Current Status of Ultrasonic Device Calibration in China

Transcription

1 APMP TCAUV - Changsha Current Status of Ultrasonic Device Calibration in China YANG Ping, NIM yangp@nim.ac.cn 1

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7 Contents 1 Ultrasound Power 2.1 Ultrasound Field Hydrophone Calibration 2.2 Ultrasound Field Field Characterization 3 Acoustic Properties in Ultrasound 4 Research and Potential Application 7

8 1 Ultrasound Power Ultrasound Power Watt and Milli-Watt Level P=cF Absorbent Target or cf/(2cos 2 θ) Reflecting Target Radiation Force Balance Frequency: (1-25) MHz Ultrasound Power Standard System CCAUV.U- K3 Power: 3 mw - 20 W Typical Uncertainty: U=5.0%(k=2) Target and Voltage Measurement

9 1 Ultrasound Power Ultrasound Power Reciprocity Method for W Low Level and High Frequency Disadvantages of RFB for Low Level and High-frequency Power 1) Small force on the target and disturbance of water; 2) High attenuation for high frequency; 3) No perfect absorbent target at high frequency. 2 2ad Ptr UlIke A 2 c 4 rd(2d) On the reciprocity theory, which is used to calibrate the hydrophone. Make the Power Measurement from Force Measurement in water to Electrical measurement, Proper for high frequency and low level. RFB and reciprocity comparison at 1 MHz

10 1 Ultrasound Power Ultrasound Power Reciprocity Method for Low Level and High Frequency RFB and reciprocity comparison at 25MHz 高频超声功率 国家 / 实验室 最小功率 最大频率 不确定度 (k=2) 英国 NPL 0.5 mw 20 MHz U=10% 德国 PTB 2.0 mw 21 MHz U=12% 中国 NIM 0.1 mw 25 MHz U=5% Measure Low Level and High Frequency Ultrasonic Power by Self-Reciprocity Technique Acta Acustica united with Acustica

11 1 Ultrasound Power Ultrasound Power High Power by Calorimetric Method Disadvantages of RFB for High Focused Power 1) Acoustic streaming affect results dramatically 2) Nonlinear effect in the high power field 3) Target easy to be damaged. 天平 RS-232 电压表 功率放大器 信号发生器 超声探头薄膜有机玻璃 Mylar 膜 PC 机 水域 蓖麻油 Schematic Diagram System Picture

12 1 Ultrasound Power Ultrasound Power High Power by Calorimetric Method Comparison experiment with RFB Transducer Array (1-7) MHz,>300W Power range: (20-300) W; Frequency: (1-5)MHz Typical Uncertainty: 5%(k=2) Transducer Array 1 MHz, >300W

13 1 Ultrasound Power Measurement service for Chongqing HAIFU

14 2.1 Ultrasound Field-Hydrophone Safety evaluation of the diagnostic equipments Measure the output dose in therapy

15 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Reciprocity ( Former IEC 60866) 信信信 信信信信信 示波器 探伤仪 调节机构 信信信信信 信信信 待测模体 信信信信 信信信信信 信信信信信 换能器 信信信信信 信信信 信信信 信信信信 平面反射体 M M Calibration system and transducer parameter measurement I 2A 1 1 * U c U 2 1 k k r G1 I1 U1 U c G 1I 1 2 Advantages:Simple and Cheap Disadvantages: Not direct traceable to Base Unit, Low frequency range, Larger uncertainty.

16 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Reciprocity Typical Uncertainty and Key Comparison 2014 hydrophone key comparison Frequency range: From former 15 MHz to 20 MHz; Uncertainty: About U =10%(k=2)

17 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Laser Homodyne (IEC 62127) P = ρcν NPL PTB NMIJ Modified Michelson interferometer

18 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Laser Homodyne Key Points: 1)Generate harmonic field with focused transducer; 2)Lock loop to measure the small vibration on the compliant membrane. Advantages: 1) Simple signal processing 2) High frequency Disadvantages: 1) Dependence of the photodiode frequency response; 2) Acoustic -optical interaction; 3) Only amplitude information. 4) Unlocked by environmental disturbance. Laser Homodyne Calibration System

19 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Laser Heterodyne 1 Vertical arrangement, cancelled the acoustic-optical interaction; 2 Less dependence on the frequency response of the photodiodes; 3 Proper for large displacement measurement, and more information; 4 Stable system. Ping Yang; Guangzhen Xing; Longbiao He. Calibration of high-frequency hydrophone up to 40 MHz by heterodyne interferometer Ultrasonics, 54(1), pp , 2014/1.

20 2.1 Ultrasound Field-Hydrophone Calibration Hydrophone Calibration Laser Heterodyne Major uncertainty includes: average effect, alignment, membrane acoustic transparency, optical system, driving voltage, etc.

21 2.1 Ultrasound Field-Hydrophone Calibration Table - Summary of the high frequency hydrophone calibration NMI Method Frequency Range Uncertainty(k=2) NPL Laser Homodyne 0.5 MHz~ 60 MHz U=12% ( f = 40 MHz) PTB Laser Homodyne 0.5 MHz ~ 50 MHz U=27.6% (f = 50 MHz) Reciprocity 0.5 MHz ~15 MHz U=22.8 % (f = 15 MHz) NMIJ Laser Homodyne 0.5 MHz ~ 40 MHz Not available TNO Reciprocity 0.5 MHz ~15 MHz U=15.0% (f = 15 MHz) Laser Heterodyne 0.5 MHz ~ 60 MHz U=16.0% (f = 40 MHz) NIM Reciprocity 0.5 MHz ~15 MHz U=15.0% (f = 15 MHz) Laser Homodyne 0.5 MHz ~40 MHz Being constructed

22 2.2 Ultrasound Field-Field Characterization Field Characterization For NDT Quantitative evaluation of results For precise NDT: We should know the transducer field parameters, to design and setup the testing procedures, such as step, focus. For precise NDE: Precise evaluation is based on the precise measurement of the field, such as size of the focus.

23 2.2 Ultrasound Field-Field Characterization Field Characterization For Industry Comply with ASTM E Measured Parameters include: Temporal response Frequency response, Ultrasound field parameters. Key Points: hydrophone average effect, directivity response, should be considered. Participated in domestic standards draft, ultrasound transducer calibration specification is being drafted.

24 2.2 Ultrasound Field-Field Characterization Field Characterization For Medical 1)Developed the scanning system for medical diagnostic equipments; 2)Provide testing service according to FDA 510K; 3)Some other research, such as the temperature and cavitations distribution; 4)Some portable device design and application. (Portable field evaluation, power standard, etc.)

25 2.2 Ultrasound Field-Field Characterization Field Characterization For Medical Pressure field and temperature distribution in phantom, measured by optical fiber sensors. 25

26 3 Acoustic Properties More attention and calibration requirements 87/469/NP Different kinds of phantom This survey was directed more toward precise performance evaluation and concluded strongly that traceability of measurements of phantom acoustic properties was critical. Stability of attenuation coefficient is critical for relative depth of penetration over time.

27 3 Acoustic Properties Major parameters IEC IEC IEC IEC_TS Major acoustic parameters: sound velocity, sound attenuation, backscatter coefficient.

28 3 Acoustic Properties Some activities Comparisons Attenuation Comparison Backscatter Comparison

29 Amplitude/mV 3 Acoustic Properties Parameters Measurements - Backscatter Coefficient Ultrasound Source Sample control Scattering signal from TMM phantom Comparisons between Original Signal and Reconstructed Signal Reconstructed Signal Original Signal Data acquisition window points Signal processing Backscatter signal processing

30 3 Acoustic Properties Parameters Measurements - Backscatter Coefficient Before the sample uniformity control

31 3 Acoustic Properties Parameters Measurements - Backscatter Coefficient After the sample uniformity control

32 3 Acoustic Properties International Comparison suggested at 2015 Questionnaire to Determine Individual Laboratory Capability for Measurement of Acoustic Properties of Materials Specify frequency range in MHz: to Specify temperature control of the laboratory i.e. both air and water? Specify measurement method(s) employed? Frequency dependant speed of sound: Frequency dependant attenuation: The Agar TMM will be prepared and supplied by INMETRO as per IEC , Annex DD. Specify sample requirements: Thickness: Diameter: Additional information specific to your laboratory (if any): Rodrigo Costa Felix of INMETRO will be responsible for this inter-laboratory comparison i.e. INMETRO will be the pilot laboratory. 32

33 3 Acoustic Properties Phantom calibration in use. 1) Drafted the calibration specification for phantom, which include the speed velocity, attenuation and target position measurement. 2) 3D phantom volume calibration (on going ) 3) Based on the 3D printing technology, we can provide some standard sample, such as contrast phantom, complex shaped phantom.

34 Summary - Ultrasonic Device Calibration in China 1 Power Meter, Power Source 2 Hydrophone, Field ( transducer, Diagnostic or therapeutic devices.) 3 Material, Phantom 4 Other Ultrasonic instrument, such as Ultrasonic thickness instrument, Ultrasonic flaw detector, etc.

35 4 Research and Interests Place Needle Hydrophone Around the Focus to Measure Cavitation Level Place Needle Hydrophone at the Focus to Measure Acoustic Intensity Place Absorbent Target Here to Measure Average Ultrasonic Power High Intensity Focused Ultrasound Transducer Array N-2 N-1 N Cavitation Bubble Ultrasonic Focus Point Transducer n The nth Transmission Unit High intensity hydrophone calibration and field mapping (Latest IEC TC87) Voltage and Power Control Cavitation quantitatively evaluation

36 4 Research and Interests Next generation underwater acoustic standards, Provide service for: 1 Hydrophone and transducer calibration, for underwater noise measurement, 2 Calibration and evaluation for marine survey and mapping equipments. 36

37 4 Research and Interests Interested Comparisons: 1) Bilateral or regional comparison for high ultrasound power; (1-3MHz, >200W ) 2) Hydrophone calibration for high intensity ultrasound field. (1 3 MHz, MPa ) 37

38 Thanks a lot and welcome to NIM