BS-EN-61157-2007.pdf

BRITISH STANDARD BS EN 61157:2007 Standard means for the reporting of the medical diagnostic ultrasonic equipment The European Standard EN 61157:2007 has the status of a British Standard ICS 11.040.55; 17.140.50 ? acoustic output of Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS EN 61157:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 © BSI 2007 ISBN 978 0 580 57378 1 National foreword This British Standard is the UK implementation of EN 61157:2007. It is identical to IEC 61157:2007. It supersedes BS EN 61157:1995 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee EPL/87, Ultrasonics. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD EN 61157 NORME EUROPÉENNE EUROPÄISCHE NORM November 2007 CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels © 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61157:2007 E ICS 11.040.50; 11.140.50 Supersedes EN 61157:1994 English version Standard means for the reporting of the acoustic output of medical diagnostic ultrasonic equipment (IEC 61157:2007) Moyens normalisés pour la déclaration des émissions acoustiques des appareils de diagnostic médical à ultrasons (CEI 61157:2007) Normverfahren für die Angabe der akustischen Ausgangsgrößen von medizinischen Ultraschalldiagnostikgeräten (IEC 61157:2007) This European Standard was approved by CENELEC on 2007-10-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI Foreword The text of document 87/356/CDV, future edition 2 of IEC 61157, prepared by IEC TC 87, Ultrasonics, was submitted to the IEC-CENELEC parallel Unique Acceptance Procedure and was approved by CENELEC as EN 61157 on 2007-10-01. This European Standard supersedes EN 61157:1994. The changes with respect to EN 61157:1994 are listed below: maintenance on this standard and the referenced standards EN 61161 and EN 62127-1; a clause on compliance has been added. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2008-07-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-10-01 NOTE The following print types are used: Requirements: in roman type Test specifications: in italic type Notes: in small roman type Words in bold in the text are defined in Clause 3. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61157:2007 was approved by CENELEC as a European Standard without any modification. _ 2 EN 61157:2007 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI CONTENTS 1 2 3 4 4.1 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 5 5.1 5.2 5.3 6 7 Figure C.1 Schematic diagram showing the relationship between the various defined surfaces and distances for a mechanical sector scanner with water stand-off Figure C.2 Schematic diagram showing the relationship between the various defined parameters and distances for a mechanical sector scanner during the Figure C.3 Schematic diagram showing various defined parameters associated with the distribution of the scan lines in a linear array scanner and mechanically- Figure C.4 Schematic diagram illustrating the peak-rarefactional acoustic pressure Table A.1 An example of reporting of the acoustic output of a 3,5 MHz scan-head for 3 EN 61157:2007 INTRODUCTION.4 Scope.5 Normative references .5 Terms, definitions and symbols 5 Requirements.15 General.15 Requirements for the reporting of acoustic output information .16 Technical data sheets information format 16 Detailed operating mode data sheets information format .17 Background information.18 Diagnostic fields in the absence of scan-frame synchronization.19 Dataset for low acoustic output equipment.19 Compliance statement20 General.20 Maximum probable values.20 Sampling.20 Test methods .21 Presentation of results21 Annex A (normative) Presentation of acoustic output information.22 Annex B (informative) Reporting requirements for extensive systems 24 Annex C (informative) Rationale 25 Index of defined terms 29 Bibliography31 distance when applied to a patient26 measurement of acoustic output.26 scanned sector scanner27 during an acoustic pulse.28 Table 1 List of symbols 14 a phased-array sector scanner in accordance with this standard23 Annex ZA (normative) Normative references to international publications with their corresponding European publications.32 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI INTRODUCTION This International Standard specifies a standard means and format for the reporting of the acoustic output of medical diagnostic ultrasonic equipment. The numerical values for reporting purposes represent the average values for the maximum output conditions for a given discrete- or combined-operating mode and are derived from measurements made in water. Intensity parameters are specified in this standard, but these are regarded as derived quantities that are meaningful only under certain assumptions related to the ultrasonic field being measured. 4 EN 61157:2007 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI STANDARD MEANS FOR THE REPORTING OF THE ACOUSTIC OUTPUT OF MEDICAL DIAGNOSTIC ULTRASONIC EQUIPMENT 1 Scope This International Standard is applicable to medical diagnostic ultrasonic equipment. It provides a set of traceable acoustic parameters describing the acoustic fields. It defines a standard means and format for the reporting of the acoustic output information. It also describes a reduced dataset recommended for equipment generating low acoustic output levels. NOTE The information tabulated in this standard format can be used for a) exposure planning for biological effects studies; b) exposure data for prospective epidemiological studies conducted using exposure conditions similar to those reported in this standard. In the absence of actual exposure data for retrospective epidemiological studies, the information tabulated in this standard format might also be used with cautionary comment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-801:1994 International Electrotechnical Vocabulary Chapter 801: Acoustics and electroacoustics IEC 61161, Ultrasonics Power measurement Radiation force balances and performance requirements IEC 62127-1, Ultrasonics Hydrophones Part 1: Measurement and characterization of medical ultrasonic fields up to 40 MHz ISO 16269-6:2005, Statistical interpretation of data Part 6: Determination of statistical tolerance intervals ISO/IEC Guide 98:1995, Guide to the expression of uncertainty in measurement (GUM) 3 Terms, definitions and symbols For the purposes of this document, the terms and definitions given in IEC 62127-1, IEC 61161, the Index of defined terms at the end of this standard and the following definitions apply. Figures C.1 to C.4 illustrate some of the defined parameters given below. 3.1 acoustic output freeze condition of a system for which the acoustic output is disabled when there is no active updating of ultrasonic echo information 5 EN 61157:2007 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 3.2 acoustic pulse waveform temporal waveform of the instantaneous acoustic pressure at a specified position in an acoustic field and displayed over a period sufficiently long to include all significant acoustic information in a single pulse or tone-burst, or in one or more cycles in a continuous wave NOTE 1 Temporal waveform is a representation (e.g. oscilloscope presentation or equation) of the instantaneous acoustic pressure. NOTE 2 Definition adapted from IEC 60469-1. 3.3 acoustic repetition period arp pulse repetition period for non-automatic scanning systems and the scan repetition period for automatic scanning systems, equal to the time interval between corresponding points of consecutive cycles for continuous wave systems NOTE 1 The acoustic repetition period is expressed in seconds (s). IEC 62127-1, definition 3.2 3.4 acoustic frequency acoustic-working frequency frequency of an acoustic signal based on the observation of the output of a hydrophone placed in an acoustic field at the position corresponding to the spatial-peak temporal-peak acoustic pressure NOTE 1 The signal is analysed using either the zero-crossing acoustic-working frequency technique or a spectrum analysis method. Acoustic-working frequencies are defined in 3.4.1 and 3.4.2. NOTE 2 In a number of cases, the present definition is not very helpful or convenient, especially for broadband transducers. In that case, a full description of the frequency spectrum should be given in order to enable any frequency-dependent correction to the signal. NOTE 3 Acoustic frequency is expressed in hertz (Hz). 3.4.1 zero-crossing acoustic-working frequency fawf this is determined according to the procedure specified in IEC/TR 60854 NOTE This frequency is intended for continuous wave systems only. 3.4.2 arithmetic-mean acoustic-working frequency fawf arithmetic mean of the most widely separated frequencies f1 and f2, within the range of three times f1, at which the magnitude of the acoustic pressure spectrum is 3 dB below the peak magnitude NOTE 1 This frequency is intended for pulse-wave systems only. NOTE 2 It is assumed that f1 f2. 3.5 bandwidth BW difference in the most widely separated frequencies f1 and f2 at which the magnitude of the acoustic pressure spectrum becomes 3 dB below the peak magnitude, at a specified point in the acoustic field NOTE Bandwidth is expressed in hertz (Hz). 6 EN 61157:2007 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 20 02:34:44 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 3.6 beam area Ab area in a specified plane perpendicular to the beam axis consisting of all points at which the pulse-pressure-squared integral is greater than a specified fraction of the maximum value of the pulse-pressure-squared integral in that plane NOTE 1 If the position of the plane is not specified, it is the plane passing through the point corresponding to the spatial-peak temporal-peak acoustic pressure in the whole acoustic field. NOTE 2 In a number of cases, the term pulse-pressure-squared integral is replaced everywhere in the above definition by any linearly related quantity, for example: a) in the case of a continuous wave signal the term pulse-pressure-squared integral is replaced by mean square acoustic pressure as defined in IEC 61689; b) in cases where signal synchronisation with the scanframe is not available the term pulse-pressure-squared integral may be replaced by temporal average intensity. NOTE 3 Some specified levels are 0,25 and 0,01 for the 6 dB and 20 dB beam areas, respectively. NOTE 4 Beam area is expressed in metres squared (m2). 3.7 beam axis straight line that passes through the beam centrepoints of two planes perpendicular to the line which connects the point of maximal pulse-pressure-squared integral with the centre of the external transducer aperture NOTE 1 The location of the first plane is the location of the plane containing the maximum pulse-pressure- squared integral or, alternatively, is one containing a single main lobe which is in the focal Fraunhofer zone. The location of the second plane is as far as is practicable from the first plane and parallel to the first with the same two orthogonal scan lines (x and y axes) used for the first plane. NOTE 2 In a number of cases, the term pulse-pressure-squared integral is replaced in the above definition by any linearly related quantity, for example: a) in the case of a continuous wave signal the term pulse-pressure-squared integral is replaced by mean square acoustic pressure as defined in IEC 61689; b) in cases where signal synchronisation with the scanframe is not available, the term pulse-pressure-squared integral may be replaced by temporal average intensity. IEV 62127-1,definition 3.8 modified 3.8 beam centrepoint position determined by the intersection of two lines passing through the beamwidth midpoints of two orthogonal planes, xz and yz 3.9 beamwidth midpoint linear average of the location of the centres of beamwidths in a plane NOTE The average is taken over as many beamwidth levels given in Table K.1 of IEC 62127-1 as signal level permits). 3.10 beamwidth w6, w