SIST EN 61391-1:2008/A1:2018

Ultrasonics - Pulse-echo scanners - Part 1: Techniques for calibrating spatial measurement systems and measurement of point-spread function response (IEC 61391-1:2006/A1:2017)

Ultraschall - Impuls-Echo-Scanner - Teil 1: Verfahren für die Kalibrierung von räumlichen Messsystemen und Messung der Charakteristik der Punktverwaschungsfunktion des Systems (IEC 61391-1:2006/A1:2017)

Spécifications pour types particuliers de fils de bobinage - Partie 0-7: Exigences générales - Fil de section circulaire, isolé en continu, en cuivre émaillé, sans défaut électrique (IEC 61391-1:2006/A1:2017)

Ultrazvok - Impulzno-odmevni skenerji - 1. del: Tehnike za kalibriranje prostorskih merilnih sistemov in meritve karakteristike funkcije razpršitve točk - Dopolnilo A1 (IEC 61391-1:2006/A1:2017)

General Information

• Status: Published
• Publication Date: 11-Dec-2017
• ICS: 11.040.55 - Diagnostic equipment
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 06-Dec-2017
• Due Date: 10-Feb-2018
• Completion Date: 12-Dec-2017
• Ref Project: EN 61391-1:2006/A1:2017 - Ultrasonics - Pulse-echo scanners - Part 1: Techniques for calibrating spatial measurement systems and measurement of system point-spread function response

Relations

• Amends: SIST EN 61391-1:2008 - Ultrasonics - Pulse-echo scanners -- Part 1: Techniques for calibrating spatial measurement systems and measurement of system point-spread function response
• Effective Date: 03-May-2016

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61391-1:2008/A1:2018
01-februar-2018
8OWUD]YRN,PSXO]QRRGPHYQLVNHQHUMLGHO7HKQLNH]DNDOLEULUDQMHSURVWRUVNLK
PHULOQLKVLVWHPRYLQPHULWYHNDUDNWHULVWLNHIXQNFLMHUD]SUãLWYHWRþN'RSROQLOR$
,(&$
Ultrasonics - Pulse-echo scanners - Part 1: Techniques for calibrating spatial
measurement systems and measurement of point-spread function response (IEC 61391-
1:2006/A1:2017)
Ultraschall - Impuls-Echo-Scanner - Teil 1: Verfahren für die Kalibrierung von räumlichen
Messsystemen und Messung der Charakteristik der Punktverwaschungsfunktion des
Systems (IEC 61391-1:2006/A1:2017)
Spécifications pour types particuliers de fils de bobinage - Partie 0-7: Exigences
générales - Fil de section circulaire, isolé en continu, en cuivre émaillé, sans défaut
électrique (IEC 61391-1:2006/A1:2017)
Ta slovenski standard je istoveten z: EN 61391-1:2006/A1:2017
ICS:
11.040.55 'LDJQRVWLþQDRSUHPD Diagnostic equipment
SIST EN 61391-1:2008/A1:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61391-1:2008/A1:2018

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SIST EN 61391-1:2008/A1:2018


EUROPEAN STANDARD EN 61391-1:2006/A1

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2017
ICS 17.140.50

English Version
Ultrasonics - Pulse-echo scanners -
Part 1: Techniques for calibrating spatial measurement systems
and measurement of system point-spread function response
(IEC 61391-1:2006/A1:2017)
Ultrasons - Scanners à impulsion et écho -  Ultraschall - Impuls-Echo-Scanner -
Partie 1: Techniques pour l'étalonnage des systèmes de Teil 1: Verfahren für die Kalibrierung von räumlichen
mesure spatiaux et des mesures de la réponse de la Messsystemen und Messung der Charakteristik der
fonction de dispersion ponctuelle du système Punktverwaschungsfunktion des Systems
(IEC 61391-1:2006/A1:2017) (IEC 61391-1:2006/A1:2017)
This amendment A1 modifies the European Standard EN 61391-1:2006; it was approved by CENELEC on 2017-08-14. CENELEC
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment 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 CEN-CENELEC
Management Centre or to any CENELEC member.
This amendment 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 CEN-CENELEC Management Centre has the same status as
the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 61391-1:2006/A1:2017 E

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SIST EN 61391-1:2008/A1:2018
EN 61391-1:2006/A1:2017
European foreword
The text of document 87/650/FDIS, future IEC 61391-1:2006/A1, prepared by IEC/TC 87 "Ultrasonics"
was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN 61391-1:2006/A1:2017.

The following dates are fixed:
(dop) 2018-06-01
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2020-12-01
standards conflicting with the
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 61391-1:2006/A1:2017 was approved by CENELEC as a
European Standard without any modification.
In the Bibliography of EN 61391-1:2006, the following notes have to be added for the standards
indicated:

IEC 62563-1:2009 NOTE Harmonized as EN 62563-1:2010 (not modified).
IEC 61391-2:2010 NOTE Harmonized as EN 61391-2:2010 (not modified).
2

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SIST EN 61391-1:2008/A1:2018
EN 61391-1:2006/A1:2017
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.

NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.

Publication Year Title EN/HD Year
In Annex ZA of EN 61391-1:2006 replace IEC 61102:1991 by the following:
IEC 62127-1 2007 Ultrasonics - Hydrophones - EN 62127-1 2007
Part 1: Measurement and characterization
of medical ultrasonic fields up to 40 MHz
Add to Annex ZA of EN 61391-1:2006 the following new references:
IEC 60050-801 1994 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 801: Acoustics and
electroacoustics
IEC 60050-802 2011 International Electrotechnical Vocabulary - - -
Part 802: Ultrasonics

3

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SIST EN 61391-1:2008/A1:2018

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SIST EN 61391-1:2008/A1:2018




IEC 61391-1

®


Edition 1.0 2017-07




INTERNATIONAL



STANDARD








colour

inside





AMENDMENT 1





Ultrasonics – Pulse-echo scanners –

Part 1: Techniques for calibrating spatial measurement systems and

measurement of system point-spread function response


























INTERNATIONAL

ELECTROTECHNICAL

COMMISSION






ICS 17.140.50 ISBN 978-2-8322-4289-6



  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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SIST EN 61391-1:2008/A1:2018
– 2 – IEC 61391-1:2006/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
87/650/FDIS 87/653/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.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.

____________

2 Normative references
Replace:
IEC 61102:1991, Measurement and characterisation of ultrasonic fields using hydrophones in
the frequency range 0,5 MHz to 15 MHz
with:
IEC 62127-1:2007, Ultrasonics – Hydrophones – Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz
Insert the following new normative references in proper numerical sequence:
IEC 60050-801:1994, International Electrotechnical Vocabulary – Chapter 801: Acoustics and
electroacoustics

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SIST EN 61391-1:2008/A1:2018
IEC 61391-1:2006/AMD1:2017 – 3 –
© IEC 2017
IEC 60050-802:2011, International Electrotechnical Vocabulary – Part 802: Ultrasonics
3 Terms and definitions
Replace the first two paragraphs with the following new paragraph:
For the purposes of this document, the terms and definitions given in IEC 60050-801:1994,
IEC 60050-802:2011, IEC 62127-1:2007 and the following apply. See also related
International Standards, Technical Specifications and Technical Reports for definitions and
explanations [1] [2] [3] [4] [34] [35] [36] [37] [38] [39].
3.25
point-spread function
PSF
Add the following new sentence at the end of the NOTE:
The problem is solved by PSF mapping – see Annex D.
Add the following new terms and definitions to Clause 3, starting with 3.45.
3.45
accuracy
closeness of agreement between a test result and the accepted reference value
[SOURCE: ISO 5725-1:1994, 3.6]
3.46
axial resolution in a PSF-map
twice the Half-Width-at-Half-Maximum (HWHM) of a function’s trace created from a set of
increasing pixel values, commencing near zero and terminating at the first maximum value
(centre of the PSF) and representing the leading edge of the echo signal from a point reflector
located on the main beam axis
Note 1 to entry: The axial resolution in a PSF map differs from the axial resolution specified by 3.5. It is used
for the PSF-mapping only to simplify the data acquisition.
Note 2 to entry: A detailed explanation of the axial resolution in the PSF-map measuring method is in D.6.1.4.
Note 3 to entry: The axial resolution mainly depends on the ultrasound frequency used, not on sonograph
construction.
Note 4 to entry: Axial resolution in a PSF-map is expressed in metres.
3.47
brightness
luminance as perceived by the human visual system
[SOURCE: IEC 62563-1:2009, 3.1.2]
3.48
contrast
C
ratio of the difference of the luminance of two image areas, L − L , divided by the average of
1 2
the two luminance values:
C = 2 (L − L )/(L + L )
1 2 1 2
[SOURCE: IEC 62563-1:2009, 3.1.6]

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SIST EN 61391-1:2008/A1:2018
– 4 – IEC 61391-1:2006/AMD1:2017
© IEC 2017
3.49
dynamic imaging
real-time imaging
imaging with a frame rate that is high enough to observe moving structures in apparently
continuous motion
3.50
elevational resolution in a PSF-map
difference of point-reflector displacements in passing through the scanning plane in an
elevational direction, which result in decreases of MER of −6 dB compared to the MER-value
in the beam centre
Note 1 to entry: The elevational resolution in a PSF-map differs from the elevational resolution specified by
3.12. It is used for the PSF-mapping only to simplify the data acquisition.
Note 2 to entry: Detailed explanation of the method is in D.6.1.3.
Note 3 to entry: Elevational resolution in a PSF-map is expressed in metres.
3.51
overall gain
G
o
basic level of gain that is uniform for the whole scan area but modified by TGC relative to the
depth of the scan
3.52
profile line
set of pixel values ordered along an abscissa according to the sequence during their
acquisition
3.53
lateral resolution in a PSF-map
Full-Width at Half-Maximum (FWHM) of the PSF, measured in a lateral direction
Note 1 to entry: The lateral resolution in a PSF-map differs from the lateral resolution specified by 3.17. It is
used for the PSF-mapping only to simplify the data acquisition.
Note 2 to entry: Detailed explanation of the method is in D.6.1.2.
Note 3 to entry: Lateral resolution in a PSF-map is expressed in metres.
3.54
measuring grid
matrix of points specified by Cartesian coordinates x and z defined in a plane parallel to the
i j
scanning plane
Note 1 to entry: Each point determines the position (x ,z ) in which individual measurement of PSF is performed.
i j
Note 2 to entry: The step ∆x is defined as an increment x – x in the lateral direction. The step ∆z is defined as
i+1 i
an increment z – z in the axial direction.
j+1 j
3.55
performance evaluation
tests performed to assess specific absolute performance of the object tested
Note 1 to entry: Typical times for ultrasound-system performance evaluation are at pre-purchase evaluation,
new- and repaired-system acceptance testing, at time of performance difficulties, and at end-of-useful-life
evaluations.
[SOURCE: IEC TS 62736:2016, 3.5]

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SIST EN 61391-1:2008/A1:2018
IEC 61391-1:2006/AMD1:2017 – 5 –
© IEC 2017
3.56
precision
closeness of agreement between independent test results obtained under stipulated
conditions
[SOURCE: ISO 5725-1:1994, 3.12]
3.57
scanning window
area on the surface of the test tank dedicated for transducer application to obtain a suitable
sonogram of the target
Note 1 to entry: It is important that the scanning window be covered by flexible foil made of material with similar
acoustic properties to the working liquid to avoid ultrasound field reflections and absorption.
Note 2 to entry: The foil flexibility should assure proper acoustical contact of any type of curved transducer.
Note 3 to entry: It is important that the foil covering the scanning-window be tough enough to prevent its damage
during coupling the measured transducer to the scanning window, to prevent resultant leakage of working liquid
from the measuring tank.
Note 4 to entry: The scanning window has the identical function as the test object scanning surface in the
case of tissue-mimicking test objects (see 3.34).
3.58
side-lobe signal
echo signal generated by ultrasound signal transmitted/received in a direction different from
the central axis of the transducer
3.59
test tank
tank designed to be suitable for providing specified kind of tests, which is filled with a
working liquid and equipped with scanning window(s)
Replace the title of Clause 4 with the following new title:
4 Symbols and abbreviated terms
Add the following symbols and abbreviated terms to Clause 4:
D diameter of the reflector sphere
A greatest a evaluated for whole measured volume
r,max r,max
a MER pixel value evaluated from ROI
r,max
a (x,y,z) MER pixel value evaluated from ROI scanned for reflector in position (x,y,z)
r,max
C contrast
G overall gain
o
I(x,y,z) ROI specified in a digital picture of scan stored with reflector in position (x,y,z)

m
M number of quantization levels defined by M = 2 where m is number of pixel
bits
p pixel size in lateral (azimuthal) direction

x
p pixel size in axial direction

z
R axial resolution in a PSF-map
A,PSF
R elevational resolution in a PSF-map
E,PSF
R lateral resolution in a PSF-map
L,PSF
W value of FWHM (full width at half of maximum)

F,HM

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SIST EN 61391-1:2008/A1:2018
– 6 – IEC 61391-1:2006/AMD1:2017
© IEC 2017
W value of HWHM (half width at half of maximum)

H,HM
W normalized W according to Formula (D.3) in D.6.1.2
F,HM,n F,HM
W normalized W according to Formula (D.3) in D.6.1.2

H,HM,n H,HM
λ ultrasound wavelength in the working liquid, calculated from the nominal
frequency of the transducer used
ATGC automatic time-gain compensation
FWHM full width at half of maximum
HFHM half width at half of maximum
LUT look-up table
MER maximum echo received
PSF point-spread function
RF radio frequency
ROI region of interest
TGC time-gain compensation
US ultrasound

6.1 Test methods
Replace:
c) a tank containing degassed working liquid.
with:
c) a tank equipped with target holder to position the target at accurately specified
positions and containing degassed working liquid.
Replace:
The specifications of these devices are given in the annexes.
with:
The specifications of these devices are given in Annexes A, B, C and D.
8.2 Test methods
Replace:
b) a tank containing degassed liquid;
with:
b) a tank containing degassed liquid and, optionally, movable targets as described in
Clause C.4 and D.5.4.2;
8.4.1 General
Add, at the end of 8.4.1, the following new sentence:
“A setting should be specified by a test instruction for each test, if it differs from the general
recommendations. See D.5.2.”

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SIST EN 61391-1:2008/A1:2018
IEC 61391-1:2006/AMD1:2017 – 7 –
© IEC 2017
8.5.1 General
Add, to the end of the fifth paragraph starting “To overcome this limitation …”, the following
new text:
“The complications generated by interference and multiple reflections inside the spherical
target may be solved by time-domain analysis of the received echo when a larger and/or
highly reflective sphere is used. See D.5.4.2.”
8.5.4 Scan slice thickness (elevational PSF and LSF) or elevational resolution
Add, at the end of 8.5.4, the following new text:
“The most accurate and flexible method to derive the complex set of parameters based on the
PSF mapping analysis is described in Annex D.”
C.4 Movable single filament or wire in water (Figures C.3, C.4)
Add, at the end of Clause C.4, the following new single-sentence paragraph:
“The use of a movable spherical target for assessing quality parameters derived by PSF-
mapping analysis is described in Annex D. ”
Insert after Annex C the following new Annex D

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SIST EN 61391-1:2008/A1:2018
– 8 – IEC 61391-1:2006/AMD1:2017
© IEC 2017
Annex D
(informative)

Quality parameters derived by PSF-mapping analysis
D.1 General
A quality assessment system is vitally needed to provide an accurate and well-defined set of
production-quality parameters for new or refurbished scanners or transducers in acceptance
tests before their introduction to medical practice. It is important that products delivered by
third-party sales groups, system-refurbishers and/or transducer manufacturers be carefully
tested to be able to declare technical parameters of their products to be comparable to those
of the new, originally manufactured systems. The methods used for quality assessment in
medical applications are not certain and accurate enough to be used for such kinds of
technical performance evaluation. PSF-mapping analysis gives reliable parameters suitable
for this kind of tests. These parameters do not directly indicate the effectivity of a clinical
diagnostic process, even though a close correlation between the assessed technical quality
and success in the diagnostic process may be expected [40].
The ultrasound scanner used as a diagnostic system is composed of the system-control/user-
interface unit and the ultrasonic-transducer assembly. Either unit can contain the transmitter-
and the receiver- electronic systems and some of the beam-former electronics. The
ultrasonic transducer converts electrical signals to ultrasound field and vice versa. Electrical
and acoustic parameters of the transducer determine quality of the scanning ultrasound
beam. The electronic system controls the transmitted and received ultrasound signal,
conversion from mechanical to electrical signals, and the signal processing and conversion to
video-signal inputted to the imaging unit. The imaging unit transfers the information to the
human preceptors. The PSF-distribution analysis evaluates qualitative parameters of the
whole ultrasound-scanner system, excluding the display unit. The analysed signal is affected
by the quality of the whole imaging cycle, and the transmitting and receiving parts of the
scanner. The analysed system function is affected by a complex set of control functions.
Therefore, it is important that the combination of the control settings of the scanner be exactly
specified and recorded as a part of the measurement.
D.2 Method
Annex D describes a method for precise and reliable measurement of several qualitative
parameters of whole ultrasound scanning systems including both the transmitting and
receiving parts of the systems, excluding the parameters of scanner display. The method is
based on PSF-distribution analysis over a scanning area. In the case of PSF-mapping, the
measured parameters are derived by analysis of sonograms generated by scanning a
spherical target moving over a defined scanning volume on a specified trajectory.
The PSF-mapping system evaluates a set of parameters acquired over a user-defined area in
one scanning plane of a B-mode grey-scale sonogram, scanned in a tank filled by degassed
working liquid and using one measuring procedure. The whole target sonogram is not
evaluated in the PSF-mapping analysis. The test signal is obtained by reflection of a
transmitted ultrasound wave from a point-reflector surface and working-liquid boundary only.
The point reflector used is a highly reflective sphere of diameter D [41].
The method is suitable for all kinds of echo(reflections)-evaluating sonographs using different
types of beam-forming and plane-wave compounding of ultrasound signal in the frequency
range 0,5 MHz to 50 MHz. The upper frequency limit is determined by a ball target of
minimum diameter available to assure reflection effectivity and fulfil the condition λ ≤ D ≤ 4λ,
where λ is the ultrasound wavelength in the working liquid [42]. Further limiting factors are a
minimum size of step and precise mechanical construction of the positioning system to assure
measurement reliability and adequate scan size.

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SIST EN 61391-1:2008/A1:2018
IEC 61391-1:2006/AMD1:2017 – 9 –
© IEC 2017
The method is relevant for all the types of transducers used with these scanners, including
• mechanical probes including annular arrays,
• electronic phased arrays,
• linear arrays,
• curved arrays,
• two-dimensional arrays, and
• 3D-volume scanning probes based on a combination of the above types.
The PSF-measuring system is not a tissue-mimicking object. It is dedicated to performing
accurate, stable and reliable measurements under conditions appropriate to achieving these
measurements of parameters, some of which may be obtained by use of sophisticated
electronic measurements of the scanner’s electronic system and some by PSF-mapping
analysis only [43].
The following data are acquired and are analysed using the method:
a) the ROI digital image stored for the scanned-plane axis in each point of the measuring
grid;
b) the echo-signal amplitude distribution over the measured area;
c) the distribution of the parameter W which is Full-Width-at-Half-Maximum (FWHM) of
F,HM
the point-spread function (PSF) in the azimuthal direction over the measured area;
d) the distribution of the parameter W Half-Width-at-Half-Maximum (HWHM) of the point-
H,HM
spread function (PSF) in the axial direction over the measured area;
e) the peak echo-amplitude received a (x,y,z) at each y step of the target position in the
r,max k
elevation (transversal) direction;
f) the (x,y,z) coordinates set for stored position of the point reflector generating a (x,y,z)
r,max
from MER in each point of the measuring grid (position in centre of ultrasound beam).
Data analysis derives the following ultrasound scanner parameters and functions:
1) focal areas in both the azimuth and the elevation directions;
2) visualization of the distribution of ultrasound scanning lines;
3) manufacturer’s preloaded TGC function;
4) width (elevation) of the scanning plane over the depth of scan;
5) side-lobes signal-level distribution in the scan plane;
6) amplification uniformity in the azimuth direction;
7) scan geometry linearity and accuracy.
D.3 Environmental conditions
The most temperature-sensitive parameters are those assessing geometry of the sonogram
and related calculations. The temperature-dependent deviations may be compensated
mathematically from known working-liquid temperature and thermal coefficient of speed of
sound.
Water condensation on electronic system components should be avoided.
D.4 General requirements of the method
Ultrasound waves produce a PSF-signal that is neither singular nor isotropic. Furthermore,
the ultrasound PSF can be asymmetrical, having different axial and lateral dimensions, and it

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SIST EN 61391-1:2008/A1:2018
– 10 – IEC 61391-1:2006/AMD1:2017
© IEC 2017
also varies with distance from the transducer in both the axial and the azimuthal directions.
Thus, it is important that many different measurements of the PSF at different positions and
depths be performed to obtain representative values of the system’s imaging performance at
specific positions along the beam axis. It is also important that the measured area be covered
by a grid of the measuring points, the density of which is determined by the expected
parameters and the accuracy of the measurement [44].
NOTE For example, determination of a focal point’s position may need an axial step ∆z = 5 mm; visualization of
scanning lines demands an azimuthal step ∆x = 0,1 mm for a conventional linear transducer of nominal frequency
3 MHz.
The following features are necessary to apply the PSF-analyser to the sonograph:
a) The sonograph to be tested:
– video-signal output of live, dynamic scanning available in analog (composite) or digital
(DVI-D, HDMI) form;
– operating instructions or skilled operator to assure proper manipulation and operating
adjustment;
– record of proper evidence and registration of the measurement process, including
identification of operator and all apparatus used, record of parameters preset in the
measured system, record of environmental conditions, including a time stamp.
b) The basic configuration of the measurement tank:
– The scanning window(s) is(are) localized in the side wall(s) of the tank.
– The spherical-target positioning system is fixed on top of the tank, controlling
movement of the target fixed in a holder.
– Filling the tank with degassed working liquid is recommended to prevent bubble
generation in the working fluid. Bubbles may mimic the point reflector and/or produce
spurious reflections from the point reflector after having accumulated on it, due to
surface tension.
– Temperature should be kept in the specified range to eliminate measurement
uncertainties generated by dependence of the speed of ultrasound propagation upon
temperature.
c) The transducer:
– The transducer is acoustically coupled to the scanning window by standard coupling
ultrasound gel. The scanning window is covered by tough, flexible foil made of
material with similar acoustic properties to the working liquid to avoid ultrasound field
reflections and absorption.
– The scanning plane is oriented in the horizontal direction and the transducer is fixed to
keep the whole slice thickness below the water surface. It is important that the lateral
orientation of the transducer be specified.
d) The positioning system:
– A computer-controlled micromanipulator is used to move the target or transducer to a
determined position. It is important that mechanical construction, accuracy and
stability of the positioning system correspond with ultrasound frequency. The shorter
the wavelength, the more accurate and robust the system should be to avoid
systematic measuring errors.
e) The control and analysing system:
– The software controls the video-signal acquisition, determines ROI, selects and saves
the ROI frames to be used for analysis and finally maintains the complex analysis of
the stored information.
– The basic parameters used for PSF-analysis are the W (Full Width at Half
F,HM
Maximum, i.e. at −6 dB down from a ) and the pixel level of noise at an area
r,max
without reflections.

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SIST EN 61391-1:2008/A1:2018
IEC 61391-1:2006/AMD1:2017 – 11 –
© IEC 2017
– The W depends upon the intensity of the received signal. Therefore, it is important
F,HM
that the receiving gain and output power be properly adjusted to utilize the whole
dynamic range of the analyser.
D.5 Measuring conditions
D.5.1 General
In Figure D.1 a principal schematic of the PSF-analyser is introduced. The PSF-analyser
consists of the data-acquisition components (test-tank and point-reflector parts of the
schema), a linear transducer, a personal computer (PC) with video-signal input, running
acquisition and analysis software. The sonograph being measured is shown with a linear
transducer but the results analysis is displayed for a sector-scan transducer to illustrate
transducer-type independency of the system.
Tested system
Sono-
graph
Video
PC
ROI
PSF
IEC

Figure D.1 – Principal schematic of the PSF-analyser function
D.5.2 Sonograph
D.5.2.1 General
Sonographs are equipped with a large set of different control functions to ensure optimal
handling of received ultrasound signals to create the best image. These control functions
affect remarkably the measure
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