1、r CENELEC EN*b120b 95 3404583 01bL259 445 BRITISH STANDARD Ultrasonics Continuous-wave Doppler systems Test procedures The European Standard EN 61206 : 1995 has the status of a British Standard BS EN 61206 : 1995 IEC 1206 : 1993 BS EN 61206 : 1996 This British Standard, having been prepared under th
2、e direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 October 1995 O BSI 1995 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee EPy87, itmwnic
3、s, upon which the following bodies were represented British Dentai Association British Institute of Radiology British Medical Ultrasound Society British Society for Rheumatology Department of Health Department of Rade and Industry (National Physical Laboratory) Institute of Laryngology and Otology I
4、nstitute of Physical Sciences in Medicine Institution of Electrical Engineers Amendments issued since publication Amd.No. lDde I Te* affected The following BSI references relate to the work on this standard Committee reference EPU87 Special announcement BSI News May 1995 ISBN O 580 24676 4 CENELEC E
5、N*bL20b 95 3404583 OLbL2bL OT3 BS EN 61206 : 1995 Contents page Committees responsible Inside front cover National foreword 11 Foreword 2 Text of EN 61206 : 1995 3 i CENELEC EN*bL206 95 m 3404583 OlbL262 T3T BS EN 61206 : 1995 National foreword This British Standard has been prepared by Technical Co
6、mmittee EPU87 and is the English language version of EN 61206 : 1995 Ultrasonics, Continuous-wave Dolrpler systems - Test procedures, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with Technical Report IEC 1206 : 1993, published by the Internatio
7、nal Electrotechnical Commission (IEC). The United Kingdom voted against this document being harmonized as an EN, as the IEC Technical Report Qpe 2 was not intended to be regarded as an International Standard, but oniy as a prospective standard for provisional application, for guidance on how stan- i
8、n this field should be used to meet an identified need. The IEC Technical Report is due for further review three years after publication, with the options of either extension for a further three years or conversion to an International Standard, or withdrawal. The EN will correspondingly be automatic
9、ally reviewed after a period of five years or earlier depending on the outcome of the IEC review. Cross-references Publication referred to EN 61102 : 1993 (mc 1102 : 1991) Corresponding British Standard BS EN 61102 : 1994 SpeCi,fiation for measurement and chamcterisation of ultrasonic fields using h
10、ydmphones in ULe fmqumuy range 0.5 MHz to 15 MHz Compliance with a British Standard does not of itself confer immunity from legal obligations. ii CENELEC EN*bL20b 95 W 3404583 OLbL2b3 976 EUROPEAN STANDm NORIME EUROPENNE EXJROP NORM EN 61206 February 1995 ICs 17.140.50 ; 11.040.50 Descriptors: Ultra
11、sound, Doppler, continuous wave, test procedure English version ulmonics Continuous-wave Doppler systems Test procedures (IEC 1206 : 1993) UItrasOnS Ultraschall Ensembles effet Doppler ondes entretenues Mthodes dessai Prfverfahren (CE1 1206 : 1993) Dauerschd Doppler System (EC 1206 : 1993) This Euro
12、pean Standard was approved by CENELEC on 199412-06. CENELEC members are bound to comply with the CENKENELEC 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
13、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
14、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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal,
15、 Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fiir Elektrotechnische Normung Centrai Secretariat: rue de Stassart 35, B-1050 Brussels O 1995 Copyright reserved to CEN
16、ELEC members Ref. No. EN 61206 : 1995 E CENELEC EN*bL20b 95 m 3404583 OLbL2b4 802 m Page 2 EN 61206 : 1995 Foreword The text of the international Standard IEC 1206 : 1995, prepared by IEC TC 87, Ultrasonics, was submitted to the formal vote and was approved by CENELEC as EN 6126 on 1994-1246 without
17、 any modincation. The foliowing 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 latest date by which the national standards confiidmg with the EN have to be withclrawn endorsement (dop) 199512-15 - (dow) 19
18、9512-15 Annexes designated normative are part of the body of the standard. Annexes designated informative are given for information ony. In this standard, mex ZA is normative and annexes A,B and C are informative. Annex ZA has been added by CENELEC. . CENELEC EN*b3206 95 3404583 0363265 749 Page 3 E
19、N 61206 : 1995 CONTENTS INTRODUCTION . SECTION 1: GENERAL Clause 1 . 1 1.2 1.3 1.4 2.1 2.2 2.3 2.4 2.5 2.6 2.7 3.1 Scope Normative reference Definitions . SECTION 2: OVERALL TESTS OF COMPLETE SYSTEMS General considerations . 2.1.1 Types of Doppler ultrasound systems 2.1.2 Worst case conditions Initi
20、al conditions . 2.2.1 Power supply . 2.2.2 Test frequency, general conditions . 2.2.3 Working distance . 2.2.4 Zero-signal noise level . Doppler frequency response 2.3.1 Frequency response range 2.3.2 Doppler frequency accuracy 2.3.3 Large-signal performance Spatial response 2.4.1 Axial response . 2
21、.4.2 Lateral response . Operating frequency 2.5.1 Acoustical measurement 2.5.2 Electrical measurement Flow direction separation . 2.6.1 Channel separation . 2.6.2 Simultaneous flow . Response to Doppler spectrum . 2.7.1 Volume-flow circuits 2.7.2 Maximum-frequency followers . SECTION 3: SPECIAL DOPP
22、LER TEST OBJECTS. Doppler test objects 3.1.1 String Doppler test object 3.1.2 Band Doppler test object 3.1.3 Disk Doppler test object . 3.1.4 Piston Doppler test object 3.1.5 Small ball test object 3.1.6 Flow Doppler test object 3.1.7 Water tank (or gel block) Symbols Annexes A (informative) Descrip
23、tion of continuous-wave Doppler ultrasound systems . B (informative) Rationale . . C (informative) Bibliography . references of the relevant European publications ZA (normative) Other international publications quoted in this standard with the 4 5 5 5 7 7 7 7 8 9 9 10 10 10 11 11 12 13 13 14 14 14 1
24、4 14 15 15 16 16 a 16 16 18 18 19 19 19 20 25 29 31 32 CENELEC ENxb120b 95 = 3404583 OLbL2bb 685 Page 4 EN 61206 : 1995 INTRODUCTION Continuous-wave ultrasonic Doppler flowmeters, velocimeters, or foetal heart detectors are widely used in clinical practice. This type of medical ultrasonic equipment
25、measures the Doppler-shift frequency which is the change in frequency of an ultrasound scattered wave caused by relative motion between a scatterer and the ultrasonic transducer. This frequency is proportional to the observed velocity, which is the component of the velocity of a scatterer that is di
26、rected towards or away from the transducer. This technical report describes a range of test methods that may be applied to determine various performance parameters for continuous-wave Doppler ultrasound systems. They may also be applied to pulsed Doppler systems although additional tests would also
27、be required. The test methods are based on the use of a number of specialised devices such as string, band, disk, piston and flow Doppler test objects. These test methods may be considered as falling into one of the following three categories. The first is routine quality control tests that can be c
28、arried out by a clinician or a technologist to ensure that the system is working adequately or has adequate sensitivity. The second is more elaborate test methods, conducted less frequently, such as when the system is suspected of not working properly. The third represents tests that would be done b
29、y a manufacturer on complete systems, as the basis of type specification of performance. CENELEC EN*b220b 95 3404583 OLbL267 511 Page 5 EN 61206 : 1995 ULTRASONICS - CONTINUOUS-WAVE DOPPLER SYSTEMS - TEST PROCEDURES SECTION 1 : GENERAL 1.1 Scope This technical report describes: - test methods for me
30、asuring the performance of continuous-wave ultrasonic Doppler flowmeters, velocimeters, or foetal heart detectors; - special Doppler test objects for determining various performance properties of Doppler ultrasound systems. This technical report applies to: - tests made on an overall Doppler ultraso
31、und system; a system which is not dis- assembled or disconnected; - tests made on continuous-wave Doppler ultrasound systems. The same tests can be applied to Doppler ultrasound systems which measure position as well as velocity, such as pulsed and frequency-modulated Doppler systems, although addit
32、ional tests may then be required. Electrical safety and acoustic output are not covered in this technical report 1.2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this technical report. At the time of publication, the e
33、dition indicated was valid. All standards are subject to revision, and parties to agreements based on this tech- nical report are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently va
34、lid International Standards. IEC 1 102: 1991, Measurement and characterisation of ultrasonic fields using hydrophones in the frequency range 0,5 MHz to 75 MHz 1.3 Definitions For the purposes of this technical report, the following definitions apply: 1.3.1 dlrectlon sensing; directional: Descriptor
35、of a type of Doppler ultrasound system which indicates whether scatterers are approaching or receding from the ultra- sonic transducer. CENELEC ENrb120b 95 = 3404583 OLbL2b8 458 Page 6 EN 61206 : 1995 1.3.2 dlrection resolvlng; direction separating: Descriptor of a type of Doppler ultra- sound syste
36、m in which the Doppler output appears at different output terminals, output channels or output devices depending upon the direction of scatterer motion relative to the transducer. 1.3.3 Doppler frequency; Doppler-shift frequency: Change in frequency of an ultra- sound scattered wave caused by relati
37、ve motion between the scatterer and the transducer. It is the difference frequency between the transmitted and the received wave. 1.3.4 Doppler frequency or at Doppler frequencies which activates the output device. Doppler output; direct output; Doppler frequency output: Voltage at the 1.3.5 Doppler
38、 output connector: Electrical connector or that part of a Doppler ultra- sound system at which the Doppler output is available for connection to external output devices. NOTE - Not all Doppler ultrasound systems have a physical connector at which the Doppler output is available. 1.3.6 sound system.
39、Doppler spectrum: Set of Doppler frequencies produced by a Doppler ultra- 1.3.7 Doppler test object: Artificial structures used in testing Doppler ultrasound systems. They produce ultrasonic reflections that are similar to those produced by the structures on which the Doppler ultrasound systems are
40、to be used. NOTE - Doppler test objects are often referred to as phantoms. 1.3.8 Doppler ultrasound system; system: Equipment designed to transmit and receive ultrasound and to generate a Doppler output from the difference in frequency between the transmitted and received waves. 1.3.9 direction sens
41、ing. non-directional: Descriptor of a type of Doppler ultrasound system which is not 1.3.10 observed velocity: Component of the velocity of a scatterer that is directed towards or away from the transducers. 1.3.1 1 operating frequency: The ultrasonic or electrical frequency of operation of an ultras
42、onic transducer forming part of a Doppler ultrasound system. 1.3.12 output channel: Part of a Doppler ultrasound system which functionally represents a particular aspect of the Doppler output. NOTE - A Doppler ultrasound system may have two output channels, each representing a How in a part- cular d
43、irection. 1.3.13 output device: Any device included in a Doppler ultrasound system or capable of being connected to it that makes the Doppler output accessible to the human senses. CENELEC ENrb120b 95 W 3404583 01bL2b9 394 m Page 7 EN 61206 : 1995 1.4 Symbols c is the average speed of sound in a med
44、ium. u is the average speed of the fluid in a flow Doppler test object. is the angle between the sound beam and the axis of the tube, string, band or disc in flow, string, band or disc Doppler test objects respectively. I is the ultrasonic wavelength. SECTION 2: OVERALL TESTS OF COMPLETE SYSTEMS 2.1
45、 General considerations 2.1 .l Types of Doppler ultrasound systems A major factor that affects performance testing of a Doppler ultrasound system (system) is whether it can be described as directional, non-directional, or as direction resolving. Directional or direction senslng refers to a type of s
46、ystem which indicates whether scatterers are approaching or receding from the ultrasonic transducer. Non-directlonal systems do not indicate direction of scatterer motion. Direction resolving, or direction separatlng systems provide for Doppler output to appear at different output channels depending
47、 upon the direction of scatterer motion. Annex A gives descriptions and examples of these different types of systems. 2.1.2 Worst case conditions A test method may be applied to determine a particular performance parameter of a system. Often a number of quantities can have a bearing on overall perfo
48、rmance, each one of which requires the application of a distinct test method. Some of these quantities need to be maximised and others need to be minimised in order to obtain the best overall performance. Considering overall performance, table 1 gives the worst case conditions for key quantities app
49、ropriate to peripheral vascular systems and the corresponding clause number which describes a suitable test method. Table 1 may need modification to be appropriate for other uses. As an example, if the noise as measured in 2.2.4 is maximised this will lead to worst case overall performance; conversely, minimising noise will lead to maximised performance. The situation for spatial response (see clause 2.4), is discussed in the rationale (see annex B). . CENELEC EN*bL20b 75 3404583 OLbL270 OOb m Worst case is the minimum value of:
