A Comparison Study of Several Ultrasonic Endoscopy Technology for Tubes’ Inspection

2021 ◽  
Author(s):  
Ze Xi ◽  
Xiangang Wang ◽  
Xiaowei Luo
Keyword(s):  
Tube Wall ◽  
Axial Direction ◽  
Detection Sensitivity ◽  
Straight Tube ◽  
Circular Array ◽  
Comparison Study ◽  
Beneficial Effects ◽  
Array Transducer ◽  
Ultrasonic Technology ◽  
Imaging Algorithms

Abstract Ultrasonic technology has developed rapidly in decades. However, few ultrasonic technologies have been proposed for tubes’ internal inspection. In this paper, 6 types of ultrasonic endoscopic transducers are brought to detect volumetric and planar flaws in tubes. Steam generator tube is application target. Beam simulations are implemented and compared using an open source acoustic simulation toolbox to illustrate beneficial effects of the different transducers. The results show the proposed endoscopic array transducers can form focused ultrasonic beams in tube wall, which do helps when detecting complex defects, such as crevice with uncertain direction. A prototype circular array transducer with 64 elements is fabricated to demonstrate the design. A straight tube (Φ19 × 3mm) made of carbon-steel with 8 longitudinal grooves and 8 ring grooves of no more than 0.5mm width on both inner and outer tube wall are applied in endoscopy experiments. The results demonstrate the detection sensitivity of the circular array transducer reaches 0.2mm in both circumferential direction and axial direction. The combination of the above proposed transducers and advanced imaging algorithms such as total focusing method may build an integrated array ultrasonic endoscopic inspection scheme for the internal inspection of tubes.

scholarly journals A Micromachined Pb(Mg1/3Nb2/3)O3-PbTiO3 Single Crystal Composite Circular Array for Intravascular Ultrasound Imaging

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Sibo Li ◽  
Jian Tian ◽  
Xiaoning Jiang
Keyword(s):  
Single Crystal ◽  
Intravascular Ultrasound ◽  
Dynamic Range ◽  
Beam Width ◽  
Axial Direction ◽  
Center Frequency ◽  
Outer Diameter ◽  
Circular Array ◽  
Intravascular Ultrasound Imaging ◽  
Array Transducer

This paper describes the design, fabrication, and characterization of a micromachined high-frequency Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) single crystal/epoxy 1–3 composite ultrasound circular array. The 1–3 composites were fabricated by deep reactive ion etching (DRIE) of PMN-PT single crystal. The feature size of single crystal pillars was 18 μm in diameter. The kerf between pillars was less than 4 μm. A 50-element circular array transducer (radially outward) with the pitch of 100 μm was wrapped around a needle resulting in an outer diameter of 1.7 mm. The array test showed that the center frequency reached 39±2 MHz and −6-dB fractional bandwidth was 82±6%. The insertion loss was −41 dB, and crosstalk between adjacent elements was −24 dB. A radial outward imaging testing with phantom wires (D = 50 μm) was conducted. The image was in a dynamic range of 30 dB to show a penetration depth of 6 mm by using the synthetic aperture method. The −6-dB beam width was estimated to be 60 μm in the axial direction at 3.1 mm distance away from the probe. The results suggest that the 40 MHz micromachined 1–3 composite circular array is promising for intravascular ultrasound (IVUS) imaging applications.

Recent Advances in Photoacoustic Tomography Based on Circular Array Transducer

2020 ◽  
Vol 57 (12) ◽  
pp. 120004-10
Author(s):  
张国鹏 Zhang Guopeng ◽  
邓丽军 Deng Lijun ◽  
白杨 Bai Yang ◽  
刘国栋 Liu Guodong ◽  
曾吕明 Zeng Lüming ◽  
...  
Keyword(s):  
Photoacoustic Tomography ◽  
Circular Array ◽  
Recent Advances ◽  
Array Transducer

Sound field calculation for a circular array transducer

1989 ◽  
Vol 86 (S1) ◽  
pp. S20-S20 ◽  
Author(s):  
Chankil Lee ◽  
Intaek Kim ◽  
Paul J. Benkeser
Keyword(s):  
Sound Field ◽  
Field Calculation ◽  
Circular Array ◽  
Array Transducer

scholarly journals Flexible magnifying endoscopy with narrow band imaging versus colposcopy for diagnosing uterine cervical neoplasms: a multicenter, prospective, non-randomized, paired comparison study

2021 ◽  
Author(s):  
Hideki Kobara ◽  
Kunihisa Uchita ◽  
Noriya Uedo ◽  
Jun Kunikata ◽  
Kenji Yorita ◽  
...  
Keyword(s):  
Pap Smear ◽  
Narrow Band ◽  
Narrow Band Imaging ◽  
Paired Comparison ◽  
Intraepithelial Neoplasia ◽  
Punch Biopsy ◽  
Magnifying Endoscopy ◽  
Detection Sensitivity ◽  
Comparison Study ◽  
Cervical Intraepithelial Neoplasia Grade

Objective To investigate the detection ability of flexible magnifying endoscopy with narrow band imaging (ME-NBI) for cervical intraepithelial neoplasia grade two or worse (CIN2+) compared with colposcopy. Design Multicenter, prospective, non-randomized, paired comparison study. Setting Three Japanese medical centers. Population Japanese women. Methods Eligible patients had positive PAP smear test results, suspicious high-grade CIN in previous colposcopy, or definitive CIN3 diagnosed previously. A gastrointestinal endoscopist examined the cervix using ME-NBI in an endoscopy room and, subsequently, a gynecologist blinded to the ME-NBI findings performed colposcopy in a different room. CIN2+ locations were documented in a scheme immediately after each examination. Punch biopsy samples were obtained from all areas diagnosed as CIN2+ with both methods and from one normal area. The reference standard was the presence of at least one histological diagnosis of CIN2+ among all biopsy specimens. Main outcome measures The primary outcome was the detection sensitivity of patients with CIN2+, comparing ME-NBI and colposcopy. Results We enrolled 88 patients. The detection sensitivity for patients with CIN2+ was not statistically different between the two methods (both: 79%, 95% CI: 66%–88%). For diagnosing CIN2+, ME-NBI tended to show a higher sensitivity than colposcopy (69% vs. 58%, respectively), while its specificity tended to be lower vs. colposcopy (55% vs. 70%, respectively). Patients reported significantly less discomfort and embarrassment with ME-NBI vs. colposcopy. Conclusion ME-NBI showed comparable sensitivity to colposcopy for detecting CIN2+ lesions, and ME-NBI was more patient-acceptable.

Numerical Studies on Modal Analysis of Curved Tube and Coil Tube in Coil-Wound Heat Exchanger

2021 ◽  
Author(s):  
Yue Wang ◽  
Peng Ren ◽  
Guorui Zhu ◽  
Wei Tan
Keyword(s):  
Heat Exchanger ◽  
Large Scale ◽  
Natural Frequencies ◽  
Axial Direction ◽  
Mode Shapes ◽  
Tube Length ◽  
Straight Tube ◽  
Element Analysis ◽  
Maximum Deformation ◽  
Curved Tube

Abstract Coil-wound heat exchanger, which has a large-scale turbulence in the shell side and a great heat transfer coefficient, has been widely used in chemical industry, such as liquefied natural gas (LNG) and crude pyrolysis of ethylbenzene. To investigate the general vibration characteristics, a complete wound tube can be divided into the curved tube and the coil tube for easy research because of its constraint condition. A finite element analysis is used to obtain the natural frequencies and corresponding mode shapes of the curved tubes and the coil tubes with various parameters. For the curved tube, the deformation of middle position of the tube is larger than that of the clamped ends. The maximum deformation occurs at the transition from the bending tube to the straight tube. With the increase of R1 and the decrease of R2, H1, H and θ, the natural frequencies of curved tube increase which is more likely to avoid the fluid-elastic instability, in which R1 is circumferential radius of the straight part of curved tube, R2 is coil radius, H1 is axial straight tube length, H is axial height of curved tube and θ is deflection angle. And for the coil tube, all the deformation for mode shape occurs in the axial direction, and there is no obvious deformation in the radial direction. With the increase of support number and the decrease of R2, the basic frequency of the coil tube increases. It provides a certain reference for the support layout of coil-wound heat exchanger.

Effect of Pre-Bending on Formability of DQ Steel and Al 5182

2018 ◽  
Author(s):  
Shabbir Memon ◽  
Obaidur Rahman Mohammed ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Axial Strain ◽  
Axial Direction ◽  
Bulge Test ◽  
Element Formulation ◽  
Straight Tube ◽  
Fe Model ◽  
Hoop Strain ◽  
Explicit Dynamic ◽  
Tube Bulging

The effect of the pre-bending operation on ductility can be significant in determining the limit strains of the final product. The strain path experienced in straight tube bulging is significantly different from that of elbow (tube with pre-bending), leading to a reduction in bulge height. The Tube bending introduces strain gradient both along the tube and across the tube. In this work the effect of pre-bending on limit strains during tube bulging process is predicted — and the results are compared to the limit strains of bulged tubes without pre-bending. The Finite Element (FE) model of the bending operation is developed which utilizes an explicit dynamic finite element formulation. The PAMSTAMP 2G code is used to perform the numerical pre-bend (and bulging) simulations. Tension side of bend tube axial strain is found to be positive and hoop strain as negative and vice versa along the compression side. During the bulging, the neck usually develops perpendicular to major strain direction. During bend tube bulge test with fixed expansion and axial feed expansion of bend tubes, in both cases the crack is found to be in the axial direction.

Validation of a Second-Generation Echo PIV System in Patient-Specific Carotid Artery Models: In Vitro Studies Using Pulsatile Flow

2008 ◽  
Author(s):  
Fuxing Zhang ◽  
Craig Lanning ◽  
Luciano Mazzaro ◽  
Bryan Rech ◽  
S. James Chen ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Pulsatile Flow ◽  
Second Generation ◽  
Axial Direction ◽  
Frame Rate ◽  
Center Frequency ◽  
Patient Specific ◽  
Maximal Velocity ◽  
Array Transducer

Echo Particle Image Velocimetry (Echo PIV), a novel opaque flow velocimetry technique developed in our laboratory, has been shown to be an effective 2-D flow measurement velocimetry method in prior studies for both steady and pulsatile flow conditions [1,2]. However, certain limitations remained in the first-generation system. These include inconsistent spatial resolution caused by the phased array transducer, and the relatively low frame rate (i.e., lower temporal resolution) [2]. To overcome these limitations, we developed a second-generation Echo PIV system with a custom-designed linear array transducer (5–14MHz, center frequency 10MHz) and customized post-processing of backscatter data. In vascular applications, the new system can provide frame rates up to 1428 fps (temporal resolution of 0.7 ms). The transducer has a consistent axial resolution of 150um, which brings a maximal velocity field resolution around 500um in axial direction. An ECG module was also integrated to enable the capture of ensemble data over the cardiac cycle.

1.5-Dimensional Circular Array Transducer for In Vivo Endoscopic Ultrasonography

2021 ◽  
pp. 1-1
Author(s):  
Qi Zhang ◽  
Qingyuan Tan ◽  
Jiamei Liu ◽  
Weicen Chen ◽  
Jiqing Huang ◽  
...  
Keyword(s):  
Endoscopic Ultrasonography ◽  
Circular Array ◽  
Array Transducer
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