1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)最新文献_第8页

Pulse inversion Doppler: a new method for detecting nonlinear echoes from microbubble contrast agents 脉冲逆多普勒:一种检测微泡造影剂非线性回波的新方法

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663301

D. Simpson, P. Burns

引用次数: 207

Thermal generation, diffusion and dissipation in 1-3 piezocomposite sonar transducers: finite element analysis and experimental measurements 1-3个压电复合声纳换能器的热产生、扩散和耗散:有限元分析和实验测量

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661725

N. Abboud, J. Mould, G. Wojcik, D. Vaughan, D. Powell, V. Murray, C. Maclean

{"title":"Thermal generation, diffusion and dissipation in 1-3 piezocomposite sonar transducers: finite element analysis and experimental measurements","authors":"N. Abboud, J. Mould, G. Wojcik, D. Vaughan, D. Powell, V. Murray, C. Maclean","doi":"10.1109/ULTSYM.1997.661725","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.661725","url":null,"abstract":"Thermal management is an important consideration in ultrasound transducer design. It arises in satisfying regulatory and safety requirements in diagnostic and therapeutic ultrasound, as well as in sustaining performance in high power applications such as underwater sonar. A finite element modeling approach was developed to aid in the analysis of this coupled electro-mechanical-thermal problem. The finite element model tracks the damping losses in the electromechanical portion of the problem and converts the lost energy into a thermal dose which constitutes the \"input\" to the thermal portion of the problem. The resultant temperature spatial and temporal distribution is then solved for. This modeling approach was used to study several 1-3 piezocomposite high power transducers for which experimental data was available. Previous experimental evaluation has demonstrated that these devices can suffer from a degradation in performance due to significant temperature rises at power levels of approximately 2 W/cm/sup 2/ for continuous operation, whereas they can operate efficiently at power levels greater than 20 W/cm/sup 2/ when the duty cycle is reduced below 10%. A detailed thermal analysis of these transducers with respect to efficiency of the thermal dissipation within them is required with a view to understanding and consequently improving the high drive performance of these devices. The goal of this preliminary study is to evaluate the modeling approach and identify key parameters to which the solution is sensitive. Parameters so identified, be they material constants or modeling approaches, will be subject to more complete characterization in follow-up studies aimed at quantitative validation of computational modeling of thermal management in ultrasonic applications.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"89 1","pages":"895-900 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80250719","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: 22

An efficient method of including electrode interactions in the Green's function model for SAW interdigital transducers 一种有效的方法，包括电极的相互作用，在绿色的函数模型，为SAW数字间换能器

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.662994

W. Liu, P.M. Smith

引用次数: 0

Sol-gel fabricated thick piezoelectric ultrasonic transducers for potential applications in industrial material processes 溶胶-凝胶制备的厚压电超声换能器在工业材料加工中的潜在应用

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661751

L. Zou, M. Sayer, C. Jen

引用次数: 16

Regularized autoregressive models for a spectral estimation scheme dedicated to medical ultrasonic radio-frequency images 医用超声射频图像频谱估计方案的正则化自回归模型

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661852

J. Gorce, D. Friboulet, J. D’hooge, B. Bijnens, I. Magnin

{"title":"Regularized autoregressive models for a spectral estimation scheme dedicated to medical ultrasonic radio-frequency images","authors":"J. Gorce, D. Friboulet, J. D’hooge, B. Bijnens, I. Magnin","doi":"10.1109/ULTSYM.1997.661852","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.661852","url":null,"abstract":"The local spectral estimation from radio-frequency (RF) signals in medical echographic ultrasound images is not a trivial task due to the noisy nature of the data resulting from a stochastic and nonstationary process, Significant improvements may be obtained by proposing a spatial regularization scheme, smoothing the local spectral estimates while preserving the discontinuities. Based on AR models, the authors propose a 2D regularization scheme in a Bayesian framework. The a-priori knowledge is expressed by means of Markovian Random Fields (MRF) defined on the reflection coefficients. The use of nonquadratic functions allows to preserve discontinuities. First the authors applied their method on simulated data containing spatial discontinuities of spectral characteristics, which showed the efficiency of the regularization technique. Then the technique was used on cardiac RF data. This shows the improvements as well for Integrated Backscatter (IBS) images as for Mean Central Frequency (MCF) Images or whole spectral estimation.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"14 1","pages":"1461-1464 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89950670","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: 6

SAW device implementation of a new weighted stepped chirp code signal for direct sequence spread spectrum communications systems SAW器件实现了一种新的加权阶跃啁啾码信号，适用于直接序列扩频通信系统

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663033

S.E. Carter, D. Malocha

引用次数: 2

High-resolution spectrometer systems based on SAW chirp filters 基于声表面波啁啾滤波器的高分辨率光谱仪系统

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.662986

Yuxing Zhang, J. Gong, Xianwen Zhou, Yulan Wei, J. Cheeke

引用次数: 6

A simple method for generating the monopole ultrasonic pulse and its sound field 一种产生单极子超声脉冲及其声场的简单方法

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661753

K. Imano, H. Inoue

引用次数: 0

Suppression of propagating second harmonic in non-linear imaging 非线性成像中传播二次谐波的抑制

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663295

S. Krishnan, J. D. Hamilton, Matthew O'Donnell

引用次数: 4

Methods for dynamic range expansion and enhancement of the signal-to-noise ratio in elastography 弹性成像中动态范围扩展和信噪比提高的方法

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661783

E. Konofagou, S. Alam, J. Ophir, T. Krouskop

引用次数: 8