IEC 60601-2-44:1999

Medical electrical equipment - Part 2-44: Particular requirements for the safety of X-ray equipment for computed tomography

Establishes requirements for safe operation of X-ray equipment for computed tomography (CT scanners).

General Information

• Status: Published
• Publication Date: 09-Feb-1999
• ICS: 11.040.50 - Radiographic equipment
• Technical Committee: SC 62B - Medical imaging equipment, software, and systems
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 21-Jun-2001

Relations

• Revised: IEC 60601-2-44:2001 - Medical electrical equipment - Part 2-44: Particular requirements for the safety of X-ray equipment for computed tomography
• Effective Date: 05-Sep-2023

Standards Content (Sample)

INTERNATIONAL
IEC
STANDARD
60601-2-44
First edition
1999-02
Medical electrical equipment –
Part 2-44:
Particular requirements for the safety
of X-ray equipment for computed tomography
Appareils électromédicaux –
Partie 2-44:
Règles particulières de sécurité pour les équipements
à rayonnement X de tomodensitométrie

Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are

available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base

publication incorporating amendments 1 and 2.

Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken by
the technical committee which has prepared this publication, as well as the list of
publications issued, is to be found at the following IEC sources:
• IEC web site*
• Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

INTERNATIONAL
IEC
STANDARD
60601-2-44
First edition
1999-02
Medical electrical equipment –
Part 2-44:
Particular requirements for the safety
of X-ray equipment for computed tomography
Appareils électromédicaux –
Partie 2-44:
Règles particulières de sécurité pour les équipements
à rayonnement X de tomodensitométrie

 IEC 1999  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
R
International Electrotechnical Commission
For price, see current catalogue

– 2 – 60601-2-44 © IEC:1999(E)

CONTENTS
Page
FOREWORD . 3

INTRODUCTION .4

Clause
SECTION 1: GENERAL
1 Scope and object .5

2 Terminology and definitions. 6
6 Identification, marking and documents. 8
SECTION 2: ENVIRONMENTAL CONDITIONS
SECTION 3: PROTECTION AGAINST ELECTRIC SHOCK HAZARDS
SECTION 4: PROTECTION AGAINST MECHANICAL HAZARDS
22 Moving parts.9
27 Pneumatic and hydraulic power . 10
SECTION 5: PROTECTION AGAINST HAZARDS FROM UNWANTED
OR EXCESSIVE RADIATION
29 X-RADIATION. 11
SECTION 6: PROTECTION AGAINST HAZARDS OF IGNITION OF
FLAMMABLE ANAESTHETIC MIXTURES
SECTION 7: PROTECTION AGAINST EXCESSIVE TEMPERATURES
AND OTHER SAFETY HAZARDS
SECTION 8: ACCURACY OF OPERATING DATA AND PROTECTION
AGAINST HAZARDOUS OUTPUT
50 Accuracy of operating data . 17

SECTION 9: ABNORMAL OPERATION AND FAULT CONDITIONS;
ENVIRONMENTAL TESTS
SECTION 10: CONSTRUCTIONAL REQUIREMENTS
Table 101 – HALF-VALUE LAYERS in CT SCANNERS . 15
Figure 101 – Coordinate system . 7
Annex AA (normative) Terminology – Index of defined terms. 18

60601-2-44 © IEC:1999(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
MEDICAL ELECTRICAL EQUIPMENT –

Part 2-44: Particular requirements for the safety of

X-ray equipment for computed tomography

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60601-2-44 has been prepared by subcommittee 62B: Diagnostic
imaging equipment, of IEC technical committee 62: Electrical equipment in medical practice.
The text of this Particular Standard is based on the following documents:
FDIS Report on voting
62B/360/FDIS 62B/364/RVD
Full information on the voting for the approval of this Particular Standard can be found in the
report on voting indicated in the above table.
Annex AA forms an integral part of this standard.
In this standard, the following print types are used:
– requirements, compliance with which can be tested and definitions: roman type;
– explanations, advice, notes, general statements and exceptions: small roman type;
– test specifications: italic type;
– TERMS DEFINED IN CLAUSE 2 OF THE GENERAL STANDARD OR OF THIS PARTICULAR STANDARD OR
IN SMALL CAPITALS
IEC 60788: .
A bilingual version of this Standard may be issued at a later date.

– 4 – 60601-2-44 © IEC:1999(E)

INTRODUCTION
The relationship of this Particular Standard with IEC 60601-1 (including the amendments) and

the Collateral Standards is explained in 1.3.

60601-2-44 © IEC:1999(E) – 5 –

MEDICAL ELECTRICAL EQUIPMENT –

Part 2-44: Particular requirements for the safety of

X-ray equipment for computed tomography

SECTION 1: GENERAL
The clauses and subclauses of this section of the General Standard apply, except as follows:
1 Scope and object
This clause of the General Standard applies, except as follows:
1.1 Scope
Addition:
This Particular Standard applies to X-RAY EQUIPMENT for COMPUTED TOMOGRAPHY (CT
SCANNERS). It does not cover the safety requirements for HV-generators which will be the
subject of another standard.
1.2 Object
Replacement:
The object of this standard is to establish requirements for safe operation of CT SCANNERS in
as far as those requirements have not yet been specified in the General Standard, the
Collateral Standards or other Particular Standards.
1.3 Particular Standards
Addition:
This Particular Standard, hereinafter referred to as "this standard", amends and supplements a
set of IEC publications, hereinafter referred to as "General Standard", consisting of
IEC 60601-1:1988, Medical electrical equipment – Part 1: General requirements for safety, its
amendments 1 (1991) and 2 (1995), and any Collateral Standard.

The numbering of sections, clauses and subclauses of this Particular Standard corresponds to
that of the General Standard. The changes to the text of the General Standard are specified by
the use of the following words:
– "Replacement" means that the clause or subclause of the General Standard is replaced
completely by the text of this Particular Standard.
– "Addition" means that the text of this Particular Standard is additional to the requirements
of the General Standard.
– "Amendment" means that the clause or subclause of the General Standard is amended as
indicated by the text of this Particular Standard.
Subclauses, figures or tables which are additional to those of the General Standard are
numbered starting from 101, additional annexes are lettered AA, BB, etc., and additional items
aa), bb), etc.
Where there is no corresponding section, clause or subclause in this Particular Standard, the
section, clause or subclause of the General Standard applies without modification.

– 6 – 60601-2-44 © IEC:1999(E)

Where it is intended that any part of the General Standard, although possibly relevant, is not to

be applied, a statement to that effect is given in this Particular Standard.

A requirement of this Particular Standard replacing or modifying requirements of the General

Standard takes precedence over the original requirements concerned.

1.3.101 Related international standards

IEC 60601-1-1:1992, Medical electrical equipment – Part 1: General requirements for safety –

1. Collateral Standard: Safety requirements for medical electrical systems

IEC 60601-1-2:1993, Medical electrical equipment – Part 1: General requirements for safety –
2. Collateral Standard: Electromagnetic compatibility – Requirements and tests
IEC 60601-1-3:1994, Medical electrical equipment – Part 1: General requirements for safety –
3. Collateral Standard: General requirements for radiation protection in diagnostic X-ray
equipment
IEC 60601-1-4:1996, Medical electrical equipment – Part 1: General requirements for safety –
4. Collateral Standard: Programmable electrical medical systems
IEC 60601-2-32:1994, Medical electrical equipment – Part 2: Particular requirements for the
safety of associated equipment of X-ray equipment
IEC 60788:1984, Medical radiology – Terminology
ISO 2092:1981, Light metals and their alloys – Code of designation based on chemical symbols
2 Terminology and definitions
This clause of the General Standard applies, except as follows:
Addition:
2.101 Definitions
In this Particular Standard, terms printed in SMALL CAPITALS are used in accordance with their
definitions in the General Standard, in this standard or in IEC 60788.

An index of defined terms used in this Particular Standard is given in annex AA.
Additional definitions:
2.101.1
CT SCANNER
X-RAY EQUIPMENT for COMPUTED TOMOGRAPHY
2.101.2
CT CONDITIONS OF OPERATION
all selectable parameters governing the operation of a CT SCANNER, for example NOMINAL
TOMOGRAPHIC SECTION THICKNESS, PITCH FACTOR, FILTRATION, PEAK X-RAY TUBE VOLTAGE and
either X-RAY TUBE CURRENT and LOADING TIME, or CURRENT TIME PRODUCT

60601-2-44 © IEC:1999(E) – 7 –

y
T x
z
1 TOMOGRAPHIC PLANE
2 PHANTOM
IEC  210/99
Figure 101 – Coordinate system
2.101.3
DOSE PROFILE
representation of the dose as a function of position along a line
2.101.4
SENSITIVITY PROFILE
relative response of a system for COMPUTED TOMOGRAPHY as a function of position along a line
perpendicular to the TOMOGRAPHIC PLANE
2.101.5
TOMOGRAPHIC PLANE
geometric plane defined by the FOCAL SPOT and perpendicular to the axis of rotation; see
figure 101
2.101.6
COMPUTED TOMOGRAPHY DOSE INDEX 100 (CTDI )
integral of the DOSE PROFILE along a line perpendicular to the TOMOGRAPHIC PLANE from
–50 mm to +50 mm, divided by the product of the number of TOMOGRAPHIC SECTIONS N
produced in a single 360° rotation of the RADIATION SOURCE and the NOMINAL TOMOGRAPHIC
SECTION THICKNESS T in a single rotation of the RADIATION SOURCE

+50 mm
Dz
()
CTDI = dz
∫
NT×
− 50 mm
where
D(z) is the DOSE PROFILE along a line z perpendicular to the TOMOGRAPHIC PLANE, where dose
is measured as ABSORBED DOSE to air;
N is the number of TOMOGRAPHIC SECTIONS produced in a single rotation of the RADIATION
SOURCE;
T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS.
NOTE 1 – The term CTDI has been introduced as a more representative value for dose than the traditional CTDI
integrated from –7T to +7T as defined by the FDA in 21 CFR Ch. I § 1020.33.

– 8 – 60601-2-44 © IEC:1999(E)

NOTE 2 – Dose is calculated as ABSORBED DOSE to air. This is required in order to avoid present confusion, as

some MANUFACTURERS of CT S
...