Introduction to medical equipments safety and testing

 A hazard is any biological, chemical,
mechanical, environmental or physical
agent that is reasonably likely to cause
harm or damage to humans, other
organisms, or the environment in the
absence of its control.
2
Most hazards are dormant or potential, with only a theoretical
risk of harm; however, once a hazard becomes "active", it can
create an emergency. A hazardous situation that has come to
pass is called an incident. Hazard and possibility interact
together to create risk

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Medical electrical equipment can present a range of hazards
to the patient, the user, or to service personnel.
Many such hazards are common to many or all types of
medical electrical equipment, whilst others are peculiar to
particular categories of equipment.
The root causes for injures involving medical equipment include
Human Error, Faulty Equipment Design & Poor Maintenance.
However, It is unwise to assume anything until a through
investigation is made and failure analysis is performed on the
equipment.

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 Electro-Surgery burns due to poor contact with grounding plate.
 Punctured intestine due to insulation breakdown on laparoscope.
 Death caused for an infant by vacuum & suction lines reversed on portable
suction machine. .
 Infant brain damage due to defective valve design on portable oxygen unit.
 Microshock electrocution due to broken ground wire in die injector line
cord.
Many such hazards are common to many or all types of
medical electrical equipment, whilst others are peculiar
to particular categories of equipment.
Listed below are various types of
common hazards.

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1 - Mechanical Hazards
2 - Risk of Fire or Explosion
3 - Absence of Function
4 - Excessive or Insufficient Output
5 - Infection
6 - Misuse
7 - Risk of exposure to spurious electric
currents
8 - Radiation

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 All types of medical electrical
equipment can present mechanical
hazards.
 These can range from insecure
fittings of controls to loose fixings of
wheels on equipment trolleys.
 The former may prevent a piece of
life supporting equipment from
being operated properly, whilst the
latter could cause serious accidents
in the clinical environment.

The Enclosure
The enclosure of the device must be sufficiently strong to retain its integrity under
conditions of normal wear and tear
Handles of portable equipment are tested with a force of four times the weight of the
product. If there is more than one handle, this weight is distributed between the
handles.
Moving Parts
Moving parts which could produce a safety hazard must be suitable guarded
to prevent access, unless exposure is essential to the operation of the equipment.
If movement of the equipment, or parts of the equipment can cause injury to the
patient, this movement can only be achieved by continuous operation of the control by
the operator.
Any electrically controlled mechanical movement must have an emergency switch.
Sharp Edges
The device must not have sharp edges, corners, etc.
Stability
Medical devices must not overbalance when tilted to an angle of 10°.
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 All mains powered electrical
equipment can present the risk of
fire in the event of certain faults
occurring such as internal or
external short circuits.
 In certain environments such fires
may cause explosions. Although
the use of explosive anesthetic
gases is not common today, it
should be recognized that many of
the medical gases in use
vigorously support combustion.

 Medical devices typically contain a number of
electro-mechanical and chemical systems and
power sources. Power can be supplied to an
actuating mechanism, or fluids and gases can be
handled through compression, dispersion or
valving. The devices typically contain items that
include foamed padding and/or structural
plastics. All of these things in combination
present an energy source for ignition, fuel and
oxidizer – good conditions for fire ignition and
propagation.
9

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 Since many pieces of medical electrical equipment
are life supporting or monitor vital functions,
the absence of function of such a piece of
equipment would not be merely inconvenient, but
could threaten life
This recommend the use of proper test
equipments to verify the correct operation of the
equipment.

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 In order to perform its desired function equipment must
deliver its specified output.
Too high an output, for example, in the case of surgical diathermy
units, would clearly be hazardous. Equally, too low an output would
result in inadequate therapy, which in turn may delay patient
recovery, cause patient injury or even death.
 This highlights the importance of correct
calibration procedures.

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 Medical equipment that has been
inadequately decontaminated after use
may cause infection through the
transmission of microorganisms to any
person who subsequently comes into
contact with it.
 Clearly, patients, nursing staff
and service personnel are potentially at
risk here.

Microbes can be carried from one person to another on
the surface of any equipment that is shared between
them unless it is decontaminated between use.
Decontamination of medical equipment involves the
destruction or removal of any organisms present in order to
prevent them infecting other patients or hospital staff.
The process by which microbes are passed from one infected
person, to cause infection in another, is known as 'cross-
infection'. Decontamination reduces the risks of cross
infection and helps to maintain the useful life of equipment.
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 Cleaning, disinfection and sterilization are all procedures
that are used in the decontamination process.
 Cleaning is the process that removes contaminants
including dust, soil, large numbers of micro -organisms
and organic matter
(e.g. blood, vomit).
 It is an essential prerequisite to disinfection and
sterilization.
 It also removes the organic matter on which micro-
organisms might subsequently thrive.

 Disinfection is a process used to reduce the
number of micro-organisms but not usually
bacterial spores.
The process does not necessarily kill or
remove all micro-organisms, but reduces
their number to a level which is not harmful
to health.
 Sterilization removes or destroys all forms
of microbial life including bacterial spores.

Risk Application of Item Recommendation
High
In close contact with broken skin
or mucous membrane
Introduced into sterile body
areas
Cleaning followed by sterilisation.
Irradiation (Gamma or E-Beam)
Ethylene Oxide
Steam Sterilization
Dry Heat Sterilization
Medium
In contact with mucous
membranes contaminated with
particularly virulent or readily
transmissible organisms
Prior to use on
immunocompromised patients
Cleaning followed by sterilization or disinfection
required. Where sterilization may damage equipment,
cleaning followed by high level disinfection may be
used as an alternative.
Sodium Hypochlorite (Bleach)
Ethyl Alcohol
Isopropyl Alcohol (70%)
Alconox, Liquinox
Cidex (Glutaraldehyde)
Low In contact with healthy skin
Not in contact with patient
Cleaning only
with a detergent and water
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Following use on a patient or when requiring inspection or service, all
medical devices must be checked for visible evidence of contamination by
the user/clinician; however, as contamination is not always visible, all
equipment must be cleaned following patient use. Every attempt must be
made by the user to adequately decontaminate the equipment prior to
transfer for repair or servicing. If it is not possible to decontaminate, then
the equipment must be safely contained and clearly identified as
‘contaminated’ until advice is obtained from the Infection Prevention and
Control Team and the Medical Electronics Department.
All equipment MUST be accompanied by the Trust Declaration of
Decontamination Status of Healthcare Equipment Following Use and Prior to
Service or Repair form,
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 If items are dispatched to suppliers, or presented for service or
inspection on the hospital’s premises without a declaration of
decontamination, the receiver will refuse to accept the item and it
will be returned to the ward/department until it is accompanied by
the aforementioned form. In some instances total decontamination
may not be possible at source i.e. point of use, due to internal
contamination of the equipment, requiring additional tools to gain
access to the affected parts. The equipment must be removed to a
suitable designated area for appropriate decontamination prior to
inspection, service or repair. In this instance, the nature of
contamination must be clearly communicated to the receiving
organisation using the Trust Declaration of Decontamination Status
of Healthcare Equipment Following Patient Use and Prior to Service
or Repair form.
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In particular situations, for example when an item
of equipment has been involved in an incident, its
condition may be altered or influenced by the
decontamination process. In such situations, advice
must be sought from those investigating the
incident, the Infection Prevention and Control Team
and Medical Electronics.
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 Any packaging must be sufficiently robust to withstand transport
and if possible packaging specifically designed for the item of
equipment must be used in accordance with the Carriage of
Dangerous Goods Regulations 2007.
 The condition of the item must be clearly labelled indicating
content and contamination status. This is so that it can be clearly
determined prior to opening the package. E.g. biohazard label if
required and Trust Declaration of Decontamination Status of
Healthcare Equipment Following Patient Use and Prior to Service or
Repair form. Transport of contaminated equipment within the Trust
must be in a suitable container via internal hospital transport.
Where appropriate all external parts of large items of mobile
equipment should be covered in orange clinical waste bags and
suitably labelled.
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Standard/process/
issue
Monitoring and audit
Method By Committee Frequenc
y
Correct completion
of Declaration of
Decontamination
Status of Healthcare
Equipment
Following Patient
Use and Prior to
Service or Repair
form
Audit Medical
Technology
Department
Hospital
Decontamination
Group
Annually
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Sample of Decontamination Confirmation form

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 Misuse of equipment is one of the most common
causes of adverse incidents involving medical
devices.
 Such misuse may be a result of inadequate user
training or of poor user instructions.
 Do not modify or alter devices, unless in the
instructions for use it is clear that the manufacturer
sanctions the modification or alteration.

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 All electrical equipment has the potential to expose people to the risk of spurious
electric currents. In the case of medical electrical equipment, the risk is potentially
greater since patients are intentionally connected to such equipment and may not
benefit from the same natural protection factors that apply to people in other
circumstances. Whilst all of the hazards listed are important, the prevention of many
of them require methods peculiar to the particular type of equipment under
consideration. For example, in order to avoid the risk of excessive output of
surgical diathermy units, knowledge of radio frequency power measurement
techniques is required. However, the electrical hazards are common to all types of
medical electrical equipment and can minimized by the use of safety testing
regimes which can be applied to all types of medical electrical equipment.
 For these reasons, it is the electrical hazards that
are the main topic of this session.

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The medical use of ionizing radiations, whether for diagnosis
or therapy, not only results in the irradiation of the patient but
may also result in some degree of exposure of radiologists,
radiographers, other workers of the department.
Although many patients benefit from radiation’s ability to
destroy cancer cells or capture real-time images of the
human body, radiation can harm healthy cells wherever it
enters the body. It is well documented that ionizing radiation
can cause damage ranging from uncontrollable cell
replication to cell death.

Ionizing Radiation
 A radiation that has
sufficient energy to
remove electrons from
atoms or molecules as it
passes through matter.
 Examples: x-rays,
gamma rays, beta
particles, and alpha
particles
Non-Ionizing Radiation
 A radiation that is not as
energetic as ionizing
radiation and cannot
remove electrons from
atoms or molecules.
 Examples: light, lasers,
heat, microwaves, and
radar

Ionizing Radiation
Cell Death
Cell Damage
Repair Transformation

Whole Body 5,000 mrem/year
Lens of the eye 15,000 mrem/year
Extremities, skin, and
individual tissues
50,000 mrem per year
Minors 500 mrem per year (10%)
Embryo/fetus* 500 mrem per 9 months
General Public 100 mrem per year
* Declared Pregnant Woman

Radiation has the power to both save and harm lives.
Radiologic technologists use radiation to provide
quality medical imaging, but they must be aware of
potential exposure to radiation’s detrimental effects.
When proper time, distance, and shielding techniques
are used, dangerous exposure levels can be avoided.
Protection techniques are even more important for a
pregnant radiologic technologist, who must safeguard
her fetus from exposure. With an employer’s
cooperation and appropriate protection in place, a
pregnant technologist should be able to work in a
radiology setting without harming her fetus.

 Minimize the amount of
time spent near sources
of radiation.
 The exposure is to be
kept as short as
possible because the
exposure is directly
proportional to time.

 Distance from the radiation
source should be kept as
great as possible
As the distance from a radioactive
source doubles,
the exposure rate decreases by a factor
of four (inverse square Law)
 Physical Law:
◦ Inverse Square Law

 A lead protective shield
is placed between the
x-ray tube and the
individuals exposed,
absorbing unnecessary
radiation
TECHNOLOGIST . 25 mm LEAD
 LEAD APRON, GLOVES
 THYROID SHIELD, GLASSES
PATIENT –
GONAD SHEILDING
. 5 mm LEAD

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Why Test & Calibration
What you cannot measure you cannot control
As components age and equipment undergoes changes in
temperature or humidity or sustains mechanical stress,
performance gradually degrades. This is called drift.
When this happens your test results become unreliable and
both design and performance quality suffer.
While drift cannot be eliminated, it can be detected and either
corrected or compensated for through the process of
calibration.

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Definitions
• Calibration: process of comparing an unknown against
a reference standard within defined limits, accuracies and
Uncertainties
• Verification: process of comparing an unknown against
a reference standard at usually one data point

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What to TEST for?
• Performance Testing
• Safety Testing
Electrical Safety Testing
Radiation safety Testing
•On newly acquired equipment prior to use
•During routine planned preventative Maintenance.
•After repairs have been carried out on equipment.
When to test

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Performance testing is the process of determining or ensuring that the
equipment is performing to the expected standards of accuracy,
reliability, free of hysteresis and linear (as designed).
Safe and effective devices need to be available for patient care , to meet
the regulations, accreditation requirements and standards
The goal of any medical equipment maintenance program is to
ensure that medical equipment is safe, accurate, and ready for
patient use
Medical equipment testing is a critical task to ensure medical
devices are performing correctly for patients, doctors, nurses and
technologists alike. In order to ensure that we use proper Test
Equipments to analyze the functioning of each
equipments

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 These test devices are used to create signals and capture
responses from electronic Devices Under Test (DUTs).
 The proper operation of the DUT can be proven or faults in the
device can be traced, repaired, and certified calibration.
 In order to increase patient safety and reducing the risks of legal
liabilities (in case of a patient mishap or accident shown to be the
investigative cause due to faulty or un-calibrated test equipment.)
These testing devices must be calibrated Periodically traceable to
the National Institute of Science and Technology (NIST), National
Metrology Institute (NMI), and comply with international standards (
i.e. ISO 9001:2008 registered, ISO/IEC 17025:2005 accredited, and
ANSI/NCSL Z-540.1-1994 compliant.).

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 Defibrillator Analyzer
 Patient Simulator
 Tachometer
 ESU analyzer
 Ultrasound Phantom
 Phototherapy Radiometer
 Electrical Safety Analyzer
 Ventilator analyzer
 Flow meter
 O2 Analyzer
 Digital Thermometer
 Multi meter
 BP Simulator
 SPO2 Analyzer./Simulator
 Infusion Pump Analyzer
 pH meter
 Test Lung
 Spectrum Analyzer
 KV & Dose meter
 Pressure Meter

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 Defibrillator testers are testing devices used in
performing output measurement tests and
performance verification on defibrillator
equipment. Mostly, these multifaceted devices
performs primary measurement of energy,
peak voltage, peak current, pulse width, and
charge time tests.
Also, the device performs cardioversion analysis, Output Energy
Measurement (in Joules), On-demand Pacemaker Testing, and
generates simulated performance waves used in defibrillator testing as
well as several additional tests. Lastly, technicians can store, print data,
or possibly transfer it to an automated computerized maintainence
management system for archival.

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 Patient Simulators (also known as ECG
testers or "Chicken-Hearts") are testing
devices used in performing output
measurement tests and performance
verification on electrocardiograph and/or
defibrillator equipment. Mostly, these
multifaceted devices performs primary
measurements of a twelve-lead ECGs
performance waves (e.g. heartrates, NSR
w/ PVCs, V-Tachycardia, V-Fibrillation,
Asystole, Bigeminy, Pacer, Trigeminy,
ST+, Block, Square Waves), Respiration,
Invasive Blood Pressure, Cardiac Output ,
and Temperature measurements.
Lastly, technicians can store, print
data, or possibly transfer it to an
automated computerized
maintenance management
system for archival

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 Blood Pressure simulators are testing
verification on blood pressure, vital
signs, or physiological monitoring
equipment. Mostly, these multifaceted
devices performs primary measurements
of Auscultatory Non-Invasive Blood
Pressure (NIBP) performance waves
(e.g. adult and infant blood pressure
Waves), leak tests, over-pressure tests,
inflate or deflate times, systolic and
diastolic pressures, manometer
readouts, heart-rate measurements.
Lastly, technicians can store, print
automated computerized maintenance
management system for archival

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 Electrosurgical Unit (ESU) testers are
testing devices used in performing output
verification on electrosurgical or Bovie
devices performs primary measurement of
energy, Load Impedance (50 Ohms), peak-
to-peak voltage, crest factor, selected load
impedance value, RF current, and RF
power tests. Also, RF Leakage tests,
including active and dispersive electrode
leakage to ground used in electrosurgical
testing as well as several additional tests.
The technicians can store, print
maintenance management
system for archival

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 Conductivity meters are testing devices
used in performing output conductivity
measurements (in µS/cm)and performance
verification for laboratory equipment in a
solution. Commonly used in hydroponics,
aquaculture and freshwater systems to
monitor the amount of nutrients, salts or
impurities in the water. Lastly, technicians
can store, print data, or possibly transfer it
to an automated computerized
maintenance management system for
archival.

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 A digital voltmeter (DMM) is an
instrument used for measuring the
electrical potential difference between
two points in an electric circuit. Analog
voltmeters move a pointer across a scale
in proportion to the voltage of the circuit;
digital voltmeters give a numerical
display of voltage by use of an analog to
digital converter.
A multimeter can be a hand-held device useful for basic fault finding and field
service work or a bench instrument which can measure to a very high degree of
accuracy. They can be used to troubleshoot electrical problems in a wide array of
industrial and household devices such as electronic equipment, motor controls,
domestic appliances, power supplies, and wiring systems.

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 Infusion pump testers are testing
verification on infusion pumps, syringe
pumps, Patient Controlled Analgesia
(PCA) Pumps, and infusion controller
devices performs primary
measurements of Average Flow Rates,
Bolus, and Total Volume Delivered and
Timing measurements, Occlusion and
Back Pressure, and generates simulated
performance waves used in infusion
testing as well as several additional
tests.
Technicians can store, print data,
or possibly transfer it to an
maintainence management
system for archiva

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 An Ultrasound Watt-meter
(Radiometer) are testing devices used
in performing output measurement
tests and performance verification on
ultrasound equipment. Mostly, these
measurements of total-pulsed or
continuous-average power (in watts)
measurements.
 These devices are tested using either
demonized/distilled and/or degassed
water (never use regular tap water for
performing measurement checks--will
result in inaccurate readings). l. Lastly, technicians can store, print data, or
possibly transfer it to an automated
computerized maintainence management
system for archival.

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 A Pulse Oximeter (SpO2)
testers are testing devices
used in performing output
measurement tests and
performance verification on
pulse oximeter equipment.
Mostly, these Multifaceted
devices performs primary
measurement of Rate,
Saturation Percentage, and
Pulse Amplitude.
Technicians can store, print data, or possibly transfer it to an
automated computerized maintainence management system for
archival.

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 A ventilator testers are testing devices
used in performing output measurement
tests and performance verification on
insufflators, medical gas and vacuum
outlets, pressure gauges, flow-meters,
aspirators and suction devices, and
anesthesia equipment. Mostly, these
measurement of high- or low-flow and
pressure, Air, O2, CO2, N2, N2O, He
measurements, Breath rate (in breaths
per minute (bpm)), Inspiratory time,
Expiratory time, Positive end-expiratory
pressure (PEEP), Mean airway pressure
(in CM H2O), and Flow (in liters per
minute (lpm)) tests
Technicians can store, print data, or
computerized maintainence
FlowAnalyser™ PF-300 ventilator tester

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 Phototherapy Radiometer is designed for the accurate
measurement of light radiation in the blue part of the
spectrum from 400-480 nanometers. Phototherapy
exposure in this range is used in the treatment of
hyperbilirubinemia in newborn children.
 It provides continuous measurement of irradiation by
simply placing the detection probe under the
phototherapy light (fluorescent lamps only). In addition
to verifying output power, the DALE40 saves costs by
eliminating premature replacement of lamps.
 Light measurement is according to the percent
response given the wavelength characteristics curve.
The detector probe, included with the unit, has a wide
angle lens which matches the cosine receiving function
of human skin.
Measurements are taken in
µW/cm2, with a range of 0-1999.
This unit of measurement can
be compared directly to other
units of measurement.

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 A Pressure Meter are testing devices used
in performing output measurement tests
and performance verification on
Ophthalmology lasers, dialysis machines,
automatic tourniquets, drainage devices,
IV pumps, diagnostic and surgical suction
devices, ventilators, and pressure gauges
devices performs primary measurement
of gas or liquid pressures Measurement
(in mmhg or cmH2O) as well as several
additional tests.
Technicians can store, print data,
or possibly transfer it to an
maintainence management
system for archival

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A spectrum analyzer are testing devices
used in performing output measurement
tests and performance verification on audio
and telemetry devices. Mostly, these
measurement of EMC/EMI, Frequency
Range, Bandwidth, Average Noise Level,
Sweep Time, and Amplitude tests. There are
analog and digital spectrum analyzers:
An analog spectrum analyzer uses either a
variable band-pass filter whose mid-
frequency is automatically tuned (shifted,
swept) through the range of frequencies of
which the spectrum is to be measured or a
superheterodyne receiver where the local
oscillator is swept through a range of
frequencies.
A digital spectrum analyzer computes the
discrete Fourier transform (DFT), a
mathematical process that transforms a
waveform into the components of its
frequency spectrum.
Some spectrum analyzers (such as "real-time
spectrum analyzers") use a hybrid technique
where the incoming signal is first down-
converted to a lower frequency using
superheterodyne techniques and then
analyzed using fast fourier transformation
(FFT) techniques.

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The thermometer is a device that
measures temperature or
temperature gradient using a variety
of different principles.
Thermometers that include an
electronic device and attached
sensors that detect and transduce
changes in temperature into
variations of some electric
characteristic (e.g., resistance,
voltage). These variations of the
electric characteristics are
processed in electronic circuits and,
in turn, displayed as temperature
readings.
Thermo meter

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The probe is designed using the latest
advances in micro system technology
and provides a complete in line real
time monitoring system with unique
versatility and design. The sensor
proves his reliability when testing the
performance of any anesthesia
delivery and monitoring systems or the
accuracy of CO2 monitoring devices.
The MultiGasAnalyser™ sensor head
measures infrared light absorption at
several different wavelengths and
exactly determines the gas
concentrations of the
mixtures.

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PH meter
A device used to measure the pH of a liquid
PH meter
Test Lung
A device used to check the function of ventilator
Infant Test Lung
Test Lung
Tacho meter
A device that measures
speed of rotation
Tacho meter

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The Firefly endoscope-testing device is a
handheld instrument designed to measure the
luminous radiation of standard medical
endoscopic light sources, fiber optic cables
and endoscopes.
The Firefly consists of an integrating sphere,
light meter and adapters to interface with
endoscopic equipment common in surgical
applications
Firefly
The Oxygen Analysers are used to measure
the concentration of the oxygen in a gas
sample
Oxygen Analyzer

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 An electrical-safety testers are testing
devices used in performing safety tests
medical equipment. Mostly, these
electrical safety tests, including mains
voltage, protective earth resistance,
insulation resistance, device current,
earth, chassis, and patient leakages,
lead-to-lead leakage, generates
simulated performance waves used in
defibrillator testing as well as several
additional tests.
technicians can store, print data, or

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 Digital kV Meter is a test device for quality
control and acceptance testing in
radiographic, mammographic, CT,
fluoroscopic and dental x-ray systems. It
enables the user to measure the new IEC
quantity "practical peak voltage" as well as
non-invasive kVp, relative mAs and
exposure time
Dosimeters measure an individual's or an
object's[ exposure to something in the
environment radiation dosimeter, which
measures exposure to ionizing radiation

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√ Ensure patient safety
 Protect against macroshock
 Protect against microshock
√ Test for electrical internal breakdown /
damage to power cord, AC mains
feed, etc.
√ Meet codes & standards
 AAMI, IEC, UL, NFPA, etc.
√ Protect against legal liability
 In case of a patient incident

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 Standards and guidance documents
 Physiological effects of electricity
 Electrical hazards
 Electrical safety testing
 Risk management

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 The International Electrotechnical
commission[1] (IEC) is a non-profit, non-
governmental international standards
organization that prepares and publishes
International Standards for all electrical,
electronic and related technologies –
collectively known as "electrotechnology".
IEC standards cover a vast range of technologies from power generation,
transmission and distribution to home appliances and office equipment,
semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine
energy as well as many others.
The IEC also manages three global conformity assessment systems that certify
whether equipment, system or components conform to its International Standards.

68
 They also first proposed a system of standards, the Giorgi System,
which ultimately became the SI, or Système International d’unités
(in English, the International System of Units).
Today, the IEC is the world's leading
international organization in its field, and
its standards are adopted as national
standards by its members. The work is
done by some 10 000 electrical and
electronics experts from industry,
government, academia, test labs and
others with an interest in the subject.

69
 The IEC cooperates closely with the International
Organization for Standardization (ISO) and the
International Telecommunication Union (ITU). In
addition, it works with several major standards
development organizations, including the IEEE with
which it signed a cooperation agreement in 2002, which
was amended in 2008 to include joint development
work.
 Other standards developed in cooperation between IEC
and ISO are assigned numbers in the 80000 series, such
as IEC 82045-1.

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 IEC standards have numbers in the range 60000–79999 and their titles
take a form such as IEC 60417: Graphical symbols for use on equipment.
The numbers of older IEC standards were converted in 1997 by adding
60000, for example IEC 27 became IEC 60027.
IEC 60027 Letter symbols to be used in electrical technology...
IEC 60034 Rotating electrical machinery
IEC 60038 IEC Standard Voltages
IEC 60044 Instrument transformers
IEC 60050 International Electrotechnical Vocabulary
IEC 60062 Marking codes for resistors and capacitors
IEC 60063 Preferred number series for resistors and capacitors
IEC 60065 Audio, video and similar electronic apparatus - Safety requirements
IEC 60068 Environmental Testing
IEC 60071 Insulation Co-ordination
IEC 60073 Basic Safety principles for man-machine interface, marking and
identification

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 IEC 60601 Medical Electrical Equipment
 IEC 62304 Medical Device Software - Software Life Cycle Processes
 IEC 62366 Medical devices—Application of usability engineering to medical
devices
 IEC 62464 Magnetic resonance equipment for medical imaging
– the IEC 60601-1-xx series of collateral standards for MEDICAL
ELECTRICAL EQUIPMENT;
– the IEC 60601-2-xx series of particular standards for particular types of
MEDICAL ELECTRICAL EQUIPMENT; and
– the IEC 60601-3-xx series of performance standards for particular types of
MEDICAL ELECTRICAL EQUIPMENT
IEC 60601-x-xx

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 IEC 60601-1-2, Medical electrical equipment – Part 1-2: General
requirements for safety Collateral standard: Electromagnetic
compatibility – Requirements and tests
 IEC 60601-1-3, Medical electrical equipment – Part 1: General
requirements for safety – 3. Collateral standard: General
requirements for radiation protection in diagnostic X-ray
equipment
requirements for safety Collateral standard: Usability
requirements for safety Collateral standard: General requirements,
tests and guidance for alarm systems in medical electrical
equipment and medical electrical systems

73
 Electrolysis (mainly near d.c.)
 Neuromuscular effects (mainly 10-100Hz)
 Heating (mainly 100KHz-30Mhz)
Physiological Effects of Electricity
Human body can easily bear electrical current of 1 milliampere passing through its body
without appreciable risk or damage. However, as the amount of current increases the
body may suffer different type of damages like. Fibrillation, Burns to parts of the body
due to heat generated by electricity, Damage to nervous system causing loss of
nervous control.
When the current passes through brain it can lead to unconsciousness and permanent
damage to the brain. including death or electrocution
The physiological effects of electrical shock include the following.

74
The human body can easily detect macro shock and violent
reactions occur to high current flow level in the body…
Below 1 ma (1,000 µa), it is often much more difficult to detect
the presence of a shock hazard from simple perception…

75
 The movement of ions of opposite polarities in
opposite directions through a medium is called
electrolysis and can be made to occur by passing
DC current through body tissues or fluids.
 If a DC current is passed through body tissues for
a period of minutes, ulceration begins to occur.
 Such ulcers, while not normally fatal, can be
painful and take long periods to heal.

76
Na+ Na+ Na+
Cl- Cl- Cl-
_ +
Sodium atoms
created at electrode
Chlorine atoms
created at electrode
Ionic Current
The formation of
sodium atoms at the
negative electrode
and chlorine atoms
at the positive
electrode causes
local chemic al
actions which kills
the cells.
Electrolysis

77
Macro shock: is the most common type of shock received and occurs when the
human body becomes a conductor of electric current passing by means other than directly
through the heart. This effect can readly occur with the use of medical electrical equipment
as the natural resistance of the skin to current flow is often reduced or bypassed by
electrodes and electorde paste or by invasion into mucous membrane.
Large current passing through the skin - a small proportion may pass through the
heart
Macroshock has the potential for both burns and cardiac arrhythmias. Currents pass
through the extremities mostly through the muscles. A current flowing from arm to arm, or
arm to leg, must pass through the thorax. In the thorax the current is split between the
chest wall and the great vessels, which obviously deliver the current directly to the
myocardium.

78
 Microshock refers to currents delivered
directly to the heart via intracardiac
electrodes or catheters. Because the current is
delivered to a very small area, only a very
small current is required to reach the
fibrillation threshold.
The currently accepted minimum current is 10
A (microamps = 1/1000 of milliamps
For a (15-100Hz) current passing between the hands, the following effects are
expected
0.5-1mA Perception
10mA Can’t let go
100mA Severe pain. Interference with breathing and heart
function
1A Sustained heart contraction

79
Heating Effects - Surgical Diathermy
In Surgical Diathermy the heat is concentrated at the tip of the probe because the
current density (A/m2) is very high but at the plate it is low. Heating will occur at the
plate if he contact area reduces (plate comes loose)
Skin Internal Skin
Current = I
Low current
density at
return
electrode
Current = I
Very high
current density
at active
electrode

80
 Classes and Types
 L1 - Hot
 L2 - Neutral
 Earth - Ground
 Mains Line - Voltage
 Applied Parts - Patient
Leads
 Enclosure/Case - Chassis
 Protective Earth -Ground Wire
 Earth Leakage Current
Leakage in Ground Wire
 Enclosure Leakage - Chassis
Leakage
 Patient Leakage - Lead Leakage
 Patient Auxiliary - Leakage
between Patient Leads
 Mains on Applied Parts - Lead
Isolation
 Insulation Resistance - Dielectric
Strength or Insulation Resistance
between Hot and Neutral to
Ground
 Earth Resistance - Ground Wire
Resistance

81
 All electrical equipment is categorised into classes
according to the method of protection against electric
shock that is used. For mains powered electrical
equipment there are usually two levels of protection
used, called "basic" and "supplementary" protection.
The supplementary protection is intended to come into
play in the event of failure of the basic protection.
 Equipment Class{I,II,III} method of protection
against electric shock
 Equipment Type{B,BF,CF} degree of protection

82
 Class I equipment has a protective earth. The basic means of protection is the
insulation between live parts and exposed conductive parts such as the metal
enclosure. In the event of a fault that would otherwise cause an exposed conductive
part to become live, the supplementary protection (i.e. the protective earth) comes
into effect. A large fault current flows from the mains part to earth via the protective
earth conductor, which causes a protective device (usually a fuse) in the mains circuit
to disconnect the equipment from the supply.
 It is important to realise that not all equipment having an earth connection is
necessarily class I. The earth conductor may be for functional purposes only such as
screening. In this case the size of the conductor may not be large enough to safely
carry a fault current that would flow in the event of a mains short to earth for the
length of time required for the fuse to disconnect the supply.
term referring to electrical equipment in which protection against
electric shock does not rely on BASIC INSULATION only, but
which includes an additional safety precaution in that means are
provided for ACCESSIBLE PARTS of metal or internal parts of
metal to be PROTECTIVELY EARTHED

83
 Class I medical electrical equipment should have fuses at the equipment end of the
mains supply lead in both the live and neutral conductors, so that the
supplementary protection is operative when the equipment is connected to an
incorrectly wired socket outlet.
 Further confusion can arise due to the use of plastic laminates for finishing
equipment. A case that appears to be plastic does not necessarily indicate that the
equipment is not class I. There is no agreed symbol in use to indicate that
equipment is class I.
 Where any doubt exists, reference should be made to equipment manuals. The
symbols below may be seen on medical electrical equipment adjacent to terminals.

84
 The method of protection against electric shock in the case of class II
equipment is either double insulation or reinforced insulation. In double
insulated equipment the basic protection is afforded by the first layer of
insulation. If the basic protection fails then supplementary protection is
provided by a second layer of insulation preventing contact with live parts.
 Reinforced insulation is defined in standards as being a single layer of
insulation offering the same degree of protection as double insulation.
 Class II medical electrical equipment should be fused at the equipment
end of the supply lead in either mains conductor or in both conductors if
the equipment has a functional earth.
 The symbol for class II equipment is two
concentric squares indicating double insulation
as shown.

85
 shock relies on the fact that no voltages higher than safety extra low voltage (SELV)
are present. SELV is defined in turn in the relevant standard as a voltage not
exceeding 25V ac or 60V dc.
 In practice such equipment is either battery operated or supplied by a
SELV transformer.
 If battery operated equipment is capable of being operated when connected to the
mains (for example, for battery charging) then it must be safety tested as either
class I or class II equipment. Similarly, equipment powered from a SELV transformer
should be tested in conjunction with the transformer as class I or class II equipment
as appropriate.
 It is interesting to note that the current IEC standard relating to safety of
medical electrical equipment does not recognize Class III equipment since
limitation of voltage is not deemed sufficient to ensure safety of the patient. All
medical electrical equipment that is capable of mains connection must be classified
as class I or class II. Medical electrical equipment having no mains connection is
simply referred to as "internally powered

86
 As described above, the class of equipment defines the method of protection
against electric shock. The degree of protection for medical electrical equipment
is defined by the type designation. The reason for the existence of type
designations is that different pieces of medical electrical equipment have
different areas of application and therefore different electrical safety
requirements. For example, it would not be necessary to make a particular piece
medical electrical equipment safe enough for direct cardiac connection if there is
no possibility of this situation arising.
 All medical electrical equipment should be marked by the manufacturer with
one of the type symbols.
 Table below shows the symbols and definitions for each type classification of
medical electrical equipment.

87
Type Symbol Definition
B
Equipment providing a particular degree of
protection against electric shock, particularly
regarding allowable leakage currents and reliability
of the protective earth connection (if present).
BF
As type B but with isolated or floating (F - type)
applied
part or parts.
CF
Equipment providing a higher degree of protection
against electric shock than type BF, particularly with
regard to allowable leakage currents, and having
floating applied parts.
Type Symbols for Medical equipments

88
A part of the equipment which in normal use:
necessarily comes into physical contact withthe
patient for the equipment to perform its function;
or can be brought into contact with the patient;
or needs to be touched by the patient
tableNo applied part

89
 Part of equipment which can be touched without
the use of a tool.
 EXAMPLE 1 Illuminated push-buttons
 EXAMPLE 2 Indicator lamps
 EXAMPLE 3 Recorder pens
 EXAMPLE 4 Parts of plug-in modules
 EXAMPLE 5 Batteries

90
 Current that is not functional.
 several different leakage currents are defined according to the paths
that the currents take.
 Earth Leakage Current
 Enclosure Leakage Current
 Patient Leakage Current
 Patient auxiliary current
Causes of Leakage currents
If any conductor is raised to a potential above that of earth, some current is bound
to flow from that conductor to earth. The amount of current that flows depends on:
1- the voltage on the conductor.
2- the capacitive reactance between the conductor and earth.
3-the resistance between the conductor and earth.

91
 current flowing from the MAINS PART through or across the
insulation into the PROTECTIVE EARTH CONDUCTOR
Under normal conditions, a person who is
in contact with the earthed metal enclosure
of the equipment and with another earthed
object would suffer no adverse effects even
if a fairly large earth leakage current were
to flow. This is because the impedance to
earth from the enclosure is much lower
through the protective earth conductor than
it is through the person. However, if the
protective earth conductor becomes open
circuited, then the situation changes. Now,
if the impedance between the transformer
primary and the enclosure is of the same
order of magnitude as the impedance
between the enclosure and earth through
the person, a shock hazard exists.

92
 LEAKAGE CURRENT
flowing from the
ENCLOSURE to earth or
to another part of the
ENCLOSURE through a
conductor other than
the protective earth
conductor.
 LEAKAGE CURRENT
flowing from the
ENCLOSURE to earth or
to another part of the
ENCLOSURE through a
conductor other than
the protective earth
conductor.

93
 Patient leakage current is
the leakage current that
flows through a patient
connected to an applied
part or parts.
 It can either flow from the
applied parts via the
patient to earth or from an
external source of high
potential via the patient
and the applied parts to
earth.
 Patient leakage current is
the leakage current that
flows through a patient
connected to an applied
part or parts.
 It can either flow from
the applied parts via the
patient to earth or from
an external source of
high potential via the
patient and the applied
parts to earth.

94
 The patient auxiliary
current is defined as
the current that
normally flows between
parts of the applied
part through the
patient, which is not
intended to produce a
physiological effect

95
 By applying mains voltage to the applied parts, the leakage current that would flow
from an external source into the patient circuits can be measured.
 Although the safety tester normally places a current limiting resistor in series with
the measuring device for the performance of this test, a shock hazard still exists.
Therefore, great care should be taken if the test is carried out in order to avoid the
hazard presented by applying mains voltage to the applied parts. Careful
consideration should be given as to the necessity or usefulness of performing this
test on a routine basis when weighed against the associated hazard and the
possibility of causing problems with equipment.
 The purpose of the test under IEC 60601-1 is to ensure that there is no danger of
electric shock to a patient who for some unspecified reason is raised to a potential
above earth due to the connection of the applied parts of the equipment under test.
The standard requires that the leakage current limits specified are not exceeded.
There is no guarantee that equipment performance will not be adversely affected by
the performance of the test. In particular, caution should be exercised in the case of
sensitive physiological measurement equipment. In short, the test is a "type test".

96
 The resistance of the protective earth conductor is measured between the earth pin
on the mains plug and a protectively earthed point on the equipment enclosure (see
figure 6). The reading should not normally exceed 0.2 O at any such point. The test
is obviously only applicable to class I equipment.
 In IEC60601, the test is conducted using a 50Hz current between 10A and 25A for a
period of at least 5 seconds. Although this is a type test, some medical equipment
safety testers mimic this method. Damage to equipment can occur if high currents
are passed to points that are not protectively earthed, for example, functional
earths. Great care should be taken when high current testers are used to ensure that
the probe is connected to a point that is intended to be protectively earthed.
 HEI 95 and DB9801 Supplement 1 recommend that the test be carried out at a
current of 1A or less for the reason described above. Where the instrument used
does not do so automatically, the resistance of the test leads used should be
deducted from the reading.
 If protective earth continuity is satisfactory then insulation tests can be performed.

97
 For a plugged-in system, it is worth doing a mains insulation test
on the system as a whole to check the integrity of the
interconnecting mains wiring and the MSO if fitted.
 For installations, this test is impractical and may be dangerous. If
the test is to be performed, a number of preliminary steps are
required. The equipment / system must be disconnected from the
electrical supply. Allowance should be made for discharging large
capacitors, which may hold considerable charge for some time after
the machine is disconnected. Also any Uninterruptible Power
Supplies (UPS) must be identified and disconnected.

Visual Inspection
Earth Resistance Test
Insulation Test
Leakage Current Test
Earth Leakage
Current
Touch Current Patient Leakage
Current

100
 For systems, inspection should include ensuring that the system’s
components are all labelled and have all been tested individually during
acceptance testing. For routine testing, the tester should ensure that the
system has not been re-configured or items substituted.
 For installations, visual inspection may include:
◦ Electrical works test certificates
◦ Electrical safety certificate for installations
◦ MEIGaN test certificate for sockets wiring, earth wiring and equipotential
bonding
◦ Review of suppliers’ EST
◦ Test certificates of other plug-in medical equipment or systems in the
patient area

101
 The resistance of the protective earth conductor is
measured between the earth pin on the mains plug
and a protectively earthed point on the equipment
enclosure (see figure 6). The reading should not
normally exceed 0.2Ω at any such point. The test is
obviously only applicable to class I equipment.
In IEC60601, the test is conducted using a 50Hz
current between 10A and 25A for a period of at least
5 seconds. Although this is a type test, some medical
equipment safety testers mimic this method.
Damage to equipment can occur if high currents are
passed to points that are not protectively earthed, for
example, functional earths
Applicable to Class I, all types
Limit: 0.2Ω
DB9801 recommended?: Yes, at 1A or
less.
HEI 95 recommended?: Yes, at 1A or
less. Notes: Ensure probe is on a
protectively earthed point

102
Equipment
Configuration
Protective Earth
Resistance
Stand alone 200 m
System without MSO 200 m
System with MSO 400 m
Permanently installed 100 m

103
Plug-in equipment

104
A
(IEC 60601)
B
(IEC XXXX)
MSO
SIP/SOP
6V, 1A
< 400 mΏ
a.c.
Plug-in system

105
DUT 1
DUT 2
ERB
Incoming
PE Conductor
Bonding
Tester
Test to all exposed conductive
parts on each DUT in turn
< 0.1 
< 0.2 
Bonding
Tester
Installation

106
 HEI 95 and DB9801 recommended that for
class I equipment the insulation resistance be
measured at the mains plug between the live
and neutral pins connected together and the
earth pin. Whereas HEI 95 recommended
using a 500V DC insulation tester, DB 9801
recommended the use of 350V DC as the test
voltage.
Applicable to Class I, all types
Limits: Not less than 50MΩ
DB9801 recommended?: Yes
HEI 95 recommended?: Yes
Notes: Equipment containing mineral
insulated heaters may give values down to
1MΩ. Check equipment is switched on

107
 HEI 95 further recommended for
class II equipment that the
insulation resistance be measured
between all applied parts
connected together and any
accessible conductive parts of the
equipment. The value should not
normally be less than 50MΩ

108
Equipment Configuration Insulation Resistance
Stand alone >50 M
System without MSO >50 M
System with MSO >50 M
Permanently installed > 50 M

110
 hygroscopic mineral-insulated heating elements, which may exhibit low values until run for
some hours to desiccate;
 interference-suppression and discharge devices such as in Visual Display Units;
 a compromise struck with competing requirements e.g. conductivity of operating theatre
electrical warming mattress.
 For a plugged-in system, it is worth doing a mains insulation test on the system as a whole to
check the integrity of the interconnecting mains wiring and the MSO if fitted.
 For installations, this test is impractical and may be dangerous. If the test is to be performed,
a number of preliminary steps are required. The equipment / system must be disconnected
from the electrical supply. Allowance should be made for discharging large capacitors, which
may hold considerable charge for some time after the machine is disconnected. Also any
Uninterruptible Power Supplies (UPS) must be identified and disconnected.
Equipment exhibiting values an order of magnitude lower may be permissible,
if they involve the following:

111
For class I equipment, earth leakage current is measured
as shown in figure 12. The current should be measured
with the mains polarity normal and reversed. HEI 95 and
DB9801 Supplement 1 recommend that the earth leakage
current be measured in normal condition (NC) only. Many
safety testers offer the opportunity to perform the test
under a single fault condition such as live or neutral
conductor open circuit

116
Current Earth
Leakage
Touch
Current
Normal
Touch
Current
SFC
Patient Leakage
Normal
Patient Leakage
SFC
Limit 5 mA 100 μA 500 μA 100 μA B, BF
10 μA CF
500 μA B, BF
50 μA CF
The following table summarises the leakage current limits (in
mA) specified by IEC60601-1 (second edition)

117
Plug-in equipment

118
Plug-in system
A
(IEC 60601)
B
(IEC XXXX)
MSO
SIP/SOP
MD
MD
MD

119
Installation
DUT 1
DUT 2
ERB
Incoming
PE Conductor
MD
A
B
< 5 mA

122
 An electrical-safety testers are testing
devices used in performing safety tests
medical equipment. Mostly, these
electrical safety tests, including mains
voltage, protective earth resistance,
insulation resistance, device current,
earth, chassis, and patient leakages,
lead-to-lead leakage, generates
simulated performance waves used in
defibrillator testing as well as several
additional tests. technicians can store, print data, or

123
Type of equipment User checks Formal visual inspection
Combined inspection and
test
Equipment loan or hire e.g. medical
equipment library, trial device
Visually inspect cable
and case
Before issue / after return According to category
MDD Risk Class I equipment
generally
Yes
On acceptance, after repair or
incident
If earthed, on acceptance, after
repair or incident
1 to 2 years
MDD Risk Class IIa; medium risk Yes 6 months to 1 year
1 to 2 years. Include leakage
currents tests
MDD Risk Class IIb; medium to high
risk
Yes 6 months to 1 year
6 months to 1 year or after repair
or incident. Include leakage
currents tests
MDD Risk Class III; high risk Yes 6 months to 1 year
6 months to 1 year or after repair
or incident. Include leakage
currents tests
Equipment used by the public, e.g. in
hotels, patients own equipment from
home
By member of staff 3 months When arrives or 1 year
Cables and plugs, extension leads Yes 6 months to 1 year (intrusive) 1 year

126
 The most advanced Electrical Safety Analyzer on the market
 EN60601-1, EN601010-1, and AAMI & ESI test loads (user selectable) into one
device
 The One-Touch-Testing user interface
 Allows user to perform rapid tests on various medical devices
 Multiple enclosure-leakage points
 Multiple patient-applied-part types
• Power ON/OFF delay
• DC only for patient- and auxiliary-leakage tests
• User-programmable test sequences
• Offers manual, auto, step, and computer-control mode operations
• ASCII data transfer
• Memory for up to 1000 device-information records
• Conducts electrical safety testing in accordance with IEC 601-1, VDE 751, VDE
701, HEI 95, IEC 1010, AAMI, and AS/NZS 3551 requirements
601PROSeriesXL

127
• Flags failures, and simulates
performance, ECG, and
arrhythmia, waveforms.
• Results automatically analyzed
and saved in non-volatile
memory
• Accepts device information
that is input using an
– External keyboard,
– Integrated keypad,
– Barcode keyboard wedge
Optional Feature
• Onboard thermal printing
601PROSeriesXL

128
Voltage Range: 0 to 300 V True RMS (single and dual lead)
Accuracy: DC - 100 Hz ± 1.5 % of reading ± 1 LSD
Insulation
Resistance Range: 0.5 to 400.0 MΩ
Accuracy: ± 5 % of reading ± 2 LSD
Current
Consumption Range: 0 to 15 A ac True RMS
Accuracy: ± 5 % of reading ± 2 LSD
Mains on Applied
Part
Applied
Voltage:
≥ 110 % of mains voltage
Accuracy: ± 2 % of reading ± 6 µA
Protective Earth
Resistance Range: 0.000 to 2.999 Ω
Accuracy:
± 5 % of reading ± 4 mΩ (1 A, 10 A, and 25 A test currents)
(Refer to Operator’s Manual for additional specs qualifying the
effects on accuracy of variations in load inductance and phase
angle.)
Supply Voltage 90 to 265 Vac, auto switching
601PROSeriesXL

129
601PROSeriesXL
IEC601-1 and AAMI
Leakage Currents
Range: 0 to 8000 µA True RMS
Accuracy:
(per IEC601-1 or AAMI filter),
-DC - 1 kHz ± 1 % of -reading ± 1 µA
-1 to 100 kHz ± 2 % of reading ± 1 µA
- 100 kHz to 1 MHz ± 5 % of reading ± 1 µA
DC-Only Frequency
Response:
DC - 5 Hz (approx)
ECG Simulation and
Performance Testing ECG Complex: 30, 60, 120, 180, 240 BPM
Performance
Pulse: 30, 60 BPM, 63 ms pulse width
600 to 700 µs rise and fall
time
Sine Waves: 10, 40, 50, 60, 100 Hz
Square Wave: 0.125, 2.000 Hz (50 % duty cycle)
Triangle Wave: 2 Hz, 2 mV
Dimensions 16.62 in L x 11.75 in W x 5.56 in H
Weight 17lb / 7.7kg

130
 Mains Voltage
 Dual Lead Voltage
 Dual Lead Leakage
 Current Consumption
 Insulation Resistance
 Protective Earth
Resistance
 Earth Leakage Current
 Enclosure Leakage
Current
 Patient Leakage
Current
 Mains on Applied Part
Leakage
 Patient Auxiliary Current
 Accessible Voltage
 Accessible Leakage
 Equivalent Device
Leakage
 Equivalent Patient
Leakage
601PROSeriesXL

131
 Probe/Safety Lead, Red - 1
 Probe/Safety Lead, Black - 1
 Adapter, Banana/Alligator - 5
 Operators Manual - 1
 Large Clamp, Red - 1
 Warranty Card - 1
 Printer Paper Roll (original) - 1
 Printer Paper Roll (new style) - 1
• Carry Case
• RS232 Cable (9M-9F)
• Printer Cable
• Barcode, Keyboard, Wedge
• Adapter, Banana, ECG
• Keyboard English
• Powercord Set Australian
• Powercord Set Schuko
• Powercord Set US 120 V
• Powercord Set UK
601PROSeriesXL
Optional Accessories

132
Keys grouped by color and functionality
 Red keys -used to access menu options
◦ Include previous key, the four SOFT KEYS, and
the enter key
 Black keys -gain access to additional functions
◦ Include the esc/stop key, the view present
settings key, the print header key, and the print
data key.
601PROSeriesXL

133
1. Using Factory Default
Settings
2. Selecting the Test Standard
3. Selecting the Printer Output
4. Selecting the RS232 Baud
Rate
5. Activating the Beeper
6. Setting the Time and Date
7. Configuring the Enclosure
Leakage for the Auto mode
Sequence
8. Selecting Language Options
9. Selecting the DC Option
10. Selecting the Auto/Step Tests:
Controlled Power Sequences
or 601CE Conventional Test
11. Sequences enabling Stop on
Failure
12. Configuring for Device
Records or Templates
601PROSeriesXL

134
1. Connecting the Device Under Test
2. The Power-Up Sequence
4. Selecting the Class/Type
5. Saving Standard, Class, Type and Test Current
6. Using View Present Settings
7. Manual Operation
601PROSeriesXL
1. Selecting Auto or Step Mode Testing
2. Executing Auto and Step Mode Tests
3. Creating/Editing a Device Record or Template
Auto/Step Modes

135
1. Sending Test Results from the 601PRO to the Host
2. Computer
3. Test Data Record: Serial Output
4. Printing Test Records
5. Deleting Test Records
601PROSeriesXL
1. Connecting the 601PRO and the Host
Computer
2. Sending Device Information Records from the
601PRO to the Host Computer
3. Receiving Device Information Records from
the Host computer
4. Device Information Record: Definition of
Fields
5. Device Information Record Format
6. Deleting Device Records and Templates
Device Records and Templates

136
1. Permanently Wired Devices
2. Portable Devices
3. Portable Devices in Isolated Power Systems
4. Testing Three-Phase Portable Devices
5. Testing Conductive Surfaces
6. Detachable Power Supply Cable
7. Battery-Powered Equipment
601PROSeriesXL
1. Accessing System Setup
3. Referring to Test Limits for the Selected Standard
Standards and Principles

138
The risk of sustaining an electric shock can be
reduced by adopting the following practices:
1. A suitable Permit-to-Work system should always be in
place and operated, to ensure the effective isolation of hard-wired equipment before
repair or maintenance work commences.
1. Due care must always be exercised when switching off main power supplies to ensure
that only the intended circuits are isolated. Lock-off systems must be used, where
necessary.
2. Switch off and withdraw the plug on items of portable electrical equipment prior to
making any alterations or modifying any circuitry.
3. Do not handle any equipment with wet hands and do not work in close proximity to water
supplies or other earthed metalwork where there may be a risk of putting one hand on
earthed metal and the other on live equipment. If equipment is suspected of being live,
switch off, and have its electrical status tested by a competent person. Record the test.

139
5. The external metal casing of electrical apparatus and associated cables and conduits must
be earthed as a legal requirement. Water and gas pipes, however, must not be used as
earth points. Such pipes must be effectively bonded, to ensure that they remain at an equal
electrical potential. Checks should be carried out at least annually, to ensure that this
continues to be the case.
6. On no account must a three-phase socket outlet be used to supply single-phase apparatus.
7. Where supplies to experimental equipment are obtained from terminals, these must be
insulated and a control/emergency switch must be close by.
8. Standard types of electrical fittings, such as 3-pin plugs, sockets and switches, should
always be used as specified by manufacturers and in accordance with good practice (e.g.
switches must not be mounted upside down and single pole switches must not be wired into
the neutral lead.)
9. If it is possible to do so, always use low voltage equipment.
10. The use of high voltage equipment must be strictly controlled, and suitable assessments of
risk, and control features, prepared prior to use.

140
Typical Voltages at the Wall Socket
Note :the preferred method of
hand wiring plugs: Long earth
wire, short live
Electrical Hazards

141
Typical Hazards in the plug
Electrical Hazards

142
Leakage Current
In Class I equipment, most leakage current is caused by
capacitance between the leads in the mains cord and a
small amount due to stray capacitance within the equipment
itself.
Electrical Hazards

143
If the earth lead becomes detached, then the current that
would normally have flowed along it will now be available
on the case of the equipment and, in the case of a Type
B applied part, it will also flow through the patient
Electrical Hazards

144
Standard Filter Circuit
Choke
Choke
Supply
Transient
Suppressor
Electrical Hazards

145
Medical Filter Circuit
Choke
Choke
Supply
Transient
Suppressor
Electrical Hazards

146
Loss of Earth in Class 1 Equipment
This is the most common and most serious hazard since a
simple failure of basic insulation will then produce a deadly
situation of the metal case being at live mains voltage
Loss of earth will only be found by testing
MP
Class 1
Electrical Hazards

147
 Extension Leads
Extension leads are not permitted in clinical areas of RCH
organisations. They may cause high earth resistance and excessive earth
leakage current. An extension lead can allow equipment to be powered
from areas other than the relevant protected treatment area. The power
from the other area may not be protected to the same level as the power in
the treatment area.
As the connection between the extension lead and the equipment mains
cable is often on the floor there is a high danger from fluid spills, tripping
and damage to the mains cable by trolleys when an extension lead is used.
 Double Adaptors
Double adaptors must not be used
in RCH organisations. They may not
sit securely in a wall outlet, may not
be able to provide adequate earth
protection and may cause overloading,
overheating, fire or loss of electrical supply

148
Risk with using domestic types
Electrical Hazards

149
IEC 60601 IEC XXXXXA/P
Functional
Connection
The medical equipment might draw large currents via the I/O
port which, under a SFC, could appear on the applied part
(Type B) or on the enclosure for Class I
Electrical Hazards

150
IEC 60601
or XXXXX
IEC XXXXX
Functional
Connection
Earth with
potential
difference
Patient
Environment
In case of an interruption of protective earthing for an equipment in the
patient environment, this potential difference may appear on the
enclosure of the equipment causing a safety hazard for
the operator or for the patient
Electrical Hazards

151
 Humidity in the plugs of blood and fluid heaters
causing device failure (Andersen C, Pold R, Nielsen HD. Ugeskr
Laeger 2000; 162(6))
 Accidental toppling of a fluid container causing spillage
onto a blood pressure monitor (Singleton RJ, Ludbrook GL,
Webb RK, Fox MA. Anaesth Intensive Care 1993; 21(5))
 Electric shocks to anaesthetists after touching a faulty
device and the chassis of another device simultaneously
(Singleton RJ, Ludbrook GL, Webb RK, Fox MA. Anaesth Intensive
Care 1993; 21(5))
Electrical Hazards

152
An anaesthetised patient was connected to an ECG device
that had been wired wrongly with the earth and neutral
connections transposed. After noticing electrical
interference with the ECG signal, the anaesthetist
instructed an assistant to plug the monitor into a 2nd wall
socket. Unknown to the assistant, the 2nd socket was
wired with reverse polarity causing the chassis of the
monitor to go live and suffered a minor shock.
Unfortunately the patient experienced an intense shock
since she was also connected to a surgical diathermy
plate. She became cyanotic and her pulse stopped but
later recovered completely (Atkin DH, Orkin LR. Anesthesiology
1973; 38(2))
Electrical Hazards

153
A 9-month old baby was found dead on a bed after
admission to hospital with suspected pneumonia. The
patient apparently put an uncovered oval shaped lamp
switch (pendant switch) into his mouth and died of electric
shock after contacting the exposed wires (Yamazaki M, Bai H,
Tun Z, Ogura Y, Wakasugi C. J Forensic Sci 1997; 42(1))
Electrical Hazards

Introduction to medical equipments safety and testing

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