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State-of-the-art imaging techniques in endoscopic ultrasound 被引量:5
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作者 Adrian Sftoiu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第6期691-696,共6页
Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment,with a major clinical impact in digestive and mediastinal diseases.State-of-the-art EUS equipment now includes real-time ... Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment,with a major clinical impact in digestive and mediastinal diseases.State-of-the-art EUS equipment now includes real-time sono-elastography,which might be useful for a better characterization of lesions and increased accuracy of differential diagnosis (for e.g.lymph nodes or focal pancreatic lesions).Contrast-enhanced EUS imaging is also available,and is already being used for the differential diagnosis of focal pancreatic masses.The recent development of low mechanical index contrast harmonic EUS imaging offers hope for improved diagnosis,staging and monitoring of anti-angiogenic treatment.Tridimensional EUS (3D-EUS) techniques can be applied to enhance the spatial understanding of EUS anatomy,especially for improved staging of tumors,obtained through a better assessment of the relationship with major surrounding vessels.Despite the progress gained through all these imaging techniques,they cannot replace cytological or histological diagnosis.However,real-time optical histological diagnosis can be achieved through the use of single-fiber confocal laser endomicroscopy techniques placed under real-time EUS-guidance through a 22G needle.Last,but not least,EUS-assisted natural orifice transluminal endoscopic surgery (NOTES) procedures offer a whole new area of imaging applications,used either for combination of NOTES peritoneoscopy and intraperitoneal EUS,but also for access of retroperitoneal organs through posterior EUS guidance. 展开更多
关键词 Endoscopic ultrasound real-time sono-elastography CONTRAST-ENHANCEMENT Tridimensional 3d Hybrid imaging Endoscopic ultrasound-guided fine needle aspiration
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Research on Automatic Elimination of Laptop Computer in Security CT Images Based on Projection Algorithm and YOLOv7-Seg
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作者 Fei Wang Baosheng Liu +1 位作者 Yijun Tang Lei Zhao 《Journal of Computer and Communications》 2023年第9期1-17,共17页
In civil aviation security screening, laptops, with their intricate structural composition, provide the potential for criminals to conceal dangerous items. Presently, the security process necessitates passengers to in... In civil aviation security screening, laptops, with their intricate structural composition, provide the potential for criminals to conceal dangerous items. Presently, the security process necessitates passengers to individually present their laptops for inspection. The paper introduced a method for laptop removal. By combining projection algorithms with the YOLOv7-Seg model, a laptop’s three views were generated through projection, and instance segmentation of these views was achieved using YOLOv7-Seg. The resulting 2D masks from instance segmentation at different angles were employed to reconstruct a 3D mask through angle restoration. Ultimately, the intersection of this 3D mask with the original 3D data enabled the successful extraction of the laptop’s 3D information. Experimental results demonstrated that the fusion of projection and instance segmentation facilitated the automatic removal of laptops from CT data. Moreover, higher instance segmentation model accuracy leads to more precise removal outcomes. By implementing the laptop removal functionality, the civil aviation security screening process becomes more efficient and convenient. Passengers will no longer be required to individually handle their laptops, effectively enhancing the efficiency and accuracy of security screening. 展开更多
关键词 Instance Segmentation PROJECTION CT image 3d Segmentation real-time detection
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Navigated liver surgery:State of the art and future perspectives 被引量:10
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作者 Paschalis Gavriilidis Bjørn Edwin +5 位作者 Egidijus Pelanis Ernest Hidalgo Nicola de’Angelis Riccardo Memeo Luca Aldrighetti Robert P Sutcliffe 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2022年第3期226-233,共8页
Background:In recent years,the development of digital imaging technology has had a significant influence in liver surgery.The ability to obtain a 3-dimensional(3D)visualization of the liver anatomy has provided surger... Background:In recent years,the development of digital imaging technology has had a significant influence in liver surgery.The ability to obtain a 3-dimensional(3D)visualization of the liver anatomy has provided surgery with virtual reality of simulation 3D computer models,3D printing models and more recently holograms and augmented reality(when virtual reality knowledge is superimposed onto reality).In addition,the utilization of real-time fluorescent imaging techniques based on indocyanine green(ICG)uptake allows clinicians to precisely delineate the liver anatomy and/or tumors within the parenchyma,applying the knowledge obtained preoperatively through digital imaging.The combination of both has transformed the abstract thinking until now based on 2D imaging into a 3D preoperative conception(virtual reality),enhanced with real-time visualization of the fluorescent liver structures,effectively facilitating intraoperative navigated liver surgery(augmented reality).Data sources:A literature search was performed from inception until January 2021 in MEDLINE(Pub Med),Embase,Cochrane library and database for systematic reviews(CDSR),Google Scholar,and National Institute for Health and Clinical Excellence(NICE)databases.Results:Fifty-one pertinent articles were retrieved and included.The different types of digital imaging technologies and the real-time navigated liver surgery were estimated and compared.Conclusions:ICG fluorescent imaging techniques can contribute essentially to the real-time definition of liver segments;as a result,precise hepatic resection can be guided by the presence of fluorescence.Furthermore,3D models can help essentially to further advancing of precision in hepatic surgery by permitting estimation of liver volume and functional liver remnant,delineation of resection lines along the liver segments and evaluation of tumor margins.In liver transplantation and especially in living donor liver transplantation(LDLT),3D printed models of the donor’s liver and models of the recipient’s hilar anatomy can contribute further to improving the results.In particular,pediatric LDLT abdominal cavity models can help to manage the largest challenge of this procedure,namely large-for-size syndrome. 展开更多
关键词 Navigated Hepatic surgery 3d Computer assistance image guidance image guided surgery Indocyanine green 3d print Visual simulation Virtual reality Augmented reality real-time navigated liver surgery
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基于稀疏布阵的实时三维成像声纳系统 被引量:11
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作者 王朋 张扬帆 +2 位作者 黄勇 刘纪元 黄海宁 《仪器仪表学报》 EI CAS CSCD 北大核心 2016年第4期843-851,共9页
水下实时三维成像声纳系统可以有效地提高对水下目标探测及识别的能力,本文提出基于稀疏面阵的实时三维成像声纳系统,该系统包括3个部分:窄带信号发射系统、稀疏布阵接收系统及信号处理系统。信号处理系统在远场情况下采用二维FFT波束... 水下实时三维成像声纳系统可以有效地提高对水下目标探测及识别的能力,本文提出基于稀疏面阵的实时三维成像声纳系统,该系统包括3个部分:窄带信号发射系统、稀疏布阵接收系统及信号处理系统。信号处理系统在远场情况下采用二维FFT波束形成获得目标三维成像,近场情况下采用自聚焦二维FFT波束形成获得三维成像结果。相比于直接相移波束形成,稀疏布阵情况下采用二维FFT波束形成算法具有更小的计算量和内存需求量的优势。基于该成像算法,设计并实现一套实时三维成像声纳系统,通过多次湖上及海上实验对该系统进行测试,实验结果表明:该系统可以获得水下近场及远场目标的三维图像并满足实时成像的要求。 展开更多
关键词 水声成像 声纳信号处理 三维成像声呐
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基于显著性检测的声呐图像快速降噪研究 被引量:18
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作者 金磊磊 梁红 杨长生 《西北工业大学学报》 EI CAS CSCD 北大核心 2019年第1期80-86,共7页
声呐图像在获取过程中易受噪声污染,而降噪性能好的算法通常时间复杂度较高。鉴于人类视觉注意机制,将基于流形排序(MR)的显著性检测方法引入声呐图像处理,将图像自动分割为显著区域和非显著区域两部分。对于占比小的显著区域采用三维... 声呐图像在获取过程中易受噪声污染,而降噪性能好的算法通常时间复杂度较高。鉴于人类视觉注意机制,将基于流形排序(MR)的显著性检测方法引入声呐图像处理,将图像自动分割为显著区域和非显著区域两部分。对于占比小的显著区域采用三维块匹配(BM3D)算法降噪以保护图像主要信息,对非显著背景区域采用执行效率较高的均值滤波(MF)算法。将所提算法同经典MF,BM3D算法进行主观和客观评价指标对比,结果表明,所提算法在提高图像视觉效果的同时,执行时间较BM3D算法大为减少,可以满足水下航行器实时作业的应用需求。 展开更多
关键词 声呐图像 图像降噪 流行排序 显著性检测 图像分割 三维块匹配 均值滤波
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海底三维声学图像实时处理系统设计
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作者 李志华 李秋峦 《海洋工程》 CSCD 北大核心 2014年第4期124-130,共7页
结合多核CPU硬件PC平台,设计了一种海底三维声学图像实时处理系统,主要包括声学前端信号处理子系统、数据传输控制子系统和PC客户端图像处理系统三个部分。声学前端信号处理子系统统根据接收到的多路声学换能器信号,通过两级FPGA信号处... 结合多核CPU硬件PC平台,设计了一种海底三维声学图像实时处理系统,主要包括声学前端信号处理子系统、数据传输控制子系统和PC客户端图像处理系统三个部分。声学前端信号处理子系统统根据接收到的多路声学换能器信号,通过两级FPGA信号处理,采集多通道水声信号,进行实时电子聚焦波束形成。为了解决海量声学数据快速传输问题,数据传输控制子系统未采用传统用户空间TCP/IP传输机制,而是直接通过嵌入式PowerPC处理器在Linux内核态采用DMA通道进行声学数据转发,减少系统调用和数据拷贝开销,有效提高网络传输效率。针对海量声学数据实时处理需求,PC客户端图像处理系统通过对复杂、耗时的单帧重建和数据拼接算法模块根据声学数据点的角度范围进行等分分割,对每个子范围声纳数据采用多线程并行处理,均衡多个CPU核之间负载,实现高性能三维声学图像实时处理。通过室内水池和湖试实验,结果表明该系统能够实时高效地进行三维声学图像采集、传输与处理。 展开更多
关键词 三维声学 实时处理 图像重建 图像拼接 嵌入式系统 海底 水声探测
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一种多节点声呐阵列在船舶水下安检系统中的应用 被引量:2
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作者 陈孟君 仝志永 曹仲 《舰船电子工程》 2019年第3期152-155,共4页
针对船舶水下安检技术发展现状,介绍了一种应用于船舶水下安检的多节点声呐阵列系统的组成和原理,开展了一系列的湖上试验和江上测试。通过对测试船只水下部分的声学扫描,得到了船底三维图像及船只吃水信息。试验结果表明,系统可应用于... 针对船舶水下安检技术发展现状,介绍了一种应用于船舶水下安检的多节点声呐阵列系统的组成和原理,开展了一系列的湖上试验和江上测试。通过对测试船只水下部分的声学扫描,得到了船底三维图像及船只吃水信息。试验结果表明,系统可应用于船只吃水检测、船底异物检查等船舶水下安检领域。 展开更多
关键词 水下安检 声呐阵列 声学扫描 三维图像
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三维成像声呐分区域FFT波束形成算法设计
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作者 于涤非 黄海宁 +1 位作者 张春华 吴长瑞 《电子与信息学报》 EI CSCD 北大核心 2017年第9期2175-2181,共7页
为解决传统均匀FFT波束形成算法引起的3维声呐成像分辨率降低的问题,该文提出分区域FFT波束形成算法。远场条件下,以保证成像分辨率为约束条件,以划分数量最少为目标,采用遗传算法作为优化手段将成像区域划分为多个区域。在每个区域内... 为解决传统均匀FFT波束形成算法引起的3维声呐成像分辨率降低的问题,该文提出分区域FFT波束形成算法。远场条件下,以保证成像分辨率为约束条件,以划分数量最少为目标,采用遗传算法作为优化手段将成像区域划分为多个区域。在每个区域内选取一个波束方向,获得每一个接收阵元收到该方向回波时的解调输出,以此为原始数据在该区域内进行传统均匀FFT波束形成。对FFT计算过程进行优化,降低新算法的计算量,使其满足3维成像声呐实时性的要求。仿真与实验结果表明,采用分区域FFT波束形成算法的成像分辨率较传统均匀FFT波束形成算法有显著提高,且满足实时性要求。 展开更多
关键词 水声学 3维成像声呐 波束形成 成像分辨率 FFT
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基于TSI方位估计的三维摄像声纳阵列幅相误差校正
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作者 袁龙涛 蒋荣欣 陈耀武 《北京工业大学学报》 CAS CSCD 北大核心 2013年第12期1761-1768,共8页
针对水下三维摄像声纳系统的大型均匀矩形阵列,提出了一种基于三步迭代(three-step-iteration,TSI)方位估计的幅相误差校正方法.该方法使用1个方位未知的远场校正源,首先采用一种新的TSI方位估计算法,获得对校正源方位的鲁棒估计;然后... 针对水下三维摄像声纳系统的大型均匀矩形阵列,提出了一种基于三步迭代(three-step-iteration,TSI)方位估计的幅相误差校正方法.该方法使用1个方位未知的远场校正源,首先采用一种新的TSI方位估计算法,获得对校正源方位的鲁棒估计;然后根据该方位估计结果和采样数据协方差矩阵,估计阵列的幅相误差.利用该方法估计得到的幅相误差参数,可使三维摄像声纳在存在阵列幅相误差的条件下仍提供良好的探测性能.通过仿真实验,对该方法和基于数据协方差矩阵Toeplitz-block特性的方法进行了比较研究.实验结果表明:该方法能处理Toeplitzblock方法无法解决的大阵列相位误差问题,同时小信噪比条件下的性能也有明显改善. 展开更多
关键词 三维摄像声纳 阵列校正 均匀矩形阵列 幅相误差 TSI方位估计
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手持式三维声纳实时成像系统设计
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作者 蒋涛琳 田翔 《计算机工程》 CAS CSCD 2014年第12期262-266,共5页
针对传统三维声纳成像系统集成度低、实时性差的问题,提出一种手持式三维声纳实时成像系统设计方案。利用DM8127实现声纳图像的处理,通过坐标转换数组预生成、自适应阈值的网格构建等方法实现实时高精度的三维建模,同时采用多线程并行... 针对传统三维声纳成像系统集成度低、实时性差的问题,提出一种手持式三维声纳实时成像系统设计方案。利用DM8127实现声纳图像的处理,通过坐标转换数组预生成、自适应阈值的网格构建等方法实现实时高精度的三维建模,同时采用多线程并行处理架构改善网格构建时的系统处理性能,降低处理时延,并利用Open GL ES2.0实现三维声纳图像的渲染和显示。实验结果证明,该系统能清晰显示水下探测目标,且实时成像速率高达25帧/s,满足系统实时性要求。 展开更多
关键词 三维声纳成像 手持式 嵌入式系统 实时性 OpenGLES2.0标准
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Optimized simulated annealing algorithm for thinning and weighting large planar arrays 被引量:2
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作者 Peng CHEN Bin-jian SHEN +1 位作者 Li-sheng ZHOU Yao-wu CHEN 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2010年第4期261-269,共9页
This paper proposes an optimized simulated annealing(SA) algorithm for thinning and weighting large planar arrays in 3D underwater sonar imaging systems.The optimized algorithm has been developed for use in designing ... This paper proposes an optimized simulated annealing(SA) algorithm for thinning and weighting large planar arrays in 3D underwater sonar imaging systems.The optimized algorithm has been developed for use in designing a 2D planar array(a rectangular grid with a circular boundary) with a fixed side-lobe peak and a fixed current taper ratio under a narrow-band excitation.Four extensions of the SA algorithm and the procedure for the optimized SA algorithm are described.Two examples of planar arrays are used to assess the efficiency of the optimized method.The proposed method achieves a similar beam pattern performance with fewer active transducers and faster convergence ability than previous SA algorithms. 展开更多
关键词 Simulated annealing(SA) Sparse planar arrays 3d underwater sonar imaging Beam pattern OPTIMIZATION
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