iec: standards of electrical technologies c… · iec 60601: particular standards electrical safety...
TRANSCRIPT
dr. Chris R. Mol, BME, NORTEC, 2015
IEC: Standards of Electrical Technologies
Electrical Safety Standards
The International Electrotechnical Commission 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, etc.
It also includes Medical Technology!
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dr. Chris R. Mol, BME, NORTEC, 2015
IEC 60601: Particular Standards
Electrical Safety Standards
Particular standards (numbered 60601-2-X) define the requirements for specific products or specific measurements built into products, e.g.
• MR scanners (IEC 60601-2-33) or • Electroencephalograms (IEC 60601-2-26)• High-frequency surgical devices (IEC 60601-2-2)
Particular standards can amend, modify, and/or supersede part of the requirements specified in IEC 60601-1.
NB. Compliance with IEC 60601-1 is not the same as medical device approval…. (see Regulations)
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dr. Chris R. Mol, BME, NORTEC, 2015 Electrical Safety Standards
hazard: unintended electric current
passing through a human body
direct through the heart
inability to let go
from hand to foot
Typical Body Impedance: 1,000 Ohms (dry, hand to hand)
0.5 mA: startle reaction threshold
Electrical shock Hazard: Physiological
Effects of Electricity
Electrical Safety is not dependent on voltage but on
(leakage) currents
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dr. Chris R. Mol, BME, NORTEC, 2015
IEC 60601: Product Classes I and II
Electrical Safety Standards
For Electrical Shock Hazard, IEC 60601-1 specifies requirements based on the product classification, which is dependent on criteria in terms of safety and intended use. For devices powered by an external source, the product may be classified as Class I or II.
• Class I is a product that is provided with a reliable Protective Earth (PE) such as a complete metal enclosure, that is tied to the ground pin of the three-pronged power plug. It has an insulation between ‘live’ parts and the metal enclosure.
• Class II is a product without a Protective Earth and where double or reinforced insulation is relied upon to provide protection against electric shock.
In the event of a fault, which would otherwise cause an exposed conductive part to become live, the protective earth comes into effect.
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dr. Chris R. Mol, BME, NORTEC, 2015
IEC 60601: The following Tests are specified
Electrical Safety Standards
for Class 1: is the metal enclosure well connected to Protective Earth (is the resistance low enough) ?
for Class 1: is the insulation between power and earth high enough ?
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for Class 2: is the insulation between power and enclosure high
enough ?
dr. Chris R. Mol, BME, NORTEC, 2015
IEC 60601: The following Tests are specified
Electrical Safety Standards
for Class I: is the electrical current leaking to earth low enough ?
for Class I and II: is the electrical current leaking from the enclosure
low enough ?
for B and BF equipment: is the electrical current leaking from the
patient to earth low enough?
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dr. Chris R. Mol, BME, NORTEC, 2015
IEC 60601: Single faults should not cause hazard
Electrical Safety Standards
Is the electrical current leaking from the patient to the ‘hot’ power line in the equipment low enough?
Is the electrical current leaking from the patient to the mains low enough?
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dr. Chris R. Mol, BME, NORTEC, 2015
Test Standards: specified limits
Electrical Safety Standards©
ENDThe creation of this presentation was supported by a grant from THET:
see https://www.thet.org/
for more details see e.g.: http://www.slideshare.net/ishoney/medical-electrical-safety