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Ultrasonic imaging of 3d displacement vectors using a simulated 2d array and beamsteering

ULTRASONICS 2013年第2期53卷 615-621页

作者： Housden, R. James Gee, Andrew H. Treece, Graham M. Prager, Richard W. Univ Cambridge Dept Engn Cambridge CB2 1PZ England

Most quasi-static ultrasound elastography methods image only the axial strain, derived from displacements measured in the direction of ultrasound propagation. In other directions, the beam lacks high resolution phase information and displacement estimation is therefore less precise. However, these estimates can be improved by steering the ultrasound beam through multiple angles and combining displacements measured along the different beam directions. Previously, beamsteering has only considered the 2d case to improve the lateral displacement estimates. In this paper, we extend this to 3d using a simulated 2d array to steer both laterally and elevationally in order to estimate the full 3d displacement vector over a volume. The method is tested on simulated and phantom data using a simulated 6-10 MHz array, and the precision of displacement estimation is measured with and without beamsteering. In simulations, we found a statistically significant improvement in the precision of lateral and elevational displacement estimates: lateral precision 35.69 mu m unsteered, 3.70 mu m steered;elevational precision 38.67 mu m unsteered, 3.64 mu m steered. Similar results were found in the phantom data: lateral precision 26.51 mu m unsteered, 5.78 mu m steered;elevational precision 28.92 mu m unsteered, 11.87 mu m steered. We conclude that volumetric 3d beamsteering improves the precision of lateral and elevational displacement estimates. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Elastography Strain imaging 3d displacement estimation Beamsteering 2d array

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3d Acoustic Manipulation of Living Cells and Organisms Based On 2d array

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IEEE TRANSACTIONS ON BIOMEdICAL ENGINEERING 2022年第7期69卷 2342-2352页

作者： Yang, Ye Ma, Teng Zhang, Qi Huang, Jiqing Hu, Qi Li, Yongchuan Wang, Congzhi Zheng, Hairong Chinese Acad Sci Shenzhen Inst Adv Technol Shenzhen Peoples R China Univ Chinese Acad Sci Shenzhen Coll Adv Technol Shenzhen Peoples R China Chinese Acad Sci Shenzhen Inst Adv Technol Shenzhen 518055 Peoples R China Univ Chinese Acad Sci Shenzhen Coll Adv Technol Beijing 100049 Peoples R China Chinese Acad Sci Shenzhen Inst Adv Technol Beijing Peoples R China

Flexible manipulation techniques for living cells and organisms are extremely useful tools for fundamental biomedical and life science research. Acoustic tweezers, which permit non-contact, label-free manipulation, are particularly suited to micromanipulation tasks as they provide a large acoustic radiation force and can be applied in various media. Here, we describe the design and fabrication of a 3 MHz, 64-element (8 x 8), 2d planar ultrasound array that realizes the multidimensional translation, rotation, orientation, and levitation of living cells and organisms. The focusing vortex and twin fields are generated using the holographic acoustic elements framework method. We demonstrate that the eggs and larvae of brine shrimp can be translated along a preset trajectory by controlling the central position of the vortex. By multiplexing counterclockwise vortices, clockwise vortices, and twin trap fields in a time sequence, the rotation direction of the shrimp eggs can be switched in real time, while non-spherical larvae can be reoriented. Moreover, the reflection of the acoustic beam can lift eggs and larvae from the bottom of the culture dish and further manipulate them in the vertical and horizontal directions. Additionally, we present quantitative analyses of the shrimp-egg rotation frequency with respect to the focal depths, topological charges of the vortex, and excitation voltages. These results indicate that acoustic tweezers based on 2d matrix arrays can realize complex and selective manipulation of living cells and organisms, thereby demonstrating their value for advancing research in the fields of cell assembly, tissue engineering, and micro-robot driving.

关键词： Acoustics Force Organisms Multiplexing Acoustic arrays Surface acoustic waves Optical vortices 3d acoustic manipulation living cells and organisms 2d array time-multiplex

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Modeling Interaction Between Silver Nanoparticles in a 2d array on a Glass Substrate

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JOURNAL OF APPLIEd SPECTROSCOPY 2017年第6期83卷 996-1000页

作者： Mikitchuk, A. P. Kozadaev, K. V. Belorussian State Univ 5 Kurchatov Str Minsk 220045 BELARUS

We have theoretically studied the interaction between Ag particles in a 2d array of nanoparticles on a glass substrate. We used the finite-integral technique when modeling the spatial distribution of the electric field strength in the nanostructure on exposure to optical radiation. Comparing the results for modeling the optical properties of 2d arrays of Ag nanospheres with experimental data for glass substrates surface-modified by Ag nanoparticles showed good agreement between theory and experiment.

关键词： 2d array Ag nanoparticles optical absorption spectrum surface plasmon resonance

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Low cost amorphous silicon based 160x120 uncooled microbolometer 2d array for high volume applications

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Conference on detectors and Associated Signal Processing

作者： Trouilleau, C Crastes, A Tissot, JL Chatard, JP Yon, JJ Astier, A CEA LETI ULIS F-38113 Veurey Voroize France

ISBN: (纸本)0819451355

Uncooled infrared focal plane arrays are being developed for a wide range of thermal imaging applications. developments are focused on the improvement of their sensitivity enabling the possibility of reducing the pixel pitch in order to decrease the total system (size and weight) by using smaller optics. The amorphous silicon technology is the latest one developed by CEA/LETI and transferred to ULIS to manufacture 160 x 120 2d arrays. We developed for this device a low cost package based on existing technologies. This device is well adapted to high volume process control applications where spatial resolution (in term of pixel number) is less important than device costs.

关键词： uncooled IRFPA 2d array microbolometer amorphous silicon vacuum package

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OPTIMIZEd 2d array dESIGN FOR ULTRASOUNd IMAGING

OPTIMIZED 2D ARRAY DESIGN FOR ULTRASOUND IMAGING

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20th European Signal Processing Conference (EUSIPCO)

作者： diarra, Bakary Liebgott, Herve Robini, Marc Tortoli, Piero Cachard, Christian Univ Lyon CREATIS Villeurbanne France INSERM U1044 F-69365 Lyon France CNRS UMR 5220 F-69365 Lyon France Univ Lyon 1 F-69365 Lyon France INSA Lyon F-69365 Lyon France Univ Florence Dept Elect & Telecommun Florence Italy

ISBN: (纸本)9781467310680

Ultrasound imaging is one of the least expensive and safest diagnostic modalities routinely used. An attractive recent development in this field is three-dimensional (3d) imaging with two-dimensional (2d) matrix probes. The difficulty in implementing these probes comes from their large number of elements;for instance, the probe considered in this paper is composed of 1024 elements, whereas the number of channels of most current beamformers ranges from 64 to 256. To reduce the number of active elements, we propose a new sparse array design technique based on simulated annealing. Our method is capable of significantly reducing the number of probe elements as well as the side lobe level in a reasonable amount of computing time. Experiments in the context of hepatic biopsy show that good imaging performance can be obtained with only 177 active elements out of the total of 1024.

关键词： ultrasound 2d array sparse array simulated annealing

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A Conversion Algorithm for ECG signals on a 2d array based on digital Signal Processing 11

A Conversion Algorithm for ECG signals on a 2D array based o...

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11th International Conference on Communications, Circuits and Systems (ICCCAS)

作者： Cesar Cabanillas, Julio Kemper, Guillermo del Carpio, Christian Univ Peruana Ciencias Aplicadas Fac Engn Sch Elect Engn Lima Peru

ISBN: (数字)9781665469890

ISBN: (纸本)9781665469890

This work proposes a computational algorithm to convert digital files containing electrocardiogram (ECG) information into 1d signals. Many medical databases have in storage files containing ECG information that is not easy to process for computational algorithms. digitization by the proposed method makes it possible to modernize the databases of many health centers in order to perform post-processing of the signals obtained. This method is based on applying digital signal processing techniques to images obtained from a PdF file produced by an electrocardiograph. The proposed algorithm takes into consideration the thickness of the printed signal in the PdF image so that it does not introduce distortion in the final 1d signal. due to the distribution of the ECG signals on the PdF files the algorithm identifies and segments the signals on 2 dimensions. The results show that the proposed method can correctly reproduce the information of the ECG waves captured in the PdF file regardless of the elements outside the ECG signal such as the background grid or the different information indicators, whether they are labels or references of the ECG signals. The algorithm has an accuracy of 95% based on the statistical analysis performed for all samples.

关键词： digital Signal Processing ECG signals Conversion Printed Signal digitization 2d array

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Low cost amorphous silicon based 160 x 120 uncooled microbolometer 2d array for high volume applications

Low cost amorphous silicon based 160 x 120 uncooled microbol...

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Infrared Technology and Applications XXIX Conference

作者： Tissot, JL Astier, A Chatard, JP Tinnes, S Trouilleau, C Yon, JJ ULIS F-38113 Veurey Voroize France

ISBN: (纸本)0819449334

Uncooled infrared focal plane arrays are being developed for a wide range of thermal imaging applications. developments are focused on the improvement of their sensitivity enabling the possibility to reduce the pixel pitch in order to decrease the total system by using smaller optics. We present the characterization of a 160 x 120 infrared focal plane array with a pixel pitch of 35 mum. The amorphous silicon technology is the latest one developed by CEA/LETI and transferred to ULIS to manufacture 160 x 120 2d arrays. We developed for this device a low cost package based on existing technologies. The readout integrated circuit structure is using an advanced skimming function to enhance the pixel signal exploitation. This device is well adapted to high volume process control applications where spatial resolution is less important than device costs. The electro-optical characterization is presented.

关键词： uncooled IRFPA 2d array microbolometer amorphous silicon vacuum package

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320 x 240 uncooled microbolometer 2d array for radiometric and process control applications

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Conference on detectors and Associated Signal Processing

作者： Fieque, B Crastes, A Tissot, JL ULIS F-38113 Veurey Voroize France

ISBN: (纸本)0819451355

Uncooled infrared focal plane arrays are being developed for a wide range of thermal imaging applications. developments are focused on the improvement of their sensitivity enabling the possibility to manufacture high performance radiometric devices with internal temperature stabilized shield to determine precisely the input infrared flux. We present the characterization of a new radiometric device obtained from 320 x 240 uncooled microbolometer array with f/1.4 aperture. This device is well adapted to radiometric or process control applications and moreover shows a high level of stability due to the internal temperature stabilized shield which prevents the detector from camera internal temperature shift artifacts.

关键词： uncooled IRFPA 2d array microbolometer amorphous silicon radiometry

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development of backing piezoelectric micromachined ultrasonic transducer (B-PMUT) 2d array

Development of backing piezoelectric micromachined ultrasoni...

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IEEE International Ultrasonics Symposium (IEEE IUS)

作者： Wang, Xu-bo Ma, You-cao He, Le-ming Wang, Yan Xu, Wei-jiang Riaud, Antoine Ren, Jun-yan Zhou, Jia Fudan Univ Sch Microelect State Key Lab ASIC & Syst Shanghai Peoples R China Univ Polytech Hauts France CNRS Univ Lille Cent LilleUMR 8520IEMNDOAE F-59313 Valenciennes France INSA Hauts France F-59313 Valenciennes France

ISBN: (纸本)9780738112091

To improve the problem of narrow bandwidth and large crosstalk in high-frequency PMUT array, a PMUT device with a damping backing structure (B-PMUT) is proposed and realized. The device is a two-dimensional array of 8x16 elements with an element pitch of 75 mu m. The results show that the bandwidth of the device with backing is more than doubled (63%) to that of without backing. The crosstalk level between two neighboring elements decreased from -13.4 dB to -17 dB.

关键词： pMUTs 2d array PdMS Backing Crosstalk

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Quick SAR measurement system by 2d array E-field sensors

Quick SAR measurement system by 2D array E-field sensors

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3rd Asia-Pacific Microwave Conference Proceedings (APMC)

作者： Gimm, Yoon-myoung Ju, Youngjun Kahng, Sungtek Lee, Yuri Lee, Seungbae Dankook Univ Sch Elect & Elect Engn Room 4092nd Eng Bldg152 Jukjeon Ro Yongin 448701 Gyeonggi Do South Korea EMF Safety Inc Yongin 448701 Gyeonggi Do South Korea Incheon Natl Univ Dept Informat & Telecommun Incheon 406772 South Korea

ISBN: (纸本)9781479914722

The safety on human body against electromagnetic fields radiating from mobile devices has been investigated for a long time. The measurement method of RF power absorption to human body from wireless devices usually adopted robot scanning in the phantom in the past. But it takes a very long time to evaluate the SAR value of a mobile device. In this paper, a quick SAR measurement system using a 2d array of E-field probes having 3 axes isotropic characteristics is proposed. It is possible to fast estimate the volume SAR by a software with the 2d surface SAR data acquired by arrayed probes deleting robot moving time.

关键词： quick SAR E-field probe radio frequency 2d array human safety

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