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IEEE International Ultrasonics Symposium (IUS)

作者： Lindsey, Brooks D. Jing, Bowen Collins, Graham Kim, Saeyoung Padala, Muralidhar Georgia Inst Technol Coulter Dept Biomed Engn Atlanta GA 30332 USA Emory Univ Atlanta GA 30322 USA Georgia Inst Technol Woodruff Dept Mech Engn Atlanta GA 30332 USA Emory Univ Sch Med Div Cardiothorac Surg Joseph P Whitehead Dept Surg Atlanta GA 30322 USA Emory Univ Hosp Midtown Carlyle Fraser Heart Ctr Struct Heart Res & Innovat Lab Atlanta GA USA

ISBN: (纸本)9781728145969

Direct estimation of 3D blood flow velocity components in vivo could provide important diagnostic information, as demonstrated by computational fluid dynamics. Several approaches have been proposed, however, direct intravascular estimation has not been demonstrated despite the value of fluid dynamics for predicting major adverse cardiac events in stable coronary artery disease. Given that minimally-invasive diagnostic procedures are routinely performed in these patients (e.g. side-viewing IVUS, FFR), a forward-viewing intravascular system could allow direct estimation of velocity components in 3D, with reduced effects of tissue motion and increased resolution relative to non-invasive approaches. Initial data acquisitions using a forward-viewing 4 mm, 118-element ring array transducer in a tissue-mimicking flow phantom and in a pig are described.

关键词： intravascular ultrasound matrix array ring array forward viewing transducer transverse oscillation vector velocity 3D ultrasound

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3D high frame rate flow measurement using a prototype matrix transducer for carotid imaging

3D high frame rate flow measurement using a prototype matrix...

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IEEE International Ultrasonics Symposium (IUS)

作者： Fool, Fabian Vos, Hendrik J. Shabanimotlagh, Maysam Soozande, Mehdi Mozaffarzadeh, Moein Kim, Taehoon Kang, Eunchul Pertijs, Michiel de Jong, Nico Verweij, Martin D. Delft Univ Technol Acoust Wavefield Imaging Imaging Phys Delft Netherlands Erasmus MC Thorax Ctr Biomed Engn Rotterdam Netherlands Delft Univ Technol Elect Instrumentat Lab Delft Netherlands

ISBN: (纸本)9781728145969

To accurately investigate the state of the carotid artery by the local haemodynamics and motion of the plaque using ultrasound, high-frame rate volumetric imaging is necessary. We have specifically designed a matrix array for this purpose. In this proceeding we will focus on imaging a volumetric flow profile using this matrix. For this purpose, we extend a fast frequency domain vector flow imaging method to 3D and perform measurements on a flow phantom. The results indicate that it is feasible to estimate 3D velocity vectors on a 3D grid using our matrix transducer and the proposed algorithm.

关键词： matrix array Fourier domain algorithm Vector velocity imaging Volumetric flow Plane wave imaging

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Comparison of different short-range sonar systems on real structures and objects

Comparison of different short-range sonar systems on real st...

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Oceans Aberdeen Conference

作者： Ehrhardt, M. Degel, C. Becker, F. J. Peter, L. Hewener, H. Fonfara, H. Fournelle, M. Tretbar, S. Fraunhofer Inst Biomed Engn IBMT Div Ultrasound Joseph von Fraunhofer Weg 1 D-66280 Sulzbach Germany

ISBN: (纸本)9781509052783

In recent years, the ultrasound division of the Fraunhofer IBMT has developed and manufactured several imaging sonar systems for different visualization purposes. For short-range high-resolution imaging, three different concepts of sonar systems have been developed and transferred into demonstrators. The first one is a 128 element multibeam echosounder with a combined transmitting and receiving aperture. The second system is a volumetric imaging sonar based on a Mills Cross antenna configuration and the third system is a real-time capable, high-resolution 3D sonar camera with a matrix antenna consisting of 32 x 32 single transducer elements. After validating these systems on various phantoms in measurement tanks, more advanced measurements on real structures and objects were performed in order to evaluate and compare the imaging capabilities of the different sonar systems. In this work we present the results of these measurements together with an analysis of the specific advantages and disadvantages of the short-range imaging systems for different visualization tasks.

关键词： SONAR 2D array multibeam echosounder matrix array real-time 3D imaging volumetric sonar bathymetry inspection beamforming

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A Magnetic Resonance Compatible E4D Ultrasound Probe for Motion Management of Radiation Therapy

A Magnetic Resonance Compatible E4D Ultrasound Probe for Mot...

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IEEE International Ultrasonics Symposium (IUS)

作者： Lee, Warren Chan, Heather Chan, Pong Fiorillo, Timothy Fiveland, Eric Foo, Thomas Mills, David Patel, Aqsa Sabatini, James Shoudy, David Smith, Scott Bednarz, Bryan Gen Elect Global Res Ctr Niskayuna NY 12309 USA Univ Wisconsin Dept Med Phys 1530 Med Sci Ctr Madison WI 53706 USA Univ Wisconsin Dept Human Oncol Madison WI USA

ISBN: (纸本)9781538633830

We developed a magnetic resonance compatible real-time, three-dimensional imaging ultrasound probe for motion management of radiation therapy for liver cancer. The probe contains an 18,000-element, 46.8 mm x 21.5 mm matrix array constructed from three tiled transducer modules with integrated beamforming ASICs. The center frequency and -6 dB fractional bandwidth of the probe was 3.6 MHz and 85 percent respectively. Ferromagnetic materials in the acoustic stack, flex interconnect and electronics boards were greatly minimized for magnetic resonance compatibility. The probe and cable were shielded to minimize the impact of radiofrequency noise on both the ultrasound and magnetic resonance images. The probe's low-profile, side-viewing design allows it to be strapped to a patient so that images may be acquired hands-free. We present simultaneously acquired ultrasound and 3 Tesla magnetic resonance images with minimal artifacts in both images.

关键词： E4D matrix array 2D array real-time three-dimensional magnetic resonance MR radiation therapy

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Three-Dimensional Beamforming Combining Micro-beamformed RF Datasets

Three-Dimensional Beamforming Combining Micro-beamformed RF ...

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IEEE International Ultrasonics Symposium (IUS)

作者： Bera, D. Vos, H. J. Raghunathan, S. B. Chen, C. Chen, Z. Verweij, M. D. Pertijs, M. A. P. de Jong, N. Bosch, J. G. Erasmus MC Biomed Engn Thoraxctr Rotterdam Netherlands Delft Univ Technol Fac Sci Appl Acoust Wavefield Imaging NL-2600 AA Delft Netherlands Delft Univ Technol Elect Instrumentat Lab Delft Netherlands

ISBN: (纸本)9781467398978

A general challenge in 3D volumetric imaging is the large channel count. One solution uses integrated micro-beamformers. The reconstruction of the entire volume from these micro-beamformed datasets can be performed in many ways. In this paper we propose two 3D multiline beamforming techniques, suitable for producing volumes at high frame rate and compare the image qualities to a fully-sampled matrix. The performance of the proposed beamforming techniques was evaluated with simulations in FieldII. Results show that the proposed simple volume reconstruction technique (using 25 transmissions) produces volumes at very high frame rate, but with sharp intensity changes within the volume. The proposed advanced technique (using 169 transmissions) produces volumes very similar to a fully-sampled matrix transducer despite the micro-beamforming.

关键词： 3D TEE matrix array micro-beamforming sub-array

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Evaluation of a high-resolution real-time capable 3D sonar camera for deep sea operation

Evaluation of a high-resolution real-time capable 3D sonar c...

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MTS/IEEE Oceans Conference

作者： Ehrhardt, M. Becker, F. J. Speicher, D. Fonfara, H. Hewener, H. Fournelle, M. Degel, C. Tretbar, S. Fraunhofer Inst Biomed Engn IBMT Div Ultrasound Joseph von Fraunhofer Weg 1 D-66280 Sulzbach Germany

ISBN: (纸本)9781509015375

In this work we present the evaluation results of our 3D sonar camera system. The system consists of a matrix antenna array with 1024 single transducer elements and our in house developed DiPhAS sonar beamformer - a 128 channel FPGA-based beamforming system with a 1: 8 multiplexing device for each channel. The system is designed to be applicable to ROV and AUV systems for real-time volumetric imaging in a deep sea environment. Defocused excitation of the transducer array is used to achieve a sound field opening angle of up to 40 degrees in lateral and elevational direction. The antenna's sound field can be adjusted electronically in order to increase either the imaged area or the image contrast in a specific area of interest. Different filter algorithms working on a raw data basis have been implemented in order to suppress image artifacts which occur during the reconstruction process. Measurements on different phantoms have been performed in order to prove the real-time imaging as well as spatial resolution capabilities of the camera system.

关键词： volumetric sonar matrix array real-time 3D imaging beamforming inspection bathymetry deep sea

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Crosstalk in Ultrasonic Transducers, a First Look

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IEEE LATIN AMERICA TRANSACTIONS 2015年第3期13卷 589-598页

作者： Dominguez, I. S. Univ Nacl Autonoma Mexico Dept Comp Syst Merida Yucatan Mexico Univ Nacl Autonoma Mexico Automat Res Inst Appl Math & Syst Unit Merida Merida Yucatan Mexico

This paper aims to show that the form of lateral vibration of piezoelectric ceramics is the main factor in the generation of crosstalk in the piezoelectric transducer arrays, although there are related on the issue of crosstalk work, no thorough studies on the lateral vibration mode. The results presented here are just the beginning on this topic of interest as part of a research focused on the development of transducers for medical applications, where the best performance of the transducers is reflected in better diagnosis.

关键词： matrix array Crosstalk lateral vibration mode transducers

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ROLE OF 3-D ULTRASOUND IN CLINICAL OBSTETRIC PRACTICE: EVOLUTION OVER 20 YEARS

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ULTRASOUND IN MEDICINE AND BIOLOGY 2015年第5期41卷 1180-1211页

作者： Tonni, Gabriele Martins, Wellington P. Guimaraes Filho, Helio Araujo Junior, Edward Guastalla Civil Hosp ASL Reggio Emilia Dept Obstet & Gynecol Reggio Emilia Italy Univ Sao Paulo EPM UNIFESP Paulista Sch Med Dept Obstet BR-05303000 Sao Paulo SP Brazil Univ Sao Paulo Ribeirao Preto Sch Med DGO FMRP Dept Obstet & Gynecol BR-14049 Ribeirao Preto SP Brazil CETRIM Ctr Imaginol Training Joao Pessoa PB Brazil

The use of 3-D ultrasound in obstetrics has undergone dramatic development over the past 20 years. Since the first publications on this application in clinical practice, several 3-D ultrasound techniques and rendering modes have been proposed and applied to the study of fetal brain, face and cardiac anatomy. In addition, 3-D ultrasound has improved calculations of the volume of fetal organs and limbs and estimations of fetal birth weight. And furthermore, angiographic patterns of fetal organs and the placenta have been assessed using 3-D power Doppler ultrasound quantification. In this review, we aim to summarize current evidence on the clinical relevance of these methodologies and their application in obstetric practice. (C) 2015 World Federation for Ultrasound in Medicine & Biology.

关键词： Doppler ultrasound Fetus Four-dimensional ultrasound HDlive matrix array Omniview Spatiotemporal image correlation Three-dimensional ultrasound Volume calculation

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Evaluation of a high-resolution real-time capable 3D sonar camera for deep sea operation

Evaluation of a high-resolution real-time capable 3D sonar c...

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OCEANS MTS/IEEE Monterey (Conference)

作者： M. Ehrhardt F. J. Becker D. Speicher H. Fonfara H. Hewener M. Fournelle C. Degel S. Tretbar Fraunhofer Institute for Biomedical Engineering IBMT Division Ultrasound

ISBN: (纸本)9781509015276

In this work we present the evaluation results of our 3D sonar camera system. The system consists of a matrix antenna array with 1024 single transducer elements and our in house developed DiPhAS sonar beamformer - a 128 channel FPGA-based beamforming system with a 1:8 multiplexing device for each channel. The system is designed to be applicable to ROV and AUV systems for real-time volumetric imaging in a deep sea environment. Defocused excitation of the transducer array is used to achieve a sound field opening angle of up to 40° in lateral and elevational direction. The antenna's sound field can be adjusted electronically in order to increase either the imaged area or the image contrast in a specific area of interest. Different filter algorithms working on a raw data basis have been implemented in order to suppress image artifacts which occur during the reconstruction process. Measurements on different phantoms have been performed in order to prove the real-time imaging as well as spatial resolution capabilities of the camera system.

关键词： Volumetric sonar matrix array Real-time 3D imaging Beamforming Inspection Bathymetry Deep sea

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Refraction Correction in 3D Transcranial Ultrasound Imaging

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ULTRASONIC IMAGING 2014年第1期36卷 35-54页

作者： Lindsey, Brooks D. Smith, Stephen W. Duke Univ Dept Biomed Engn Durham NC 27708 USA Univ N Carolina Joint Dept Biomed Engn Chapel Hill NC USA N Carolina State Univ Chapel Hill NC USA

We present the first correction of refraction in three-dimensional (3D) ultrasound imaging using an iterative approach that traces propagation paths through a two-layer planar tissue model, applying Snell's law in 3D. This approach is applied to real-time 3D transcranial ultrasound imaging by precomputing delays offline for several skull thicknesses, allowing the user to switch between three sets of delays for phased array imaging at the push of a button. Simulations indicate that refraction correction may be expected to increase sensitivity, reduce beam steering errors, and partially restore lost spatial resolution, with the greatest improvements occurring at the largest steering angles. Distorted images of cylindrical lesions were created by imaging through an acrylic plate in a tissue-mimicking phantom. As a result of correcting for refraction, lesions were restored to 93.6% of their original diameter in the lateral direction and 98.1% of their original shape along the long axis of the cylinders. In imaging two healthy volunteers, the mean brightness increased by 8.3% and showed no spatial dependency.

关键词： transcranial refraction 3D ultrasound matrix array

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