2002 IEEE Ultrasonics Symposium, 2002. Proceedings.最新文献_第5页

Numerical efficiency of IDT charge spatial spectrum evaluation methods IDT电荷空间谱评价方法的数值效率

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193406

Y. Tasinkevych, E.J. Danicki

引用次数: 4

High frequency ultrasound with an eigen-decomposition filter to assess the effect of laser cyclophotocoagulation treatment on blood flow 高频超声特征分解滤波评价激光光凝治疗对血流的影响

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192578

D. Kruse, M. Lim, D. Redline, P. Eisele, K. Ferrara

引用次数: 6

Extending the synthetic aperture focusing algorithm to deal with flat and curved features in NDT 扩展了合成孔径聚焦算法以处理无损检测中的平面和曲面特征

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193526

S. Cochran, J. Earnshaw, B. Bargain, K. Kirk

{"title":"Extending the synthetic aperture focusing algorithm to deal with flat and curved features in NDT","authors":"S. Cochran, J. Earnshaw, B. Bargain, K. Kirk","doi":"10.1109/ULTSYM.2002.1193526","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193526","url":null,"abstract":"The synthetic aperture focusing (SAF) technique allows exploration of ultrasonic array imaging performance with minimal hardware and it can provide excellent imaging results for point defects, such as fatigue crack tips, commonly found in non-destructive testing (NDT). However, it performs less well when imaging defects which are flat or curved with radii large relative to the ultrasonic wavelength. Here, we report an enhanced time-domain algorithm which can deal with flat and curved defects and which we have termed \"synthetic aperture correlation\". It is based on processing signals from multiple overlapping subsets of elements from an entire array. The algorithm has roots in SAF, matched filtering, beam steering and biomedical ultrasonic imaging. The data collection process is the same as for SAF and the new algorithm operates entirely in reception, off-line. It has been tested using a 96-element linear array operating at 6 MHz on aluminum test objects. We present simulated and experimental results and compare these with B-scans showing timer-of-flight diffraction (TOFD) characteristics and with conventional SAF. We highlight the advantages of the new algorithm, such as its enhanced capability to deal with noise, and drawbacks such-as increased computational expense.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128032805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of electrode resistance for acoustic coupler using quadrature electrode 正交电极对声耦合器电极电阻的影响

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193395

T. Shiba, Y. Fujita, S. Kondo, J. Hamasaki, Mayumi Ide, S. Ogawa, K. Oda

引用次数: 1

A new type SPUDT SAW for use in high frequency around 2 GHz 一种用于2ghz左右高频的新型SPUDT SAW

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193402

Chun-Yun Jian, S. Beaudin

引用次数: 8

Prediction of frequency-dependent ultrasonic backscatter in cancellous bone using statistical weak scattering model 利用统计弱散射模型预测松质骨中频率相关的超声后向散射

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192543

F. Jenson, F. Padilla, P. Laugier

{"title":"Prediction of frequency-dependent ultrasonic backscatter in cancellous bone using statistical weak scattering model","authors":"F. Jenson, F. Padilla, P. Laugier","doi":"10.1109/ULTSYM.2002.1192543","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192543","url":null,"abstract":"The goal of this study is to propose a model for the ultrasonic frequency-dependent backscatter coefficient in cancellous bone. A weak scattering model is used. It allows us to address the inverse problem and to predict the mean trabecular thickness. The backscatter coefficient is expressed in terms of an autocorrelation function of the medium. Comparison is made with experimental data for 19 specimens and for frequency ranging from 0.4 to 1.2 MHz. For each specimen a non-linear regression is performed and the mean trabecular thickness is estimated. Experimental data and theoretical predictions are averaged over the 19 specimens. A good agreement between experimental data and predictions was found for both the magnitude and the frequency-dependence of the backscatter coefficient. We also found a good agreement between the experimental mean trabecular thickness (Tb.Th=130/spl plusmn/6.5 /spl mu/m) derived from the analysis of bone 3-D micro-architecture using high resolution micro-tomography and theoretical predictions (d/sub Gauss/ = 140/spl plusmn/10 /spl mu/m, d/sub exponential/=153/spl plusmn/12.5 /spl mu/m). These results open interesting prospects for the estimation of the mean trabecular thickness from in vivo measurements.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115769286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Towards virtual biopsy through an all fiber optic ultrasonic miniaturized transducer: a proposal 通过全光纤超声微型换能器实现虚拟活检:一个建议

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192558

A. Acquafresca, E. Biagi, S. Cerbai, L. Masotti

引用次数: 5

Ringdown reduction for an intraluminal ultrasound array using depth-dependent azimuthal filters 利用深度相关的方位滤波器减少腔内超声阵列的振铃

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192642

F. J. de Ana, M. O’Donnell

{"title":"Ringdown reduction for an intraluminal ultrasound array using depth-dependent azimuthal filters","authors":"F. J. de Ana, M. O’Donnell","doi":"10.1109/ULTSYM.2002.1192642","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192642","url":null,"abstract":"Vibration of piezoelectric elements after electrical excitation creates ringdown artifacts in ultrasound images close to the transducer surface. For intraluminal applications, high quality images are often needed at depths close to the catheter surface. Consequently, ringdown artifacts pose a serious problem for intraluminal circumferential arrays. A current method to reduce these artificial echoes subtracts a precalibrated ringdown signal from each frame in a data set. The dynamic nature of the ringdown artifact, however, reduces the effectiveness of this subtraction algorithm with time following data collection. The ringdown signal has very distinctive characteristics, especially in the near field azimuthal spectrum. An in-depth study of those characteristics presents new alternatives to minimize ringdown artifacts. Using a set of depth-dependent azimuthal filters, we present a method to significantly reduce ringdown artifacts while minimally affecting the real signal. Rubber phantoms with embedded graphite particles were imaged close to the transducer surface to study potential improvements obtained with the azimuthal filters. Results show a reduction of the ringdown signal by at least 10 dB, while increasing the dynamic range between the real signal and the ringdown from 2 dB to 15 dB. The combination of azimuthal filtering with ringdown subtraction can greatly enhance contrast at ranges close to the transducer surface.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129981483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

High coupling, zero TCD SH wave on LGX 高耦合，LGX上零TCD SH波

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193425

M. Pereira da Cunha, D. Malocha, D. Puccio, J. Thiele, T. Pollard

{"title":"High coupling, zero TCD SH wave on LGX","authors":"M. Pereira da Cunha, D. Malocha, D. Puccio, J. Thiele, T. Pollard","doi":"10.1109/ULTSYM.2002.1193425","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193425","url":null,"abstract":"This paper reports predicted and measured properties of the pure shear horizontal (SH) mode for the LGX family of crystals, which includes langasite (LGS), langanite (LGN), and langatate (LGT). Our results show high electromechanical coupling and zero temperature coefficient of delay (TCD) along LGX Euler angles (0/spl deg/, /spl theta/, 90/spl deg/), /spl theta/ between 10/spl deg/ and 25/spl deg/, with penetration depths which are comparable to SAW devices. In particular along LGT (0/spl deg/, 13.5/spl deg/, 90/spl deg/), experimental results are disclosed with resonators and delay line structures which verify the high electromechanical coupling (0.8%), about 10 times stronger than the 36/spl deg/ Y rotated quartz SH orientation, and zero TCD around 140 *C. The penetration depth of 7 wavelengths is about eight times shallower than 36/spl deg/ Y quartz. The phase velocity of 2660 m/s is within 0.2% of the calculated value, which is about 55% below the phase velocity of 36/spl deg/ Y quartz, thus leading to smaller Surface Transverse Wave (STW) devices. With such positive predicted and measured coupling and propagation characteristics, these orientations suggest the fabrication of high coupling, zero TCD, and smaller STW devices for liquid sensor, filtering, and frequency control applications.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134505087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Measurement of behavior at welding resin parts using ultrasonic technique 用超声波技术测量树脂零件焊接时的性能

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193524

N. Nishiwaki, S. Hori, N. Otsuki, S. Zhou

引用次数: 0