2002 IEEE Ultrasonics Symposium, 2002. Proceedings.最新文献_第3页

Shear-horizontal-type surface acoustic waves on quartz with Ta/sub 2/O/sub 5/ thin film Ta/sub - 2/O/sub - 5/薄膜石英上的剪切水平型表面声波

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193434

S. Kakio, Y. Shimatai, Y. Nakagawa

引用次数: 1

Limited diffraction maps for pulsed wave annular arrays 脉冲波环形阵列的有限衍射图

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193457

Paul D Fox

引用次数: 0

Ultra high speed imaging of elasticity 超高速弹性成像

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192651

M. Fink, L. Sandrin, M. Tanter, S. Catheline, S. Chaffai, J. Bercoff, J. Gennisson

引用次数: 36

Comparison of finite elements model elastograms and IVUS elastograms acquired from phantoms and arteries 有限元模型弹性图与幻影和动脉IVUS弹性图的比较

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192674

R. Baldewsing, C. D. de Korte, F. Mastik, J. Schaar, A. V. D. van der Steen

引用次数: 6

Acoustic nonlinear parameter measurement in solid with a contact phase modulation method 接触式相位调制法测量固体中声学非线性参数

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193538

O. Matar, S. D. Santos, Michel Vila, F. Meulen

引用次数: 13

Relationship between skin-collagen micro-architecture and ultrasonic backscatter parameters at 20 MHz 皮肤胶原微结构与20 MHz超声后向散射参数的关系

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193480

C. Fournier, S. Bridal, A. Coron, P. Laugier

{"title":"Relationship between skin-collagen micro-architecture and ultrasonic backscatter parameters at 20 MHz","authors":"C. Fournier, S. Bridal, A. Coron, P. Laugier","doi":"10.1109/ULTSYM.2002.1193480","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193480","url":null,"abstract":"This in vitro study investigates the role of skin-collagen in the variation of the integrated backscatter coefficient (IBS) and the frequency dependence of backscatter (n). IBS and n (11-27 MHz) were estimated from spectral analysis of radio frequency (RF) signals acquired in 31 human skin specimens of abdomen and breast dermis at depths of 370, 620 and 880 /spl mu/m beneath the skin surface. Microscopic morphometrical analysis was applied at matched depths of histologic sections from each specimen to estimate mean thickness of collagen bundles (TH), mean space between bundles (SP) and percent fractional-area occupied by the collagen (%A). Both IBS and n decreased with depth of the measurement region beneath the skin surface and were significantly different for abdomen and breast. For abdomen specimens, n was inversely correlated to TH and %A in the most superficial depth. IBS was inversely correlated to %A in the most superficial depth. For breast samples, IBS significantly decreased as SP increased at all three depths. Knowledge of the relationship between dermal collagen distribution and acoustic properties should aid interpretation of in vivo ultrasound measurements.","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":"116111700","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: 3

An improved four-focal zone high-frequency ultrasound analog beamformer 一种改进的四焦区高频超声模拟波束形成器

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193478

J. Stitt, R. Tutwiler, K. Shung

引用次数: 11

Paper characterization by measurement of thickness and plate resonances using air-coupled ultrasound 利用空气耦合超声测量厚度和板共振的纸张特性

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193534

T. Gómez, B. González, F. Montero

引用次数: 18

Design of a real time digital beamformer for a 50MHz annular array ultrasound transducer 50MHz环形超声换能器实时数字波束形成器的设计

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192604

P. Cao, K. Shung, N. Karkhanis, Wohsing Chen

{"title":"Design of a real time digital beamformer for a 50MHz annular array ultrasound transducer","authors":"P. Cao, K. Shung, N. Karkhanis, Wohsing Chen","doi":"10.1109/ULTSYM.2002.1192604","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192604","url":null,"abstract":"A Field Programmable Gate Array (FPGA) based real time beamformer was developed for a six-ring annular array ultrasound transducer. Six analog to digital converters (AD9054, Analog Devices Inc.) were used to digitized the echoes at 200MHz. A Xilinx Virtex E FPGA chip which works at a 200MHz clock was used to delay the digitized echoes for beamforming. The delay for each channel was accomplished in two steps. A programmable FIFO was used for the delays of integer multiples of the clock period, a 4-tap Fractional Delay (FD) FIR filter was used for the delays less than one clock period. A high speed Cypress FIFO was used to transfer the summed beam to a DSP microprocessor (ADSP21065L). The DSP microprocessor completes envelope detection, imaging processing and transfers the image data to a computer for display through a PCI bus I/O card (PCI6534, National Instruments). The source codes for FPGA were written in VHDL language and schematic capture. A lookup table method based multiplier was designed to improve the speed of algorithm. The whole beamformer was designed in a pipeline structure; it is capable of working at 240MHz clock frequency after implemented in ISE Foundation 4.2i (Xilinx Inc). Using a Gaussian modulated sinusoidal pulse, with a 50MHz center frequency and a 50% bandwidth, the Matlab simulation study shows that the FD filter gave a maximal error of 11.2% in amplitude from the ideal waveform, and a 0.3% maximum mean square error when the required delay was 0.2 of the clock period.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"3 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":"129517662","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: 11

Compensating transducer diffraction effects in synthetic aperture imaging for immersed solids 浸没固体合成孔径成像中的补偿传感器衍射效应

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193502

F. Lingvall, T. Stepinski

{"title":"Compensating transducer diffraction effects in synthetic aperture imaging for immersed solids","authors":"F. Lingvall, T. Stepinski","doi":"10.1109/ULTSYM.2002.1193502","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193502","url":null,"abstract":"One of the fundamental requirements for the successful application of the classical synthetic aperture focusing technique (SAFT) is the use of a transducer that emits spherical (cylindrical) waves. For a planar transducer, the performance of the SAFT algorithm will deteriorate if its active area becomes too large comparing to the wavelength. This is due to the spatial impulse responses (SIRs) associated with the transducer that no longer resemble Dirac functions since the emitted waves is not spherical. Therefore, to achieve a high resolution or finite-sized transducers, the SIRs must be taken into consideration. Here, we propose a method that is based on a discrete linear model of the imaging system. The method uses a spatio-temporal deconvolution technique designed to minimize the mean squared reconstruction error of the imaging system. To demonstrate the performance of the proposed method we present experiments using a phased array for the inspection of a copper specimen. The results obtained using the deconvolution method for finite apertures are compared to those obtained with a time-domain SAFT algorithm and a focused phased array.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"65 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":"128295102","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