IEC 61828:2001

Ultrasonics - Focusing transducers - Definitions and measurement methods for the transmitted fields

This International Standard - provides definitions for the transmitted field characteristics of focusing transducers for applications in medical ultrasound; - relates these definitions to theoretical descriptions, design, and measurement of the transmitted fields of focusing transducers; - gives measurement methods for obtaining defined characteristics of focusing transducers; - specifies beam axis alignment methods appropriate for focusing transducers. This International Standard relates to focusing ultrasonic transducers operating in the frequency range appropriate to medical ultrasound (0,5 MHz to 40 MHz) for both therapeutic and diagnostic applications. It shows how the characteristics of the transmitted field of transducers may be described from the point of view of design, as well as measured by someone with no prior knowledge of the construction details of a particular device. The radiated ultrasound field for a specified excitation is measured by a hydrophone in either a standard test medium (for example, water) or in a given medium. The standard applies only to media where the field behaviour is essentially like that in a fluid (i.e. where the influence of shear waves and elastic anisotropy is small), including soft tissues and tissue-mimicking gels. Any aspects of the field that affect their theoretical description or are important in design are also included. These definitions would have use in scientific communications, system design and description of the performance and safety of systems using these devices.

Ultrasons - Transducteurs focalisants - Définitions et méthodes de mesurage pour les champs transmis

La présente Norme internationale spécifie: - des définitions des caractéristiques du champ transmis de transducteurs focalisants pour des applications ultrasonores médicales; - la relation entre ces définitions et les descriptions théoriques, la conception et le mesurage des champs transmis par des transducteurs focalisants; - des méthodes de mesurage pour l'obtention de caractéristiques définies de transducteurs focalisants; - des méthodes d'alignement de l'axe du faisceau adaptées aux transducteurs focalisants. La présente Norme internationale se réfère à des transducteurs ultrasonores focalisants fonctionnant dans la plage de fréquences appropriée pour des applications ultrasonores médicales (soit de 0,5 MHz à 40 MHz) aussi bien thérapeutiques que diagnostiques. La présente norme montre comment les caractéristiques du champ transmis par les transducteurs peuvent être décrites du point de vue de la conception et mesurées par une personne n'ayant aucune connaissance préalable des détails de construction d'un appareil spécifique. Le champ ultrasonore émis pour une excitation spécifiée est mesuré par un hydrophone soit dans un milieu d'essai standard (par exemple de l'eau), soit dans un autre milieu donné. La Norme s'applique uniquement à des milieux où le comportement du champ est essentiellement similaire à celui constaté dans un fluide (c'est-à-dire où l'influence des ondes de cisaillement et de l'anisotropie élastique est faible), cela comprenant les tissus mous et les gels imitant un tissu. Tous les aspects du champ affectant leur description théorique ou qui sont importants pour la conception sont aussi inclus. Ces définitions peuvent être utiles dans des communications scientifiques, pour la conception d'appareils et pour la description du rendement et de la sécurité de systèmes utilisant ces dispositifs.

General Information

• Status: Published
• Publication Date: 28-May-2001
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 17.140.50 - Electroacoustics
• Technical Committee: TC 87 - Ultrasonics
• Drafting Committee: WG 6 - TC 87/WG 6
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 15-Dec-2020

Relations

• Revised: IEC 61828:2020 - Ultrasonics - Transducers - Definitions and measurement methods regarding focusing for the transmitted fields
• Effective Date: 05-Sep-2023

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD
First edition
2001-05
Ultrasonics – Focusing transducers –
Definitions and measurement methods
for the transmitted fields
Ultrasons – Transducteurs focaliseurs –
Définitions et méthodes de mesure
des champs transmis
Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

Consolidated editions
The IEC is now publishing consolidated versions of its publications. 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.
Further information on IEC publications
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
this publication, including its validity, is available in the IEC Catalogue of
publications (see below) in addition to new editions, amendments and corrigenda.
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 also available from the following:
• IEC Web Site (www.iec.ch)
• Catalogue of IEC publications
The on-line catalogue on the IEC web site (www.iec.ch/catlg-e.htm) enables
you to search by a variety of criteria including text searches, technical
committees and date of publication. On-line information is also available on
recently issued publications, withdrawn and replaced publications, as well as
corrigenda.
• IEC Just Published
This summary of recently issued publications (www.iec.ch/JP.htm) is also
available by email. Please contact the Customer Service Centre (see below) for
further information.
• Customer Service Centre
If you have any questions regarding this publication or need further assistance,
please contact the Customer Service Centre:
Email: [e-mail]
Tel: [phone]
Fax: [phone]
INTERNATIONAL IEC
STANDARD
First edition
2001-05
Ultrasonics – Focusing transducers –
Definitions and measurement methods
for the transmitted fields
Ultrasons – Transducteurs focaliseurs –
Définitions et méthodes de mesure
des champs transmis
 IEC 2001  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
X
International Electrotechnical Commission
For price, see current catalogue

– 2 – 61828 © IEC:2001(E)
CONTENTS
FOREWORD.4

INTRODUCTION.5

1 Scope.6

2 Normative references .6

3 General .7

3.1 Focusing transducers .7

3.1.1 Focusing methods .7
3.1.2 Known and unknown focusing transducers .7
3.1.3 Focusing and beamwidth .8
3.1.4 New focusing parameter definitions .8
3.1.5 Applications of focusing definitions .9
3.1.6 Relation of present definitions to physiotherapy transducers (treatment heads).9
3.2 System and measurement requirements.9
3.2.1 Transmitted pressure waveforms .9
3.2.2 Radiated fields .9
3.3 General focused field descriptions.10
3.3.1 General field descriptions for transducers of known construction .10
3.3.2 The scan plane and the steering of beams.11
4 Focusing definitions.12
4.1 Background information.12
4.2 Definitions .12
5 List of symbols .23
6 Measurement procedures .24
6.1 General .24
6.1.1 Set-up .25
6.2 Finding the beam axis .25
6.3 Determining if transducer is focusing.27
6.4 Measuring other focal parameters of a focusing transducer .28
Annex A (informative) Background for the transmission/Characteristics

of focusing transducers.38
Annex B (informative) Methods for determining the beam axis for well-behaved beams .43
Annex C (informative) Methods for determining the beam axis for beams that
are not well-behaved.47
Bibliography.49

61828 © IEC:2001(E) – 3 –
Figure 1 – Transducer options – Top: Transducer with a radius of curvature R and a focal

length equal to R – Middle: Transducer with a plano-concave lens – Bottom: Transducer

with a plano-convex lens.29

Figure 2 – Definitions for focusing measurements when the transducer geometry is

unknown .30

Figure 3 – Field parameters for non-focusing and focusing transducers .31

Figure 4 – Beam contour plot – Contours at –6, –12, and –20 dB for a 5 MHz transducer

with a diameter of 25 mm and a radius of curvature of 50 mm centred at location 0,0
(bottom centre of graph) .32

Figure 5 – Parameters for describing a focusing transducer of a known geometry.33

Figure 6 – Path difference parameters for describing a focusing transducer of a known
geometry .34
Figure 7 – Beamwidth focus in a principal longitudinal plane.35
Figure 8 –Types of geometric focusing.36
Figure 9 – Pressure focus in a principal longitudinal plane.37
Figure B.1 – X-axis scan at 9 cm depth for the first focal zone with beam centre.44
Figure B.2 – X-axis scan at 4,4 cm depth for the second focal zone.45
Figure C.1 – Asymmetric beam showing beamwidth midpoint method .48
Table B.1 – Standard deviations for x and y scans using three methods of determining
the centre of the beam .43
Table B.2 – –dB beamwidth levels for determining midpoints .46

– 4 – 61828 © IEC:2001(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
ULTRASONICS – FOCUSING TRANSDUCERS –

DEFINITIONS AND MEASUREMENT METHODS

FOR THE TRANSMITTED FIELDS
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 specifications, 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 61828 has been prepared by IEC technical committee 87:
Ultrasonics.
The text of this standard is based on the following documents:
FDIS Report on voting
87/196/FDIS 87/204/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A, B and C are for information only.
The committee has decided that the contents of this publication will remain unchanged
until 2005. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61828 © IEC:2001(E) – 5 –
INTRODUCTION
Focusing transducers are essential in medical applications for obtaining high-resolution

images, Doppler and flow data and for concentrating ultrasonic energy at desired sites for

therapy. Present terminology for focusing transducers is inadequate for communicating

precisely the characteristics of the focused fields of the wide variety of transducers and

transducer array types and focusing means in common usage.

This International Standard provides specific definitions appropriate for describing the

focused field from a theoretical viewpoint for transducers with known characteristics intended

by design. Other specific definitions included in this standard, based on measurement

methods, provide a means of determining focusing properties, if any, of a transducer of
unknown field characteristics. The measurement method and definitions provide criteria for
determining if the transducer is focusing, as well as a means of describing the focusing
properties of the field. Beam axis alignment methods are given for focusing transducers.

– 6 – 61828 © IEC:2001(E)
ULTRASONICS – FOCUSING TRANSDUCERS –

DEFINITIONS AND MEASUREMENT METHODS

FOR THE TRANSMITTED FIELDS
1 Scope
This International Standard
− provides definitions for the transmitted field characteristics of focusing transducers for
applications in medical ultrasound;
− relates these definitions to theoretical descriptions, design, and measurement of the
transmitted fields of focusing transducers;
− gives measurement methods for obtaining defined characteristics of focusing transducers;
− specifies beam axis alignment methods appropriate for focusing transducers.
This International Standard relates to focusing ultrasonic transducers operating in the
frequency range appropriate to medical ultrasound (0,5 MHz to 40 MHz) for both therapeutic
and diagnostic applications. It shows how the characteristics of the transmitted field of
transducers may be described from the point of view of design, as well as measured by
someone with no prior knowledge of the construction details of a particular device. The
radiated ultrasound field for a specified excitation is measured by a hydrophone in either a
standard test medium (for example, water) or in a given medium. The standard applies only to
media where the
...

IEC 61828
Edition 1.0 2001-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ultrasonics – Focusing transducers – Definitions and measurement methods for
the transmitted fields
Ultrasons – Transducteurs focalisants – Définitions et méthodes de mesurage
pour les champs transmis
All rights reserved. Unless otherwise specified, 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 either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: [e-mail]
Tel.: [phone]
Fax: [phone]
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
ƒ Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
ƒ Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
ƒ Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
ƒ Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: [e-mail]
Tél.: [phone]
Fax: [phone]
IEC 61828
Edition 1.0 2001-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ultrasonics – Focusing transducers – Definitions and measurement methods for
the transmitted fields
Ultrasons – Transducteurs focalisants – Définitions et méthodes de mesurage
pour les champs transmis
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XA
CODE PRIX
ICS 17.140.50 ISBN 2-8318-5793-7
– 2 – 61828 © CEI:2001
SOMMAIRE
AVANT-PROPOS.6
INTRODUCTION.10
1 Domaine d’application .12
2 Références normatives.12
3 Généralités.14
3.1 Transducteurs focalisants.14
3.2 Exigences pour le système et les mesures .18
3.3 Descriptions générales du champ focalisé.20
4 Définitions de focalisation.24
4.1 Informations générales .24
4.2 Définitions .24
5 Liste des symboles.50
6 Procédures de mesure .52
6.1 Généralités.52
6.2 Déterminer l’axe du faisceau .52
6.3 Déterminer si le transducteur est focalisant .56
6.4 Mesurage d’autres paramètres de focalisation d’un transducteur focalisant.58

Annexe A (informative) Informations générales concernant la transmission /
Caractéristiques des transducteurs focalisants .80
Annexe B (informative) Méthodes de détermination de l’axe du faisceau pour des
faisceaux réguliers.90
Annexe C (informative) Méthodes de détermination de l’axe du faisceau pour des
faisceaux non réguliers .98

Bibliographie.102

Figure 1 – Options de transducteur – En haut: transducteur avec un rayon de courbure
R et une longueur focale égale à R – Au milieu: transducteur à lentille plano-concave –
En bas: transducteur à lentille plano-convexe .62
Figure 2 – Définitions pour mesurages de focalisation lorsque la géométrie du
transducteur est inconnue.64
Figure 3 – Paramètres de champ pour des transducteurs non focalisants et focalisants.66
Figure 4 – Graphe de contour du faisceau – Contours à –6 dB, –12 dB et –20 dB pour
un transducteur de 5 MHz avec un rayon de 25 mm et un rayon de courbure de 50 mm
centré à la position 0,0 (au centre de l’axe inférieur du graphe) .68
Figure 5 – Paramètres de description d’un transducteur focalisant de géométrie
connue.70
Figure 6 – Paramètres de différence de trajectoire pour la description d’un

transducteur focalisant de géométrie connue .72
Figure 7 – Foyer de largeur de faisceau dans un plan longitudinal principal.74
Figure 8 – Types de focalisations géométriques.76
Figure 9 – Foyer pression dans un plan longitudinal principal .78

61828 © IEC:2001 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11
1 Scope.13
2 Normative references .13
3 General .15
3.1 Focusing transducers .15
3.2 System and measurement requirements.19
3.3 General focused field descriptions.21
4 Focusing definitions.25
4.1 Background information.25
4.2 Definitions .25
5 List of symbols .51
6 Measurement procedures .53
6.1 General .53
6.2 Finding the beam axis .53
6.3 Determining if transducer is focusing.57
6.4 Measuring other focal parameters of a focusing transducer .59

Annex A (informative) Background for the transmission/ Characteristics of focusing
transducers .81
Annex B (informative) Methods for determining the beam axis for well-behaved
beams .91
Annex C (informative) Methods for determining the beam axis for beams that are not
well-behaved .99

Bibliography.103

Figure 1 – Transducer options – Top: Transducer with a radius of curvature R and a focal
length equal to R – Middle: Transducer with a plano-concave lens – Bottom: Transducer
with a plano-convex lens.63
Figure 2 – Definitions for focusing measurements when the transducer geometry is
unknown .65
Figure 3 – Field parameters for non-focusing and focusing transducers .67
Figure 4 – Beam contour plot – Contours at –6, –12, and –20 dB for a 5 MHz transducer
with a diameter of 25 mm and a radius of curvature of 50 mm centred at location 0,0
(bottom centre of graph) .69
Figure 5 – Parameters for describing a focusing transducer of a known geometry.71
Figure 6 – Path difference parameters for describing a focusing transducer of a known
geometry .73
Figure 7 – Beamwidth focus in a principal longitudinal plane.75
Figure 8 –Types of geometric focusing.77
Figure 9 – Pressure focus in a principal longitudinal plane.79

– 4 – 61828 © CEI:2001
Figure B.1 – Balayage selon l’axe X à 9 cm de profondeur pour la première zone
focale à centre de faisceau .92
Figure B.2 – Balayage selon l’axe X à 4,4 cm de profondeur pour la secon
...