IEC 60601-1:2005/AMD1:2012/ISH1:2021

 IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
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IEC 60601-1
Edition 3.0  2005-12
Amendement 1  2012-07
MEDICAL ELECTRICAL EQUIPMENT –

Part 1: General requirements for basic safety and essential performance

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by subcommittee 62A: Common aspects of
electrical equipment used in medical practice, of IEC technical committee 62: Electrical
equipment in medical practice.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
62A/1403/DISH 62A/1414/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

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Interpretation of Subclauses 4.3 of IEC 60601-1:2005/AMD1:2012 and 4.7 of
IEC 60601-1:2005
This interpretation sheet is intended to clarify the requirements which are needed to maintain
ESSENTIAL PERFORMANCE in SINGLE FAULT CONDITION.
Subclause 4.3 * ESSENTIAL PERFORMANCE
The requirements in this subclause of IEC 60601-1:2005/AMD1:2012 are clarified by the
following.
aa) IEC 60601-1:2005/AMD1:2012 requires that both the NORMAL CONDITION and the SINGLE
FAULT CONDITIONS are to be considered in the identification of ESSENTIAL PERFORMANCE,
because:
ICS 11.040.01
IEC 60601-1:2005-12/AMD1:2012-07/ISH1:2021-03(en)

– 2 – IEC 60601-1:2005/AMD1:2012/ISH1:2021
 IEC 2021
1) ESSENTIAL PERFORMANCE is defined in terms of the performance of a clinical function
(see 3.27);
NOTE 1 ESSENTIAL PERFORMANCE can have multiple aspects.
2) in particular, SINGLE FAULT CONDITIONS can cause or contribute to the loss or
degradation of such a clinical function that results in unacceptable RISK; and
3) according to IEC 60601-1:2005, 4.7, ME EQUIPMENT is required to remain SINGLE FAULT
SAFE or the RISK remains acceptable and this also applies to ESSENTIAL PERFORMANCE.
bb) The subclause requires the MANUFACTURER to:
NOTE 2 Many particular standards specify performance limits, RISK CONTROL measures and VERIFICATION
methods for some aspects of ESSENTIAL PERFORMANCE.
1) identify performance of clinical functions, other than that related to BASIC SAFETY, that
is necessary to achieve the INTENDED USE or that could affect safety;
2) specify performance limits between fully functional and total loss of the identified
performance in both
i) NORMAL CONDITION, and
ii) SINGLE FAULT CONDITION;
NOTE 3 The specified performance limits can be different in NORMAL CONDITION and SINGLE FAULT
.
CONDITION
3) evaluate the RISK from loss or degradation of the identified performance beyond the
specified limits;
i) Where the resulting RISK is unacceptable, the identified performance is
ESSENTIAL PERFORMANCE.
RISK CONTROL measures to reduce these RISKS to an acceptable level for
4) implement
both
i) NORMAL CONDITION, and
ii) SINGLE FAULT CONDITION;
5) assess and determine which RISK CONTROL measures need VERIFICATION of
effectiveness; and
6) specify methods for the VERIFICATION of the effectiveness of the RISK CONTROL
measures.
cc) The requirements
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