1996 IEEE Ultrasonics Symposium. Proceedings最新文献_第7页

Surface acoustic wave humidity sensor based on the changes in the viscoelastic properties of a polymer film 表面声波湿度传感器基于聚合物薄膜粘弹性特性的变化

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584009

J. Cheeke, N. Tashtoush, N. Eddy

{"title":"Surface acoustic wave humidity sensor based on the changes in the viscoelastic properties of a polymer film","authors":"J. Cheeke, N. Tashtoush, N. Eddy","doi":"10.1109/ULTSYM.1996.584009","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584009","url":null,"abstract":"In the present work, a 50 MHz SAW device has been successfully applied as a humidity sensor. A YZ-cut lithium niobate substrate was used. The polymer (polyXIO) was deposited either over the substrate or over a metal film on the substrate. A turn-around in the frequency shift and a jump in the attenuation were observed when the polymer was deposited over the substrate directly, and the relative humidity range cannot be covered completely. However, when a metal was deposited between the polymer and the substrate, both the turn-around and the jump disappeared, and the curve was very smooth for the whole range of relative humidity (0-100%). Moreover, the change in attenuation was found to be less for the metallized path. The viscoelastic mechanism appears to dominate for almost the whole range of relative humidity. The sensor was found to be reproducible with a moderate hysteresis effect, of the order of 5%. The sensor appears to have no cross effects from other gases and seems to be highly selective to humidity. This absence of cross effects makes the device a good sensor candidate for humidity measurements in general and to eliminate humidity effects in electronic nose systems.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122287454","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: 46

Velocity shifts and reflection coefficients for periodic interdigital transducers: a demonstration of the equivalence of three methods 周期数字间换能器的速度偏移和反射系数:三种方法等价性的论证

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583958

C. Thoma, Y. Hahn

引用次数: 0

Tissue mimicking material and image artifacts in intravascular elastography 血管内弹性成像中的组织模拟材料和图像伪影

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584201

E. Cespedes, C. D. de Korte, A. V. D. van der Steen, B. Norder, K. te Nijenhuis

{"title":"Tissue mimicking material and image artifacts in intravascular elastography","authors":"E. Cespedes, C. D. de Korte, A. V. D. van der Steen, B. Norder, K. te Nijenhuis","doi":"10.1109/ULTSYM.1996.584201","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584201","url":null,"abstract":"Intravascular ultrasound is being investigated as a tool for imaging the local elasticity of atherosclerotic vessels: obtaining images of the compression modulus is the ultimate goal. In practice, radial strain is used to depict local hardness: this simplification causes artifacts that must be understood or corrected. Phantoms mimicking vessels with atherosclerotic lesions were constructed using agar-gelatin gels. The mechanical properties of these gels were investigated. Gels with varying compression moduli were made using a gelatin solution (8% by weight) with a variable amount of agar (1%-3% by weight). The modulus is determined using a dynamic mechanical analyser. The modulus is strongly dependent on the age and the actual temperature of the samples. By varying the agar concentration, compression moduli spanning a useful range for vascular phantom construction can be achieved. Phantom studies and finite element modelling were used to describe and characterise artifacts. In simple morphologies compensation for the artifacts may be possible, but complex morphologies require complex compensations. In these cases, the finite element method can assist in a correct interpretation of local tissue hardness from strain images.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121121050","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

High intensity focused ultrasound (HIFU) treatment of human pancreatic cancer 高强度聚焦超声(HIFU)治疗胰腺癌

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584238

A. V. Zaitsev, Narendra T. Sanghvi, S. Ikenberry, J. Worzalla, Richard M. Schultz, Tracy D. Self

{"title":"High intensity focused ultrasound (HIFU) treatment of human pancreatic cancer","authors":"A. V. Zaitsev, Narendra T. Sanghvi, S. Ikenberry, J. Worzalla, Richard M. Schultz, Tracy D. Self","doi":"10.1109/ULTSYM.1996.584238","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584238","url":null,"abstract":"The authors performed a pilot study to evaluate both the ability of HIFU to ablate the pancreatic tumor xenografts PANG-1 and efficacy of combination of HIFU treatment with Gemcitabine, a novel antimetabolite chemotherapeutic agent. Gemcitabine hydrochloride (Gemzar(R)) was administered four times every 3 days. HIFU treatment was performed 24 hrs. After first Gemzar(R) injection. Sonablate-200/sup TM/ machine (Focus Surgery Inc.) was used for tumor HTFU ablation. Two spacing sizes between insonation points were used: 0.5 mm linear/spl times/0.8 mm transverse step and 1.0 mm linea/spl times/1.6 mm transverse step. In groups with step size 0.5/spl times/0.8 mm and 1.0/spl times/1.6 mm, 16 out of 16 and 14 out of 16 animals were cured respectively. Combination of Gemzar(R) and HIFU ablation with 1.0/spl times/1.6 mm step size resulted in 100% curative rate. Gemzar(R) alone resulted in 3.2 days of tumor quadrupling delay time. Also the authors simulated the situation when tumor cells are located in the near field of HIFU beam. Whereas treatment in the near field with HIFU alone resulted in 4.2 days of growth delay time, addition of Gemzar(R) to HIFU treatment increased tumor growth delay time up to 10.7 days. The authors' results demonstrate at least additive effect of combination of Gemzar(R) and HIFU ablation.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"430 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116057818","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

Wave equation based analysis of phase aberrations in inhomogeneous tissue 基于波动方程的非均匀组织相像差分析

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584297

B. Ystad, E. Halvorsen, L. Odegaard, B. Angelsen, M. Lygren

{"title":"Wave equation based analysis of phase aberrations in inhomogeneous tissue","authors":"B. Ystad, E. Halvorsen, L. Odegaard, B. Angelsen, M. Lygren","doi":"10.1109/ULTSYM.1996.584297","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584297","url":null,"abstract":"An analysis of phase aberrations and correction algorithms in ultrasound echography is presented. A wave equation for time-harmonic waves in an inhomogeneous energy absorbing tissue is developed, which separates scales that can be treated by geometrical acoustics and scales that have to be treated by perturbation methods. In the experiments sound waves in water are generated and registered by a linear phased array and reflected by a point scatterer. A sample of pork tissue is placed between the array and the point scatterer. Various mixtures of muscle cells and fat with different structures are used. The analysis shows that when the dimensions of inhomogeneities are sufficiently large compared to the transducer dimensions, the amplitude fluctuations over the transducer increase as the distance between the tissue and the transducer is increased. As the dimensions of the tissue decrease, amplitude fluctuations become important at all distances. This happens within the regime of geometrical acoustics. In some experiments highly irregular mixtures of muscle cells and fat induce large variations in the amplitude of the wave over the transducer. As a result the signals are very weak for some elements. These large variations may create problems for correction algorithms that correlate the signals of neighbouring elements of the transducer.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116712234","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

A 2.5 MHz 2D array with Z-axis backing 带有z轴的2.5 MHz二维阵列

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584368

M. Greenstein, P. Lum, H. Yoshida, M. Seyed-Bolorforosh

引用次数: 14

Synthetic aperture imaging with a virtual source element 虚拟源元件合成孔径成像

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584381

C. H. Frazier, W. O’Brien

{"title":"Synthetic aperture imaging with a virtual source element","authors":"C. H. Frazier, W. O’Brien","doi":"10.1109/ULTSYM.1996.584381","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584381","url":null,"abstract":"Currently ultrasonic imaging is performed in one of two modes: conventional B-scan imaging with a focused transducer or array imaging using beamforming processing to achieve the focus. Conventional B-mode imaging suffers from a limited depth of focus while synthetic aperture imaging is limited by a low signal to noise ratio (SNR). A new technique has been proposed that combines these two techniques to overcome the limited depth of focus. The new technique involves focusing the region beyond the focus of the transducer by considering the focus a virtual element. In this paper, the use of the focus as a virtual element is examined, considering the model for the focus as an element, the use of apodization weights to lower sidelobes, and the SNR of the processed image. Using data collected with tungsten wires in a waterbath, it was found that resolution comparable to the resolution at the focus could be achieved while obtaining an acceptable SNR. Apodization was found to lower the sidelobes, but only at the expense of lateral resolution. With these experiments, the virtual source has been shown to exhibit the same behavior as an actual transducer element in response to synthetic aperture processing techniques.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125002110","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

Non invasive echographic techniques for arterial wall characterization 动脉壁特征的无创超声技术

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584174

O. Bonnefous, M. Montaudon, J.C. Sananes, E. Denis

{"title":"Non invasive echographic techniques for arterial wall characterization","authors":"O. Bonnefous, M. Montaudon, J.C. Sananes, E. Denis","doi":"10.1109/ULTSYM.1996.584174","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584174","url":null,"abstract":"The authors' goal is the definition of new vascular ultrasound modalities for the detection and the characterization of vascular diseases. They propose quantitative approaches for local arterial wall lesions evaluations based on ultrasonic measurements of the wall motion dynamics. A conventional ultrasound scanner is configured to provide a very high frame rate up to 200 frames per second. The arterial segments are axially visualized and the resulting RF signals are cross-correlated from frame to frame for the extraction of wall incremental motions. Wall displacements and intraparietal strain images are reconstructed providing dynamic images sequences. Arterial dilations and wall displacements are dynamically superimposed on the grey scale images. In vitro and in vivo data have been processed in order to test and validate these new procedures. In particular, strain images acquired in vitro on arterial samples are compared with the corresponding anatomo-pathological analysis. Wall displacements measurements are confronted to a mechanical model describing arterial lesions as local defects in elastic tubes. The proposed displays are very attractive to observe the arterial wall behaviour in case of plaques or stenoses. Moreover, the obtained wall motions are in good accordance with the modelized ones. These new ultrasonic procedures dynamically describe the mechanical consequences of arterial lesions. It will probably enable physicians to evaluate vascular diseases with pertinent criteria based directly on the arterial wall state.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125019298","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: 25

Determination of SAW phase velocities on the nanoscale 纳米尺度上SAW相速度的测定

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584118

T. Hesjedal, E. Chilla, H.-J. Frohlich

引用次数: 2

A new pulse-echo system for real-time 3D ultrasonic imaging-phantom tests 一种用于实时三维超声成像-模体测试的新型脉冲回波系统

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584304

Jian Shen, C. Simon, O. Haddadin, S. Lucas, E. Ebbini

引用次数: 4