SIST EN 61157:2008
(Main)Standard means for the reporting of the acoustic output of medical diagnostic ultrasonic equipment
Standard means for the reporting of the acoustic output of medical diagnostic ultrasonic equipment
Establishes requirements for the declaration of the acoustic output information: 1.to be presented in technical data sheets supplied to prospective purchasers of equipment by manufacturers; 2.to be declared in the accompanying literature/ manual supplied by manufacturers; 3.as background information to be made available on request to interested parties by manufacturers.
Normverfahren für die Angabe der akustischen Ausgangsgrößen von medizinischen Ultraschalldiagnostikgeräten
Moyens normalisés pour la déclaration des émissions acoustiques des appareils de diagnostic médical à ultrasons
Définit les critères pour la déclaration des informations intéressant les émissions acoustiques: 1. à présenter dans des bordereaux de données techniques fournis par les fabricants aux acheteurs éventuels des appareils; 2. à déclarer dans la documentation/le manuel d'accompagnement fournis par les fabricants; 3. sous la forme d'informations de fond devant être présentées, sur demande, aux parties intéressées par les fabricants.
Standardni načini poročanja o akustičnem izhodu medicinske ultrazvočne diagnostične opreme (IEC 61157:2007)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2008
1DGRPHãþD
SIST EN 61157:2002
6WDQGDUGQLQDþLQLSRURþDQMDRDNXVWLþQHPL]KRGXPHGLFLQVNHXOWUD]YRþQH
GLDJQRVWLþQHRSUHPH ,(&
Standard means for the reporting of the acoustic output of medical diagnostic ultrasonic
equipment
Normverfahren für die Angabe der akustischen Ausgangsgrößen von medizinischen
Ultraschalldiagnostikgeräten
Moyens normalisés pour la déclaration des émissions acoustiques des appareils de
diagnostic médical à ultrasons
Ta slovenski standard je istoveten z: EN 61157:2007
ICS:
11.040.50 Radiografska oprema Radiographic equipment
11.040.55 'LDJQRVWLþQDRSUHPD Diagnostic equipment
17.140.50 Elektroakustika Electroacoustics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 61157
NORME EUROPÉENNE
November 2007
EUROPÄISCHE NORM
ICS 11.040.50; 11.140.50 Supersedes EN 61157:1994
English version
Standard means for the reporting of the acoustic output
of medical diagnostic ultrasonic equipment
(IEC 61157:2007)
Moyens normalisés pour la déclaration Normverfahren für die Angabe
des émissions acoustiques des appareils der akustischen Ausgangsgrößen
de diagnostic médical à ultrasons von medizinischen
(CEI 61157:2007) Ultraschalldiagnostikgeräten
(IEC 61157:2007)
This European Standard was approved by CENELEC on 2007-10-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61157:2007 E
Foreword
The text of document 87/356/CDV, future edition 2 of IEC 61157, prepared by IEC TC 87, Ultrasonics,
was submitted to the IEC-CENELEC parallel Unique Acceptance Procedure and was approved by
CENELEC as EN 61157 on 2007-10-01.
This European Standard supersedes EN 61157:1994.
The changes with respect to EN 61157:1994 are listed below:
– maintenance on this standard and the referenced standards EN 61161 and EN 62127-1;
– a clause on compliance has been added.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-10-01
NOTE The following print types are used:
– Requirements: in roman type
– Test specifications: in italic type
– Notes: in small roman type
– Words in bold in the text are defined in Clause 3.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61157:2007 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 61689 NOTE Harmonized as EN 61689:2007 (not modified).
IEC 61828 NOTE Harmonized as EN 61828:2001 (not modified).
__________
– 3 – EN 61157:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
IEC 60050-801 1994 International Electrotechnical Vocabulary – –
(IEV) -
Chapter 801: Acoustics and electroacoustics
1) 2)
IEC 61161 – Ultrasonics - Power measurement - EN 61161 2007
Radiation force balances and performance
requirements
1) 2)
IEC 62127-1 – Ultrasonics - Hydrophones - EN 62127-1 2007
Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz
ISO 16269-6 2005 Statistical interpretation of data - – –
Part 6: Determination of statistical tolerance
intervals
ISO/IEC Guide 98 1995 Guide to the expression of uncertainty in – –
measurement (GUM)
1)
Undated reference.
2)
Valid edition at date of issue.
IEC 61157
Edition 2.0 2007-08
INTERNATIONAL
STANDARD
Standard means for the reporting of the acoustic output of medical diagnostic
ultrasonic equipment
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
V
ICS 11.040.50; 11.140.50 ISBN 2-8318-9257-0
– 2 – 61157 © IEC:2007(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.6
2 Normative references .6
3 Terms, definitions and symbols .6
4 Requirements .16
4.1 General .16
4.2 Requirements for the reporting of acoustic output information .17
4.2.1 Technical data sheets information format .17
4.2.2 Detailed operating mode data sheets information format .18
4.2.3 Background information.19
4.2.4 Diagnostic fields in the absence of scan-frame synchronization.20
4.2.5 Dataset for low acoustic output equipment.20
5 Compliance statement .21
5.1 General .21
5.2 Maximum probable values .21
5.3 Sampling .21
6 Test methods .22
7 Presentation of results.22
Annex A (normative) Presentation of acoustic output information.23
Annex B (informative) Reporting requirements for extensive systems .25
Annex C (informative) Rationale .26
Index of defined terms .30
Bibliography.32
Figure C.1 – Schematic diagram showing the relationship between the various defined
surfaces and distances for a mechanical sector scanner with water stand-off
distance when applied to a patient.27
Figure C.2 – Schematic diagram showing the relationship between the various defined
parameters and distances for a mechanical sector scanner during the
measurement of acoustic output .27
Figure C.3 – Schematic diagram showing various defined parameters associated with
the distribution of the scan lines in a linear array scanner and mechanically-
scanned sector scanner.28
Figure C.4 – Schematic diagram illustrating the peak-rarefactional acoustic pressure
during an acoustic pulse.29
Table 1 – List of symbols .15
Table A.1 – An example of reporting of the acoustic output of a 3,5 MHz scan-head for
a phased-array sector scanner in accordance with this standard.24
61157 © IEC:2007(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
STANDARD MEANS FOR THE REPORTING
OF THE ACOUSTIC OUTPUT OF MEDICAL DIAGNOSTIC
ULTRASONIC EQUIPMENT
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of 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, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61157 has been prepared by IEC technical committee 87:
Ultrasonics.
This second edition cancels and replaces the first edition published in 1992. This edition
constitutes a minor revision.
The changes with respect to the previous edition are listed below:
• maintenance on this standard and the referenced standards IEC 61161 and IEC 62127-1.
• a clause on compliance has been added.
The text of this standard is based on the following documents:
Enquiry draft Report on voting
87/356/CDV 87/374/RVC
– 4 – 61157 © IEC:2007(E)
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 2.
NOTE The following print types are used:
– Requirements: in roman type
– Test specifications: in italic type
– Notes: in small roman type
– Words in bold in the text are defined in Clause 3.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
61157 © IEC:2007(E) – 5 –
INTRODUCTION
This International Standard specifies a standard means and format for the reporting of the
acoustic output of medical diagnostic ultrasonic equipment. The numerical values for reporting
purposes represent the average values for the maximum output conditions for a given
discrete- or combined-operating mode and are derived from measurements made in water.
Intensity parameters are specified in this standard, but these are regarded as derived
quantities that are meaningful only under certain assumptions related to the ultrasonic field
being measured.
– 6 – 61157 © IEC:2007(E)
STANDARD MEANS FOR THE REPORTING
OF THE ACOUSTIC OUTPUT OF MEDICAL DIAGNOSTIC
ULTRASONIC EQUIPMENT
1 Scope
This International Standard is applicable to medical diagnostic ultrasonic equipment.
– It provides a set of traceable acoustic parameters describing the acoustic fields.
– It defines a standard means and format for the reporting of the acoustic output information.
– It also describes a reduced dataset recommended for equipment generating low acoustic
output levels.
NOTE The information tabulated in this standard format can be used for
a) exposure planning for biological effects studies;
b) exposure data for prospective epidemiological studies conducted using exposure conditions similar
to those reported in this standard. In the absence of actual exposure data for retrospective
epidemiological studies, the information tabulated in this standard format might also be used with
cautionary comment.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-801:1994 International Electrotechnical Vocabulary – Chapter 801: Acoustics and
electroacoustics
IEC 61161, Ultrasonics – Power measurement – Radiation force balances and performance
requirements
IEC 62127-1, Ultrasonics – Hydrophones – Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz
ISO 16269-6:2005, Statistical interpretation of data – Part 6: Determination of statistical
tolerance intervals
ISO/IEC Guide 98:1995, Guide to the expression of uncertainty in measurement (GUM)
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in IEC 62127-1, IEC 61161,
the Index of defined terms at the end of this standard and the following definitions apply.
Figures C.1 to C.4 illustrate some of the defined parameters given below.
3.1
acoustic output freeze
condition of a system for which the acoustic output is disabled when there is no active
updating of ultrasonic echo information
61157 © IEC:2007(E) – 7 –
3.2
acoustic pulse waveform
temporal waveform of the instantaneous acoustic pressure at a specified position in an
acoustic field and displayed over a period sufficiently long to include all significant acoustic
information in a single pulse or tone-burst, or in one or more cycles in a continuous wave
NOTE 1 Temporal waveform is a representation (e.g. oscilloscope presentation or equation) of the instantaneous
acoustic pressure.
NOTE 2 Definition adapted from IEC 60469-1.
3.3
acoustic repetition period
arp
pulse repetition period for non-automatic scanning systems and the scan repetition period
for automatic scanning systems, equal to the time interval between corresponding points of
consecutive cycles for continuous wave systems
NOTE 1 The acoustic repetition period is expressed in seconds (s).
[IEC 62127-1, definition 3.2]
3.4
acoustic frequency
acoustic-working frequency
frequency of an acoustic signal based on the observation of the output of a hydrophone
placed in an acoustic field at the position corresponding to the spatial-peak temporal-peak
acoustic pressure
NOTE 1 The signal is analysed using either the zero-crossing acoustic-working frequency technique or a
spectrum analysis method. Acoustic-working frequencies are defined in 3.4.1 and 3.4.2.
NOTE 2 In a number of cases, the present definition is not very helpful or convenient, especially for broadband
transducers. In that case, a full description of the frequency spectrum should be given in order to enable any
frequency-dependent correction to the signal.
NOTE 3 Acoustic frequency is expressed in hertz (Hz).
3.4.1
zero-crossing acoustic-working frequency
f
awf
this is determined according to the procedure specified in IEC/TR 60854
NOTE This frequency is intended for continuous wave systems only.
3.4.2
arithmetic-mean acoustic-working frequency
f
awf
arithmetic mean of the most widely separated frequencies f and f , within the range of three
1 2
times f , at which the magnitude of the acoustic pressure spectrum is 3 dB below the peak
magnitude
NOTE 1 This frequency is intended for pulse-wave systems only.
NOTE 2 It is assumed that f < f
1 2
.
3.5
bandwidth
BW
difference in the most widely separated frequencies f and f at which the magnitude of the
1 2
acoustic pressure spectrum becomes 3 dB below the peak magnitude, at a specified point in
the acoustic field
NOTE Bandwidth is expressed in hertz (Hz).
– 8 – 61157 © IEC:2007(E)
3.6
beam area
A
b
area in a specified plane perpendicular to the beam axis consisting of all points at which the
pulse-pressure-squared integral is greater than a specified fraction of the maximum value
of the pulse-pressure-squared integral in that plane
NOTE 1 If the position of the plane is not specified, it is the plane passing through the point corresponding to the
spatial-peak temporal-peak acoustic pressure in the whole acoustic field.
NOTE 2 In a number of cases, the term pulse-pressure-squared integral is replaced everywhere in the above
definition by any linearly related quantity, for example:
a) in the case of a continuous wave signal the term pulse-pressure-squared integral is replaced by mean
square acoustic pressure as defined in IEC 61689;
b) in cases where signal synchronisation with the scanframe is not available the term pulse-pressure-squared
integral may be replaced by temporal average intensity.
NOTE 3 Some specified levels are 0,25 and 0,01 for the −6 dB and −20 dB beam areas, respectively.
NOTE 4 Beam area is expressed in metres squared (m ).
3.7
beam axis
straight line that passes through the beam centrepoints of two planes perpendicular to the
line which connects the point of maximal pulse-pressure-squared integral with the centre of
the external transducer aperture
NOTE 1 The location of the first plane is the location of the plane containing the maximum pulse-pressure-
squared integral or, alternatively, is one containing a single main lobe which is in the focal Fraunhofer zone. The
location of the second plane is as far as is practicable from the first plane and parallel to the first with the same two
orthogonal scan lines (x and y axes) used for the first plane.
NOTE 2 In a number of cases, the term pulse-pressure-squared integral is replaced in the above definition by
any linearly related quantity, for example:
a) in the case of a continuous wave signal the term pulse-pressure-squared integral is replaced by mean square
acoustic pressure as defined in IEC 61689;
b) in cases where signal synchronisation with the scanframe is not available, the term pulse-pressure-squared
integral may be replaced by temporal average intensity.
[IEV 62127-1,definition 3.8 modified]
3.8
beam centrepoint
position determined by the intersection of two lines passing through the beamwidth
midpoints of two orthogonal planes, xz and yz
3.9
beamwidth midpoint
linear average of the location of the centres of beamwidths in a plane
NOTE The average is taken over as many beamwidth levels given in Table K.1 of IEC 62127-1 as signal level
permits).
3.10
beamwidth
w , w , w
6 12 20
greatest distance between two points on a specified axis perpendicular to the beam axis
where the pulse-pressure-squared integral falls below its maximum on the specified axis by
a specified amount
NOTE 1 In a number of cases, the term pulse-pressure-squared integral is replaced in the above definition by
any linearly related quantity, for example:
61157 © IEC:2007(E) – 9 –
a) in the case of a continuous wave signal the term pulse-pressure-squared integral is replaced by mean
square acoustic pressure as defined in IEC 61689,
b) in cases where signal synchronisation with the scanframe is not available the term pulse-pressure-squared
integral may be replaced by temporal average intensity.
NOTE 2 Commonly used beamwidths are specified at –6 dB, –12 dB and –20 dB levels below the maximum. The
decibel calculation implies taking 10 times the logarithm of the ratios of the integrals.
NOTE 3 Beamwidth is expressed in metres (m).
3.11
central scan line
for automatic scanning systems, the ultrasonic scan line closest to the symmetry axis of the
scan plane
3.12
external transducer aperture
part of the surface of the ultrasonic transducer or ultrasonic transducer element group
assembly that emits ultrasonic radiation into the propagation medium
NOTE 1 This surface is either directly in contact with the patient or is in contact with a water or liquid path to the
patient (see IEC 62127-1, Figure 1).
[IEC 62127-1,definition 3.27 modified]
3.13
instantaneous acoustic pressure
p(t)
pressure minus the ambient pressure at a particular instant in time and at a particular point in
an acoustic field (see also IEV 801-21-19)
NOTE Instantaneous acoustic pressure is expressed in pascals (Pa).
3.14
instantaneous intensity
I(t)
acoustic energy transmitted per unit time in the direction of acoustic wave propagation per
unit area normal to this direction at a particular instant in time and at a particular point in an
acoustic field
NOTE 1 Instantaneous intensity is the product of instantaneous acoustic pressure and particle velocity. It is
difficult to measure intensity in the ultrasound frequency range. For the measurement purposes referred to in this
standard, and if it is reasonable to assume far field conditions, the instantaneous intensity, I is approximated as
p(t)
I(t) = (1)
ρ c
where
p(t) is the instantaneous acoustic pressure;
ρ is the density of the medium;
c is the velocity of sound in the medium.
NOTE 2 Instantaneous intensity is expressed in watts per metre squared (W/m ).
3.15
medical diagnostic ultrasonic equipment (or system)
combination of the ultrasound instrument console and the transducer assembly making up
a complete diagnostic system
– 10 – 61157 © IEC:2007(E)
3.16
nominal frequency
the ultrasonic frequency of operation of an ultrasonic transducer or ultrasonic transducer
element group quoted by the designer or manufacturer
[IEC 60854, definition 3.7 modified]
3.17
operating mode
3.17.1
combined-operating mode
mode of operation of a system that combines more than one discrete-operating modes
NOTE Examples of combined-operating modes are real-time B-mode combined with M-mode (B+M), real-time
B-mode combined with pulsed Doppler (B+D), colour M-mode (cM), real-time B-mode combined with M-mode and
pulsed Doppler (B+M+D), real-time B-mode combined with real-time flow-mapping Doppler (B+rD), i.e. flow-
mapping in which different types of acoustic pulses are used to generate the Doppler information and the imaging
information.
[IEC 62127-1, definition 3.39.1]
3.17.2
discrete-operating mode
mode of operation of medical diagnostic ultrasonic equipment in which the purpose of the
excitation of the ultrasonic transducer or ultrasonic transducer element group is to utilize only
one diagnostic methodology
NOTE 1 Examples of discrete-operating modes are A-mode (A), M-mode (M), static B-mode (sB), real-time B-
mode (B), continuous wave Doppler (cwD), pulsed Doppler (D), static flow-mapping (sD) and real-time flow-
mapping Doppler (rD) using only one type of acoustic pulse.
[IEC 62127-1, definition 3.39.2]
3.17.3
inclusive mode
combined-operating mode having acoustic output levels (p and I ) less than those
r spta
corresponding to a specified discrete-operating mode
[IEC 62127-1, definition 3.39.3]
3.17.4
non-scanning mode
mode of operation of a system that involves a sequence of ultrasonic pulses which give rise
to ultrasonic scan lines that follow the same acoustic path
[IEC 62127-1, definition 3.39.4]
3.17.5
scanning mode
mode of operation of a system that involves a sequence of ultrasonic pulses which give rise
to ultrasonic scan lines that do not follow the same acoustic path
NOTE The sequence of pulses is not necessarily made up of identical pulses. For instance, the use of sequential
multiple focal-zones is considered a scanning mode.
[IEC 62127-1, definition 3.39.5]
61157 © IEC:2007(E) – 11 –
3.18
output beam area
A
ob
area of the ultrasonic beam derived from the −12 dB beam area at the external transducer
aperture
NOTE 1 For reasons of measurement accuracy, the –12 dB output beam area may be derived from
measurements at a distance chosen to be as close as possible to the face of the transducer, and, if possible, no
more than 1 mm from the face.
NOTE 2 For contact transducers, this area can be taken as the geometrical area of the ultrasonic transducer or
ultrasonic transducer element group.
NOTE 3 The output beam area is expressed in metres squared (m ).
[IEC 62127-1, definition 3.40]
3.19
output beam dimensions
X , Y
ob ob
dimensions of the ultrasonic beam (–12 dB beamwidth) in specified directions perpendicular
to each other and in a direction normal to the beam axis and at the external transducer
aperture
NOTE 1 For reasons of measurement accuracy, the –12 dB output beam dimensions may be derived from
measurements at a distance chosen to be as close as possible to the face of the transducer, and, if possible, no
more than 1 mm from the face.
NOTE 2 For contact transducers, these dimensions can be taken as the geometrical dimensions of the ultrasonic
transducer or ultrasonic transducer element group.
NOTE 3 Output beam dimensions are expressed in metres (m)
[IEC 62127-1, definition 3.41]
3.20
output beam intensity
I
ob
temporal-average power output divided by the output beam area
NOTE Output beam intensity is expressed in watts per metre squared (W/m ).
[IEC 62127-1, definition 3.42]
3.21
patient entry plane
plane perpendicular to the beam axis, or the axis of symmetry of the scan plane for an
automatic scanner, which passes through the point on the said axis at which the ultrasound
enters the patient
NOTE See Figure C.1.
3.22
peak-rarefactional acoustic pressure
p (or p )
-
r
maximum of the modulus of the negative instantaneous acoustic pressure in an acoustic
field or in a specified plane during an acoustic repetition period
NOTE 1 Peak-rarefactional acoustic pressure is expressed as a positive number.
NOTE 2 Peak-rarefactional acoustic pressure is expressed in pascals (Pa).
NOTE 3 The definition of peak-rarefactional acoustic pressure also applies to peak-negative acoustic pressure
which is also in use in literature.
– 12 – 61157 © IEC:2007(E)
NOTE 4 See Figure C.4.
[IEC 62127-1, definition 3.44]
3.23
pulse-pressure-squared integral
ppsi
time integral of the square of the instantaneous acoustic pressure at a particular point in an
acoustic field integrated over the acoustic pulse waveform
NOTE 1 The pulse-pressure-squared integral is expressed in pascal squared seconds (Pa s).
[IEC 62127-1, definition 3.50]
3.24
pulse repetition period
prp
time interval between equivalent points on successive pulses or tone-bursts
NOTE 1 This applies to single element non-automatic scanning systems and automatic scanning systems. See
also IEC 60469-1:1987, 5.3.2.1.
NOTE 2 The pulse repetition period is expressed in seconds (s).
[IEC 62127-1, definition 3.51]
3.25
pulse repetition rate
prr
reciprocal of the pulse repetition period
NOTE 1 See also IEC 60469-1:1987, 5.3.2.2.
NOTE 2 The pulse repetition rate is expressed in hertz (Hz).
[IEC 62127-1, definition 3.51]
3.26
reference direction
for systems with scanning modes, the direction normal to the beam axis for an ultrasonic
scan line and in the scan plane. For systems with only non-scanning modes, the direction
normal to the beam axis and parallel to the direction of maximum −12 dB beamwidth
3.27
scan direction
for systems with scanning modes, the direction in the scan plane and perpendicular to a
specified ultrasonic scan line
3.28
scan plane
for automatic scanning systems, a plane containing all the ultrasonic scan lines.
NOTE 1 See 62127-1, Figure 1.
NOTE 2 Some scanning systems have the ability to steer the ultrasound beam in two directions. In this case,
there is no scan plane that meets this definition. However, it might be useful to consider a plane through the
major-axis of symmetry of the ultrasound transducer and perpendicular to the transducer face (or another suitable
plane) as being equivalent to the scan plane.
[IEC 62127-1, definition 3.56]
61157 © IEC:2007(E) – 13 –
3.29
scan repetition period
srp
time interval between identical points on two successive frames, sectors or scans, applying to
automatic scanning systems with a periodic scan sequence only
NOTE 1 In general, this standard assumes that an individual scan line repeats exactly after a number of acoustic
pulses. In the case where an ultrasonic transducer or ultrasonic transducer element group radiates ultrasound
without any sequence of repetition, it will not be possible to characterize a scanned mode in the way described in
this standard. The approach described in Annex F of IEC 62127-1 can be useful when synchronization cannot be
achieved.
NOTE 2 The scan repetition period is expressed in seconds (s).
[IEC 62127-1, definition 3.57]
3.30
scan repetition rate
srr
reciprocal of the scan repetition period
NOTE 1 The scan repetition rate is expressed in hertz (Hz).
[IEC 62127-1, definition 3.58]
3.31
spatial-peak temporal-average intensity
I
spta
maximum value of the temporal-average intensity in an acoustic field or in a specified plane
NOTE 1 For systems in combined-operating mode, the time interval over which the temporal average is taken is
sufficient to include any period during which scanning may not be taking place.
NOTE 2 Spatial-peak temporal-average intensity is expressed in watts per metre squared (W/m ).
[IEC 62127-1, definition 3.62]
3.32
temporal-average intensity
I
ta
time-average of the instantaneous intensity at a particular point in an acoustic field
NOTE 1 The time-average is taken normally over an integral number of acoustic repetition periods, if not, it
should be specified.
NOTE 2 Temporal-average intensity is expressed in watts per metre squared (W/m ).
[IEC 62127-1, definition 3.65]
3.33
transducer assembly
those parts of medical diagnostic ultrasonic equipment comprising the ultrasonic
transducer and/or ultrasonic transducer element group, together with any integral
components, such as an acoustic lens or integral stand-off
NOTE 1 The transducer assembly is usually separable from the ultrasound instrument console.
[IEC 62127-1, definition 3.69]
3.34
transducer output face
external surface of a transducer assembly which is either directly in contact with the patient
or is in contact with a water or liquid path to the patient
NOTE See Figures C.1 and C.2.
– 14 – 61157 © IEC:2007(E)
3.35
transducer stand-off distance
z
ts
shortest distance between the transducer output face and the patient entry plane
NOTE 1 The term "contact" is used to connote direct contact between the transducer output face and the patient,
with the transducer stand-off distance equal to zero.
NOTE 2 The transducer stand-off distance z is expressed in metres (m).
ts
NOTE 3 See Figure C.1.
3.36
transducer to transducer output face distance
z
tt
distance along the beam axis between the surface containing the active face of the
ultrasonic transducer or ultrasonic transducer element group and the transducer output
face
NOTE See Figures C.1 and C.2.
3.37
ultrasonic scan line
for scanning systems, the beam axis for a particular ultrasonic transducer element group,
or for a particular excitation of an ultrasonic transducer or ultrasonic transducer element
group
NOTE 1 Here, an ultrasonic scan line refers to the path of acoustic pulses and not to a line on an image on the
display screen of a system.
NOTE 2 In general, this standard assumes that an individual scan line repeats exactly after a given number of
acoustic pulses. In case an ultrasonic transducer or ultrasonic transducer element group radiates ultrasound
without any sequence of repetition, it will not be possible to characterize a scanned mode in the way described in
this standard. The approach described in Annex F of IEC 62127-1 can be useful when synchronization cannot be
achieved.
NOTE 3 The case where a single excitation produces ultrasonic beams propagating along more than one beam
axis is not considered.
[IEC 62127-1, definition 3.71]
3.38
ultrasonic scan line separation
s
s
for automatic scanning systems, the distance between the points of intersection of two
consecutive ultrasonic scan lines of the same type and a specified line in the scan plane
NOTE 1 It is assumed here that consecutive ultrasonic scan lines are spatially adjacent; this is not true for all
types of scanning equipment.
NOTE 2 The ultrasonic scan line separation is expressed in metres (m).
NOTE 3 See Figure C.3.
[IEC 62127-1, definition 3.72]
3.39
ultrasound instrument console
electronic unit to which the transducer assembly is attached
3.40
ultrasonic transducer
device capable of converting electrical energy to mechanical energy within the ultrasonic
frequency range and/or reciprocally of converting mechanical energy to electrical energy
[IEC 62127-1, definition 3.73]
61157 © IEC:2007(E) – 15 –
3.41
ultrasonic transducer element
element of an ultrasonic transducer that is excited in order to produce an acoustic signal
[IEC 62127-1, definition 3.74]
3.42
ultrasonic transducer element group
group of elements of an ultrasonic transducer which are excited together in order to produce
an acoustic signal
[IEC 62127-1, definition 3.75]
3.43
ultrasonic transducer element group dimensions
dimensions of the surface of the group of elements of an ultrasonic transducer element
group which includes the distance between the elements, hence representing the overall
dimensions
NOTE 1 Ultrasonic transducer element group dimensions are expressed in metres (m).
NOTE 2 This direction is along the central scan line of a sector scan. When the ultrasonic transducer is
symmetric, the unsteered beam may be chosen to be near the symmetry axis or a symmetry plane of the
ultrasonic transducer.
[IEC 62127-1, definition 3.76]
Table 1 – List of symbols
Symbol Term Reference
arp acoustic repetition period IEC 62127-1
A output beam area IEC 62127-1
ob
f arithmetic-mean acoustic-working frequency IEC 62127-1
awf
I (z) temporal-average intensity IEC 62127-1
ta
I (z) spatial-peak temporal-average intensity IEC 62127-1
spta
I output beam intensity IEC 62127-1
ob
ppsi pulse pressure squared integral IEC 62127-1
p peak-rarefactional acoustic pressure IEC 62127-1
r
prp pulse repetition period IEC 62127-1
prr pulse repetition rate IEC 62127-1
srp scan repetition period IEC 62127-1
srr scan repetition rate IEC 62127-1
s ultrasonic scan line separation IEC 62127-1
s
−12dB output beam dimensions IEC 62127-1
X , Y
ob ob
z axial distance from the source to a specified point IEC 62127-1
z transducer stand-off distance
ts
z transducer to transducer output face distance
tt
w −12 dB beamwidth IEC 62127-1
– 16 – 61157 © IEC:2007(E)
4 Requirements
4.1 General
Statements of acoustic output shall be given in accordance with the specification given in
Clause 7, 8.1 and 8.2 of IEC 62127-1 (see Clause 5 of this standard). The reporting of the
information should be in accordance with the requirements of Clause 7 of this standard.
To simplify the tabulation of acoustical parameters, the following symbols may be used to
indicate the various modes of operation of medical diagnostic ultrasonic equipment:
A A-mode
B Real-time B-mode
sB Static B-mode
M M-mode
D Static pulsed Doppler mode
cwD Continuous-wave Doppler mode (cw Doppler)
rD Real-time flow-mapping Doppler mode (colour Doppler)
sD Static flow-mapping Doppler mode
cM Colour M-mode
B+M B-mode combined with M-mode
B+D B-mode combined with pulsed Doppler mode
B+rD B-mode combined with real-time flow mapping Doppler mode
B+D+M B-mode combined with pulsed Doppler mode and M-mode
Any discrete-operating modes or combined-operating modes other than those given
above shall be identified by using similar notation; definitions shall be given where the
meaning is not obvious by reference to the above list.
For all discrete-operating modes, the general requirements for reporting are:
• acoustic output information shall be given in accordance with 4.2;
• inclusive modes shall be stated (the combined-operating modes whose acoustic output
parameters [p and I ] do not exceed the levels of this specified discrete-operating
r spta
mode).
NOTE The modes which make up the combined-operating mode do not necessarily include this specific
discrete-operating mode.
For combined-operating modes, the general requirements for reporting are:
• acoustic output information shall be specified if the system can only operate in a
combined-operating mode;
• acoustic output information shall be specified if the value of p or I for any combined-
r spta
operating mode is greater than the larger (or largest) of the corresponding values when
the system is operating in the discrete-operating modes;
• if the acoustic output levels (p and I ) of a combined-operating mode are lower than
r spta
the levels specified for a discrete-operating mode of a system, then the combined-
operating mode shall be specified as an inclusive mode of the particular discrete-
operating mode,
NOTE When acoustic output information is specified for a combined-operating mode, it should be possible
to achieve this by specifying the acoustic output of one or more dominant discrete-operating modes.
• a combined-operating mode is composed of a dominant discrete-operating mode if it
consists of a sequence of acoustic pulses for which the acoustic output parameters (p and
r
61157 © IEC:2007(E) – 17 –
I ) are determined by those pulses associated with one or more discrete-operating
spta
modes which make up the combined-operating mode. In this case, the reporting of the
acoustic output of the combined-operating mode shall be based on that for the dominant
discrete-operating mode.
Some systems capable of operating only in combined-operating modes during clinical use
may have internal test options which allow operation in discrete-operating modes for
measurement purposes. For such systems, acoustic output information for the various types
of acoustic pulses or discrete-operating modes can be determined. With the knowledge of
the appropriate pulsing sequences for the combined-operating modes, it may be possible to
make reliable estimates of the output of the combined-operating modes. This process of
estimation may be applied in all cases where the output of combined-operating modes is to
be determined.
A discrete- or combined-operating mode may consist of a sequence of acoustic pulses of
different types used to generate one ultrasonic scan line, such as a system operating in
multiple-focus mode. In this case, the acoustic pressure parameters shall be derived from the
particular acoustic pulse in the sequence which yields the highest values of the acoustical
output parameters. For instance, they would be determined from one particular focal-zone
firing. However, I wou
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...