2002 IEEE Ultrasonics Symposium, 2002. Proceedings.最新文献_第8页

A FEA/BEM approach to simulate complex electrode structures devoted to guided elastic wave periodic transducers 一种用于导向弹性波周期换能器的复杂电极结构的FEA/BEM模拟方法

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193411

S. Ballandras, V. Laude, T. Pastureaud, M. Wilm, W. Daniau, A. Reinhardt, W. Steichen, R. Lardat

引用次数: 27

Real time vector Doppler for tissue motion 实时矢量多普勒组织运动

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192587

A. Criton, R. Steel, P. Hoskins, W. Mcdicken, H. Routh

{"title":"Real time vector Doppler for tissue motion","authors":"A. Criton, R. Steel, P. Hoskins, W. Mcdicken, H. Routh","doi":"10.1109/ULTSYM.2002.1192587","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192587","url":null,"abstract":"Tissue Doppler Imaging (TDI) can assess tissue motion in vascular and cardiac imaging. However, a major drawback of these measurements is that the motion estimation is limited to the component along the ultrasound beam axis. Cardiac and vessel wall motion studies have shown that complex three-dimensional motions can be observed, and that there is a clinical need to fully assess the three components of the vector motion. This work describes how TDI can be extended by acquiring a real time two-component velocity vector via a dual beam vector Doppler technique. A vector Doppler velocity estimator using a small interbeam angle can suffer from both bias and large variance. This estimator is also strongly dependent on the settings of the echographic system. To reduce the large bias and variance, most vector velocity techniques use a very large ensemble length (EL) (>20), which does not allow real time implementation. We propose a new processing technique, which reduces the bias and the standard deviation of the vector velocity estimate. The new method assumes that the vector velocity angle varies slowly over the cardiac cycle. The angle can then be estimated using a large time window. The performance of this new technique has been tested experimentally using a tissue mimicking rotating phantom. It is shown that the factors influencing the results are the EL, the precision of the TDI estimates and the time window. The results indicate that the variance and bias of velocity magnitude and orientation estimates decrease with increasing EL, increasing precision of the TDI estimates and increasing time window. Using an EL of 9, 8 bits for the velocity estimate, and an observation time of one second, a 5-degree bias of the angle estimate is observed, with a variance below 7 degree averaged over all angles. A 10% bias of the velocity magnitude is observed, with a variance of 1%. In conclusion, TDI can be improved with vector Doppler providing two-dimensional tissue motion estimation, enabling more accurate biomechanical tissue property assessment.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"25 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":"132993746","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: 4

80 MHz three-dimensional ultrasound imaging of corneal lesions induced by cataract surgery 白内障手术致角膜病变的80 MHz三维超声成像

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193477

C. Jolly, A. Coron, M. Pérez, P. Laugier, A. Saied

{"title":"80 MHz three-dimensional ultrasound imaging of corneal lesions induced by cataract surgery","authors":"C. Jolly, A. Coron, M. Pérez, P. Laugier, A. Saied","doi":"10.1109/ULTSYM.2002.1193477","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193477","url":null,"abstract":"The surgery of cataract (phakoemulsification) requires the use of devices that limit the corneal incision burn. The current study aims at evaluating corneal microincision and burn induced by different phacotips using 80 MHz three dimensional (3D) ultrasonography. The study was performed in vitro on 4 fresh pig eyes. Three pig-eyes underwent clear corneal phacoemulsification, using 3 various phacomicrotips. One pig-eye served as control and underwent Clear Corneal Incision (CCI). After surgery, 3D data were acquired from the entire corneal incision volume of each eye using an 80 MHz ultrasound backscatter microscope. The -6dB axial resolution of the system was 25 /spl mu/m at focus. Thermal effects of the phakotips and generation of corneal burns were evaluated on both B-scan images and 3D volume-rendered images of the corneal tunnel reconstructed after manual delineation and selection of the incision regions. Ultrasound images allowed the visualization of corneal tunnel shape and thermal damage due to the different phakotips on the tissue. Comparative study showed the ability of high resolution 3D ultrasonography in detecting the efficiency of phakomicrotips in the prevention of corneal burns.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"11 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":"126455793","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

Monitoring antivascular therapy with high frequency ultrasound flow imaging 高频超声血流显像监测抗血管治疗

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192577

D. Goertz, J. Yu, R. Kerbel, P. Burns, F. Foster

引用次数: 1

Low loss wide band filters and resonator filters using high temperature stable high electromechanical coupling surface acoustic wave substrates 采用高温稳定高机电耦合表面声波基片的低损耗宽带滤波器和谐振器滤波器

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193381

K. Yamanouchi, T. Ishii

引用次数: 1

cMUT echographic probes: design and fabrication process cMUT超声探头:设计和制造过程

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192479

G. Caliano, R. Carotenuto, A. Caronti, M. Pappalardo

{"title":"cMUT echographic probes: design and fabrication process","authors":"G. Caliano, R. Carotenuto, A. Caronti, M. Pappalardo","doi":"10.1109/ULTSYM.2002.1192479","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192479","url":null,"abstract":"The electrostatic capacitive, silicon micro fabricated, ultrasonic transducer (cMUT), approached in the last years, is a new promising alternative to the piezoelectric transducer for echographic probes. The cMUT transducer inherently has a larger bandwidth for immersion application and, because it takes advantage of the well established microelectronic technology it is, potentially, less expensive and gives much more flexibility in the design of complex 1D and 2D arrays than piezoelectric transducers. In perspective, a further advantage of the cMUT is the possibility to be integrated with the front-end electronics on the same silicon wafer. In this paper the design and the fabrication process of a 64-elements cMUT probe is described. We are fabricating an array with a pitch of 0.245 mm, kerf 27 Am, elevation 14 mm, glued on a commercial backing and soldered using a typical connection-comb to permit the electrical connection to the printing circuits, as used in commercial probes. With the addition of the biasing voltage, the probe is ready to be connected to a commercial echographic system, like Technos/spl reg/ (ESAOTE). Due to the inherently large bandwidth, the probe can be used as a linear array at about 7 MHz, and as a phased array at about MHZ..","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"225 1-2 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":"114157379","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: 19

Modelling of ZnO-based BAWs at high signal levels 高信号电平下zno基BAWs的建模

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193561

J. Ella, M. Ylilammi

引用次数: 13

Broadband ultrasonic transducers using a LiNbO/sub 3/ plate with a ferroelectric inversion layer 宽带超声换能器采用带铁电反转层的LiNbO/ sub3 /板

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192516

K. Nakamura, K. Fukazawa, K. Yamada, S. Saito

引用次数: 11

Ultrasound intensity calculations for a vessel with simulated wall lesion 模拟血管壁病变的超声强度计算

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192648

R.S. Thompson, C. Macaskill, L. Farnell, W. Fraser

{"title":"Ultrasound intensity calculations for a vessel with simulated wall lesion","authors":"R.S. Thompson, C. Macaskill, L. Farnell, W. Fraser","doi":"10.1109/ULTSYM.2002.1192648","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192648","url":null,"abstract":"Vascular disease alters the shape of the lumen of a blood vessel. The lumen is not circular from the early stages of the disease, where there is intimal thickening, through to advanced stages where a large plaque may protrude into the lumen. Using a mathematical model we investigated the ultrasound intensity distribution, both within the vessel wall and across the lumen, in the presence of a simulated wall lesion. Acoustic impedance interfaces due to wall lesions have dimensions (typically /spl sim/ 1 mm) only slightly greater than the wavelength (/spl sim/ 0.3 mm for 5 MHz ultrasound). Full wave solutions for the acoustic field are therefore required. Exact solutions in terms of Bessel functions are known for the case of a cylindrical vessel, and a collocation method based on this was developed for non-circular interfaces. By considering two such interfaces we developed a novel model representation of a vessel with a simulated wall lesion. The results of this study show how vessel wall properties may alter the ultrasound intensity distribution within the vessel wall and across the lumen. In the case of non-circular impedance interfaces there can be significant effects due to the local curvature and orientation of the interface.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"10 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":"123855702","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

Piezoelectric transformers - state of the art and development trends 压电变压器的技术现状及发展趋势

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193485

T. Hemsel, W. Littmann, J. Wallaschek

引用次数: 17