scholarly journals Improvement of Performance Degradation in Synthetic Aperture Extension of Enhanced Axial Resolution Ultrasound Imaging Based on Frequency Sweep

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2414
Author(s):  
Jing Zhu ◽  
Norio Tagawa
Keyword(s):  
Finite Element Method ◽  
Performance Degradation ◽  
Original Method ◽  
Frame Rate ◽  
Synthetic Aperture ◽  
Axial Resolution ◽  
Frequency Sweep ◽  
Type Method ◽  
Range Resolution ◽  
Pulse Transmission

We are studying a method based on the carrier frequency sweep for axial high resolution ultrasonic imaging to provide the range resolution that corresponds to the carrier wavelength. The first proposal for this type of method was based on the focused pulse transmission. Then, to improve the frame rate, the method was extended to a synthetic aperture-type method that transmits divergent pulses. While the method is effective in terms of the frame rate, degradation of the enhanced axial resolution performance is a concern. Therefore, using finite element method simulations and simple experiments, the performance of the synthetic aperture method with high axial resolution is evaluated via comparison with the original method using focused pulses. The evaluation confirmed that the performance degradation of the synthetic aperture method is caused by weakness in the transmitted wave intensity and deterioration of the phase coherence in the reception beamforming. Based on this result, we propose a method that is less affected by the latter cause and show its effectiveness.

scholarly journals Architecture Exploration of a Backprojection Algorithm for Real-Time Video SAR

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8258
Author(s):  
Seokwon Lee ◽  
Inmo Ban ◽  
Myeongjin Lee ◽  
Yunho Jung ◽  
Wookyung Lee
Keyword(s):  
Frame Rate ◽  
Synthetic Aperture ◽  
Profile Data ◽  
Pixel Resolution ◽  
Multiple Gpus ◽  
Range Resolution ◽  
Full Resolution ◽  
Range Profile ◽  
Processing Data ◽  
Target Data

This paper explores novel architectures for fast backprojection based video synthetic aperture radar (BP-VISAR) with multiple GPUs. The video SAR frame rate is analyzed for non-overlapped and overlapped aperture modes. For the parallelization of the backprojection process, a processing data unit is defined as the phase history data or range profile data from partial synthetic-apertures divided from the full resolution target data. Considering whether full-aperture processing is performed and range compression or backprojection are parallelized on a GPU basis, we propose six distinct architectures, each having a single-stream pipeline with a single GPU. The performance of these architectures is evaluated in both non-overlapped and overlapped modes. The efficiency of the BP-VISAR architecture with sub-aperture processing in the overlapped mode is accelerated further by filling the processing gap from the idling GPU resources with multi-stream based backprojection on multiple GPUs. The frame rate of the proposed BP-VISAR architecture with sub-aperture processing is scalable with the number of GPU devices for large pixel resolution. It can generate 4096 × 4096 video SAR frames of 0.5 m cross-range resolution in 23.0 Hz on a single GPU and 73.5 Hz on quad GPUs.

scholarly journals Broadband Generalized Sidelobe Canceler Beamforming Applied to Ultrasonic Imaging

2020 ◽  
Vol 10 (4) ◽  
pp. 1207
Author(s):  
Jiake Li ◽  
Zhe Ma ◽  
Lei Mao ◽  
Zhengjun Wang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Near Field ◽  
Simulated Data ◽  
Noise Signal ◽  
Frame Rate ◽  
Synthetic Aperture ◽  
Lateral Resolution ◽  
Wavelet Domain ◽  
Sidelobe Level ◽  
Wave Emission ◽  
Single Emission

A broadband generalized sidelobe canceler (Broadband-GSC) application for near-field beamforming is proposed. This approach is implemented in the wavelet domain. Broadband-GSC provides a set of complex, adapted apodization weights for each wavelet subband. The proposed method constrains interference and noise signal to improve the lateral resolution with only one single emission. Performance of the proposed beamforming is tested on simulated data obtained with Field II. Experiments have proved that the new beamforming can significantly increase the image quality compared with delay-and-sum (DAS) and synthetic aperture (SA). Imaging of scattering points show that Broadband-GSC improves the lateral resolution by 43.2% and 58.0% compared with SA and DAS, respectively. Meanwhile，Broadband-GSC reduces the peak sidelobe level by 11.6 dB and 26.4 dB compared with SA and DAS, respectively. Plane wave emission experiment indicates that Broadband-GSC can improve the lateral resolution by 44.2% compared with DAS. Furthermore, the new beamforming introduces the possibility for higher frame-rate and higher investigation depth with increased lateral resolution.

scholarly journals High frame rate synthetic aperture vector flow imaging for transthoracic echocardiography

2016 ◽  
Author(s):  
Carlos A. Villagómez-Hoyos ◽  
Matthias B. Stuart ◽  
Thor Bechsgaard ◽  
Michael Bachmann Nielsen ◽  
Jørgen Arendt Jensen
Keyword(s):  
Transthoracic Echocardiography ◽  
Frame Rate ◽  
Synthetic Aperture ◽  
Flow Imaging ◽  
High Frame Rate

scholarly journals High frame rate synthetic aperture duplex imaging

2013 ◽  
Author(s):  
Matthias Bo Stuart ◽  
Borislav Gueorguiev Tomov ◽  
Michael Johannes Pihl ◽  
Jorgen Arendt Jensen
Keyword(s):  
Frame Rate ◽  
Synthetic Aperture ◽  
High Frame Rate ◽  
Duplex Imaging
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