IEEE Ultrasonics Symposium, 2005.最新文献_第3页

Peripheral vascular ARFI imaging: phantom and clinical results 周围血管ARFI成像:幻像和临床结果

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1602925

D. Dumont, E. Miller, J.D. Allen, C. Moyer, S. Hsu, G. Trahey

{"title":"Peripheral vascular ARFI imaging: phantom and clinical results","authors":"D. Dumont, E. Miller, J.D. Allen, C. Moyer, S. Hsu, G. Trahey","doi":"10.1109/ULTSYM.2005.1602925","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1602925","url":null,"abstract":"Non-invasive characterization of focal and dif- fuse atherosclerosis is difficult with existing techniques, but clinically important in guiding the selection of drug, surgical and other treatments. We describe new non-invasive tech- niques for monitoring vascular health with ARFI imaging. Custom ECG-gated beam sequencing was implemented on the Siemens SONOLINE Antares scanner to measure radiation force induced displacements for in vivo vascular tissue. We have developed layered polyvinyl alcohol cryogel (PVA- C) vessel phantoms to mimic arterial layers in the vascular wall. A custom phantom with layers of varying stiffness but homogeneous echogenicity is statically pressurized over the physiological range, and then imaged with acoustic radiation force. Layers are well visualized in the corresponding ARFI images with little contrast seen in the matched B-mode image. Displacement data is examined over the physiological range and suggests that PVA-C demonstrates some nonlinear behavior over physiologically realistic pressures. We present the preliminary results of a clinical pilot study involving twenty-four volunteers with no predisposition for peripheral vascular disease (PVD), and fifteen patients with diagnosed PVD. Both proximal and distal vascular walls are well visualized in the corresponding ARFI displacement images. Plaques that are present in the B-mode image are also well resolved in the corresponding ARFI image, with ARFI displacement images showing higher contrast between the plaque and surrounding vascular tissue than the conventional B-mode image.","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121141659","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

Analysis of serial versus simultaneous XY acoustooptic deflectors 串联与同步XY声光偏转器的分析

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1602829

D. Hecht

{"title":"Analysis of serial versus simultaneous XY acoustooptic deflectors","authors":"D. Hecht","doi":"10.1109/ULTSYM.2005.1602829","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1602829","url":null,"abstract":"Acoustooptic Deflection in two transverse directions (x & y) can be implemented in two ways: 1) serially in which the light passes first through an AO deflector for one direction (x) and then through an AO deflector for the other direction (y) or 2) simultaneously, where acoustic waves induce diffraction in both transverse directions in the same interaction volume. This paper presents comparative analyses and results for the two cases. The first case involves two a two mode (beam) coupled interaction involving deflection in a first direction (x) followed by a pair two mode (beam) coupled interactions involving deflection in the second direction (y); the second case involves one four mode (beam) coupled interaction involving deflections in x and y simultaneously. The interactions considered are Bragg regime with independent arbitrary drive levels in the X and Y directions. The results obtained show that the four output beam intensities I (00), I (10), I (01), I (11), have precisely the same behavior in the two cases, provided that the undeflected beam from the first serial interaction proceeds undisturbed to the second serial interaction. Importantly, the key doubly deflected intensity I (11) is the same in all these cases.","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"286 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125740806","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

Spatio-temporal deconvolution of pulsed ultrasonic fields received by a transducer of linear aperture : a simulation study 线性孔径换能器接收脉冲超声场的时空反卷积:仿真研究

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1603212

W. Djerir, T. Boutkedjirt, M. O. Si-chaib, H. Djelouah

{"title":"Spatio-temporal deconvolution of pulsed ultrasonic fields received by a transducer of linear aperture : a simulation study","authors":"W. Djerir, T. Boutkedjirt, M. O. Si-chaib, H. Djelouah","doi":"10.1109/ULTSYM.2005.1603212","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1603212","url":null,"abstract":"In ultrasonic field measurements, the signal delivered by the receiving transducer is affected by the receiver spatio temporal transmission properties. The pressure is spatially averaged over its finite-size aperture. Furthermore, frequency variations of its transfer function may distort the output signal. The efficiency of the deconvolution of these effects is shown by means of numerical simulations. The pulsed pressure field radiated by a wideband 10.3mm-radius planar transducer, with a central frequency fc = 2.25 MHz ( c: corresponding ultrasonic wavelength in water) is considered. The receiver is a linear aperture 25 μm- thick PVDF membrane hydrophone. The study shows that the quality of the reconstructed signal depends strongly upon the signal-to-noise ratio (SNR), the aperture dimensions and the distance from the source. For an aperture of length L = 2.6 mm ≈3.9c, placed on axis at z = 3 mm, correlation coefficients between the reconstructed pressure and the original one, rppˆ , of 0.999, 0.988 and 0.655 have been obtained, for SNRs of 60, 40 and 20 dB respectively. For a greater aperture (L = 4.6=mm ≈6.9c) and SNR = 40 dB, no satisfactory results could be obtained at this distance ( rppˆ = 0.912). At a greater axial distance (z = 20 mm), better deconvolution results could be achieved ( rppˆ = 0.928).","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126170364","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

Above-IC FBAR technology for WCDMA and WLAN applications 用于WCDMA和WLAN应用的ic以上FBAR技术

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1602802

M. Dubois, C. Billard, J. Carpentier, P. Vincent, G. Parat, C. Muller

引用次数: 6

Analysis of saw propagation under a periodic multi-electrode-type grating 周期性多电极型光栅下锯的传播分析

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1602943

T. Pastureaud, R. Lardat, W. Steichen, P. Ventura

引用次数: 3

Enhanced echographic images obtained improving the membrane structural layer of the cMUT probe 增强的超声图像改善了cMUT探头的膜结构层

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1603259

A. Savoia, G. Caliano, R. Carotenuto, C. Longo, P. Gatta, A. Caronti, E. Cianci, V. Foglietti, M. Pappalardo

{"title":"Enhanced echographic images obtained improving the membrane structural layer of the cMUT probe","authors":"A. Savoia, G. Caliano, R. Carotenuto, C. Longo, P. Gatta, A. Caronti, E. Cianci, V. Foglietti, M. Pappalardo","doi":"10.1109/ULTSYM.2005.1603259","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1603259","url":null,"abstract":"The validity of cMUT technology for medical imag- ing applications has been proved by many authors. The large bandwidth obtainable with capacitive Micromachined Ultrasonic Transducers (cMUT) leads to improved image resolution if compared to their piezoelectric counterpart. However cMUTs actually show lower sensitivity than piezoelectric transducers, mainly due to their non optimized design and fabrication technol- ogy. Recently, we developed in our laboratories a dual-frequency plasma-enhanced chemical-vapour-deposition (DF-PECVD) pro- cess, improving the electrical and mechanical characteristics of the silicon nitride films that we employed to fabricate cMUTs. The DF-PECVD technique makes it possible to control, with extreme precision and over a wide range of values, the stress of the grown silicon nitride film. The result is an increased cohesion and an increased resistivity of the silicon nitride film. As a consequence, the porosity of the obtained DF-PECVD nitride film is extremely reduced thus contributing to effectively sealing the underlying cavities of the cMUT membranes. The improvement of both mechanical and electrical properties of the cMUT structural layer has led to higher transmission and reception sensitivity. Using this silicon nitride deposition technique, we have fabricated 64-elements, 5 MHz echographic probes featuring 100% bandwidth and higher sensitivity characteristics leading to a remarkable improvement in the quality of the echographic images.","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115512844","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: 20

Nonlinear corruption of ultasound transmission by microbubble contrast agents 微泡造影剂对超声传输的非线性破坏

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1603190

R. Eckersley, M. Tang

{"title":"Nonlinear corruption of ultasound transmission by microbubble contrast agents","authors":"R. Eckersley, M. Tang","doi":"10.1109/ULTSYM.2005.1603190","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1603190","url":null,"abstract":"Current techniques for detection of microbubble contrast agents make use of their nonlinear behavior under ultrasound insonation. For these techniques there is a problem which has been largely ignored so far; the bubbles along the ultrasound transmission path between transducer and target bubbles alter the ultrasound signal nonlinearly and contribute to the nonlinearity of the echoes. This process can lead to imaging artifacts, especially in regions at depth. In this paper the nonlinear alteration of ultrasound transmission due to microbubbles is referred to as corruption. The aim of this work is to provide insight into the nonlinear corruption caused by microbubble contrast agents and the effects on current nonlinear imaging techniques. The corruption is investigated through both simulation and experimental measurements. Results show that the imaging artifact due to this corruption is significant when detection techniques deploying multiple insonation pulses, such as power modulation and combined phase and amplitude modulation are used. Further investigation reveals that the corruption affects both amplitude and phase of ultrasound transmission and is dependent on both the initial amplitude and phase of the insonation pulse. Our results also suggest that forward scattering may play a significant role in the nonlinear corruption process.","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122511948","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: 2

A study of motion artifacts of fourier-based image construction 基于傅里叶图像构造的运动伪影研究

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1603127

Jing Wang, Jian-yu Lu

引用次数: 10

Development of broadband, omni-directional transducers for NDE applications 用于无损检测应用的宽带、全向传感器的开发

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1602880

O. Keitmann-Curdes, M. Parusel, W. Wilkening, M. Mienkina, H. Ermert

{"title":"Development of broadband, omni-directional transducers for NDE applications","authors":"O. Keitmann-Curdes, M. Parusel, W. Wilkening, M. Mienkina, H. Ermert","doi":"10.1109/ULTSYM.2005.1602880","DOIUrl":"https://doi.org/10.1109/ULTSYM.2005.1602880","url":null,"abstract":"In order to image highly reflecting (metallic) surfaces in a water-oil-emulsion under high pressure by means of ultrasound, broadband transducers with a wide opening angle (point-sources, spherical waves) are needed, which are not commercially available. Thus, efforts were made to develop and produce such ultrasonic transducers with a potential resistance against high static pressure of up to 400 bar. Most promising for this problem are piezoceramic hemispheres. Such elements generate spherical waves on either side. We decided to use the convex side of the hemisphere as the emitting ultrasonic aperture. Our transducer designs incorporate backing material and a twolayer matching to water. Different materials were investigated regarding their suitability as transducer backing media and regarding their compatibility with the designated ambient conditions. On the aperture side, two matching layers were designed consisting of metal and perspex (plexiglas). We present different realizations of ultrasonic transducers with 1...2 MHz center frequencies and optimized backing and matching materials. Recipes for easy transducer modeling will be provided. The presented transducers are mainly characterized by 6dBbandwidths of more than 50 % and opening angles of more than 120°. KeywordsNDE, Transducers","PeriodicalId":302030,"journal":{"name":"IEEE Ultrasonics Symposium, 2005.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114281287","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

Organic vapor sensing and discrimination using enhanced sensitivity thickness shear mode devices 使用增强灵敏度厚度剪切模式装置的有机蒸汽传感和鉴别

IEEE Ultrasonics Symposium, 2005. Pub Date : 2005-09-18 DOI: 10.1109/ULTSYM.2005.1603134

R.D. Williams, S. Cular, V. Bhethanabotla

引用次数: 0