2002 IEEE Ultrasonics Symposium, 2002. Proceedings.最新文献_第7页

An approach to perfection of the characteristics of leaky surface acoustic wave on LST-cut quartz 一种完善lst切割石英泄漏表面声波特性的方法

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193345

T. Watanabe

引用次数: 5

Mathematical optimisation of multilayer piezoelectric devices with non-uniform layer thicknesses by simulated annealing 非均匀层厚多层压电器件的模拟退火数学优化

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192510

A. Abrar, S. Cochran

{"title":"Mathematical optimisation of multilayer piezoelectric devices with non-uniform layer thicknesses by simulated annealing","authors":"A. Abrar, S. Cochran","doi":"10.1109/ULTSYM.2002.1192510","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192510","url":null,"abstract":"We report a theoretical investigation of multilayer piezoelectric structures with non-uniform layer thicknesses. Our results come from a study of such structures using computer code based on solving the one-dimensional wave equation by matrix manipulation and validation using finite element analysis. We first show how structures with nonuniform layer thicknesses generate even harmonics in their frequency response as well as the odd harmonics generated by devices with uniform layer thicknesses. We have found that control can be exerted over the complete frequency response by appropriate choice of layer thickness. However, for most transducer configurations, the relationship between frequency response and layer thicknesses is very complicated. To overcome this, we have investigated the stochastic optimisation technique of simulated annealing. This allows a transducer configuration to be obtained with a desired frequency response expressed as a cost function. The cost function reported here maximises uniformity of the fundamental and second and third harmonics of output pressure, which we have achieved to approximately /spl plusmn/3%. The results are promising and may deliver additional bandwidth for applications in underwater sonar and biomedical imaging. To illustrate their potential, we also describe a three-layer 1-3 connectivity piezocomposite transducer with a strong response extending over the fundamental and first two harmonics.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"50 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":"124582803","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

Sound source with direction-variable beam using annular transducer array 采用环形换能器阵列的变向波束声源

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192485

H. Masuyama, K. Mizutani, K. Nagai

引用次数: 3

Associations between parameters of ultrasound transmission and structural parameters of cortical bone 超声传输参数与骨皮质结构参数之间的关系

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192611

R. Barkmann, C. Gluer

引用次数: 6

Microsphere capture and perfusion in microchannels using flexural plate wave structures 利用弯曲板波结构在微通道中捕获和灌注微球

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193445

J. Black, R. White, J. Grate

引用次数: 11

Shear strain elastography 剪切应变弹性学

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192671

F. Viola, W. Walker

{"title":"Shear strain elastography","authors":"F. Viola, W. Walker","doi":"10.1109/ULTSYM.2002.1192671","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192671","url":null,"abstract":"In the breast, prostate and other organs increased tissue stiffness is often associated with the presence of disease. While palpation remains widely used, it has limited sensitivity which is highly dependent upon the skill of the clinician. To overcome this and other limitations a variety of automated approaches have been developed in recent years. These techniques generate tissue deformation by applying acoustic radiation force internally, shear waves superficially, or axial compression. In this paper we propose an alternate approach for elasticity imaging. A shear deformation is applied to the tissue surface. Ultrasound images obtained before and after shear application are processed to yield images of shear strain. We tested this method experimentally on custom acrylamide gel phantoms using a Philips SONOS 5500 imaging system. The phantoms consisted of a 5% acrylamide background with 15% acrylamide inclusions. 50 /spl mu/m sephadex spheres were used in the background and inclusion to introduce ultrasonic scattering. 4% shear rates were generated by translating the upper surface of the 5 cm thick phantoms by 2.0 mm. The shear strains observed within the inclusions of each phantom were roughly one third those seen in the background region. As anticipated, little axial deformation was observed. Experimentally obtained shear strain images clearly delineate the inclusions with few artifacts, although some noise is visible. This noise undoubtedly arises from jitter in the lateral displacement estimates. Theoretical analysis suggests that signal decorrelation under lateral shear will be very small. This, coupled with the minimal artifacts visible in the shear strain images may make shear elastography an attractive alternative to techniques.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"7 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":"125840108","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: 7

Stepping motion analysis of surface acoustic wave motor toward nanometer resolution positioning system 面向纳米分辨率定位系统的表面声波电机步进运动分析

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193487

T. Shigematsu, M.K. Kuroswa, K. Asai

引用次数: 5

Three-dimensional real-time synthetic aperture imaging using a rotating phased array transducer 利用旋转相控阵换能器进行三维实时合成孔径成像

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192596

S. Nikolov, J. A. Jensen, R. Dufait, Armin Schoisswohl

{"title":"Three-dimensional real-time synthetic aperture imaging using a rotating phased array transducer","authors":"S. Nikolov, J. A. Jensen, R. Dufait, Armin Schoisswohl","doi":"10.1109/ULTSYM.2002.1192596","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192596","url":null,"abstract":"Current 3D real-time imaging is done either with sparse 2D arrays, or with mechanically moved phased arrays. The former results in a poor resolution and contrast due to a limited amount of elements. The latter has the disadvantage of low frame rates due to the sequential acquisition of the volume line-by-line and plane-by-plane. This paper describes an approach which combines mechanically moved phased array with synthetic transmit aperture imaging, resulting in high volume acquisition rates without a trade-off in image quality. The scan method uses a conventional fully populated 64 element phased array, which is rotated over the volume of interest. The data is acquired using coded signals and synthetic transmit aperture imaging. Only one group of elements transmits at a time. The delays are set such as to form a cylindrical wave. The back-scattered signal carries information not only from the plane located directly below the transducer, but also from neighboring planes. A complete dataset for all elements for the whole rotation is acquired and stored. The volume is then focused from this complete data set in order to obtain dynamic transmit and receive focusing in all directions.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"31 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":"125014000","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: 24

A mechanical vibration sensing technique using a liquid delay line oscillator 一种利用液体延迟线振荡器的机械振动传感技术

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193541

T. Fujita, K. Toda

引用次数: 0

Finite element simulation of bulk- and surface acoustic wave (SAW) interaction in SAW devices 声表面波与体声相互作用的有限元模拟

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193351

M. Hofer, N. Finger, G. Kovacs, J. Schoberl, U. Langer, R. Lerch

引用次数: 28