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

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

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

Propagation of acoustic waves in plates bordered with viscous liquid 声波在有粘性液体的板中的传播

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663044

B. Zaitsev, V. Kunetsova, S. Joshi

{"title":"Propagation of acoustic waves in plates bordered with viscous liquid","authors":"B. Zaitsev, V. Kunetsova, S. Joshi","doi":"10.1109/ULTSYM.1997.663044","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663044","url":null,"abstract":"This paper is concerned with the influence of a viscous liquid on the propagation of acoustic waves in thin plates of lithium niobate. The characteristics of the three lowest order wave modes that such a plate can support (zeroth order antisymmetric Lamb wave A/sub 0/, symmetric Lamb wave S/sub 6/, and quasi-shear-horizontal wave QSH/sub 6/) are investigated. It is assumed that the liquid is isotropic such that its viscous properties are described by two independent components of viscosity tensor /spl eta//sub 11/ and /spl eta//sub 44/. It is found that the attenuation of the waves depends primarily on the shear component of viscosity /spl eta//sub 44/. The influence of expansion component /spl eta//sub 11/ is negligible. The attenuation per unit length is proportional to (/spl eta//sub 44/)/sup 1/2 / and f/sup 1,3/, where f is the frequency of the wave. Under identical conditions, the lowest value of attenuation is for the S/sub 0/ mode, while the highest is for the A/sub 0/ mode. For example, for h//spl lambda/=0.025 (h=plate thickness, /spl lambda/=acoustic wavelength) and /spl eta//sub 44/=0.003 Ns/m/sup 2/, the attenuation in dB/cm at a frequency of 1 MHz for A/sub 0/, S/sub 0/ and QSH/sub 0/ modes is 13.5, 0.024, and 0.073, respectively. The above results indicate that the S/sub 0/ wave is most suitable for use in devices operating in contact with a viscous liquid. The results also show that by using the three different wave modes, one can develop a viscosity meter with a very wide measurable range of viscosity.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"17 1","pages":"381-384 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82138540","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: 14

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

Ultrasound attenuation measurement of tissue in frequency range 2.5-40 MHz using a multi-resonance transducer 使用多共振换能器在2.5-40 MHz频率范围内测量组织的超声衰减

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661789

N. Kudo, T. Kamataki, K. Yamamoto, H. Onozuka, T. Mikami, A. Kitabatake, Y. Ito, H. Kanda

引用次数: 6

Multi-parametric imaging of atherosclerotic plaque by 50 MHz ultrasound and 3 Tesla magnetic resonance 动脉粥样硬化斑块的50 MHz超声和3特斯拉磁共振多参数成像

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661765

S. Bridal, J. Toussaint, J. Raynaud, P. Fornés, A. Leroy-Willig, G. Berger

引用次数: 2

Medical ultrasonic transducers with switchable frequency bands centered about f/sub 0/ and 2f/sub 0/ 以f/sub 0/和2f/sub 0/为中心的可切换频带的医用超声换能器

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663314

T. R. Gururaja, A. Shurland, J. Chen

引用次数: 11