BS EN 62359-2011 Ultrasonics Field characterization Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields《声学 声场特性 与医疗.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationUltrasonics Field characterization Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fieldsBS EN 62359:2011National fo

2、rewordThis British Standard is the UK implementation of EN 62359:2011. It is identical to IEC 62359:2010. It supersedes BS EN 62359:2005, which will be withdrawn on 1 February 2014.The UK participation in its preparation was entrusted to Technical Committee EPL/87, Ultrasonics.A list of organization

3、s 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. BSI 2011ISBN 978 0 580 61958 8 ICS 11.040.55; 17.140.50Compliance with a British Sta

4、ndard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2011.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 62359:2011EUROPEAN STANDARD EN 62359 NORME E

5、UROPENNE EUROPISCHE NORM February 2011 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2011 CENELEC - All rights of exploitation in

6、any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62359:2011 E ICS 17.140.50 Supersedes EN 62359:2005English version Ultrasonics - Field characterization - Test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields

7、 (IEC 62359:2010) Ultrasons Caractrisation du champ Mthodes dessai pour la dtermination dindices thermique et mcanique des champs dultrasons utiliss pour le diagnostic mdical (CEI 62359:2010) Ultraschall - Charakterisierung von Feldern - Prfverfahren fr die Ermittlung des thermischen und des mechani

8、schen Indexes bezogen auf medizinische Ultraschalldiagnostikfelder (IEC 62359:2010) This European Standard was approved by CENELEC on 2011-02-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status

9、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

10、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, Croat

11、ia, 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. BS EN 62359:2011EN 62

12、359:2011 Foreword The text of document 87/445/FDIS, future edition 2 of IEC 62359, prepared by IEC TC 87, Ultrasonics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62359 on 2011-02-01. This European Standard supersedes EN 62359:2005. Major changes with respect to

13、EN 62359:2005 include the following: The methods of determination set out in EN 62359:2005 were based on those contained in the American standard for Real-Time Display of Thermal and Mechanical Acoustic Output Indices on Diagnostic Ultrasound Equipment (ODS) and were intended to yield identical resu

14、lts. While EN 62359:2010 also follows the ODS in principal and uses the same basic formulae and assumptions (see Annex A), it contains a few significant modifications which deviate from the ODS. One of the primary issues dealt with in preparing EN 62359:2010 was “missing” TI equations. In EN 62359:2

15、005 there were not enough equations to make complete “at-surface” and “below-surface” summations for TIS and TIB in combined-operating modes. Thus major changes with respect to EN 62359:2005 are related to the introduction of new calculations of thermal indices to take into account both “at-surface“

16、 and “below-surface“ thermal effects. For the specific technical changes involved please see Annex E. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such pa

17、tent rights. 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) 2011-11-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2014-02-

18、01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 62359:2010 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following note has to be added for the standard indicated: IEC 616

19、89 NOTE Harmonized as EN 61689. _ BS EN 62359:2011EN 62359:2011 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only

20、 the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IE

21、C 60601-2-37 - Medical electrical equipment - Part 2-37: Particular requirements for the basic safety and essential performance of ultrasonic medical diagnostic and monitoring equipment EN 60601-2-37 - IEC 61157 2007 Standard means for the reporting of the acoustic output of medical diagnostic ultra

22、sonic equipment EN 61157 2007 IEC 61161 2006 Ultrasonics - Power measurement - Radiation force balances and performance requirementsEN 61161 2007 IEC 61828 2001 Ultrasonics - Focusing transducers - Definitions and measurement methods for the transmitted fields EN 61828 2001 IEC 62127-1 2007 Ultrason

23、ics - Hydrophones - Part 1: Measurement and characterization of medical ultrasonic fields up to 40 MHz EN 62127-1 2007 IEC 62127-2 2007 Ultrasonics - Hydrophones - Part 2: Calibration of hydrophones to be used in ultrasonic fields up to 40 MHz EN 62127-2 2007 IEC 62127-3 2007 Ultrasonics - Hydrophon

24、es - Part 3: Properties of hydrophones for ultrasonic fields up to 40 MHz EN 62127-3 2007 BS EN 62359:201162359 IEC:2010 CONTENTS INTRODUCTION. 6 1 Scope.7 2 Normative references 7 3 Terms and definitions 8 4 List of symbols .21 5 Test methods for determining the mechanical index and the thermal ind

25、ex . 23 5.1 General .23 5.2 Determination of mechanical index .23 5.2.1 Determination of attenuated peak-rarefactional acoustic pressure 23 5.2.2 Calculation of mechanical index 23 5.3 Determination of thermal index general . 24 5.4 Determination of thermal index in non-scanning mode. .24 5.4.1 Dete

26、rmination of soft tissue thermal index for non-scanning modes 24 5.4.2 Determination of bone thermal index, TIB, for non-scanning modes 25 5.5 Determination of thermal index in scanning modes 26 5.5.1 Determination of soft tissue thermal index for scanning modes 26 5.5.2 Determination of bone therma

27、l index for scanning modes .27 5.6 Calculations for combined-operating mode . 28 5.6.1 Acoustic working frequency 28 5.6.2 Thermal index. 28 5.6.3 Mechanical index29 5.7 Summary of measured quantities for index determination 29 Annex A (informative) Rationale and derivation of index models . 30 Anne

28、x B (informative) Guidance notes for measurement of output power in combined modes, scanning modes and in 1 cm 1 cm windows. .51 Annex C (informative) The contribution of transducer self-heating to the temperature rise occurring during ultrasound exposure. .58 Annex D (informative) Guidance on the i

29、nterpretation of TI and MI . .59 Annex E (informative) Differences from IEC 62359 Edition 1. 61 Bibliography. 64 Figure 1 Schematic diagram of the different planes and lines in an ultrasonic field (modified from IEC 61828 and IEC 62127-1) 12 Figure A.1 Focusing transducer with a f-number of about 7.

30、 37 Figure A.2 Strongly focusing transducer with a low f-number of about 1. .37 Figure A.3 Focusing transducer (f-number 10) with severe undulations close to the trans-ducer . .38 Figure A.4 Focusing transducer 44 Figure A.5 Focusing transducer with smaller aperture than that of Figure A.4 . .44 Fig

31、ure A.6 Focusing transducer with a weak focus near zbp 45 Figure A.7 Weakly focusing transducer . 45 Figure B.1 Example of curved linear array in scanning mode 53 Figure B.2 Suggested 1 cm 1 cm square-aperture mask56 BS EN 62359:201162359 IEC:2010 Figure B.3 Suggested orientation of transducer, mask

32、 aperture and RFB target.56 Figure B.4 Suggested orientation of transducer and 1 cm-square RFB target. 57 Table 1 Summary of combination formulae for each of the THERMAL INDEX categories28 Table 2 Summary of the acoustic quantities required for the determination of the indices . .29 Table A.1 Therma

33、l index categories and models 36 Table A.2 Consolidated thermal index formulae .41 Table E.1 Summary of differences . 63 BS EN 62359:2011 6 62359 IEC:2010 INTRODUCTION Medical diagnostic ultrasonic equipment is widely used in clinical practice for imaging and monitoring purposes. Equipment normally

34、operates at frequencies in the low megahertz frequency range and comprises an ultrasonic transducer acoustically coupled to the patient and associated electronics. There is an extremely wide range of different types of systems in current clinical practice. The ultrasound entering the patient interac

35、ts with the patients tissue, and this interaction can be considered in terms of both thermal and non-thermal effects. The purpose of this International standard is to specify methods of determining thermal and non-thermal exposure indices that can be used to help in assessing the hazard caused by ex

36、posure to a particular ultrasonic field used for medical diagnosis or monitoring. It is recognised that these indices have limitations, and knowledge of the indices at the time of an examination is not sufficient in itself to make an informed clinical risk assessment. It is intended that these limit

37、ations will be addressed in future revisions of this standard and as scientific understanding increases. While such increases remain pending, several organizations have published prudent-use statements. Under certain conditions specified in IEC 60601-2-37, these indices are displayed on medical ultr

38、asonic equipment intended for these purposes. BS EN 62359:201162359 IEC:2010 7 ULTRASONICS FIELD CHARACTERIZATION TEST METHODS FOR THE DETERMINATION OF THERMAL AND MECHANICAL INDICES RELATED TO MEDICAL DIAGNOSTIC ULTRASONIC FIELDS 1 Scope This International standard is applicable to medical diagnost

39、ic ultrasound fields. This standard establishes parameters related to thermal and non-thermal exposure aspects of diagnostic ultrasonic fields; methods for the determination of an exposure parameter relating to temperature rise in theoretical tissue-equivalent models, resulting from absorption of ul

40、trasound; methods for the determination of an exposure parameter appropriate to certain non-thermal effects. NOTE 1 In Clause 3 of this standard, SI units are used (per ISO/IEC Directives, Part 2, ed. 5, Annex I b) in the Notes below definitions of certain parameters, such as beam areas and intensit

41、ies; it may be convenient to use decimal multiples or submultiples in practice. Users must take care of decimal prefixes used in combination with the units when using and calculating numerical data. For example, beam area may be specified in cm2and intensities in W/cm2or mW/cm2. NOTE 2 Underlying ca

42、lculations have been done from 0,25 MHz to 15 MHz for MI and 0,5 MHz to 15 MHz for TI. NOTE 3 The thermal indices are steady state estimates based on the acoustic output power required to produce a 1C temperature rise in tissue conforming to the “homogeneous tissue 0,3 dBcm-1MHz-1attenuation model”

43、1 1) and may not be appropriate for radiation force imaging, or similar techniques that employ pulses or pulse bursts of sufficient duration to create a significant transient temperature rise. 2 2 Normative references The following referenced documents are indispensable for the application of this d

44、ocument. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60601-2-37, Medical electrical equipment Part 2-37: Particular requirements for the basic safety and essential performance of u

45、ltrasonic medical diagnostic and monitoring equipment IEC 61157:2007, Standard means for the reporting of the acoustic output of medical diagnostic ultrasonic equipment IEC 61161:2006, Ultrasonics Power measurement Radiation force balances and performance requirements IEC 61828:2001, Ultrasonics Foc

46、using transducers Definitions and measurement methods for the transmitted fields IEC 62127-1:2007, Ultrasonics Hydrophones Part 1: Measurement and characterization of medical ultrasonic fields up to 40 MHz _ 1)Figures in square brackets refer to Bibliography. BS EN 62359:2011 8 62359 IEC:2010 IEC 62

47、127-2:2007, Ultrasonics Hydrophones Part 2: Calibration for ultrasonic fields up to 40 MHz IEC 62127-3:2007, Ultrasonics Hydrophones Part 3: Properties of hydrophones for ultrasonic fields up to 40 MHz 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC

48、62127-1:2007, IEC 62127-2:2007, IEC 62127-3:2007, IEC 61157:2007 and IEC 61161:2006 (several of which are repeated below for convenience) apply. NOTE Units below definitions are given is SI units as per ISO/IEC Directives, Part 2, ed. 5, Annex I b). Users must be alert to possible need to convert un

49、its when using this standard in situations where data are received in units that are different from those used in the SI system. 3.1 acoustic attenuation coefficient coefficient intended to account for ultrasonic attenuation of tissue between the external transducer aperture and a specified point NOTE 1 A linear dependence on frequency is assumed. NOTE 2 Acoustic attenuation coefficient is expressed in neper