IEC 62359:2010/AMD1:2017
(Amendment)Amendment 1 - Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields
Amendment 1 - Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields
Amendement 1 - Ultrasons - Caractérisation du champ - Méthodes d'essais pour la détermination d'indices thermique et mécanique des champs d'ultrasons utilisés pour le diagnostic médical
General Information
Relations
Overview
IEC 62359:2010/AMD1:2017 (Amendment 1) updates the international standard for ultrasonics field characterization used to determine exposure indices related to medical diagnostic ultrasonic fields. The amendment adds measurement methods for attenuated spatial-peak temporal-average intensity (I_spta,a) and attenuated spatial-peak pulse-average intensity (I_sppa,a) at specified beam-axis locations called out in IEC 60601-2-37:2007/AMD1:2015. It also updates normative references and refines terms and definitions used for calculating thermal index (TI) and mechanical index (MI) parameters.
Key topics and technical requirements
- New annex for attenuated intensities: Methods for determining I_spta,a and I_sppa,a at spatial maxima on the beam axis beyond the break-point depth, to meet IEC 60601-2-37 requirements.
- Refined terminology and definitions: Updates include acoustic working frequency, break-point depth, depth for maximum pulse-intensity integral (pii), attenuated pulse-pressure-squared integral (ppsi), and related terms for scanning vs non‑scanning modes.
- Attenuation corrections: Definitions and formula structure for attenuated instantaneous acoustic pressure, attenuated pii and ppsi, and use of an acoustic attenuation coefficient and working frequency (awf) for depth-based correction.
- Scanning vs non‑scanning mode treatment: Clarified procedures for equivalent aperture diameter, –12 dB beam area, and how to treat scan-line sums (sii, s_ppsi) when computing scan-frame integrals.
- Normative references updated: Cross-references to IEC 60601-2-37:2007/AMD1:2015, IEC 62127-1:2007/AMD1:2013 (hydrophones), IEC 61157 and IEC 61161 are refreshed to align measurement and reporting practices.
Practical applications and users
Who uses IEC 62359:2010/AMD1:2017:
- Medical ultrasound device manufacturers - for acoustic output characterization, safety labeling, and regulatory compliance.
- Accredited test laboratories and CE/IEC conformity assessors - to perform hydrophone-based field measurements and calculate TI/MI metrics.
- Biomedical engineers and physicists - to design transducer testing protocols and interpret beam-axis intensity data.
- Regulatory and standards bodies - to harmonize acoustic output reporting and safety thresholds.
Practical value:
- Enables consistent, repeatable measurement of attenuated intensities used in TI/MI calculations.
- Supports compliance with IEC 60601-2-37 requirements for maximum-field reporting.
- Clarifies measurement locations (beam axis, beyond break-point depth), attenuation methodology, and scanning mode considerations - improving traceability of test data.
Related standards (selected)
- IEC 60601-2-37:2007/AMD1:2015 - medical electrical equipment: ultrasonic diagnostic equipment requirements
- IEC 62127-1:2007/AMD1:2013 - hydrophones: measurement and characterization of medical ultrasonic fields
- IEC 61157:2007/AMD1:2013, IEC 61161:2013 - reporting and output measurement guidance
Keywords: IEC 62359, ultrasonics, field characterization, thermal index, mechanical index, I_spta,a, I_sppa,a, hydrophone measurement, medical diagnostic ultrasonic fields.
Standards Content (Sample)
IEC 62359 ®
Edition 2.0 2017-09
INTERNATIONAL
STANDARD
AMENDMENT 1
Ultrasonics – Field characterization –
Test methods for the determination of thermal and mechanical indices related
to medical diagnostic ultrasonic fields
IEC 62359:2010-10/AMD1:2017-09(en)
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.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland 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.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.
IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC 62359 ®
Edition 2.0 2017-09
INTERNATIONAL
STANDARD
AMENDMENT 1
Ultrasonics – Field characterization –
Test methods for the determination of thermal and mechanical indices related
to medical diagnostic ultrasonic fields
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.140.50 ISBN 978-2-8322-4821-8
– 2 – IEC 62359:2010/AMD1:2017
© IEC 2017
FOREWORD
This amendment has been prepared by IEC technical committee 87: Ultrasonics.
The text of this amendment is based on the following documents:
FDIS Report on voting
87/661/FDIS 87/665/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website 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.
_____________
Introduction to Amendment
The second edition of IEC 62359 was published in 2010. Since then,
IEC 60601-2-37:2007/AMD1:2015 has been published and calls for provision of attenuated
spatial peak temporal average intensity, I , and attenuated spatial peak pulse
spta,a
average intensity, I , at specific spatial maximum points in the ultrasonic field on the
sppa,a
beam axis. No IEC standard describes the determination of these quantities at these specific
positions. IEC 62359 for determining the thermal indices currently uses similar values at other
positions, therefore, the determination of attenuated spatial peak temporal average
, and attenuated spatial peak pulse average intensity, I , has been
intensity, I
spta,a sppa,a
added as an annex in this amendment.
Additionally, references to newly published collateral standards have been updated.
_____________
© IEC 2017
2 Normative references
Replace the first reference by the following:
IEC 60601-2-37:2007, Medical electrical equipment – Part 2-37: Particular requirements for
the basic safety and essential performance of ultrasonic medical diagnostic and monitoring
equipment
IEC 60601-2-37:2007/AMD1:2015
Replace the second reference by the following:
IEC 61157:2007, Standard means for the reporting of the acoustic output of medical
diagnostic ultrasonic equipment
IEC 61157:2007/AMD1:2013
Replace, in the third reference, "IEC 61161:2006" by "IEC 61161:2013".
Replace the fifth reference by the following:
IEC 62127-1:2007, Ultrasonics – Hydrophones – Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz
IEC 62127-1:2007/AMD1:2013
3 Terms and definitions
Replace the first existing paragraph by the following new paragraph:
For the purposes of this document, the terms and definitions given in IEC 60601-2-37,
IEC 62127-1, IEC 62127-2, IEC 62127-3, IEC 61157 and IEC 61161 apply. Several of these
are repeated below for convenience and others are listed because they have been modified
for application to this standard.
3.3
acoustic repetition period
Replace the existing definition by the following new definition:
time interval between corresponding points of consecutive cycles, pulses or scans, depending
on the current operating mode
Add the following new NOTES 2 and 3:
NOTE 2 For continuous wave modes, the acoustic repetition period is the time interval between corresponding
points of consecutive cycles
NOTE 3 For combined operating modes where transmit pulsing of the constituent modes may be interrupted,
the arp determination should take into account non-pulsing time to calculate an average period.
Replace "NOTE 2" by NOTE 4".
3.4
acoustic working frequency
Replace, in the existing definition, the words "at the position corresponding to the spatial-
peak temporal-peak acoustic pressure" by "on the beam axis, beyond the break-point
depth, corresponding to depth of maximum pulse-intensity integral z ."
pii
Replace, in existing NOTE 2, the words "at the position of maximum pulse-pressure-squared
integral" by "at the depth for peak pulse-intensity integral".
– 4 – IEC 62359:2010/AMD1:2017
© IEC 2017
3.7
attenuated peak-rarefactional acoustic pressure
Replace, in the existing definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (2), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.8
attenuated pulse-intensity integral
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (3), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
Replace "NOTE" by "NOTE 1".
Add new NOTE 2:
NOTE 2 For measurement purposes of this standard, pii is equivalent to 1/(ρc) times the attenuated pulse-
α
pressure-squared integral at depth z, with ρc denoting the characteristic acoustic impedance of pure water.
3.9
attenuated spatial-average temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (4), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.10
attenuated spatial-peak temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (5), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.11
attenuated temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (6), the words "z is the distance from the external
is the distance from the external
transducer aperture to the point of interest" by "z
transducer aperture along the beam axis to the plane containing the point of interest".
3.13
beam-axis
Replace the term "beam-axis" by "beam axis".
© IEC 2017
3.17
bone thermal index
Delete, in the definition, "or neonatal cephalic (through the fontanelle)".
3.19
break-point depth
Add, after the existing definition, the words "acoustic working frequency and intensity
parameters (such as attenuated spatial-peak temporal-average intensity)"
Add, after "where D is the equivalent aperture diameter" the words "for non-scanning
eq
modes".
Replace the existing NOTE 2 by the following new note:
NOTE 2 For scanning modes, use the non-scanning mode D value calculation [Equation (8)]. Do this using
eq
the output beam area of one ultrasonic scan line; the central scan line, corresponding to the beam axis (i.e. the
line where pii MI, and f are measured).
,
awf
3.21
cranial-bone thermal index
Replace the existing definition by the following new definition:
thermal index for applications in which the ultrasound beam passes through bone near the
beam entrance into the body, such as paediatric and adult cranial or neonatal cephalic
applications
3.22
default setting
Replace, in the definition, "ultrasonic diagnostic equipment" by "medical diagnostic
ultrasonic equipment".
3.23
depth for mechanical index
Replace, in the definition, the words "to the plane of maximum attenuated pulse-intensity
integral (pii )" by "to the plane of maximum attenuated pulse-pressure-squared-integral
a
(ppsi )".
a
Add new NOTE 1:
NOTE 1 Because z may occur closer to the transducer than the break-point depth z , use of ppsi rather than
MI bp α
pii is technically more appropriate. If z is larger than z , then z and z are equal.
α ppsi,α bp ppsi,α pii,α
Replace "NOTE" by "NOTE 2".
3.24
depth for peak pulse-intensity integral
Replace the existing term, definition and note by the following new term, definition and notes:
3.24
depth for maximum pulse intensity integral
depth z on the beam axis and beyond the break-point depth z from the external
bp
transduscer aperture to the plane of maximum pulse-intensity integral (pii) as
approximated by the pulse-pressure-squared integral (ppsi)
NOTE 1 Depth for maximum pii is expressed in metres (m).
NOTE 2 Depth for maximum pii is termed "depth for peak pulse-intensity integral" in
IEC 60601-2-37:2007/AMD1:2015.
– 6 – IEC 62359:2010/AMD1:2017
© IEC 2017
NOTE 3 At this depth the acoustic working frequency is determined.
3.27
Discrete-perating mode
Replace the term "Discrete-perating mode" by "discrete-operating mode".
Replace, in the definition, "ultrasonic diagnostic equipment" by "medical diagnostic
ultrasonic equipment".
3.28
equivalent aperture diameter
Replace the existing definition and equation by the following new definition and equation:
diameter of a circle the area A of which is the –12 dB output beam area A for non-
ob
scanning modes and the –12 dB scanned aperture area A for scanning modes, given by
sa
D = A
(8)
eq
π
Replace the existing NOTE 1 by the following new note:
NOTE 1 Equation (8) is used in the calculation of the cranial-bone thermal index; for non-scanning modes with
A = A and for scanning modes with A = A .
ob sa
Add new NOTE 2:
NOTE 2 Equation (8) with A = A is also used in calculating the break-point depth.
ob
Replace "NOTE 2" by "NOTE 3".
3.33
medical diagnostic ultrasonic equipment
Replace "NOTE" by "NOTE 1".
Add new NOTE 2:
NOTE 2 IEC 60601-2-37:2007 uses the term "ultrasonic diagnostic equipment" instead of medical diagnostic
ultrasonic equipment.
3.34
non-scanning mode
Replace, in the definition, the words "ultrasonic diagnostic equipment" by "medical
diagnostic ultrasonic equipment".
3.37
output power
Replace, in the source, "IEC 61161:2006" by "IEC 61161:2013".
3.40
prudent-use statements
Replace the existing definition by the following new definition:
affirmations of the principle that only necessary clinical information should be acquired and
that high exposure levels and long exposure times should be avoided
© IEC 2017
3.44
pulse repetition period
Add new NOTE 1:
NOTE 1 In general, for non-scanning modes the pulse repetition period needs to be adjusted to represent a
‘per-second’ average taking into account interruptions-in, or non-constant, pulsing; e.g. such as may occur in
combined operating modes.
Replace "NOTE" by "NOTE 2".
3.49
scanning mode
Replace, in the definition, the words "an ultrasonic diagnostic equipment" by "a medical
diagnostic ultrasonic equipment".
3.54
spatial-peak temporal-average intensity
Replace the existing NOTE 1 by the following new note:
NOTE 1 For systems in combined-operating modes, the averaging time period needs to be sufficient to include
periods in which scanning or pulsing is interrupted.
3.56
thermal index
Replace, in the definition, the two occurrences of the words " attenuated acoustic power" by
"attenuated output power"
Add the following new definitions:
3.61
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
NOTE Instantaneous acoustic pressure is expressed in pascals (Pa).
[SOURCE: IEC 62127-1:2007, 3.33, modified – The reference to IEV 801-01-19 has been
removed in the definition]
3.62
attenuated instantaneous acoustic pressure
(z,t)
p
α
value of the instantaneous acoustic pressure at time t after attenuation on a plane
perpendicular to the beam axis at a specified distance z from the source, and given by
(−a z f 20 dB)
awf
p (z,t)= p(z,t)10 (26)
a
where
a is the acoustic attenuation coefficient;
z is the distance from the source to the point (plane) of interest;
f is the acoustic working frequency;
awf
p(z,t) is the instantaneous acoustic pressure
NOTE Attenuated instantaneous acoustic pressure is expressed in pascals (Pa).
– 8 – IEC 62359:2010/AMD1:2017
© IEC 2017
3.63
attenuated pulse-pressure-squared integral
ppsi (z)
α
time integral of the square of the attenuated instantaneous acoustic pressure, integrated
over the acoustic pulse waveform, on a plane perpendicular to the beam axis at a specified
distance z in an acoustic field
2 (−a z f 20 dB) (−a z f 10 dB)
awf awf
ppsi (z)= p (z,t)dt= [p(z,t)10 ] dt= ppsi(z)×10
a a (27)
∫ ∫
where
p(z,t) is the instantaneous acoustic pressure at depth z.
a is the acoustic attenuation coefficient;
z is the distance from the source to the point (plane) of interest;
f is the acoustic working frequency;
awf
ppsi is the pulse-pressure-squared integral
NOTE 1 Attenuated pulse-pressure-squared integral is expressed in pascal squared seconds (Pa s).
NOTE 2 See definition 3.43 for the non-attenuated version; with the addition here of the perpendicular plane at
depth z.
3.64
attenuated scan intensity integral
sii (z)
α
sum of the attenuated pulse intensity integrals in one scan (one frame of ultrasonic scan
lines) at depth z
–2
NOTE 1 Attenuated scan intensity integral is expressed in joules per square metre (Jm ).
NOTE 2 For measurement purposes of this standard, sii (z) is equivalent to 1/(ρc) times the sum of attenuated
α
pulse-pressure-squared integrals at depth z, for z ≥ z , with ρc denoting the characteristic acoustic impedance of
bp
pure water.
NOTE 3 See definition 3.79 for the non-attenuated version.
3.65
attenuated spatial-peak pulse-average intensity
I (z)
sppa,α
maximum value of the spatial-peak pulse-average intensity after attenuation, on a plane
perpendicular to the beam axis at a specified distance z from the source, and given by
I (z)= pii (z)
sppa,a a (28)
t (z)
d
where
t (z) is the pulse duration at the same depth z;
d
pii (z) is the attenuated pulse-intensity integral at depth z
α
–2
NOTE 1 Attenuated spatial-peak pulse-average intensity is expressed in watts per square metre (Wm ).
NOTE 2 For measurement purposes of this standard, pii (z) is equivalent to 1/(ρc) times the attenuated pulse-
α
pressure-squared integrals at depth z, ppsi (z), for z ≥ z , with ρc denoting the characteristic acoustic impedance
α bp
of pure water.
NOTE 3 See definition 3.81 for the non-attenuated version.
© IEC 2017
3.66
attenuated sum of pulse-pressure-squared integrals
s ppsi (z)
α
attenuated value of the sum of pulse-pressure-squared integrals in one scan (one frame of
ultrasonic scan lines) at depth z
NOTE 1 Attenuated sum of pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 The attenuated sum of pulse-pressure-squared integrals at depth z will be equal to the sum of
attenuated pulse-pressure-squared integrals if each ultrasonic scan line in the frame which is included in the
sum has the same acoustic working frequency.
NOTE 3 See F.3.1.4.2 for additional explanation.
NOTE 4 See definition 3.83 for the non-attenuated version.
3.67
depth for maximum I
sppa
z
sppa,max
depth z on the beam axis and beyond the break-point depth z of maximum spatial-peak
bp
pulse-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
sppa
NOTE 2 This depth is equivalent to the depth for maximum pii.
3.68
depth for maximum I
sppa,α
z
sppa,α,max
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
spatial-peak pulse-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
sppa,α
NOTE 2 This depth is equivalent to the depth for maximum pii .
α
3.69
depth for maximum I
spta
z
spta,max
depth z on the beam axis and beyond the break-point depth z of maximum spatial-peak
bp
temporal-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
spta
NOTE 2 For non-scanning modes, this depth is equivalent to the depth for maximum pii. For scanning modes,
it is equivalent to the depth for maximum sii.
3.70
depth for maximum I
spta,α
z
spta,α,max
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
spatial-peak temporal-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
spta,α
NOTE 2 For non-scanning modes, this depth is equivalent to the depth for maximum pii . For scanning modes,
α
it is equivalent to the depth for maximum sii .
α
3.71
depth for maximum pii
α
z
pii,α
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
pulse-intensity integral
– 10 – IEC 62359:2010/AMD1:2017
© IEC 2017
NOTE 1 Depth for maximum pii is expressed in metres (m).
α
NOTE 2 This depth is equivalent to the depth for maximum ppsi , z , when z occurs beyond the break-
α ppsi,α ppsi,α
point depth (see 3.73).
NOTE 3 Depth for maximum pii is termed "depth for peak attenuated pulse-intensity integral" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.72
depth for maximum ppsi
z
ppsi
depth z on the beam axis of maximum pulse-pressure-squared integral
NOTE 1 Depth for maximum ppsi is expressed in metres (m).
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum pii,
(see 3.24).
z
pii
3.73
depth for maximum ppsi
α
z
ppsi,α
depth z on the beam axis of maximum attenuated pulse-pressure-squared integral
NOTE 1 Depth for maximum ppsi is expressed in metres (m).
α
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum pii ,
α
z (i.e. depth for maximum attenuated pulse-intensity integral).
pii,α
NOTE 3 This depth is the depth for mechanical index, z (see 3.23).
MI
3.74
sii
depth for maximum
z
sii
depth z on the beam axis and beyond the break-point depth z of maximum scan-intensity
bp
integral
NOTE 1 Depth for maximum sii is expressed in metres (m).
NOTE 2 This depth is equivalent to the depth for maximum sppsi, z , when z occurs beyond the break-
sppsi sppsi
point depth (see 3.76).
NOTE 3 Depth for maximum sii is termed "depth for peak sum of pulse-intensity integrals" in
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.75
depth for maximum sii
α
z
sii,α
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
scan-intensity integral
NOTE 1 Depth for maximum sii is expressed in metres (m).
α
NOTE 2 This depth is equivalent to the depth for maximum sppsi , z , when z occurs beyond the
α sppsi,α sppsi,α
break-point depth (see 3.77).
NOTE 3 Depth for maximum sii is termed "depth for peak sum of attenuated pulse-intensity integrals" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.76
depth for maximum sppsi
z
sppsi
depth z on the beam axis of maximum sum of pulse-pressure-squared integrals
NOTE 1 Depth for maximum sppsi is expressed in metres (m).
© IEC 2017
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum sii, z
sii
(see 3.74).
NOTE 3 Depth for maximum sppsi is termed "depth for peak sum of pulse-intensity integrals" in
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.77
depth for maximum sppsi
α
z
sppsi,α
depth z on the beam axis of maximum sum of attenuated pulse-pressure-squared
integrals
NOTE 1 Depth for maximum sppsi is expressed in metres (m).
α
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum sii ,
α
z (see 3.75).
sii,α
NOTE 3 Depth for maximum sppsi is termed "depth for peak sum of attenuated pulse-intensity integrals" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.78
pulse-average intensity
I
pa
quotient of the pulse-intensity integral to the pulse duration at a particular point in an
acoustic field
NOTE 1 This definition applies to pulses and bursts.
–2
NOTE 2 Pulse-average intensity is expressed in watts per square metre (Wm ).
[IEC 62127-1:2007+IEC 62127-1:2007/AMD1:2013, 3.47]
3.79
scan intensity integral
sii
sum of the pulse intensity integrals in one scan (one frame of ultrasonic scan lines) at
depth z in the acoustic field
–2
NOTE 1 Scan intensity integral is expressed in joules per square metre (Jm ).
NOTE 2 For measurement purposes of this standard, sii is equivalent to 1/(ρc) times the sum of pulse-pressure-
squared integral at depth z where ρc is the characteristic acoustic impedance of pure water.
3.80
scan repetition rate
srr
inverse of the scan repetition period (see 3.50)
NOTE Scan repetition rate is expressed in hertz (Hz).
3.81
spatial-peak pulse-average intensity
I (z)
sppa
maximum value of the pulse-average intensity on a plane perpendicular to the beam axis at
a specified distance z from the source, and given by
I (z)= pii(z)
sppa (29)
t (z)
d
where
t (z) is the pulse duration at the same depth z;
d
pii(z) is the pulse-intensity integral at depth z
– 12 – IEC 62359:2010/AMD1:2017
© IEC 2017
–2
NOTE 1 Spatial-peak pulse-average intensity is expressed in watts per square metre (Wm ).
NOTE 2 For measurement purposes of this standard, pii(z) is equivalent to 1/(ρc) times the pulse-pressure-
squared integral at depth z, ppsi(z), for z ≥ z , with ρc denoting the characteristic acoustic impedance of pure
bp
water.
NOTE 3 See IEC 62127-1:2007, 3.60, which has been modified to specify the perpendicular plane at depth z.
Equation (29) and Note 2 have been added, in accordance with IEC 62127-1:2007, Equation (15).
3.82
sum of attenuated pulse-pressure-squared integrals
sppsi (z)
α
sum of the attenuated pulse-pressure-squared integrals in one scan (one frame of
ultrasonic scan lines) at depth z
NOTE 1 Sum of attenuated pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 Closely related to the attenuated scan intensity integral, see 3.64.
NOTE 3 The sum of attenuated pulse-pressure-squared integrals at depth z will be equal to the attenuated
sum of pulse-pressure-squared integrals at depth z if each ultrasonic scan line in the frame which is included
in the sum has the same acoustic working frequency.
3.83
sum of pulse-pressure-squared integrals
sppsi(z)
sum of pulse-pressure-squared integrals in one scan (one frame of ultrasonic scan lines)
at depth z
NOTE 1 Sum of pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 The sppsi at depth z may also be referred to as the scan pulse pressure squared integral and is
proportional to the scan intensity integral for z ≥ z .
bp
4 List of symbols
Replace the symbols "TIB " and "TIB " by "TIC " and "TIC ".
as,sc as,ns sc ns
Replace "depth for peak pulse-intensity integral" by "depth for maximum pii".
© IEC 2017
Add the following new symbols:
I spatial-peak pulse-average intensity
sppa
attenuated spatial-peak pulse-average intensity
I
sppa,α
temporal-average intensity
I
ta
attenuated pulse-pressure-squared integral
ppsi
α
scan intensity integral
sii
attenuated scan intensity integral
sii
α
sum of pulse-pressure-squared integrals
sppsi
attenuated sum of pulse-pressure-squared integrals
s ppsi
α
sum of attenuated pulse-pressure-squared integrals
sppsi
α
scan repetition rate
srr
z depth for maximum pii
pii,α α
z depth for maximum ppsi
ppsi
z depth for maximum ppsi
ppsi,α α
z depth for maximum sii
sii
z depth for maximum sii
sii,α α
z depth for maximum I
sppa,max sppa
z depth for maximum I
sppa,α,max sppa,α
z depth for maximum I
spta,max spta
z depth for maximum I ,
spta,α,max sptaα
z depth for maximum sppsi
sppsi
z depth for maximum sppsi
sppsi,α α
5.1 General
Replace, in the first and second paragraphs, the words "ultrasonic diagnostic equipment"
by "medical diagnostic ultrasonic equipment".
5.4.2.1 Determination of bone thermal index at surface for non-scanning modes,
TIC (= TIB )
ns as,ns
Delete, in the subclause's title, "(= TIB )".
as,ns
Replace the existing Equation (17) by the following new equation:
P / D
eq
TIC =
ns (17)
C
TIC
Replace, in the definition list below Equation (17), the words "is the equivalent aperture
diameter" by "is the equivalent aperture diameter; calculation for non-scanning modes as
described in 3.28 using the output beam area A ".
ob
Replace the existing note by the following new note:
NOTE TIC applies to the bone-at-surface case for non-scanning modes.
ns
– 14 – IEC 62359:2010/AMD1:2017
© IEC 2017
5.5.2.1 Determination of bone thermal index at surface for scanning modes,
TIC (= TIB )
sc as,sc
Delete, in the subclause's title, "(= TIB )".
as,sc
Add, at the end of the first sentence of the first paragraph, the words "A as described in
sa
3.28."
Replace the existing Equation (24) by the following new equation:
P / D
eq
TIC =
sc (24)
C
TIC
Replace, in the definition list below Equation (24), the words "is the equivalent aperture
diameter" by "is the equivalent aperture diameter; calculation for scanning modes as
described in 3.28 using the scanned aperture area A ".
sa
Replace the existing note by the following new note:
NOTE TIC applies to the bone-at-surface case for scanning modes.
sc
Table 1 – Summary of combination formulae for each of the THERMAL INDEX categories
Replace, in the equation in the first row, "TIC " by "TIC " and "TIC " by "TIC ".
as,ns ns as,sc sc
Table 2 – Summary of the acoustic quantities required for the determination of the
indices
Delete, in the last column of the top row, "(TIB )".
as
A.3.1 Rationale
Replace, in the second paragraph, the three occurrences of the words "ultrasonic diagnostic
equipment" by "medical diagnostic ultrasonic equipment".
A.4.1.3 Rationale for choosing a break-point depth (z )
bp
Replace, in the first sentence of the existing Note 1, the words "acoustic power" by "acoustic
output power".
A.4.1.5 Rationale for at surface TI in non-scanning mode and scanning mode
Replace the existing text of A.4.1.5 by the following new text:
Implementation of the soft tissue thermal index (TIS) assumes a homogenous tissue-path
model. One basic equation covers all cases for the at-surface case, scanning modes (such
as colour-flow mapping and B-mode) and non-scanning modes (such as Doppler and M-
mode).
In this document, the at-surface TIS-equations for all modes (scanning and non-scanning)
use P and the at-surface TIS is calculated for all aperture sizes. See A.4.1.4 for the
1x1
rationale for using the attenuated bounded-square output power in the numerator of the
thermal index equations.
There is an expectation that scanning mode and non-scanning mode TI values should
converge smoothly as the number of scan lines narrows to 1 (non-scanned), and as the depth
of interest moves from below the surface (z > 0) to the surface (z = 0).
© IEC 2017
For the at-surface TIS equation, is the bounded-square output power and
P (z) P
1x1,a 1x1
equation A results (see Table A.2).
The TIB (bone below-surface) and TIC (bone at surface) equations are fundamentally the
same. For TIC, the non-attenuated power is used, since it is an at-surface estimate. These
approximations are discussed in A.4.3 (see Table A.2).
If the dimensions of the active aperture are larger than 1 cm × 1 cm, then the thermal
perfusion length of one centimetre (1 cm) is assumed to be exceeded. In this case the
bounded-square output power is measured by a radiation force balance using an
intermediate absorbing mask with a one-square centimetre window (the mask is 1 cm × 1 cm
square), or by other masking means (e.g. electronic), or the bounded-square output power
may be measured via hydrophone planar scanning.
NOTE Temperature rise in tissue due to transducer surface self-heating has not been taken into account in the
determination of the thermal index [10] (see Annex C).
A.4.2.1 Derivation of break-point depth
Add, after "where A is the output beam area" in the second paragraph, the following new
ob
note:
NOTE 1 Equation (A.3) is a re-statement of Equation (8) (from 3.28), with a single pulse corresponding to a
non-scanning mode.
Table A.2 – Consolidated thermal index formulae
Delete, in the row labelled "C", the symbols "= TIB ".
as
A.4.3.4 Derivation notes for bone at-focus for non-scanning modes (TIB )
bs,ns
Replace, in the definition list below Equation (A.17), the words "I is spatial-average
sata
temporal-average intensity" by "I is the attenuated spatial-average temporal-average
,
sata α
intensity".
Replace, in the fourth paragraph, the words "Since output power…" by "Since attenuated
output power …".
)
A.4.3.6 Derivation notes for bone at-surface [TIC] for non-scanning modes (TIB
as,ns
and for scanning modes (TIB )
as,sc
" by "TIC " and "TIB " by "TIC ".
Replace, in the subclause's title, "TIB
as,ns ns as,sc sc
Replace the existing Note 2 by the following new note:
NOTE 2 For non-scanning modes D is calculated as described in A.4.2.1 and in 3.28 using the output beam
eq
area A , and for scanning modes D is calculated as described in 3.28 using the scanned aperture area A .
ob eq sa
B.1 General
Replace the last sentence of the fourth paragraph by "Steered beams are dealt with in the
same way".
Replace, in the sixth paragraph, "20 %" by "30 %".
Delete, in Note 2, the words "Edition 2".
– 16 – IEC 62359:2010/AMD1:2017
© IEC 2017
B.4.1 General
Replace the existing second paragraph by the following new paragraph:
The two techniques of defining the apertures in Clause B.4 have somewhat different sources
of error. Agreement of the compared results from these methods, or compared to results from
the method of Clause B.5, should give reasonable confidence that the aperture is defined
accurately. Use of these methods, absorbing mask (B.4.2) or absorbing target (B.4.3), to limit
detection to a 1 cm × 1 cm area at the front surface of the active scan aperture is
recommended when the method of Clause B.5 is not feasible (e.g. for testing mechanically
scanned sector probes, or third-party testing of all ultrasonic transducers).
B.4.2 1 cm × 1 cm aperture in a mask
Replace, in the last sentence of the note, the words "beam-width" by "beam width".
Figure B.4 – Suggested orientation of transducer and 1 cm-square RFB target
Replace, the axis labelling "Mask x or y axis" by "Target x or y axis".
B.5 Creating a 1 cm × 1 cm window using electronic control
Add, at the end of the clause's title, the words "or using calculations".
Replace, in last paragraph, the two occurrences of "mathematically" by "mathematical".
Delete, in the last paragraph, the last sentence.
B.6 Measurement of bounded-square output power
Replace, in the first paragraph, the words "of B.4.2 or B.4.3 to mask" by "of B.4.2 or B.4.3 or
Clause B.5 to eliminate".
Replace, in the second paragraph, the words "in either B.4.2 or B.4.3" by "in either B.4.2 or
Clause B.5, or the target used in B.4.3".
E.1 General
Add, after the last paragraph, the following new paragraph and note:
Annex F was added to Edition 2 of this standard to support the definition and determination of
maximum positions and values of I , I , I and I specified by IEC 60601-2-37.
spta spta,α sppa sppa,α
NOTE Similar to the below-surface TI values, these are also specified to be found on the beam axis beyond the
break-point depth z .
bp
E.2 Differences from IEC 62359 Edition 1
Add, after the third paragraph "Table E.1 summarizes some of the major changes", the
following new note:
NOTE The I (z ) and I (z ) values shown in Table E.1 are not the "maximum" attenuated spatial-
,
spta,α b,ns spta α s,ns
peak temporal-average intensity values described in Annex F, because they are at the depth for TIB and the
depth for TIS, respectively.
© IEC 2017
Add, at the end of the existing text in the first row, right column of Table E.1, the following
new sentence:
z is also applied to I , I , I and I determination described in Annex F.
, ,
bp spta spta α sppa sppa α
Add, after Annex E, the following new Annex F:
– 18 – IEC 62359:2010/AMD1:2017
© IEC 2017
Annex F
(informative)
Rationale and determination of maximum non-attenuated
and attenuated spatial-peak temporal-average intensity
and spatial-peak pulse-average intensity values
F.1 Rationale
This standard establishes parameters and methods related to thermal and non-thermal
exposure aspects of diagnostic ultrasonic fields sufficient to calculate mechanical index (MI)
and thermal index (TI) for display as specified in IEC 60601-2-37.
In the process of describing the determination of the thermal index and the mechanical
index, this standard defines and describes the key components for deriving maximum non-
attenuated and attenuated spatial-peak temporal-average and spatial-peak pulse-average
intensities at any depth z in the acoustic field. Meanwhile, the acoustic output reporting tables
specified in IEC 60601-2-37 require the provision of the spatial maximum values of these
parameters in the acoustic field at specific depths z; including providing spatial maximum
values over all depths z on the beam axis beyond the break-point depth, and "local" spatial
maximum values at other depths on the beam axis.
NOTE 1 Other interested parties also require provision of these parameters at ‘global’ spatial maximum positions,
and in some cases have established regulatory limits on their values.
NOTE 2 Recall from the definitions in Clause 3 that "spatial peak" in the terms "attenuated spatial-peak
temporal-average intensity" and "attenuated spatial-peak pulse-average intensity" is the peak value at a given
depth, z (i.e. not the peak value over all depths, z).
NOTE 3 The depths at which the MI and below-surface TIS and below-surface TIB are determined will not
generally be the same depths at which the maximum values of I , I , I or I occur.
spta spta,α sppa sppa,α
This standard refers to IEC 62127-1, IEC 62127-2 and IEC 62127-3 for definitions,
specifications of properties and calibration of measurement equipment and for hydrophone-
based measurement methods. IEC 62127-1 defines various acoustic parameters which can be
used to specify and characterize ultrasonic fields propagating in water using hydrophones.
IEC 61157 also defines various acoustic parameters which can be used to specify and
characterize ultrasonic fields propagating in water.
While these standards provide valuable information on the measurement of ultrasound fields,
they do not describe standardized determination of maximum non-attenuated or attenuated
spatial-peak temporal-average intensity, I and I nor non-attenuated or attenuated
,
spta spta α
spatial-peak pulse-average intensity I and I . Therefore, standardized means and
,
sppa sppa α
definitions for their determination are provided in Annex F.
In combination with IEC 62127 and IEC 61161, this standard describes a complete set of
methods for determining all acoustic output parameters for medical diagnostic ultrasonic
equipment used within the ultrasound community, including those parameters called for by
IEC 60601-2-37.
F.2 Overview
The goal of this Annex F is to describe standardized methods for determination of maximum
positions and values of non-attenuated and attenuated spatial-peak temporal-average
intensity I and I , and non-attenuated and attenuated spatial-peak pulse-average
,
spta spta α
intensity I and I , in the acoustic field of a medical diagnostic ultrasound device.
,
sppa sppa α
© IEC 2017
Other, non-IEC, measurement standards define the determination of I and I for
, ,
spta α sppa α
regulatory agency purposes. Reference [44] is used widely and is referenced in IEC 62127-1.
The methods listed in this Annex F are intended to be consistent with [44].
–1 –1
The standard attenuation coefficient value chosen is 0,3 dB cm MHz ; the same value is
introduced and used by this standard in the derivation of the below-surface thermal index
and the mechanical index.
Another key similarity to the below-surface thermal index and the mechanical index is to
remain on the beam axis when finding the position of spatial maximum values.
Similarly, this standard defines the break-point depth, and applies it in the determination of
the below-surface thermal indices TIS and TIB for non-scanning modes. This same break-
point depth is used for maximum I , I , I and I and is applied for both
, ,
spta sppa spta α sppa α
scanning modes and non-scanning modes.
As shown, for non-scanning modes one depth z is used for the depth of maximum
,
pii α
I and depth of maximum I , and one depth z is used for the depth of maximum
, ,
sptaα sppaα pii
I and depth of maximum I .
spta sppa
However, as shown, for scanning modes the depths of maximum I and I (and I
,
spta,α sppa α spta
and I ) can be different, and the depths of maximum I and I often are not at the
,
sppa spta spta α
same depth as they occur for non-scanning modes.
Describing the determination of the I and I for scanning modes is the most
,
spta α spta
complicated and large part of Annex F. F.3.3.2 and F.3.1.4.2 give the summarized
expressions while Clause F.4 gives more detailed information.
F.3 Test methods
F.3.1 Common parameters
F.3.1.1 Attenuation coefficient and frequency
The acoustic attenuation coefficient value α used for the determination of maximum I
,α
spta
–1 –1
and I is 0,3 dB cm MHz with linear frequency dependence.
,
sppa α
NOTE 1 This value is the same as is used in the determination of the MI and TI, and it matches the attenuation
coefficient used in [41] and [44].
Repeating Equation (A.6) in A.4.2.3:
The attenuated spatial-peak temporal-average intensity is denoted:
(-a z f /10dB)
awf
I (z)= I (z) 10
spta,α spta
where
I (z) is the spatial-peak temporal-average intensity at distance z,
spta
α is the acoustic attenuation coefficient,
is the acoustic-working frequency, and
f
awf
z is the distance from the external transducer aperture to the point of interest.
NOTE 2 In accordance with 3.4, NOTE 2, and 3.24, the acoustic-working frequency is determined at the depth
for peak pulse-intensity integral on the beam axis.
NOTE 3 See A.4.2.3, 5.1 and Clause D.2 for additional discussion.
– 20 – IEC 62359:2010/AMD1:2017
© IEC 2017
F.3.1.2 Use of the beam axis
Measurements for I , I , I and I in non-scanning modes should be made on
,
sppa sppa α spta spta,α
the beam axis.
NOTE While there can be side-lobes with higher intensity and pressure values, the same methodology and
justification as is employed for the below-surface thermal index and the mechanical index is used, for the sake of
measurement repeatability and ease.
F.3.1.3 Determination and use of the break-point depth
Measurements for I , I , , I and I , in scanning modes and non-scanning
sppa sppa α spta spta α
modes are made at or beyond (farther-than) the break-point depth z .
bp
Care is to be taken when determining the z so that the equivalent aperture diameter is
bp
correctly determined using only the –12 dB output beam area.
For scanning modes where ultrasonic scan lines that comprise a frame do not have the
same –12 dB aperture size, the aperture size corresponding to the central scan line of each
sppsi sum is to be used in the determination of the break-point depth.
For combined-operating modes where measurement of multiple modes and tran
...
IEC 62359 ®
Edition 2.0 2017-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Ultrasonics – Field characterization – Test methods for the determination of
thermal and mechanical indices related to medical diagnostic ultrasonic fields
Ultrasons – Caractérisation du champ – Méthodes d'essai pour la détermination
d'indices thermique et mécanique des champs d'ultrasons utilisés pour le
diagnostic médical
IEC 62359:2010-10/AMD1:2017-09(en-fr)
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 l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.
IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) 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 IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 21 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.
Recherche de publications IEC -
Glossaire IEC - std.iec.ch/glossary
webstore.iec.ch/advsearchform
67 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC et en français, extraites des articles Termes et Définitions des
en utilisant différents critères (numéro de référence, texte, publications IEC parues depuis 2002. Plus certaines entrées
comité d’études,…). Elle donne aussi des informations sur les antérieures extraites des publications des CE 37, 77, 86 et
projets et les publications remplacées ou retirées. CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just Si vous désirez nous donner des commentaires sur cette
Published détaille les nouvelles publications parues. publication ou si vous avez des questions contactez-nous:
Disponible en ligne et aussi une fois par mois par email. sales@iec.ch.
IEC 62359 ®
Edition 2.0 2017-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Ultrasonics – Field characterization – Test methods for the determination of
thermal and mechanical indices related to medical diagnostic ultrasonic fields
Ultrasons – Caractérisation du champ – Méthodes d'essai pour la détermination
d'indices thermique et mécanique des champs d'ultrasons utilisés pour le
diagnostic médical
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.50 ISBN 978-2-8322-5301-4
– 2 – IEC 62359:2010/AMD1:2017
© IEC 2017
FOREWORD
This amendment has been prepared by IEC technical committee 87: Ultrasonics.
This bilingual version (2018-01) corresponds to the monolingual English version, published in
2017-09.
The text of this amendment is based on the following documents:
FDIS Report on voting
87/661/FDIS 87/665/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The French version of this amendment has not been voted upon.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website 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.
_____________
Introduction to Amendment
The second edition of IEC 62359 was published in 2010. Since then,
IEC 60601-2-37:2007/AMD1:2015 has been published and calls for provision of attenuated
spatial peak temporal average intensity, I , and attenuated spatial peak pulse
spta,a
, at specific spatial maximum points in the ultrasonic field on the
average intensity, I
sppa,a
beam axis. No IEC standard describes the determination of these quantities at these specific
positions. IEC 62359 for determining the thermal indices currently uses similar values at other
positions, therefore, the determination of attenuated spatial peak temporal average
intensity, I , and attenuated spatial peak pulse average intensity, I , has been
spta,a sppa,a
added as an annex in this amendment.
Additionally, references to newly published collateral standards have been updated.
_____________
© IEC 2017
2 Normative references
Replace the first reference by the following:
IEC 60601-2-37:2007, Medical electrical equipment – Part 2-37: Particular requirements for
the basic safety and essential performance of ultrasonic medical diagnostic and monitoring
equipment
IEC 60601-2-37:2007/AMD1:2015
Replace the second reference by the following:
IEC 61157:2007, Standard means for the reporting of the acoustic output of medical
diagnostic ultrasonic equipment
IEC 61157:2007/AMD1:2013
Replace, in the third reference, "IEC 61161:2006" by "IEC 61161:2013".
Replace the fifth reference by the following:
IEC 62127-1:2007, Ultrasonics – Hydrophones – Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz
IEC 62127-1:2007/AMD1:2013
3 Terms and definitions
Replace the first existing paragraph by the following new paragraph:
For the purposes of this document, the terms and definitions given in IEC 60601-2-37,
IEC 62127-1, IEC 62127-2, IEC 62127-3, IEC 61157 and IEC 61161 apply. Several of these
are repeated below for convenience and others are listed because they have been modified
for application to this standard.
3.3
acoustic repetition period
Replace the existing definition by the following new definition:
time interval between corresponding points of consecutive cycles, pulses or scans, depending
on the current operating mode
Add the following new NOTES 2 and 3:
NOTE 2 For continuous wave modes, the acoustic repetition period is the time interval between corresponding
points of consecutive cycles
NOTE 3 For combined operating modes where transmit pulsing of the constituent modes may be interrupted,
the arp determination should take into account non-pulsing time to calculate an average period.
Replace "NOTE 2" by NOTE 4".
3.4
acoustic working frequency
Replace, in the existing definition, the words "at the position corresponding to the spatial-
peak temporal-peak acoustic pressure" by "on the beam axis, beyond the break-point
depth, corresponding to depth of maximum pulse-intensity integral z "
pii
Replace, in existing NOTE 2, the words "at the position of maximum pulse-pressure-squared
integral" by "at the depth for peak pulse-intensity integral".
– 4 – IEC 62359:2010/AMD1:2017
© IEC 2017
3.7
attenuated peak-rarefactional acoustic pressure
Replace, in the existing definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (2), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.8
attenuated pulse-intensity integral
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (3), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
Replace "NOTE" by "NOTE 1".
Add new NOTE 2:
NOTE 2 For measurement purposes of this standard, pii is equivalent to 1/(ρc) times the attenuated pulse-
α
pressure-squared integral at depth z, with ρc denoting the characteristic acoustic impedance of pure water.
3.9
attenuated spatial-average temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (4), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.10
attenuated spatial-peak temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (5), the words "z is the distance from the external
transducer aperture to the point of interest" by "z is the distance from the external
transducer aperture along the beam axis to the plane containing the point of interest".
3.11
attenuated temporal-average intensity
Replace, in the definition, the words "at a specified distance from" by "on a plane
perpendicular to the beam axis at a specified distance z from".
Replace, in the definition list after Equation (6), the words "z is the distance from the external
is the distance from the external
transducer aperture to the point of interest" by "z
transducer aperture along the beam axis to the plane containing the point of interest".
3.13
beam-axis
Replace the term "beam-axis" by "beam axis".
© IEC 2017
3.17
bone thermal index
Delete, in the definition, "or neonatal cephalic (through the fontanelle)".
3.19
break-point depth
Add, after the existing definition, the words "acoustic working frequency and intensity
parameters (such as attenuated spatial-peak temporal-average intensity)"
Add, after "where D is the equivalent aperture diameter" the words "for non-scanning
eq
modes".
Replace the existing NOTE 2 by the following new note:
NOTE 2 For scanning modes, use the non-scanning mode D value calculation [Equation (8)]. Do this using
eq
the output beam area of one ultrasonic scan line; the central scan line, corresponding to the beam axis (i.e. the
line where pii MI, and f are measured).
,
awf
3.21
cranial-bone thermal index
Replace the existing definition by the following new definition:
thermal index for applications in which the ultrasound beam passes through bone near the
beam entrance into the body, such as paediatric and adult cranial or neonatal cephalic
applications
3.22
default setting
Replace, in the definition, "ultrasonic diagnostic equipment" by "medical diagnostic
ultrasonic equipment".
3.23
depth for mechanical index
Replace, in the definition, the words "to the plane of maximum attenuated pulse-intensity
integral (pii )" by "to the plane of maximum attenuated pulse-pressure-squared-integral
a
(ppsi )".
a
Add new NOTE 1:
NOTE 1 Because z may occur closer to the transducer than the break-point depth z , use of ppsi rather than
MI bp α
pii is technically more appropriate. If z is larger than z , then z and z are equal.
α ppsi,α bp ppsi,α pii,α
Replace "NOTE" by "NOTE 2".
3.24
depth for peak pulse-intensity integral
Replace the existing term, definition and note by the following new term, definition and notes:
3.24
depth for maximum pulse intensity integral
depth z on the beam axis and beyond the break-point depth z from the external
bp
transduscer aperture to the plane of maximum pulse-intensity integral (pii) as
approximated by the pulse-pressure-squared integral (ppsi)
NOTE 1 Depth for maximum pii is expressed in metres (m).
NOTE 2 Depth for maximum pii is termed "depth for peak pulse-intensity integral" in
IEC 60601-2-37:2007/AMD1:2015.
– 6 – IEC 62359:2010/AMD1:2017
© IEC 2017
NOTE 3 At this depth the acoustic working frequency is determined.
3.27
Discrete-perating mode
Replace the term "Discrete-perating mode" by "discrete-operating mode".
Replace, in the definition, "ultrasonic diagnostic equipment" by "medical diagnostic
ultrasonic equipment".
3.28
equivalent aperture diameter
Replace the existing definition and equation by the following new definition and equation:
diameter of a circle the area A of which is the –12 dB output beam area A for non-
ob
scanning modes and the –12 dB scanned aperture area A for scanning modes, given by
sa
D = A
(8)
eq
π
Replace the existing NOTE 1 by the following new note:
NOTE 1 Equation (8) is used in the calculation of the cranial-bone thermal index; for non-scanning modes with
A = A and for scanning modes with A = A .
ob sa
Add new NOTE 2:
NOTE 2 Equation (8) with A = A is also used in calculating the break-point depth.
ob
Replace "NOTE 2" by "NOTE 3".
3.33
medical diagnostic ultrasonic equipment
Replace "NOTE" by "NOTE 1".
Add new NOTE 2:
NOTE 2 IEC 60601-2-37:2007 uses the term "ultrasonic diagnostic equipment" instead of medical diagnostic
ultrasonic equipment.
3.34
non-scanning mode
Replace, in the definition, the words "ultrasonic diagnostic equipment" by "medical
diagnostic ultrasonic equipment".
3.37
output power
Replace, in the source, "IEC 61161:2006" by "IEC 61161:2013".
3.40
prudent-use statements
Replace the existing definition by the following new definition:
affirmations of the principle that only necessary clinical information should be acquired and
that high exposure levels and long exposure times should be avoided
© IEC 2017
3.44
pulse repetition period
Add new NOTE 1:
NOTE 1 In general, for non-scanning modes the pulse repetition period needs to be adjusted to represent a
‘per-second’ average taking into account interruptions-in, or non-constant, pulsing; e.g. such as may occur in
combined operating modes.
Replace "NOTE" by "NOTE 2".
3.49
scanning mode
Replace, in the definition, the words "an ultrasonic diagnostic equipment" by "a medical
diagnostic ultrasonic equipment".
3.54
spatial-peak temporal-average intensity
Replace the existing NOTE 1 by the following new note:
NOTE 1 For systems in combined-operating modes, the averaging time period needs to be sufficient to include
periods in which scanning or pulsing is interrupted.
3.56
thermal index
Replace, in the definition, the two occurrences of the words " attenuated acoustic power" by
"attenuated output power"
Add the following new definitions:
3.61
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
NOTE Instantaneous acoustic pressure is expressed in pascals (Pa).
[SOURCE: IEC 62127-1:2007, 3.33, modified – The reference to IEV 801-01-19 has been
removed in the definition]
3.62
attenuated instantaneous acoustic pressure
(z,t)
p
α
value of the instantaneous acoustic pressure at time t after attenuation on a plane
perpendicular to the beam axis at a specified distance z from the source, and given by
(−a z f 20 dB)
awf
( ) ( )
p z,t = p z,t 10 (26)
a
where
a is the acoustic attenuation coefficient;
z is the distance from the source to the point (plane) of interest;
f is the acoustic working frequency;
awf
p(z,t) is the instantaneous acoustic pressure
NOTE Attenuated instantaneous acoustic pressure is expressed in pascals (Pa).
– 8 – IEC 62359:2010/AMD1:2017
© IEC 2017
3.63
attenuated pulse-pressure-squared integral
ppsi (z)
α
time integral of the square of the attenuated instantaneous acoustic pressure, integrated
over the acoustic pulse waveform, on a plane perpendicular to the beam axis at a specified
distance z in an acoustic field
2 (−a z f 20 dB) (−a z f 10 dB)
awf awf
ppsi (z)= p (z,t)dt= [p(z,t)10 ] dt= ppsi(z)×10
a a (27)
∫ ∫
where
p(z,t) is the instantaneous acoustic pressure at depth z.
a is the acoustic attenuation coefficient;
z is the distance from the source to the point (plane) of interest;
f is the acoustic working frequency;
awf
ppsi is the pulse-pressure-squared integral
NOTE 1 Attenuated pulse-pressure-squared integral is expressed in pascal squared seconds (Pa s).
NOTE 2 See definition 3.43 for the non-attenuated version; with the addition here of the perpendicular plane at
depth z.
3.64
attenuated scan intensity integral
sii (z)
α
sum of the attenuated pulse intensity integrals in one scan (one frame of ultrasonic scan
lines) at depth z
–2
NOTE 1 Attenuated scan intensity integral is expressed in joules per square metre (Jm ).
NOTE 2 For measurement purposes of this standard, sii (z) is equivalent to 1/(ρc) times the sum of attenuated
α
pulse-pressure-squared integrals at depth z, for z ≥ z , with ρc denoting the characteristic acoustic impedance of
bp
pure water.
NOTE 3 See definition 3.79 for the non-attenuated version.
3.65
attenuated spatial-peak pulse-average intensity
I (z)
sppa,α
maximum value of the spatial-peak pulse-average intensity after attenuation, on a plane
perpendicular to the beam axis at a specified distance z from the source, and given by
I (z)= pii (z)
sppa,a a (28)
t (z)
d
where
t (z) is the pulse duration at the same depth z;
d
pii (z) is the attenuated pulse-intensity integral at depth z.
α
–2
NOTE 1 Attenuated spatial-peak pulse-average intensity is expressed in watts per square metre (Wm ).
NOTE 2 For measurement purposes of this standard, pii (z) is equivalent to 1/(ρc) times the attenuated pulse-
α
pressure-squared integrals at depth z, ppsi (z), for z ≥ z , with ρc denoting the characteristic acoustic impedance
α bp
of pure water.
NOTE 3 See definition 3.81 for the non-attenuated version.
© IEC 2017
3.66
attenuated sum of pulse-pressure-squared integrals
s ppsi (z)
α
attenuated value of the sum of pulse-pressure-squared integrals in one scan (one frame of
ultrasonic scan lines) at depth z
NOTE 1 Attenuated sum of pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 The attenuated sum of pulse-pressure-squared integrals at depth z will be equal to the sum of
attenuated pulse-pressure-squared integrals if each ultrasonic scan line in the frame which is included in the
sum has the same acoustic working frequency.
NOTE 3 See F.3.1.4.2 for additional explanation.
NOTE 4 See definition 3.83 for the non-attenuated version.
3.67
depth for maximum I
sppa
z
sppa,max
depth z on the beam axis and beyond the break-point depth z of maximum spatial-peak
bp
pulse-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
sppa
NOTE 2 This depth is equivalent to the depth for maximum pii.
3.68
depth for maximum I
sppa,α
z
sppa,α,max
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
spatial-peak pulse-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
sppa,α
NOTE 2 This depth is equivalent to the depth for maximum pii .
α
3.69
depth for maximum I
spta
z
spta,max
depth z on the beam axis and beyond the break-point depth z of maximum spatial-peak
bp
temporal-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
spta
NOTE 2 For non-scanning modes, this depth is equivalent to the depth for maximum pii. For scanning modes,
it is equivalent to the depth for maximum sii.
3.70
depth for maximum I
spta,α
z
spta,α,max
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
spatial-peak temporal-average intensity
NOTE 1 Depth for maximum I is expressed in metres (m).
spta,α
NOTE 2 For non-scanning modes, this depth is equivalent to the depth for maximum pii . For scanning modes,
α
it is equivalent to the depth for maximum sii .
α
3.71
depth for maximum pii
α
z
pii,α
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
pulse-intensity integral
– 10 – IEC 62359:2010/AMD1:2017
© IEC 2017
NOTE 1 Depth for maximum pii is expressed in metres (m).
α
NOTE 2 This depth is equivalent to the depth for maximum ppsi , z , when z occurs beyond the break-
α ppsi,α ppsi,α
point depth (see 3.73).
NOTE 3 Depth for maximum pii is termed "depth for peak attenuated pulse-intensity integral" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.72
depth for maximum ppsi
z
ppsi
depth z on the beam axis of maximum pulse-pressure-squared integral
NOTE 1 Depth for maximum ppsi is expressed in metres (m).
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum pii,
(see 3.24).
z
pii
3.73
depth for maximum ppsi
α
z
ppsi,α
depth z on the beam axis of maximum attenuated pulse-pressure-squared integral
NOTE 1 Depth for maximum ppsi is expressed in metres (m).
α
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum pii ,
α
z (i.e. depth for maximum attenuated pulse-intensity integral).
pii,α
NOTE 3 This depth is the depth for mechanical index, z (see 3.23).
MI
3.74
sii
depth for maximum
z
sii
depth z on the beam axis and beyond the break-point depth z of maximum scan-intensity
bp
integral
NOTE 1 Depth for maximum sii is expressed in metres (m).
NOTE 2 This depth is equivalent to the depth for maximum sppsi, z , when z occurs beyond the break-
sppsi sppsi
point depth (see 3.76).
NOTE 3 Depth for maximum sii is termed "depth for peak sum of pulse-intensity integrals" in
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.75
depth for maximum sii
α
z
sii,α
depth z on the beam axis and beyond the break-point depth z of maximum attenuated
bp
scan-intensity integral
NOTE 1 Depth for maximum sii is expressed in metres (m).
α
NOTE 2 This depth is equivalent to the depth for maximum sppsi , z , when z occurs beyond the
α sppsi,α sppsi,α
break-point depth (see 3.77).
NOTE 3 Depth for maximum sii is termed "depth for peak sum of attenuated pulse-intensity integrals" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.76
depth for maximum sppsi
z
sppsi
depth z on the beam axis of maximum sum of pulse-pressure-squared integrals
NOTE 1 Depth for maximum sppsi is expressed in metres (m).
© IEC 2017
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum sii, z
sii
(see 3.74).
NOTE 3 Depth for maximum sppsi is termed "depth for peak sum of pulse-intensity integrals" in
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.77
depth for maximum sppsi
α
z
sppsi,α
depth z on the beam axis of maximum sum of attenuated pulse-pressure-squared
integrals
NOTE 1 Depth for maximum sppsi is expressed in metres (m).
α
NOTE 2 When it occurs beyond the break-point depth, this depth is equivalent to the depth for maximum sii ,
α
z (see 3.75).
sii,α
NOTE 3 Depth for maximum sppsi is termed "depth for peak sum of attenuated pulse-intensity integrals" in
α
IEC 60601-2-37:2007+IEC 60601-2-37:2007/AMD1:2015.
3.78
pulse-average intensity
I
pa
quotient of the pulse-intensity integral to the pulse duration at a particular point in an
acoustic field
NOTE 1 This definition applies to pulses and bursts.
–2
NOTE 2 Pulse-average intensity is expressed in watts per square metre (Wm ).
[IEC 62127-1:2007+IEC 62127-1:2007/AMD1:2013, 3.47]
3.79
scan intensity integral
sii
sum of the pulse intensity integrals in one scan (one frame of ultrasonic scan lines) at
depth z in the acoustic field
–2
NOTE 1 Scan intensity integral is expressed in joules per square metre (Jm ).
NOTE 2 For measurement purposes of this standard, sii is equivalent to 1/(ρc) times the sum of pulse-pressure-
squared integral at depth z where ρc is the characteristic acoustic impedance of pure water.
3.80
scan repetition rate
srr
inverse of the scan repetition period (see 3.50)
NOTE Scan repetition rate is expressed in hertz (Hz).
3.81
spatial-peak pulse-average intensity
I (z)
sppa
maximum value of the pulse-average intensity on a plane perpendicular to the beam axis at
a specified distance z from the source, and given by
I (z)= pii(z)
sppa (29)
t (z)
d
where
t (z) is the pulse duration at the same depth z;
d
pii(z) is the pulse-intensity integral at depth z.
– 12 – IEC 62359:2010/AMD1:2017
© IEC 2017
–2
NOTE 1 Spatial-peak pulse-average intensity is expressed in watts per square metre (Wm ).
NOTE 2 For measurement purposes of this standard, pii(z) is equivalent to 1/(ρc) times the pulse-pressure-
squared integral at depth z, ppsi(z), for z ≥ z , with ρc denoting the characteristic acoustic impedance of pure
bp
water.
NOTE 3 See IEC 62127-1:2007, 3.60, which has been modified to specify the perpendicular plane at depth z.
Equation (29) and Note 2 have been added, in accordance with IEC 62127-1:2007, Equation (15).
3.82
sum of attenuated pulse-pressure-squared integrals
sppsi (z)
α
sum of the attenuated pulse-pressure-squared integrals in one scan (one frame of
ultrasonic scan lines) at depth z
NOTE 1 Sum of attenuated pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 Closely related to the attenuated scan intensity integral, see 3.64.
NOTE 3 The sum of attenuated pulse-pressure-squared integrals at depth z will be equal to the attenuated
sum of pulse-pressure-squared integrals at depth z if each ultrasonic scan line in the frame which is included
in the sum has the same acoustic working frequency.
3.83
sum of pulse-pressure-squared integrals
sppsi(z)
sum of pulse-pressure-squared integrals in one scan (one frame of ultrasonic scan lines)
at depth z
NOTE 1 Sum of pulse-pressure-squared integrals is expressed in pascal squared seconds (Pa s).
NOTE 2 The sppsi at depth z may also be referred to as the scan pulse pressure squared integral and is
proportional to the scan intensity integral for z ≥ z .
bp
4 List of symbols
Replace the symbols "TIB " and "TIB " by "TIC " and "TIC ".
as,sc as,ns sc ns
Replace "depth for peak pulse-intensity integral" by "depth for maximum pii".
© IEC 2017
Add the following new symbols:
I spatial-peak pulse-average intensity
sppa
attenuated spatial-peak pulse-average intensity
I
sppa,α
temporal-average intensity
I
ta
attenuated pulse-pressure-squared integral
ppsi
α
scan intensity integral
sii
attenuated scan intensity integral
sii
α
sum of pulse-pressure-squared integrals
sppsi
attenuated sum of pulse-pressure-squared integrals
s ppsi
α
sum of attenuated pulse-pressure-squared integrals
sppsi
α
scan repetition rate
srr
z depth for maximum pii
pii,α α
z depth for maximum ppsi
ppsi
z depth for maximum ppsi
ppsi,α α
z depth for maximum sii
sii
z depth for maximum sii
sii,α α
z depth for maximum I
sppa,max sppa
z depth for maximum I
sppa,α,max sppa,α
z depth for maximum I
spta,max spta
z depth for maximum I ,
spta,α,max sptaα
z depth for maximum sppsi
sppsi
z depth for maximum sppsi
sppsi,α α
5.1 General
Replace, in the first and second paragraphs, the words "ultrasonic diagnostic equipment"
by "medical diagnostic ultrasonic equipment".
5.4.2.1 Determination of bone thermal index at surface for non-scanning modes,
TIC (= TIB )
ns as,ns
Delete, in the subclause's title, "(= TIB )".
as,ns
Replace the existing Equation (17) by the following new equation:
P / D
eq
TIC =
ns (17)
C
TIC
Replace, in the definition list below Equation (17), the words "is the equivalent aperture
diameter" by "is the equivalent aperture diameter; calculation for non-scanning modes as
described in 3.28 using the output beam area A ".
ob
Replace the existing note by the following new note:
NOTE TIC applies to the bone-at-surface case for non-scanning modes.
ns
– 14 – IEC 62359:2010/AMD1:2017
© IEC 2017
5.5.2.1 Determination of bone thermal index at surface for scanning modes,
TIC (= TIB )
sc as,sc
Delete, in the subclause's title, "(= TIB )".
as,sc
Add, at the end of the first sentence of the first paragraph, the words "A as described in
sa
3.28."
Replace the existing Equation (24) by the following new equation:
P / D
eq
TIC =
sc
(24)
C
TIC
Replace, in the definition list below Equation (24), the words "is the equivalent aperture
diameter" by "is the equivalent aperture diameter; calculation for scanning modes as
described in 3.28 using the scanned aperture area A ".
sa
Replace the existing note by the following new note:
NOTE TIC applies to the bone-at-surface case for scanning modes.
sc
Table 1 – Summary of combination formulae for each of the THERMAL INDEX categories
Replace, in the equation in the first row, "TIC " by "TIC " and "TIC " by "TIC ".
as,ns ns as,sc sc
Table 2 – Summary of the acoustic quantities required for the determination of the
indices
Delete, in the last column of the top row, "(TIB )".
as
A.3.1 Rationale
Replace, in the second paragraph, the three occurrences of the words "ultrasonic diagnostic
equipment" by "medical diagnostic ultrasonic equipment".
A.4.1.3 Rationale for choosing a break-point depth (z )
bp
Replace, in the first sentence of the existing Note 1, the words "acoustic power" by "acoustic
output power".
A.4.1.5 Rationale for at surface TI in non-scanning mode and scanning mode
Replace the existing text of A.4.1.5 by the following new text:
Implementation of the soft tissue thermal index (TIS) assumes a homogenous tissue-path
model. One basic equation covers all cases for the at-surface case, scanning modes (such
as colour-flow mapping and B-mode) and non-scanning modes (such as Doppler and M-
mode).
In this document, the at-surface TIS-equations for all modes (scanning and non-scanning)
use P and the at-surface TIS is calculated for all aperture sizes. See A.4.1.4 for the
1x1
rationale for using the attenuated bounded-square output power in the numerator of the
thermal index equations.
There is an expectation that scanning mode and non-scanning mode TI values should
converge smoothly as the number of scan lines narrows to 1 (non-scanned), and as the depth
of interest moves from below the surface (z > 0) to the surface (z = 0).
© IEC 2017
For the at-surface TIS equation, is the bounded-square output power and
P (z) P
1x1,a 1x1
equation A results (see Table A.2).
The TIB (bone below-surface) and TIC (bone at surface) equations are fundamentally the
same. For TIC, the non-attenuated power is used, since it is an at-surface estimate. These
approximations are discussed in A.4.3 (see Table A.2).
If the dimensions of the active aperture are larger than 1 cm × 1 cm, then the thermal
perfusion length of one centimetre (1 cm) is assumed to be exceeded. In this case the
bounded-square output power is measured by a radiation force balance using an
intermediate absorbing mask with a one-square centimetre window (the mask is 1 cm × 1 cm
square), or by other masking means (e.g. electronic), or the bounded-square output power
may be measured via hydrophone planar scanning.
NOTE Temperature rise in tissue due to transducer surface self-heating has not been taken into account in the
determination of the thermal index [10] (see Annex C).
A.4.2.1 Derivation of break-point depth
Add, after "where A is the output beam area" in the second paragraph, the following new
ob
note:
NOTE 1 Equation (A.3) is a re-statement of Equation (8) (from 3.28), with a single pulse corresponding to a
non-scanning mode.
Table A.2 – Consolidated thermal index formulae
Delete, in the row labelled "C", the symbols "= TIB ".
as
A.4.3.4 Derivation notes for bone at-focus for non-scanning modes (TIB )
bs,ns
Replace, in the definition list below Equation (A.17), the words "I is spatial-average
sata
temporal-average intensity" by "I is the attenuated spatial-average temporal-average
,
sata α
intensity".
Replace, in the fourth paragraph, the words "Since output power…" by "Since attenuated
output power …".
A.4.3.6 Derivation notes for bone at-surface [TIC] for non-scanning modes (TIB )
as,ns
and for scanning modes (TIB )
as,sc
Replace, in the subclause's title, "TIB " by "TIC " and "TIB " by "TIC ".
as,ns ns as,sc sc
Replace the existing Note 2 by the following new note:
NOTE 2 For non-scanning modes D is calculated as described in A.4.2.1 and in 3.28 using the output beam
eq
area A , and for scanning modes D is calculated as described in 3.28 using the scanned aperture area A .
ob eq sa
B.1 General
Replace the last sentence of the fourth paragraph by "Steered beams are dealt with in the
same way".
Replace, in the sixth paragraph, "20 %" by "30 %".
Delete, in Note 2, the words "Edition 2".
– 16 – IEC 62359:2010/AMD1:2017
© IEC 2017
B.4.1 General
Replace the existing second paragraph by the following new paragraph:
The two techniques of defining the apertures in Clause B.4 have somewhat different sources
of error. Agreement of the compared results from these methods, or compared to results from
the method of Clause B.5, should give reasonable confidence that the aperture is defined
accurately. Use of these methods, absorbing mask (B.4.2) or absorbing target (B.4.3), to limit
detection to a 1 cm × 1 cm area at the front surface of the active scan aperture is
recommended when the method of Clause B.5 is not feasible (e.g. for testing mechanically
scanned sector probes, or third-party testing of all ultrasonic transducers).
B.4.2 1 cm × 1 cm aperture in a mask
Replace, in the last sentence of the note, the words "beam-width" by "beam width".
Figure B.4 – Suggested orientation of transducer and 1 cm-square RFB target
Replace, the axis labelling "Mask x or y axis" by "Target x or y axis".
B.5 Creating a 1 cm × 1 cm window using electronic control
Add, at the end of the clause's title, the words "or using calculations".
Replace, in last paragraph, the two occurrences of "mathematically" by "mathematical".
Delete, in the last paragraph, the last sentence.
B.6 Measurement of bounded-square output power
Replace, in the first paragraph, the words "of B.4.2 or B.4.3 to mask" by "of B.4.2 or B.4.3 or
Clause B.5 to eliminate".
Replace, in the second paragraph, the words "in either B.4.2 or B.4.3" by "in either B.4.2 or
Clause B.5, or the target used in B.4.3".
E.1 General
Add, after the last paragraph, the following new paragraph and note:
Annex F was added to Edition 2 of this standard to support the definition and determination of
maximum positions and values of I , I , I and I specified by IEC 60601-2-37.
spta spta,α sppa sppa,α
NOTE Similar to the below-surface TI values, these are also specified to be found on the beam axis beyond the
break-point depth z .
bp
E.2 Differences from IEC 62359 Edition 1
Add, after the third paragraph "Table E.1 summarizes some of the major changes", the
following new note:
NOTE The I (z ) and I (z ) values shown in Table E.1 are not the "maximum" attenuated spatial-
,
spta,α b,ns spta α s,ns
peak temporal-average intensity values described in Annex F, because they are at the depth for TIB and the
depth for TIS, respectively.
© IEC 2017
Add, at the end of the existing text in the first row, right column of Table E.1, the following
new sentence:
z is also applied to I , I , I and I determination described in Annex F.
, ,
bp spta spta α sppa sppa α
Add, after Annex E, the following new Annex F:
– 18 – IEC 62359:2010/AMD1:2017
© IEC 2017
Annex F
(informative)
Rationale and determination of maximum non-attenuated
and attenuated spatial-peak temporal-average intensity
and spatial-peak pulse-average intensity values
F.1 Rationale
This standard establishes parameters and methods related to thermal and non-thermal
exposure aspects of diagnostic ultrasonic fields sufficient to calculate mechanical index (MI)
and thermal index (TI) for display as specified in IEC 60601-2-37.
In the process of describing the determination of the thermal index and the mechanical
index, this standard defines and describes the key components for deriving maximum non-
attenuated and attenuated spatial-peak temporal-average and spatial-peak pulse-average
intensities at any depth z in the acoustic field. Meanwhile, the acoustic output reporting tables
specified in IEC 60601-2-37 require the provision of the spatial maximum values of these
parameters in the acoustic field at specific depths z; including providing spatial maximum
values over all depths z on the beam axis beyond the break-point depth, and "local" spatial
maximum values at other depths on the beam axis.
NOTE 1 Other interested parties also require provision of these parameters at ‘global’ spatial maximum positions,
and in some cases have established regulatory limits on their values.
NOTE 2 Recall from the definitions in Clause 3 that "spatial peak" in the terms "attenuated spatial-peak
temporal-average intensity" and "attenuated spatial-peak pulse-average intensity" is the peak value at a given
depth, z (i.e. not the peak value over all depths, z).
NOTE 3 The depths at which the MI and below-surface TIS and below-surface TIB are determined will not
generally be the same depths at which the maximum values of I , I , I or I occur.
spta spta,α sppa sppa,α
This standard refers to IEC 62127-1, IEC 62127-2 and IEC 62127-3 for definitions,
specifications of properties and calibration of measurement equipment and for hydrophone-
based measurement methods. IEC 62127-1 defines various acoustic parameters which can be
used to specify and characterize ultrasonic fields propagating in water using hydrophones.
IEC 61157 also defines various acoustic parameters which can be used to specify and
characterize ultrasonic fields propagating in water.
While these standards provide valuable information on the measurement of ultrasound fields,
they do not describe standardized determination of maximum non-attenuated or attenuated
spatial-peak temporal-average intensity, I and I nor non-attenuated or attenuated
,
spta spta α
spatial-peak pulse-average intensity I and I . Therefore, standardized means and
,
sppa sppa α
definitions for their determination are provided in Annex F.
In combination with IEC 62127 and IEC 61161, this standard describes a complete set of
methods for determining all acoustic output parameters for medical diagnostic ultrasonic
equipment used within the ultrasound community, including those parameters called for by
IEC 60601-2-37.
F.2 Overview
The goal of this Annex F is to describe standardized methods for determination of maximum
positions and values of non-attenuated and attenuated spatial-peak temporal-average
intensity I and I , and non-attenuated and attenuated spatial-peak pulse-average
,
spta spta α
intensity I and I , in the acoustic field of a medical diagnostic ultrasound device.
,
sppa sppa α
© IEC 2017
Other, non-IEC, measurement standards define the determination of I and I for
, ,
spta α sppa α
regulatory agency purposes. Reference [44] is used widely and is referenced in IEC 62127-1.
The methods listed in this Annex F are intended to be consistent with [44].
–1 –1
The standard attenuation coefficient value chosen is 0,3 dB cm MHz ; the same value is
introduced and used by this standard in the derivation of the below-surface thermal index
and the mechanical index.
Another key similarity to the below-surface thermal index and the mechanical index i
...
Frequently Asked Questions
IEC 62359:2010/AMD1:2017 is a standard published by the International Electrotechnical Commission (IEC). Its full title is "Amendment 1 - Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields". This standard covers: Amendment 1 - Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields
Amendment 1 - Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields
IEC 62359:2010/AMD1:2017 is classified under the following ICS (International Classification for Standards) categories: 17.140.50 - Electroacoustics. The ICS classification helps identify the subject area and facilitates finding related standards.
IEC 62359:2010/AMD1:2017 has the following relationships with other standards: It is inter standard links to IEC 62359:2010. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase IEC 62359:2010/AMD1:2017 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of IEC standards.
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...