高频环阵换能器数字波束聚焦技术
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摘要
超声诊断中为了观察更小和更细微的组织结构，通常要求提高超声工作频率和实现超声波束聚焦。在本课题中，我们采用五环10MHz高频超声环阵换能器实现多点数字化聚焦，通过FPGA可编程逻辑芯片EP1C12Q240产生同步触发信号，受触发后的发射器产生高压电脉冲激励换能器向检测目标(实验中采用尼龙靶线)发射超声脉冲。由目标形成的超声回波脉冲信号经换能器接收后转化成模拟电信号，超声回波模拟电信号经过滤波和可变增益放大芯片AD8332调节放大100倍，模数转换芯片AD9238以40MHz采样率对放大的超声回波模拟电信号进行数字化采样，五路数字回波输入到可编程逻辑芯片EP1C12Q240中，采用EP1C12Q240芯片构造五路FIFO来存储五路数字回波，依次控制五路FIFO中的数字回波延迟输出，输出的同相位数字回波通过加法器相迭加实现环阵换能器超声波束多点聚焦，最终将回波信号通过高频数模转换芯片AD9772A输出进行验证。
实验结果表明，采用超声回波数字化相控聚焦技术，实现了声束轴上多点聚焦，减少了声束的3dB波束宽度，提高了声束轴上成像点的分辨率。
In the ultrasound diagnosis, in order to observing the smaller configuration andorganization, it demands rising the ultrasound frequency and realizing ultrasoundbeam focus. We adopt 10MHz high frequency annular transducer to achieve digitalbeam focusing. The transducer transmits synchronal pulse from the programminglogic chip EP1C12Q240C8. The trigger produces high voltage to inspirit thetransducer emitting ultrasound pulse. In the experiment, we use the nylon line as thedetected target. The ultrasound echo is changed to electric signal, then filtered andchanged the amplitude to 40dB gain by the chip AD8332. The chip AD9238 samplesthe ultrasound echo with the speed in 40MHz, and the five digital echoes enter theprogramming chip EP1C12Q240, which constructs five FIFO to storage the fivedigital ultrasound echoes. We control the digital ultrasound echo output according tothe delay time, the in-phase digital echoes added by the adder to achieve the fivedigital beam focused. Finally the focused digital echo is exported to the highfrequency D/A chip AD9772A to validate the result.
The experiment result indicates that adopting the phased control technology,many focuses can be achieved in the beam axis, which reduces the 3dB width of theultrasound beam and improves the image resolving power.
实验结果表明，采用超声回波数字化相控聚焦技术，实现了声束轴上多点聚焦，减少了声束的3dB波束宽度，提高了声束轴上成像点的分辨率。
In the ultrasound diagnosis, in order to observing the smaller configuration andorganization, it demands rising the ultrasound frequency and realizing ultrasoundbeam focus. We adopt 10MHz high frequency annular transducer to achieve digitalbeam focusing. The transducer transmits synchronal pulse from the programminglogic chip EP1C12Q240C8. The trigger produces high voltage to inspirit thetransducer emitting ultrasound pulse. In the experiment, we use the nylon line as thedetected target. The ultrasound echo is changed to electric signal, then filtered andchanged the amplitude to 40dB gain by the chip AD8332. The chip AD9238 samplesthe ultrasound echo with the speed in 40MHz, and the five digital echoes enter theprogramming chip EP1C12Q240, which constructs five FIFO to storage the fivedigital ultrasound echoes. We control the digital ultrasound echo output according tothe delay time, the in-phase digital echoes added by the adder to achieve the fivedigital beam focused. Finally the focused digital echo is exported to the highfrequency D/A chip AD9772A to validate the result.
The experiment result indicates that adopting the phased control technology,many focuses can be achieved in the beam axis, which reduces the 3dB width of theultrasound beam and improves the image resolving power.
引文
[1] 万明习，卞正中，程敬之．医学超声学，西安交通大学出版社，1992．
[2] 甘心照．近代电子医疗设备与技术，南京大学出版社，1991．
[3] 范毅明等．医用B超仪与超声多普勒系统，第二军医大学出版社，1999．
[4] 周永昌，郭万学主编．超声医学，科学技术文献出版社，1998．
[5] 冯若．超声诊断设备原理与设计，中国医药科技出版社，1993．
[6] Goldberg RL, Smith SW. Transducers for medical ultrasound [M]. In:Bronzino JD, editor. Biomedical Engineering Handbook. Boca Raton, FL: CRC Press, 1995:1077-1092.
[7] D.G.Wildes, R.Y.Chiao, C.M.W.Daft, et al. Elevation Performance of 1.25D and 1.5D Transducer Arrays[J]. IEEE Trans. Ultrason. Ferro.Freq. Control, 1997, 1027-1037.
[8] 袁建人．国外医疗超声换能器的应用研究和发展[J]．中国医疗器械信息，2004，10(5)：48-52。
[9] Giorgio Rizzatto. Ultrasound transducers [J]. European Journal of Radiology, 1998, 6(4):188-195.
[10] Rizzatto G, Chersevani R, Abbona M, et al. High-resolution sonography of breast carcinoma[J]. Eur J Radiol, 1997, 24:9-11.
[11] A. Fenster, D. B. Downey. 3-D Ultrasound Imaging-A Review[J]. IEEE Engineering in Medicine and Biology, 1996, 15(6): 41-51.
[12] 张臣禹．全数字化超声成像系统，现代科学仪器，N0．4，35-36，1997．
[13] D.G.Wildes, R.Y.Chiao, C.M.W.Daft, et al. Elevation Performance of 1.25D and 1.5D Transducer Arrays[J]. IEEE Trans. Ultrason. Ferro.Freq. Control, 1997, 027-1037.
[14] K. K. Shung, M. Zipparo. Ultrasonic Transducers and Arrays[J]. IEEE Engineering in Medical and Biology, 1996, 15(6):20-30;
[15] 白净．医学超声成像机理，清华大学出版社，1998．
[16] 何证权，谭欧．数字多声束形成技术．电子科技大学学报．VoL．25，no．8，230-234，1996．
[17] Remo M.L Tolf, August Vieli, Samuel Basler:Ultrasound Phased-array Scanner with Digital Echo Synthesis for Doppler Echo-card graphy, IEE Transaction on Ultrasonic, Ferroelectrics, and Frequency Control, VoL.36, No.5, 494-506, 1989;
[18] Bermard D.Steinberg, Life Fellow.Digital Beamforming inUltrsaound, IEEE Transaction. on Ultrasonic Ferroelectrics and Frequency Control, VoL.39, No.6, 716-721, 1992.
[19] Pei-Jie Cao, k.kirk Shung. Design of a real Time Digital Beamformer For a 50MHZ Annuar Array ultrasound Transducer[J]. IEEE Ultrasonics Symposium, 2002, 3: 1619-1623.
[20] Ritter J.Universal phased array UT probe for nondestructive examinations using composite crystal technology[J/OL]. The e Journal of Nondestructive Testing, www.nde.net, 2000, 5(9).
[21] 舒贞权，姚锦钟．医学超声影像技术的新进展[J]．世界医疗器械，2000，6(4)：12-17．
[22] 张光义．相控阵雷达系统，国防工业出版社，1994．
[23] Analog Devices Inc. AD9238 12 b, 20/ 40/ 65 MSPSdualA / Dconverter data sheet, 2002.
[24] Analog Devices Inc News. ADIiotroducesthe indu-stry's fastest dual-channel converter ideal for portable and low-powerapplications, 2002.
[25] Analog Devices Inc. Mixed signaland DSPdesigntechniques, 2002.
[26] 苗书立 杨建宇等．12bit双通道高速A/D转换器AD9238的原理及应用，现代电子技术，2006．
[27] 杨小牛，楼才艺等．软件无线电原理与应用．电子工业出版社，2002：21～26．
[28] 徐晓建，陈亮辉等．数模转换芯片AD9772A的特点及其应用，电子工程师，2003．
[29] J. V. Hatfield, N.R. Scales. An Integrated Multi-Element Array Transducer for Ultrasound Imaging, Sensors and Actuators A, VoL.41-42, 167-173, 1994.
[30] L.azar, Y.Shi, S.C.Wooth:Beam focusing behavior of linear phased arrays, NDT&E Internationgal 33, 189-198, 2000.
[31] TAlK.Song and Song b.Park. A new digital phased array system for dynamic and steeting with reduced samlpling rate, Ultrasonic Imaging, VoL.12, N0.1-16, 1990.
[32] 张家骏．第十三届世界无损检测会议仪器展览见闻，无损检测，VoL 15．No．4．115-116，1993．
[33] 吴平，相控阵超声换能器的研制，西安交通大学硕士论文，1987．
[34] P.Cioran, D.Mac Gillivray, A.Lamarre, and F.Jacques, Feasibility study of ultrasounic inspection using phased array of turbine blade root and totor steeple grooves-pan, EPRI Phased Array Seminar-Portland, Sept, 1998.
[2] 甘心照．近代电子医疗设备与技术，南京大学出版社，1991．
[3] 范毅明等．医用B超仪与超声多普勒系统，第二军医大学出版社，1999．
[4] 周永昌，郭万学主编．超声医学，科学技术文献出版社，1998．
[5] 冯若．超声诊断设备原理与设计，中国医药科技出版社，1993．
[6] Goldberg RL, Smith SW. Transducers for medical ultrasound [M]. In:Bronzino JD, editor. Biomedical Engineering Handbook. Boca Raton, FL: CRC Press, 1995:1077-1092.
[7] D.G.Wildes, R.Y.Chiao, C.M.W.Daft, et al. Elevation Performance of 1.25D and 1.5D Transducer Arrays[J]. IEEE Trans. Ultrason. Ferro.Freq. Control, 1997, 1027-1037.
[8] 袁建人．国外医疗超声换能器的应用研究和发展[J]．中国医疗器械信息，2004，10(5)：48-52。
[9] Giorgio Rizzatto. Ultrasound transducers [J]. European Journal of Radiology, 1998, 6(4):188-195.
[10] Rizzatto G, Chersevani R, Abbona M, et al. High-resolution sonography of breast carcinoma[J]. Eur J Radiol, 1997, 24:9-11.
[11] A. Fenster, D. B. Downey. 3-D Ultrasound Imaging-A Review[J]. IEEE Engineering in Medicine and Biology, 1996, 15(6): 41-51.
[12] 张臣禹．全数字化超声成像系统，现代科学仪器，N0．4，35-36，1997．
[13] D.G.Wildes, R.Y.Chiao, C.M.W.Daft, et al. Elevation Performance of 1.25D and 1.5D Transducer Arrays[J]. IEEE Trans. Ultrason. Ferro.Freq. Control, 1997, 027-1037.
[14] K. K. Shung, M. Zipparo. Ultrasonic Transducers and Arrays[J]. IEEE Engineering in Medical and Biology, 1996, 15(6):20-30;
[15] 白净．医学超声成像机理，清华大学出版社，1998．
[16] 何证权，谭欧．数字多声束形成技术．电子科技大学学报．VoL．25，no．8，230-234，1996．
[17] Remo M.L Tolf, August Vieli, Samuel Basler:Ultrasound Phased-array Scanner with Digital Echo Synthesis for Doppler Echo-card graphy, IEE Transaction on Ultrasonic, Ferroelectrics, and Frequency Control, VoL.36, No.5, 494-506, 1989;
[18] Bermard D.Steinberg, Life Fellow.Digital Beamforming inUltrsaound, IEEE Transaction. on Ultrasonic Ferroelectrics and Frequency Control, VoL.39, No.6, 716-721, 1992.
[19] Pei-Jie Cao, k.kirk Shung. Design of a real Time Digital Beamformer For a 50MHZ Annuar Array ultrasound Transducer[J]. IEEE Ultrasonics Symposium, 2002, 3: 1619-1623.
[20] Ritter J.Universal phased array UT probe for nondestructive examinations using composite crystal technology[J/OL]. The e Journal of Nondestructive Testing, www.nde.net, 2000, 5(9).
[21] 舒贞权，姚锦钟．医学超声影像技术的新进展[J]．世界医疗器械，2000，6(4)：12-17．
[22] 张光义．相控阵雷达系统，国防工业出版社，1994．
[23] Analog Devices Inc. AD9238 12 b, 20/ 40/ 65 MSPSdualA / Dconverter data sheet, 2002.
[24] Analog Devices Inc News. ADIiotroducesthe indu-stry's fastest dual-channel converter ideal for portable and low-powerapplications, 2002.
[25] Analog Devices Inc. Mixed signaland DSPdesigntechniques, 2002.
[26] 苗书立 杨建宇等．12bit双通道高速A/D转换器AD9238的原理及应用，现代电子技术，2006．
[27] 杨小牛，楼才艺等．软件无线电原理与应用．电子工业出版社，2002：21～26．
[28] 徐晓建，陈亮辉等．数模转换芯片AD9772A的特点及其应用，电子工程师，2003．
[29] J. V. Hatfield, N.R. Scales. An Integrated Multi-Element Array Transducer for Ultrasound Imaging, Sensors and Actuators A, VoL.41-42, 167-173, 1994.
[30] L.azar, Y.Shi, S.C.Wooth:Beam focusing behavior of linear phased arrays, NDT&E Internationgal 33, 189-198, 2000.
[31] TAlK.Song and Song b.Park. A new digital phased array system for dynamic and steeting with reduced samlpling rate, Ultrasonic Imaging, VoL.12, N0.1-16, 1990.
[32] 张家骏．第十三届世界无损检测会议仪器展览见闻，无损检测，VoL 15．No．4．115-116，1993．
[33] 吴平，相控阵超声换能器的研制，西安交通大学硕士论文，1987．
[34] P.Cioran, D.Mac Gillivray, A.Lamarre, and F.Jacques, Feasibility study of ultrasounic inspection using phased array of turbine blade root and totor steeple grooves-pan, EPRI Phased Array Seminar-Portland, Sept, 1998.