scholarly journals Cylindrical Three-Dimensional Millimeter-Wave Imaging via Compressive Sensing

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Guoqiang Zhao ◽  
Shiyong Li ◽  
Bailing Ren ◽  
Qingwei Qiu ◽  
Houjun Sun

Millimeter-wave (MMW) imaging techniques have been used for the detection of concealed weapons and contraband carried by personnel. However, the future application of the new technology may be limited by its large number of antennas. In order to reduce the complexity of the hardware, a novel MMW imaging method based on compressive sensing (CS) is proposed in this paper. The MMW images can be reconstructed from the significantly undersampled backscattered data via the CS approach. Thus the number of antennas and the cost of system can be further reduced than those based on the traditional imaging methods that obey the Nyquist sampling theorem. The effectiveness of the proposed method is validated by numerical simulations as well as by real measured data of objects.

Author(s):  
Nora Rat ◽  
Iolanda Muntean ◽  
Diana Opincariu ◽  
Liliana Gozar ◽  
Rodica Togănel ◽  
...  

Development of interventional methods has revolutionized the treatment of structural cardiac diseases. Given the complexity of structural interventions and the anatomical variability of various structural defects, novel imaging techniques have been implemented in the current clinical practice for guiding the interventional procedure and for selection of the device to be used. Three– dimensional echocardiography is the most used imaging method that has improved the threedimensional assessment of cardiac structures, and it has considerably reduced the cost of complications derived from malalignment of interventional devices. Assessment of cardiac structures with the use of angiography holds the advantage of providing images in real time, but it does not allow an anatomical description. Transesophageal Echocardiography (TEE) and intracardiac ultrasonography play major roles in guiding Atrial Septal Defect (ASD) or Patent Foramen Ovale (PFO) closure and device follow-up, while TEE is the procedure of choice to assess the flow in the Left Atrial Appendage (LAA) and the embolic risk associated with a decreased flow. On the other hand, contrast CT and MRI have high specificity for providing a detailed description of structure, but cannot assess the flow through the shunt or the valvular mobility. This review aims to present the role of modern imaging techniques in pre-procedural assessment and intraprocedural guiding of structural percutaneous interventions performed to close an ASD, a PFO, an LAA or a patent ductus arteriosus.


2012 ◽  
Vol 128 ◽  
pp. 519-537 ◽  
Author(s):  
Bailing Ren ◽  
Shiyong Li ◽  
Hou-Jun Sun ◽  
Weidong Hu ◽  
Xin Lv

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 748
Author(s):  
Yulong An ◽  
Yanmei Zhang ◽  
Haichao Guo ◽  
Jing Wang

Low-cost Laser Detection and Ranging (LiDAR) is crucial to three-dimensional (3D) imaging in applications such as remote sensing, target detection, and machine vision. In conventional nonscanning time-of-flight (TOF) LiDAR, the intensity map is obtained by a detector array and the depth map is measured in the time domain which requires costly sensors and short laser pulses. To overcome such limitations, this paper presents a nonscanning 3D laser imaging method that combines compressive sensing (CS) techniques and electro-optic modulation. In this novel scheme, electro-optic modulation is applied to map the range information into the intensity of echo pulses symmetrically and the measurements of pattern projection with symmetrical structure are received by the low bandwidth detector. The 3D imaging can be extracted from two gain modulated images that are recovered by solving underdetermined inverse problems. An integrated regularization model is proposed for the recovery problems and the minimization functional model is solved by a proposed algorithm applying the alternating direction method of multiplier (ADMM) technique. The simulation results on various subrates for 3D imaging indicate that our proposed method is feasible and achieves performance improvement over conventional methods in systems with hardware limitations. This novel method will be highly valuable for practical applications with advantages of low cost and flexible structure at wavelengths beyond visible spectrum.


2007 ◽  
Vol 29 (3) ◽  
pp. 155-166 ◽  
Author(s):  
Ai-Ho Liao ◽  
Li-Yen Chen ◽  
Wen-Fang Cheng ◽  
Pai-Chi Li

Small-animal models are used extensively in disease research, genomics research, drug development and developmental biology. The development of noninvasive small-animal imaging techniques with adequate spatial resolution and sensitivity is therefore of prime importance. In particular, multimodality small-animal imaging can provide complementary information. This paper presents a method for registering high-frequency ultrasonic (microUS) images with small-animal positron-emission tomography (microPET) images. Registration is performed using six external multimodality markers, each being a glass bead with a diameter of 0.43–0.60 mm, with 0.1 μl of [18F]FDG placed in each marker holder. A small-animal holder is used to transfer mice between the microPET and microUS systems. Multimodality imaging was performed on C57BL/6J black mice bearing WF-3 ovary cancer cells in the second week after tumor implantation and rigid-body image registration of the six markers was also performed. The average registration error was 0.31 mm when all six markers were used and increased as the number of markers decreased. After image registration, image segmentation and fusion are performed on the tumor. Our multimodality small-animal imaging method allows structural information from microUS to be combined with functional information from microPET, with the preliminary results showing it to be an effective tool for cancer research.


Author(s):  
Mikko K. Leino ◽  
Juha Ala-Laurinaho ◽  
Zenith Purisha ◽  
Simo Sarkka ◽  
Ville Viikari

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