19: Example of a 12 lead ECG

6.3 Unipolar vs. bipolar leads

ECG leads are split between unipolar and bipolar

leads. The limb leads (I, II and III) are bipolar,

having both a positive and negative pole. The

augmented leads (aVL, aVF and aVR) and

precordial leads (V1-6) are considered unipolar,

having only a true positive pole. The negative

pole consists of signals from other poles.

6.4 Color coding

ECG leads are marked with both abbreviations

and color coding according to the corresponding

placement on the body. There are 2 common

markings available on the market today. These

are shown in the table below.

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HR 62 bpm

14:37:18

QRS 0:112s

0.390s/0.395s

27 80 49

x1.0 .05-150Hz 25mm/sec

Name:

ID:

Patient ID

Incident:

Age: 26

12-Lead 2

hhh

PR0.138s

QT/QTc

P-QRS-Axes

aVR

Normal ECG **Unconfirmed**

Normal sinusrhythm

Sex:

o

ooo

o

lv1lv4

lv5lv2l aVL

l aVF lv3lv6

Table 1: ECG Abbreviations and color coding

Colour

White ❑

Black ■

Green ■

Red ■

Brown/Red ■

Brown/Yellow ■

Brown/Green ■

Brown/Blue ■

Brown/Orange ■

Brown/Violet ■

Abbreviation

RA

LA

RL

LL

V1

V2

V3

V4

V5

V6

Colour

Red ■

Yellow ■

Black ■

Green ■

White/Red ■

White/Yellow ■

White/Green ■

White/Brown ■

White/Black ■

White/Violet ■

Abbreviation

R

L

N

F

C1

C2

C3

C4

C5

C6

Right Arm

Left Arm

Right Leg

Left Leg

Chest 1

Chest 2

Chest 3

Chest 4

Chest 5

Chest 6

Elecrode IEC Code 1 IEC Code 2 (American)

6.5 The ECG Machine

To observe an ECG, the difference between two

electrical signals at different points on the body

must be amplified. Then the electrical potentials

can be displayed on the screen. ECG machines

may typically use 3 lead, 5 lead or 12 lead

configurations.

Placement of the ECG leads is standardized so

that the interpretation of the ECG is consistent.

Cardiac conditions that can be diagnosed using

ECG’s include abnormally fast heart rate

(tachycardia), abnormally slow rate

(bradychardia), heart block, acute myocardial

infraction (a blood clot in the heart), ischemia (a

restriction in the blood supply to a part of the

heart) and numerous other conditions. These

conditions come under the generic term of heart

arrhythmias.

Figure 20: Patient on ECG recorder

6.6 Testing ECG monitor

Due to the important analyzing role of the ECG

monitor, it is crucial to ensure that the input

circuits of the ECG monitor are able to measure

the small ECG signals accurately. That the

software is able to interpret these signals to the

corresponding conditions and that alarms are

visible and audible according to the

manufacturers specifications.

Therefore, the following simulations and

performance tests are often part of the regular

maintenance:

■Linearity of heart rate measurement

■QRS Beep

■Alarms (high and low)

■Alarms for disconnected electrodes

■Arrhythmias recognition (asystolic)

■Sensibility test

■Zero offset

■Frequency response

■Printer calibration (amplitude, timing)

The most common instrument used for the

above is a patient or ECG simulator. In the

example below, the patient simulator from the

UNI-SIM is used;

Figure 21: Test setup: Connecting the ECG

simulator

22

HR 70 BPM

UNI-SiM

ECG Recorder

1

2

3

4

5

RA

LA

LL

RL

1V

V2

V3

V4

V5

V6

6

7

8

9

10

!

ECG

Interface

ECG

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6.6.1 Linearity of heart rate measurement

The purpose of this test is to verify the capability

of the monitor to measure and display heart rate

accurately. It is recommended to simulate several

values in range spanning 30-300 beats per

minute (bpm).

Compare the readings with the simulated values

and check whether this is within manufacturer

specifications (normally +/- 1 bpm or +/- 1% of

reading).

6.6.2 QRS beep

To aid the monitoring process, it is a requirement

to fit the ECG monitor with an audible QRS beep.

This provides a clear “beep” each time the QRS

wave passes. Frequency and pitch variations can

provide a clear indication of the heart rate without

having to have line of sight to the ECG recorder.

6.6.3 Alarms (high and low)

IEC 60601-1-8 provides the requirements for

alarms on medical devices. Alarms can vary in

frequency, pitch, volume and melody. In general,

the greater the urgency, the higher the pitch,

volume and pulse frequency (or melody).

During the performance test of the ECG recorder,

alarms can be tested by simulating different heart

rates and arrhythmias using a patient simulator.

At the end of the test, the final alarm condition

can be tested by disconnecting the leads one by

one. The monitor should go into alarm condition

when this happens.

Record whether the alarm on the monitor occurs

at the set value(s) and whether the alarm(s) is at

the correct pitch and frequency (refer to the

instruction manual).

6.6.4 Arrhythmias recognition (asystolic)

ECG monitors, which are able to interpret the

ECG recording, are required to provide an alarm

when they detect a seizure in blood circulation (or

lack of pulse). This is the case during ventricular

fibrillation and asystole (flat line) when no electrical

nor mechanical activity is present in the heart.

Ventricular fibrillation is a condition whereby the

ventricles contract erratically with the net result of

poor to no blood circulation from the ventricles to

the body. During coarse VFIB, the waveform

amplitudes are significantly larger than during fine

VFIB. The latter is close to an asystole.

All cases of VFIB lead to rapid loss of

consciousness in the patient and must be

treated immediately with the use of a defibrillator.

6.6.5 Sensitivity test (gain)

To ensure the input circuits of the ECG recorder

are sensitive enough to measure the ECG mV

signals, the input amplifier settings are tested by

supplying a normal sinus rhythm (NSR) at (e.g.)

60 bpm and with a 1mV amplitude.

When the NSR is displayed on the screen, change

the gain of the monitor and check if the changes

in amplitude are relative to the gain change i.e. a

doubling in gain would result in a doubling of

amplitude. The heart rate should not be affected.

Some ECG recorders are supplied with a printer

and can allow for gain and amplitude settings to

be easily crossed referenced.

6.6.6 Zero offset

The zero offset test demonstrates the aligning of the

isoelectric line of the ECG wave form with the zero

line of the ECG recorder. This is achieved by

checking whether the ECG line (flat line on the

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recorder) is at zero mV when no leads are

connected. When the recorder is equipped (usually)

with a printer, the printed line shall be at zero mVolt.

6.6.7 Frequency response

To limit the sensitivity of the ECG recorder from

external signals i.e. mains frequency and other

artifacts, the input circuits are equipped (usually)

with filters. So called high pass filters – HPF’s

(allowing signals of greater frequency to pass

through) and low pass filters – LPF’s (allowing

frequencies of lower frequencies to pass through)

provide a bandwidth of allowable frequencies.

Typical values are 0.5Hz / 1 Hz for HPF’s and 40 Hz

for LPF’s inmonitormode and 0.05 Hz for HPF and

40 / 100 / 150 Hz for LPF’s in diagnostic mode.

These filter settings can be selected based upon

the application. To test the settings of the filters,

performance wave forms such as a sinus of

triangular waveform can be simulated to the ECG

recorder. By varying the frequency in-and outside

the bandwidth, the performance can be verified.

6.6.8 Printer calibration (amplitude, timing)

ECG recorders with build-in printer facility are

required to be tested for linearity of the printer

speed. Printer rolls typically move at 25 mm /

seconds. To test printer speed and linearity, a

fixed frequency sinusoidal wave can be

simulated. This should result in a consistent wave

length width across the print out and must

correspond to the print speed.

ECG recording paper consists of a matrix of

squares each 1mm x 1mm. At a speed of

25mm/s and a sensitivity of 10mm/mV each

square represents 0.04s and 0.1mV respectively.

A signal with an amplitude of 1 mV and frequency

of 1 Hz should have an amplitude of 10 mm and

wave length of 25 mm.

Figure 22: A sinusoidal test signal of 1Hz

and 1mV amplitude

7 Respiration

Unless a human is subject to mechanical

ventilation, inspiration of the lungs is controlled

by the increase in volume of the thoracic cavity.

The thoracic cavity volume is increased as a

result of (Involuntary) contraction of the

diaphragm (layer between lungs and abdominal

cavity). In addition to the diaphragm, the

intercostal muscles also aid the breathing

process by lifting the lower and upper ribs.

Expiration of the lungs is a result of the elasticity

of the lungs, forcing air out when the diaphragm

and intercostals muscles relax.

When a patient is under general anaesthetic,

he/she might no longer be able to sustain the

involuntary control of the diaphragm and

intercostals muscles. A mechanical ventilator is

then required to deliver a set volume per breath

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1 mV

-1mV

0

1s

1mV

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and respiratory rate (breaths per minute).

Monitoring the respiration rate on patients

subject to anesthesia is vital as it provides

immediate warning of changes to the respiration

rate including obstruction of the trachea (airpipe).

An obstruction in the trachea stops the oxygen

supply to the lungs and stops the expiring of

carbon dioxide from the blood which can lead to

a cardiac arrest and subsequent death if

untreated e.g. removing the obstruction via an

endotrachea tube).

There are several ways of deriving respiration rate

from the ECG leads and signals.

1. Most commonly used, is the measurement of

the transthoracic impedance between the ECG

leads ie Lead I, II or III. As the thoracic cavity

expands (inspiration), the impedance of the chest

increases. While during expiration, the thoracic

cavity reduces in volume thus decreasing its

impedance.

2. Another method of determining the respiration

is through observing the change in the ECG

amplitude (ECG Derived Respiration – EDR) as a

result of changes in the position between

electrodes and heart as the chest cavity expands

and the heart moves as a result of changes in the

position of the diaphragm. This method can be

visualized on a recorded ECG.

3. A third method to establish the respiration rate

is by observing the changes in R-R intervals.

(time between the R-peaks of two successive

QRS waves).

Figure 23: Respiration through limb and

augmented leads

In all instances, the ECG leads are placed on a

human chest as shown above. Respiration rates

can be monitored through all limb and

augmented leads. Most monitors and recorders

allow a selection of leads.

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R

N

L

C1C2

C3

C4C5C6

F

R

N

L

C1C2

C3

C4C5C6

F

7.1 Testing respiration function

The most common method of monitoring

respiration at bedside is through impedance

measurement across the ECG leads.

The tests to perform on such monitor are:

■Linearity of respiration measurement

■Sleep apnea

■Alarms (high and low)

Figure 24: Test setup: Connecting the

respiration / ECG simulator

7.1.1 Linearity of respiration measurement

The purpose of this test is to verify the capability

of the monitor to measure and display respiration

rate values. It is recommended to simulate

several values across a range rates from 100

bpm down to (sleep) apnea (see 7.1.2).

Check the specification of the monitor to verify

the readings are within the required accuracy.

Typical accuracies are within +/- 1bpm.

7.1.2 Sleep apnea

During our sleep, our airways can become

obstructed, preventing oxygen to reach the lungs

and stopping the expiring of carbon dioxide from

the blood. As a result, the level of carbon dioxide

increases in the blood (level of oxyhemoglobin

drops) as it is not able to pass out through the

lungs and no new oxyhemoglobin enter the

blood stream. While this is not a direct health risk

as the brain will signal a wake-up, when left

untreated, it can lead to more serious conditions

such as high blood pressure and heart failure.

While sleep apnea can be monitored indifferent

ways (CO2 monitoring, SpO2 etc), its most

commonly monitored through the respiration rate

on bedside monitors via ECG leads. Sleep apnea

will appear as an absence in breath rate (breath

rate = 0) and a respiration monitor should sound

an alarm when sleep apnea is detected.

7.1.3 Testing apnea alarms

In order to act swiftly to a deteriorating condition

of the patient, respiration monitors are supplied

with alarms to indicate a unacceptable change in

respiration rate (too high, too low or apnea).

Using a patient simulator, normal (e.g. 15 breath

per minute —bpm), low (e.g. 5 bpm), high (e.g. 30

bpm) and apnea (0 bpm) can be simulated.

Depending on the application of the monitor (i.e.

adult or pediatric monitoring), the range of values

could vary due to natural change in respiration

rate in infants (higher) and adults (lower) or when

testing monitors used for exercise stress testing

(>30 bpm).

Record whether the alarm on the monitor occurs

at the set value(s) and whether the alarm(s) is at

the correct pitch and frequency (refer to the

instruction manual).

26

RESP 15 bpm

UNI-SiM

ECG Recorder

1

2

3

4

5

RA

LA

LL

RL

1V

V2

V3

V4

V5

V6

6

7

8

9

10

!

ECG

Interface

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8 Temperature

One of the most commonly monitored vital signs is

the body temperature. Several devices have been

marketed over the years from contact based

temperature measurement such as the mercury

filled thermometers (no longer available due to the

toxic nature of mercury) and resistor based sensors

to non-contact infrared based temperature sensors.

Our core body temperature (Tc) varies by gender

and can vary between different stages of the day.

In women, the core body temperature also

changes during the menstrual cycle, peaking at

the time of ovulation.

The average core body temperature is 37°C ±

0.5°C. Depending on the placement, application

and method, different temperature readings are

expected in healthy individuals as shown in table

2 on the following page.

The most common temperature sensors used on

bedside monitoring are electrical temperature

sensors based on a temperature related varying

resistor (thermistors). These thermistors are

commonly known as NTC’s (negative temperature

coefficient – meaning that that the resistance

decreases when temperature increases) and PTC’s

(positive temperature coefficient – meaning that the

resistance is increasing as temperature increases).

The YSI 400 and YSI 700 have become the

standard NTC’s used in the medical industry.

While the YSI 400 is slightly more accurate over

the range of 0-75ºC, the YSI 700, which contains

a dual element (Ra = 6kΩ@ 25ºC and Rb = 30kΩ

@ 25ºC), is able to provide it’s accuracy over a

wider range (-25ºC to 100ºC).

Body temperature is simulated by the different

resistor values corresponding to the required

temperature.

Please see table 3 on the following page.

8.1 Testing temperature function on

multiparametric monitors

We have the following performance tests :

■Linearity of temperature measurement

■Alarms (high and low)

Ensure the correct temperature sensor (YSI400

or 700) on the patient simulator is selected.

Figure 25: Test setup: Connecting the

temperature simulator

8.1.1 Linearity of temperature measurement

The purpose of this test is to verify the linearity of

the monitor over the most typical range of

temperatures such as body normal, fever (high),

hypothermia (low) and room temperature.

A patient simulator is often able to simulate

across this range between 25-41°C. Check the

specification of the monitor to verify the readings

are within the required accuracy.

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T1 37 C

T2 25 C

YSI 400

o

o

UNI-SiM

Temperature

Monitor

8.1.2 Testing temperature alarms

In order to act swiftly to a deteriorating condition

of the patient, temperature monitors are supplied

with alarms to indicate an acceptable change in

core or skin temperature. (too high or too low).

Using a patient simulator, normal (37°C), low

(33°C), high (41°C ) and room (25°C) temperature

may be simulated.

Record whether the alarm on the monitor occurs

at the set value(s) and whether the alarm(s) is at

the correct pitch and frequency (refer to the

instruction manual).

9 Record keeping

Overall, the area of risk assessment and the

creation of risk management files has become a

growing feature of routine safety and performance

testing decisions, with different organizations and

departments drawing-up individual plans to deal

with specific safety hazards. Comparison with

previous and expected test results will therefore

allow you to monitor deterioration of the device

under test and prevent potential failure before a

fault occurs.

To ensure proper record keeping is maintained it

is important to provide a procedure in which data

is collected regarding:

■Inspection date

■Visual inspection

■Electrical safety

■Functional testing

■Next inspection date

Rigel Medical have developed Med-eBase, a

software package to automate the generation of

test reports including visual inspection, electrical

safety and performance testing. An example of

such test template is provided in Appendix D.

28

Table 2: Different temperature reading methods

Accuracy

Core temperature (Tc)

Core temperature (Tc)

0.3 to 0.6˚C < Tc

0.6 to 1.2˚C < Tc

Depending on direct environment

Method

contact and non-contact

contact

contact

contact

contact and non-contact

Application

Non-invasive

Invasive

Invasive

Non-invasive

Non-invasive

Placement

Ear (Tympanic)

Rectally

Orally

Armpit (Axillary)

Skin temperature

Table 3: Resistor values on YSI 400 and 700 sensors

YSI 700 (b)

15,520 Ω

18,210 Ω

21,430 Ω

30,000 Ω

YSI 700 (a)

3,070 Ω

3,610 Ω

4,260 Ω

6,000 Ω

Resistor Value

YSI 400

1,152 Ω

1,355 Ω

1,599 Ω

2,252 Ω

(Body) temperature

41˚C

37˚C

33˚C

25˚C (room)

A more detailed range of resistor values vs temperature is provided in Appendix C.

29

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Going forward, determining the appropriate

levels of both electrical and functional testing will

be central to the introduction of cost effective yet

reliable preventative maintenance campaigns.

Conclusion

Planned preventative maintenance is an important

aspect during the useful life of a medical electronic

device. To ensure safety of the patient and

operator, procedures are required to cover:

■Visual inspection

■Electrical safety testing (see IEC 62353)

■Performance or functional testing

■Record keeping

This booklet has provided a basic introduction to

vital signs monitoring and suggested test

procedures for each vital sign. Always ensure that

the function and operation of the DUT is

understood before commencing on the planned

preventative maintenance. Without fully

understanding the function and or operation,

visual inspections, electrical safety tests and

functional tests might be incorrect or incomplete.

Prior to any testing, ensure that the manufacturer’s

recommendations are available as they often

supersede any general inspection guidelines.

Considerations and recommendations

1. Ensure that the operator of test equipment is

properly trained on both the test equipment and

DUT to ensure that valid measurements are

taken and understood and prevent unnecessary

danger during the safety test.

2. Always ensure that the DUT does not pose

any danger to the user and / or people within the

vicinity to the safety test. (e.g. moving parts,

open conductors, live components, heat etc).

3. Ensure that manufacturer’s instructions are

followed and any performance is checked

against manufacturer’s documentation.

4. Ensure high accuracy and repeatability of

simulations and measurement readings (some

manufacturers might specify full scale accuracy

which will effect the accuracy of low value

readings or measurements).

5. When determining the correct means of

testing a specific medical device, ensure that the

chosen test procedures are applicable to the

DUT and are clearly documented for future use.

Rigel Medical offers a range of test equipment to

cover simulation and performance testing as well

as a range of electrical safety analyzers to meet

the IEC 62353 and IEC 60601 requirements.

Please visit our website www.rigelmedical.com

for a full overview of our product offering or

register online for our free newsletter on future

product releases and product innovations.

For further questions or comments relating to this

booklet or on the Rigel Medical product offering,

please contact John Backes via email at

johnb@rigelmedical.com

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Appendix A

IEC 60601-1 Collateral Standards (© IEC Geneva, Switzerland)

30

IEC 60601-1-1

IEC 60601-1-2 (ACDV)

IEC 60601-1-3

IEC 60601-1-4

IEC 60601-1-6

IEC 60601-1-8 (CCDV)

IEC 60601-1-9

IEC 60601-1-10

IEC 60601-1-11

IEC 60601-1-12 (CDM)

MEDICAL ELECTRICAL EQUIPMENT – PART 1: GENERAL REQUIREMENTS FOR SAFETY 1: COLLATERAL

STANDARD: SAFETY REQUIREMENTS FOR MEDICAL ELECTRICAL SYSTEMS

MEDICAL ELECTRICAL EQUIPMENT - PART 1-2: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: ELECTROMAGNETIC PHENOMENA -

REQUIREMENTS AND TESTS

MEDICAL ELECTRICAL EQUIPMENT – PART 1: GENERAL REQUIREMENTS FOR SAFETY – COLLATERAL

STANDARD: GENERAL REQUIREMENTS FOR RADIATION PROTECTION IN DIAGNOSTIC X-RAY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT: PART 1-4: GENERAL REQUIREMENTS FOR COLLATERAL STANDARD:

PROGRAMMABLE ELECTRICAL MEDICAL SYSTEMS

MEDICAL ELECTRICAL EQUIPMENT - PART 1-6: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: USABILITY

MEDICAL ELECTRICAL EQUIPMENT - PART 1-8: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: GENERAL REQUIREMENTS, TESTS AND

GUIDANCE FOR ALARM SYSTEMS IN MEDICAL ELECTRICAL EQUIPMENT AND MEDICAL ELECTRICAL

SYSTEMS

MEDICAL ELECTRICAL EQUIPMENT - PART 1-9: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: REQUIREMENTS FOR ENVIRONMENTALLY

CONSCIOUS DESIGN

MEDICAL ELECTRICAL EQUIPMENT - PART 1-10: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: REQUIREMENTS FOR THE DEVELOPMENT OF

PHYSIOLOGIC CLOSED-LOOP CONTROLLERS

MEDICAL ELECTRICAL EQUIPMENT - PART 1-11: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: REQUIREMENTS FOR MEDICAL ELECTRICAL

EQUIPMENT AND MEDICAL ELECTRICAL SYSTEM USED IN HOME CARE APPLICATIONS

MEDICAL ELECTRICAL EQUIPMENT - PART 1-12: GENERAL REQUIREMENTS FOR BASIC SAFETY AND

ESSENTIAL PERFORMANCE - COLLATERAL STANDARD: REQUIREMENTS FOR MEDICAL ELECTRICAL

EQUIPMENT AND MEDICAL ELECTRICAL SYSTEMS USED IN THE EMERGENCY MEDICAL SERVICES

ENVIRONMENT

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Appendix B

IEC 60601-2 Particular Standards (© IEC Geneva, Switzerland)

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IEC 60601-2-1

IEC 60601-2-2

IEC 60601-2-3 (ADIS)

IEC 60601-2-4

IEC 60601-2-5

IEC 60601-2-6 (ADIS)

IEC 60601-2-7

IEC 60601-2-8

IEC 60601-2-10 (CCDV)

IEC 60601-2-11

IEC 60601-2-13

IEC 60601-2-16 (RDIS)

IEC 60601-2-17

IEC 60601-2-18

IEC 60601-2-19

IEC 60601-2-20

IEC 60601-2-21

IEC 60601-2-22

MEDICAL ELECTRICAL EQUIPMENT - PART 2-1: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ELECTRON ACCELERATORS IN THE RANGE 1 MEV TO 50 MEV

MEDICAL ELECTRICAL EQUIPMENT - PART 2-2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

HIGH FREQUENCY SURGICAL EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

SHORT-WAVE THERAPY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

CARDIAC DEFIBRILLATORS AND CARDIAC DEFIBRILLATORS MONITORS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-5: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ULTRASONIC PHYSIOTHERAPY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

MICROWAVE THERAPY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-7: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

HIGH-VOLTAGE GENERATORS OF DIAGNOSTIC X-RAY GENERATORS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-8: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

THERAPEUTIC X-RAY EQUIPMENT OPERATING IN THE RANGE 10 KV TO 1 MV

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

NERVE AND MUSCLE STIMULATORS

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

GAMMA BEAM THERAPY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-13: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ANAESTHETIC WORKSTATIONS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-16: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF HAEMODIALYSIS, HAEMODIAFILTRATION AND

HAEMOFILTRATION EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

REMOTE-CONTROLLED AUTOMATICALLY DRIVEN GAMMARAY AFTER-LOADING EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ENDOSCOPIC EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS OF SAFETY OF BABY

INCUBATORS

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

TRANSPORT INCUBATORS

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

INFANT RADIANT WARMERS

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

DIAGNOSTIC AND THERAPEUTIC LASER EQUIPMENT

32

IEC 60601-2-23

IEC 60601-2-24 (ADIS)

IEC 60601-2-25

IEC 60601-2-26 (ADIS)

IEC 60601-2-27

IEC 60601-2-28

IEC 60601-2-29

IEC 60601-2-31

IEC 60601-2-32

IEC 60601-2-33

IEC 60601-2-34

IEC 60601-2-36 (1CD)

IEC 60601-2-37

IEC 60601-2-39

IEC 60601-2-40

IEC 60601-2-41 (CCDV)

IEC 60601-2-43

IEC 60601-2-44 (CCDV)

MEDICAL ELECTRICAL EQUIPMENT - PART 2-23: PARTICULAR REQUIREMENTS FOR THE SAFETY,

INCLUDING ESSENTIAL PERFORMANCE, OF TRANSCUTANEOUSPARTIAL PRESSURE MONITORING

EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-24: PARITCULAR REQUIREMENTS FOR THE SAFETY OF

INFUSION PUMPS AND CONTROLLERS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-25: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ELECTROCARDIOGRAPHS

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ELECTROENCEPHALOGRAPHS

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ELECTROCARDIOGRAPHIC MONITORING EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF X-

RAY SOURCE ASSEMBLIES AND X-RAY TUBE ASSEMBLIES FOR MEDICAL DIAGNOSIS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-29: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

RADIOTHERAPY SIMULATORS

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

EXTERNAL CARDIAC PACEMAKERS WITH INTERNAL POWER SOURCE

MEDICAL ELECTRICAL EQUIPMENT PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ASSOCIATED EQUIPMENT OF X-RAY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

MAGNETIC RESONANCE EQUIPMENT FOR MEDICAL DIAGNOSIS

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY,

INCLUDING ESSENTIAL PERFORMANCE, OF INVASIVE BLOOD PRESSURE MONITORING EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

EQUIPMENT FOR EXTRACORPOREALLY INDUCED LITHOTRIPSY

MEDICAL ELECTRICAL EQUIPMENT - PART 2-37: PARTICULAR REQUIREMENTS FOR THE BASIC

SAFETY AND ESSENTIAL PERFORMANCE OF ULTRASONIC MEDICAL DIAGNOSTIC AND MONITORING

EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-39: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

PERITONEAL DIALYSIS EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-40: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

ELETROMYOGRAPHS AND EVOKED RESPONSE EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-41: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

SURGICAL LUMINAIRES AND LUMINAIRES FOR DIAGNOSIS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-43: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

X-RAY EQUIPMENT FOR INTERVENTIONAL PROCEDURES

MEDICAL ELECTRICAL EQUIPMENT - PART 2-44: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

X-RAY EQUIPMENT FOR COMPUTED TOMOGRAPHY

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IEC 60601-2-45

IEC 60601-2-46

IEC 60601-2-47 (RDIS)

IEC 60601-2-49

IEC 60601-2-50

IEC 60601-2-51

IEC 60601-2-52

IEC 60601-2-53

IEC 60601-2-54

IEC 60601-2-56

IEC 60601-2-57

IEC 60601-2-62 (ACDV)

IEC 60601-2-63 (CCDV)

IEC 60601-2-65 (CCDV)

MEDICAL ELECTRICAL EQUIPMENT - PART 2-45: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

MAMMOGRAPHIC X-RAY EQUIPMENT AND MAMMOGRAPHIC STEREOTACTIC DEVICES

MEDICAL ELECTRICAL EQUIPMENT - PART 2-46: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

OPERATING TABLES

MEDICAL ELECTRICAL EQUIPMENT - PART 2-47: PARTICULAR REQUIREMENTS FOR THE SAFETY,

INCLUDING ESSENTIAL PERFORMANCE, OF AMBULATORY ELECTROCARDIOGRAPHIC SYSTEMS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-49: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

MULTIFUNCTION PATIENT MONITORING EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-5O: PARTICULAR REQUIREMENTS FOR THE SAFETY OF

INFANT PHOTOTHERAPY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-51: PARTICULAR REQUIREMENTS FOR SAFETY,

INCLUDING ESSENTIAL PERFORMANCE, OF RECORDING AND ANALYSING SINGLE CHANNEL AND

MULTICHANNEL ELECTROCARDIOGRAPHS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-52: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF MEDICAL BEDS

MEDICAL ELECTRICAL EQUIPMENT, PART 2-53: PARTICULAR REQUIREMENTS FOR THE SAFETY AND

ESSENTIAL PERFORMANCE OF A STANDARD COMMUNICATIONS PROTOCOL FOR COMPUTER

ASSISTED ELECTROCARDIOGRAPHY

MEDICAL ELECTRICAL EQUIPMENT - PART 2-54: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF X-RAY EQUIPMENT FOR RADIOGRAPHY AND RADIOSCOPY

MEDICAL ELECTRICAL EQUIPMENT - PART 2-56: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF SCREENING THERMOGRAPHS FOR HUMAN FEBRILE

TEMPERATURE SCREENING

PARTICULAR REQUIREMENTS FOR THE SAFETY AND ESSENTIAL PERFORMANCE OF INTENSE LIGHT

SOURCES USED ON HUMANS AND ANIMALS FOR MEDICAL AND COSMETIC PURPOSES

MEDICAL ELECTRICAL EQUIPMENT - PART 2-62: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF HIGH INTENSITY THERAPEUTIC ULTRASOUND (HITU) SYSTEMS

MEDICAL ELECTRICAL EQUIPMENT - PART 2-63: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF DENTAL EXTRA-ORAL X-RAY EQUIPMENT

MEDICAL ELECTRICAL EQUIPMENT - PART 2-65: PARTICULAR REQUIREMENTS FOR BASIC SAFETY

AND ESSENTIAL PERFORMANCE OF DENTAL INTRA-ORAL X-RAY EQUIPMENT

34

Appendix C

YSI 400 & 700 resistance reference table

-1˚C

0˚C

1˚C

2˚C

3˚C

4˚C

5˚C

6˚C

7˚C

8˚C

9˚C

10˚C

11˚C

12˚C

13˚C

14˚C

15˚C

16˚C

17˚C

18˚C

19˚C

20˚C

21˚C

22˚C

23˚C

24˚C

25˚C

7741Ω

7355Ω

6989Ω

6644Ω

6319Ω

6011Ω

5719Ω

5444Ω

5183Ω

4937Ω

4703Ω

4482Ω

4273Ω

4074Ω

3886Ω

3708Ω

3539Ω

3378Ω

3226Ω

3081Ω

2944Ω

2814Ω

2690Ω

2572Ω

2460Ω

2354Ω

2252Ω

20620Ω

19590Ω

18620Ω

17700Ω

16830Ω

16010Ω

15240Ω

14500Ω

13810Ω

13150Ω

12530Ω

11940Ω

11380Ω

10850Ω

10350Ω

9878Ω

9428Ω

9000Ω

8594Ω

8210Ω

7844Ω

7496Ω

7166Ω

6852Ω

6554Ω

6270Ω

6000Ω

99800Ω

94980Ω

90410Ω

86090Ω

81990Ω

78110Ω

74440Ω

70960Ω

67660Ω

64530Ω

61560Ω

58750Ω

56070Ω

53540Ω

51130Ω

48840Ω

46670Ω

44600Ω

42640Ω

40770Ω

38990Ω

37300Ω

35700Ω

34170Ω

32710Ω

31320Ω

30000Ω

Temp 'C YSI 400

Resistance

YSI 700

Resistance A

YSI 700

Resistance B

26˚C

27˚C

28˚C

29˚C

30˚C

31˚C

32˚C

33˚C

34˚C

35˚C

36˚C

37˚C

38˚C

39˚C

40˚C

41˚C

42˚C

43˚C

44˚C

45˚C

46˚C

47˚C

48˚C

49˚C

50˚C

51˚C

2156Ω

2064Ω

1977Ω

1894Ω

1815Ω

1739Ω

1667Ω

1599Ω

1533Ω

1471Ω

1412Ω

1355Ω

1301Ω

1249Ω

1200Ω

1152Ω

1107Ω

1064Ω

1023Ω

983.8Ω

946.2Ω

910.2Ω

875.8Ω

842.8Ω

811.3Ω

781.1Ω

5744Ω

5500Ω

5266Ω

5046Ω

4834Ω

4634Ω

4442Ω

4260Ω

4084Ω

3918Ω

3760Ω

3610Ω

3466Ω

3328Ω

3196Ω

3070Ω

2950Ω

2836Ω

2726Ω

2620Ω

2520Ω

2424Ω

2334Ω

2246Ω

2162Ω

2080Ω

28740Ω

27540Ω

26400Ω

25310Ω

24270Ω

23280Ω

22330Ω

21430Ω

20570Ω

19740Ω

18960Ω

18210Ω

17490Ω

16800Ω

16150Ω

15520Ω

14920Ω

14350Ω

13800Ω

13280Ω

12770Ω

12290Ω

11830Ω

11390Ω

10970Ω

10570Ω

Temp 'C YSI 400

Resistance

YSI 700

Resistance A

YSI 700

Resistance B

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Appendix D

Example documentation template

Appendix D Example documentation template

Testing organization: Test before putting into service (reference value)

Recurrent Test

Test after repair

Name of testing person:

Responsible organization:

Equipment:

Type: Production No./Serial Nr.:

Manufacturer: Class of protection: I II Battery

Applied part type: 0 B BF CF

Accessories:

Visual inspection:

Functional Test (parameters tested):

Deficiency / Note:

Overall Assessment:

Name:

PIE PERMANENT INSTALLED EQUIPMENT

NPS NON-DETACHABLE POWER SUPPLY CORD

DPS DETACHABLE POWER SUPPLY CORD

Date/Signature:

Next recurrent test necessary in 6 / 12 / 24 / 36 months

No safety or functional deficiencies were detected

No direct risk, deficiencies detected may be corrected on short term

Equipment shall be taken out of operation until deficiencies are corrected

Equipment does not comply – Modifications / Exchange of components / Taking out of service – is recommended

Measurements: Measured value

Protective ground resistance Ω

Equipment leakage current (according to Figure.....) mA

Patient leakage current (according to Figure....) mA

Insulation resistence (according to Figure.....) MΩ

Test:

Measurement equipment:

Complies

Yes No

Mains connection: PIE NPS DPS

ID Number:

1)

1)

Bibliography

Jacobson, B., & Murray, A. (2007). Medical Devices; Use and Safety, Churchill Livingstone: Elsevier.

Webster,G.J., (Ed.). (1997). Design of Pulse Oximeters (1st ed.), New York: Medical Science Series

12-Lead ECG System, http://www.bem.fi/book/15/15.htm (Aug 2011)

36

Rigel UNI-SIM

Vital Signs Simulator

The world’s first combined, fully functional

NIBP, SpO2 and patient simulator in a single

hand-held unit. Extremely accurate and featuring

full synchronized functionality. A breakthrough in

the way safety testing is implemented, the

UNI-SIM saves time and money, as well as

simplifying the testing process.

Features include:

■Light, hand-held, battery operation

■Combined NIBP, SpO2 and

patient simulator in one unit

■User configurable simulations

■Full sychronised functionality

■Memory for up to 10,000 devices

Rigel BP-SIM

NIBP Simulator

The first hand-held NIBP simulator to incorporate

custom settings, including pediatric and adult

NIBP pressure simulations, pulse volume

adjustments, heart rate and manufacturer-

specific envelopes. Large capacity internal

memory for data capture, storage and

downloading of test results via Bluetooth.

Features include:

■Light, hand-held, battery operation

■Adult & pediatric NIBP simulations

■Manufacturer specific O-curves

■Overpressure and leak test

■Memory for up to 10,000 devices

Med-ekit

compatible

Med-eBase

compatible

Mains

powered

Barcode

scanner

Battery

powered

Bluetooth

compatible

Vital Signs Simulators

37

rigelmedical.com

I

nnovating

T

ogether

Please visit rigelmedical.com for more information

Rigel SP-SIM

SpO2 Simulator

The first hand-held SpO2 simulator featuring

pulse volume adjustments, heart rate and

manufacturer-specific R-curves. The large

capacity internal memory enables test results

to be captured, stored and downloaded

via Bluetooth.

Features include:

■Light, hand-held, battery operation

■Tests probe and monitor both at the same time

■User configurable simulations

■Manufacturer R-curves

■Memory for up to 10,000 devices

Rigel 333

Patient Simulator

The 333 is one of the smallest, most powerful

and fully comprehensive patient simulators

available. Providing a true 12 lead ECG signal

with 43 arrhythmias, dual invasive blood

pressure, respiration, temperature and

industry standard waveforms.

Features include:

■Light, hand-held, battery operation

■Accurate 12-lead simulation of 43 arrhythmias

■Invasive blood pressure

■Temperature & respiration

■Performance wave forms

38

Electrical Safety Analyzers

Rigel 266 Plus

Electrical Safety

Analyzer

The Rigel 266 Plus is a

highly compact,

easy-to-use safety

analyzer designed to test

in accordance with

IEC/EN 60601-1, MDA

DB9801 and AS/NZ

3200. This compact unit

provides a highly effective

and portable test solution.

Features include:

■Small and compact

■Conform IEC 60601,

MDA DB 9801

■1-25A ground bond

test current

■Up to 5 applied parts

■Direct print facility

Rigel 288

Electrical Safety

Analyzer

The 288 is the first truly

hand-held medical

electrical safety analyzer to

combine the features of an

automatic/manual tester

with a data logging/asset

management facility.

Control is through a menu

driven GUI. A large data

memory and Bluetooth

facility make this an

effective mobile unit.

Features include:

■Light, hand-held,

battery operation

■Conform IEC 62353 /

60601/ VDE 0751 /

NFPA-99 /

AS-NZS 3551

■Memory for up to

10,000 devices

■Bluetooth

communication

■Full, semi automatic &

manual tests

Rigel 277 Plus

Electrical Safety

Analyzer

The Rigel 277 Plus is a

fully comprehensive

electrical medical safety

analyzer used within the

widest possible range of

applications. The ability to

manage results and print

records means that the

user can manage the test

and re-test procedure

more productively.

Features include:

■Conform IEC 60601 /

61010 / AAMI /

NFPA-99 /

S-NZS 3200

■Onboard printer &

QWERTY keyboard

■100mA to 25A

ground bond current

■Full, semi automatic &

manual tests

■Memory for up to

2,500 devices

Rigel 62353

Electrical Safety

Analyzer

The Rigel 62353 is a cost

effective automatic safety

analyzer dedicated to the

IEC 62353 standard for

routine and testing after

repair of medical devices.

Offering automatic test

sequences, data entry

and storage as well as PC

download capabilities.

Features include:

■Light, hand-held,

battery operation

■Conform IEC 62353

■Fully customisable test

sequences

■Data entry and storage

■PC download

■Full, semi automatic

& manual tests

39

Rigel Multi-Flo

Infusion Pump

Analyzer

The market defining Rigel

Multi-Flo infusion pump

analyzer is a portable

instrument to accurately

and swiftly verify the

performance of all infusion

devices. Offering

instantaneous flow and

available in 1, 2 and 4

individual channel

configuration. The Multi-Flo

boasts a large color

screen, providing precise

information on flow rate,

occlusion and back

pressure and trumpet

curves.

Features include:

■IEC 60601-2-24

compliant

■Instant flow and

pressure

■Compatible with all

infusion devices

■On-screen trumpet

curve

■Onboard data storage

Performance Analyzers

rigelmedical.com

Rigel Uni-Pulse

Defibrillator Analyzer

The innovative Rigel Uni-Pulse

defibrillator analyzer is the

most compact and

versatile instrument on the

market, able to accurately

verify all mono and bi-

phasic defibrillators and

AED’s. Features include:

onscreen waveform

capture, built-in 12-lead

ECG simulator, onboard

memory and optional

variable load box ensuring

the Rigel Uni-Pulse meets all

the requirements

of IEC 60601-2-4.

Features include:

■IEC 60601-2-4

compliant

■Mono and bi-phasic

■Waveform capture,

store & replay

■Built-in 12 lead ECG

simulator

■Auto AED testing

Rigel Uni-Therm

Electrosurgical

Analyzer

The Rigel Uni-Therm

offers the latest

technology in high

frequency power

measurement. It’s small,

easy-to-use, has a large

color display and

innovative navigation

making this a fast,

efficient test tool for

testing the performance

of all diathermy machines.

A large internal memory

and PC communication

provides traceability of the

test data.

Features include:

■HF leakage test

■Power distribution from

0-5100Ω

■Current measurement

up to 6A RMS

■Return plate security

test (Rem)

■Onboard data storage

40

Med-eKit Elite

The Med-eKit Elite is a

handy and more

specialised carrying

solution. It has a hard-

wearing pelican case

which can be customised

to hold up to two

individual testers (the

Rigel 288 and UNI-SIM,

for instance). It can also

include a label and results

printer, barcode scanner

and PC software.

Features include:

■Configurable with up

to 4 tester functions

■Lightweight design

■Durable and robust

enclosure

■Water-proof design

■Secure locking

Med-eKit Lite

This new case is a

standard accessory for

the Rigel 288,

UNI-SIM and Uni-Pulse

biomedical testing

instruments. It can be

configured to hold a

number of different items

of test equipment and

accessories like

a label results printer and

a barcode scanner.

Features include:

■Carry securely on

back/ easy access

from front

■Configurable

compartments for

testers and accessories

■Extremely lightweight

design

■Suitable for up to 5

tester functions

■Durable and water

repellent design

Med-eKit Plus

The Med-eKit Plus is a

solution package offering

a complete test set that

includes electrical safety,

vital signs simulator,

ventilator test and more. It

can also feature a laptop

of your specification

and our latest asset

management software.

You could make life a lot

more efficient for yourself

if you included a range of

accessories like the

compact barcode scanner

and results/label printer.

Features include:

■Cost effective package

deal

■Configurable including

up to 5 tester functions

■Optional laptop

included

■Extremely lightweight

design

■Durable and water

repellent design

Med-eKit Pro

If you’re after a complete

biomedical workshop on

wheels, take a look at our

configurable Rigel Med-

eKit Pro. Housed in a

durable and handy trolley

case, it accommodates up

to 10 different testers and

simulators, so you can

carry your analyzer, vital

signs simulator, defib

analyzer, ventilator tester

and more, safely and

conveniently.

Features include:

■Integral wheels and

extendable handle for

easy use

■Configurable with up

to 10 tester functions

■Durable and robust

enclosure

■Water-proof design

■Secure locking

Med-eKit Solutions

41

You saw database management and work order

schedules as a major benefit, as they lead to fast,

efficient test device configuration. You asked for time

and money-saving software to provide monthly schedule

tests you could upload to your testers for easy re-test.

You also wanted preventative maintenance which

analysed and compared results and which also sent you

an alarm when devices could be deteriorating or needed

to be replaced.

And you asked for test certificate software customisable

for details and logos in PDF format.

So we created Med-eBase software which can be

used in a number of database environments,

including: SQL and SQLite. This way your data’s secure

and easily accessible. It can also be easily interrogated

by third party software which makes compatibility with

other software packages easy and straightforward.

Asset Management Software

rigelmedical.com

Rigel Medical, Seaward Group USA,

6304 Benjamin Road, Suite 506,

Tampa, Florida, 33634, United States

Tel: 813-886-2775 Email: enquiry@rigelmedical.com

Web: rigelmedical.com

Version 1.2 - 2012

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