- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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3D self-gated cardiac cine imaging at 3 Tesla using stack-of-stars bSSFP with tiny golden angles and compressed sensing
摘要： Purpose: To develop and evaluate an accelerated 3D self‐gated cardiac cine imaging technique at 3 Tesla without the use of external electrocardiogram triggering or respiratory gating. Methods: A 3D stack‐of‐stars balanced steady‐state free precession sequence with a tiny golden angle sampling scheme was developed to reduced eddy current effect‐related artefacts at 3 Tesla. Respiratory and cardiac motion were derived from a central 5‐point self‐gating signal extraction approach. The data acquired around the end‐expiration phases were then sorted into individual cardiac bins and used for reconstruction with compressed sensing. To evaluate the performance of the proposed method, image quality (1: the best; 4: the worst) was quantitatively compared using both the proposed method and the conventional 3D golden‐angle self‐gated method. Linear regression and Bland‐Altman analysis were used to assess the functional measurements agreement between the proposed method and the routine 2D breath‐hold multi‐slice technique. Results: Compared to the conventional 3D golden‐angle self‐gated method, the proposed method yielded images with much less streaking artifact and higher myocardium edge sharpness (0.50 ± 0.06 vs. 0.45 ± 0.05, P = 0.004). The proposed method provided an inferior image quality score to the routine 2D technique (2.13 ± 0.35 vs. 1.38 ± 0.52, P = 0.063) but a superior one to the conventional self‐gated method (2.13 ± 0.35 vs. 3.13 ± 0.64, P = 0.031). Left ventricular functional measurements between the proposed method and routine 2D technique were all well in agreement. Conclusion: This study presents a novel self‐gating approach to realize rapid 3D cardiac cine imaging at 3 Tesla.
关键词： self‐gated cardiac cine,compressed sensing,free breathing,3 Tesla,3D,tiny golden angle
更新于2025-09-09 09:28:46
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Generation of breathing solitons in the propagation and interactions of Airy–Gaussian beams in a cubic–quintic nonlinear medium
摘要： Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian (AiG) beams in a cubic–quintic nonlinear medium in one transverse dimension. We show that the propagation of single AiG beams can generate stable breathing solitons that do not accelerate within a certain initial power range. The propagation direction of these breathing solitons can be controlled by introducing a launch angle to the incident AiG beams. When two AiG beams accelerated in opposite directions interact with each other, different breathing solitons and soliton pairs are observed by adjusting the phase shift, the beam interval, the amplitudes, and the light ?eld distribution of the initial AiG beams.
关键词： Airy–Gaussian beams,breathing solitons,propagation and interactions,cubic–quintic nonlinear medium
更新于2025-09-09 09:28:46
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Non-contact fatigue crack detection in civil infrastructure through image overlapping and crack breathing sensing
摘要： Fatigue cracks are of critical structural safety concern in civil infrastructure. Many existing fatigue crack sensing methods are contact-based, hence extensive human operation is necessary for sensor and/or actuator deployment. In this study, we propose a vision-based non-contact approach to detect fatigue cracks through image overlapping. We treat crack breathing behavior, the small cyclic movement of the crack perpendicular to the crack path under repetitive fatigue loads, as a robust indicator for crack identification. The differential image features provoked by a breathing crack can be extracted, enhanced, and visualized through a series of image processing techniques. The performance of the proposed approach is experimentally validated through two laboratory setups including a small-scale steel compact specimen and a large-scale bridge to cross-frame connection specimen. Test results demonstrate the capability of the proposed approach in reliably identifying the fatigue crack, even the true crack is surrounded by other non-crack features.
关键词： Computer vision,Bridges,Civil infrastructure,Feature matching,Non-contact sensing,Image processing,Structural health monitoring,Image registration,Breathing crack,Fatigue crack detection
更新于2025-09-04 15:30:14
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[IEEE 2018 XIV International Scientific-Technical Conference on Actual Problems of Electronics Instrument Engineering (APEIE) - Novosibirsk, Russia (2018.10.2-2018.10.6)] 2018 XIV International Scientific-Technical Conference on Actual Problems of Electronics Instrument Engineering (APEIE) - Up-to-Date Thermal Imaging Systems in the Multichannel Automated Measurements
摘要： A highly informative methodology, the essence of which is to obtain the parameters of an object under study by means of the data synchronous acquisition from several measurement channels, predominantly based on different physical principles, infrared thermography (IRT) as a leading research tool included in such a multichannel (multimodal) measuring system is considered in some detail. The IRT-aided multichannel approach is demonstrated with studying the physiological characteristics in humans. The measurement synchronism of different technical means is realized by the computerization and automation of the experiment. The programmable microcontroller ESP32 served as main operating and readout unit. With a time resolution of 100-200 measurements per second, the experimental data were obtained. It made it possible to reveal the human physiological characteristics as follows: the extremities temperature change, pulse waves and their velocity in the radial artery, breathing dynamics, blood pressure evaluated in two different regimes of brachial cuff air filling – inflation and deflation. The brachial cuff inflation also served as external interventional impact on the organism. It is found that, after the brachial artery cross-clamping, the pulse wave velocity in the radial artery is capable of doubling in comparison with that measured before compression. It is shown that the multimodal technology is a promising means in modern experimental science.
关键词： SEIRT,blood pressure measurement,breathing dynamics,experiment automation,multichannel (multimodal) measurements,pulse wave velocity,Infrared thermography,thermal imaging,programmable microcontroller,pulse wave,computer-aided measurements
更新于2025-09-04 15:30:14