2014 IEEE International Ultrasonics Symposium最新文献_第6页

An improved method of determining peak blood velocity 一种测定峰值血流速度的改进方法

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0559

S. Ricci, D. Vilkomerson, R. Matera, P. Tortoli

{"title":"An improved method of determining peak blood velocity","authors":"S. Ricci, D. Vilkomerson, R. Matera, P. Tortoli","doi":"10.1109/ULTSYM.2014.0559","DOIUrl":"https://doi.org/10.1109/ULTSYM.2014.0559","url":null,"abstract":"The peak blood velocity is used in important diagnostic applications, e.g. for determining the stenosis degree. The peak velocity is typically assessed by detecting the highest frequency in the Doppler spectrum. The selected frequency is then converted to velocity by the Doppler equation. This procedure contains multiple potential sources of error: the peak frequency selection is sensitive to noise and affected by spectral broadening, and the frequency to velocity conversion is altered by the Doppler angle uncertainty. The result is an inaccurate estimate. In this work we propose a new method that removes the aforementioned errors. By exploiting a mathematical model of the Doppler spectrum the exact frequency to be converted to velocity, with no need of broadening compensation, is determined. The angle ambiguity is solved by calculating the Doppler spectra backscattered from two different receive apertures. The proposed methods uses, in transmission and receive, defocused steered waves that produce a wide sample volume. This includes the whole vessel section making the probe positioning quick and easy. The method, validated through Field II simulations and phantom experiments, featured a mean error lower than 1%.","PeriodicalId":153901,"journal":{"name":"2014 IEEE International Ultrasonics Symposium","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133261740","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

Active induction of microbubbles in flow at T-form bifurcation through acoustic focal points with phase variation 通过相位变化的声焦点在t形分叉处主动诱导流动中的微气泡

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0259

K. Masuda, N. Hosaka, R. Koda, Shinya Miyazawa, T. Mochizuki

{"title":"Active induction of microbubbles in flow at T-form bifurcation through acoustic focal points with phase variation","authors":"K. Masuda, N. Hosaka, R. Koda, Shinya Miyazawa, T. Mochizuki","doi":"10.1109/ULTSYM.2014.0259","DOIUrl":"https://doi.org/10.1109/ULTSYM.2014.0259","url":null,"abstract":"We have ever reported the method to produce three-dimensional acoustic force field to prevent microbubbles dispersing in flow. However, because produced acoustic force worked only to propel microbubbles in the direction of propagation of ultrasound, there was a limitation in direction to affect the behavior of microbubbles. In this research we examined to produce attractive force toward the transducer by considering phase variation of acoustic field. We used a flat matrix array transducer including 64 PZT elements, which was specially developed to produce a continuous wave. We prepared a T-form bifurcation model as artificial blood vessel, which was difficult to control the course of microbubbles. We produced an acoustic field of two focal points with opposite phase, where the middle of the points covers the bifurcation. As the results, when microbubbles suspension (average diameter of 4 um, density of 2.35 μl/ml) was injected with velocity of 40 mm/s, we confirmed that microbubbles aggregations were produced before reaching the bifurcation point and entered the bifurcation to be propelled to the desired path, where the course of microbubbles corresponded to the middle of the two focal points.","PeriodicalId":153901,"journal":{"name":"2014 IEEE International Ultrasonics Symposium","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128889649","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

Design of a minimally invasive low-frequency microtransducer for ultrasonic neuromodulation 用于超声神经调节的微创低频微换能器的设计

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0100

Amit P. Mulgaonkar, Rahul S. Singh, G. Saddik, Ashkan Maccabi, W. Melega, M. Culjat, W. Grundfest

引用次数: 0

Full-field characterization of surface vibrations in microacoustic components by supercontinuum laser stroboscopic white-light interferometry 超连续介质激光频闪白光干涉法研究微声元件表面振动的全场表征

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0040

L. Lipiainen, K. Kokkonen, S. Novotny, I. Shavrin, H. Ludvigsen, M. Kaivola

引用次数: 1

In-vivo convex array vector flow imaging 体内凸阵列矢量流成像

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0082

J. Jensen, A. Brandt, M. Nielsen

{"title":"In-vivo convex array vector flow imaging","authors":"J. Jensen, A. Brandt, M. Nielsen","doi":"10.1109/ULTSYM.2014.0082","DOIUrl":"https://doi.org/10.1109/ULTSYM.2014.0082","url":null,"abstract":"In-vivo VFI scans obtained from the abdomen of a human volunteer using a convex array transducers and transverse oscillation vector flow imaging (VFI) are presented. A 3 MHz BK Medical 8820e (Herlev, Denmark) 192-element convex array probe is used with the SARUS experimental ultrasound scanner. A sequence with a 129-line B-mode image is followed by a VFI sequence in 17 directions with 32 emissions in each direction. The pulse repetition frequency was set to 5 kHz, and the intensity and MI were measured with the Acoustic Intensity Measurement System AIMS III (Onda, Sunnyvale, California, USA). The derated Ispta.3 was 79.7 mW/m2 and MI was 1.32, which are within FDA limits for abdominal scans. The right liver lobe of a 28-year healthy volunteer was scanned with a view of the main portal vein and vena cava inferior at a frame rate of 7.4 Hz. Thirty frames were acquired, giving 4 seconds of data. For this volunteer the duration corresponded to roughly 3 heartbeats. The velocities were found at a beam-to-flow angle of 72 ± 21°, where a conventional CFM scan would yield poor results. Three VF images from the same position in the cardiac cycle were investigated and the mean lateral velocities were -0.079, -0.081 and -0.080 m/s showing the consistence of the in-vivo results.","PeriodicalId":153901,"journal":{"name":"2014 IEEE International Ultrasonics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131332857","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: 9

Accurate finite element model of equiaxed-grain engineering material for ultrasonic inspection 等轴晶粒工程材料超声检测的精确有限元模型

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0337

Bo Xiao, R. O’Leary, A. Gachagan, Wenqi Li, T. Burnett

{"title":"Accurate finite element model of equiaxed-grain engineering material for ultrasonic inspection","authors":"Bo Xiao, R. O’Leary, A. Gachagan, Wenqi Li, T. Burnett","doi":"10.1109/ULTSYM.2014.0337","DOIUrl":"https://doi.org/10.1109/ULTSYM.2014.0337","url":null,"abstract":"Finite element (FE) simulation of grained material with equiaxed grain distribution is of interest for the virtual prototyping of array structures and the assessment of signal processing algorithms. Construction of such models can be computationally intensive due to the large number of crystallographic orientations required to represent the material. This paper concentrates on analysis and processing of orientation data in order to establish a computationally efficient 2D FE model whilst maintaining appropriate accuracy of the grained structure. Two approaches for orientation processing are proposed and their performances are compared. Parametric studies show that the trade-off between computational overhead and model accuracy will reach the optimal point when Euler space is segmented with a bin size of 15 degree per Euler phase. A transducer array is then incorporated into the FE model to generate B-scan image of the material. The image is compared with experimental equivalent for FE model validation purpose. The minor difference of images proves that the constructed FE model is accurate, highlighting the potential of the proposed methods for application on other equiaxed-grain materials.","PeriodicalId":153901,"journal":{"name":"2014 IEEE International Ultrasonics Symposium","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115201545","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

Estimation of model parameters characterizing dispersion in ARFI induced shear waves in in vivo human liver ARFI诱导的人体肝脏横波弥散模型参数的估计

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0241

N. Rouze, M. Palmeri, K. Nightingale

引用次数: 3

Acoustic filtering of particles in a flow regime 流态中粒子的声波过滤

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0355

Kristoffer Johansen, Torstein Yddal, S. Kotopoulis, M. Postema

引用次数: 0

Comparative study of lithium niobate crystal cuts for use as high-voltage acoustic wave sensors 用于高压声波传感器的铌酸锂晶体切割的比较研究

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0493

N. Patel, D. Branch, S. Cular, E. Schamiloglu

引用次数: 0

FPGA embedded system for ultrasound particle manipulation with Sonotweezers 基于Sonotweezers的超声粒子操纵FPGA嵌入式系统

2014 IEEE International Ultrasonics Symposium Pub Date : 2014-10-23 DOI: 10.1109/ULTSYM.2014.0356

Han Wang, Y. Qiu, C. Démoré, S. Cochran

引用次数: 1