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Temperature rise induced by an annular focused transducer with a wide aperture angle in multi-layer tissue
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作者 戚萌 刘杰惠 +1 位作者 毛一葳 刘晓宙 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期390-395,共6页
In order to improve the operability and accuracy of high-intensity focused ultrasound (HIFU), an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time mon... In order to improve the operability and accuracy of high-intensity focused ultrasound (HIFU), an annular focused transducer, whereby a B-ultrasound probe is placed in its center, is used to realize the real time monitoring and control of the treatment. In this paper, the spheroidal beam equation (SBE) was used to calculate the sound lield by an annular focused transducer with a wide aperture angle to first derive the heat deposition and the Pennes equation was used to calculate the temperature field in multi-layer tissue. We studied the effect of different parameters on the temperature of the tissues. The result shows that the focal length has a significant influence on both maximum liver temperature rise and skin temperature rise, and both increase with the increase in the focal length. When the frequency increases, the temperature rise first undergoes a rapid increase before gradually reaching a maximum, and then finally decreasing. The temperature rise increases while the inner radius decreases or the sound pressure increases. By choosing suitable parameters, the proper temperature rise both on the target tissue and skin via an annular tbcused transducer with a wide aperture angle can be obtained. 展开更多
关键词 spheroidal beam equation annular focused transducer multi-layer tissue temperature field
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Scanning photoacoustic imaging of submucosal gastric tumor based on a long focused transducer in phantom and in vitro experiments 被引量:1
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作者 Hua-Qin Wu Hao-Yu Wang +4 位作者 Wen-Ming Xie Shu-Lian Wu Zhi-Fang Li Xiao-Man Zhang Hui Li 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2019年第3期55-66,共12页
Photoacoustic imaging,which can provide the maximum intensity contrast in tissue depth imaging without ionizing radiation,will be a promising imaging trend for tumor detection.In this paper,a column diffusionfiber was... Photoacoustic imaging,which can provide the maximum intensity contrast in tissue depth imaging without ionizing radiation,will be a promising imaging trend for tumor detection.In this paper,a column diffusionfiber was employed to carry a pulsed laser for irradiating stomach directly through esophagus based on the characteristics of gastric tissue structure.A long focused ultrasonic transducer was placed outside the body to detect photoacoustic signals of gastric tissue.Phantom and in vitro experiments of submucosal gastric tumors were carried out to check the sensitivity of scanning photoacoustic tomography system,including the lateral and longitudinal resolution of the system,sensitivity of different absorption coefficient in imaging,capability of transversal detection,and probability of longitudinal detection.The results demonstrate that our innovative technique can improve the parameters of imaging.The lateral resolution reaches 2.09 mm.Then a depth of 5.5mm with a longitudinal accuracy of 0.36mm below gastric mucosa of early gastric cancer(EGC)has been achieved.In addition,the optimal absorption coefficient differences among absorbers of system are 3.3-3.9 times.Results indicate that our photoacoustic imaging(PAI)system,is based on a long focusing transducer,can provide a potential application for detecting submucosal EGC without obvious symptoms. 展开更多
关键词 Column diffusionfiber long focusing transducer gastric tumor detection scanning photoacoustic tomography phantom experiment
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NEW FOCUSED ULTRASOUND TRANSDUCER FOR FAT CELL DISRUPTION
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作者 YANG CUI JUE PENG +2 位作者 HU TANG TIANFU WANG SIPING CHEN 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2012年第1期85-90,共6页
Being an emerging body-shaping technology of fat cell disruption,high-intensity focused ultrasound has been investigated intensively in recent years for its favorable natures such as painlessness,safety and noninvasio... Being an emerging body-shaping technology of fat cell disruption,high-intensity focused ultrasound has been investigated intensively in recent years for its favorable natures such as painlessness,safety and noninvasion.One of the major problems for the technology,however,is the overheating of transducers.In this study,we modified the transducer design in order to solve the overheating problem.We simulated the performance of the modified design by finite element analysis and fabricated the newly designed transducer.By measuring the actual performance data,we proved that the new design can effectively reduce temperature rise while keeping the acoustic intensity field unaffected. 展开更多
关键词 focused ultrasound transducer fat disruption acoustic field OVERHEATING
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Reflection-mode photoacoustic microscopy using a hollow focused ultrasound transducer for in vivo imaging of blood vessels
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作者 袁毅 杨思华 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期283-287,共5页
A reflection-mode photoacoustic microscope using a hollow focused ultrasound transducer is developed for highresolution in vivo imaging.A confocal structure of the laser and the ultrasound is used to improve the syste... A reflection-mode photoacoustic microscope using a hollow focused ultrasound transducer is developed for highresolution in vivo imaging.A confocal structure of the laser and the ultrasound is used to improve the system resolution.The axial and lateral resolutions of the system are measured to be ~ 32 μm and ~ 58 μm,respectively.Ex vivo and in vivo modes are tested to validate the imaging capability of the photoacoustic microscope.The adjacent vein and artery can be seen clearly from the reconstructed photoacoustic images.The results demonstrate that the reflectionmode photoacoustic microscope can be used for high-resolution imaging of micro-blood vessels,which would be of great benefit for monitoring the neovascularization in tumor angiogenesis. 展开更多
关键词 photoacoustic microscopy hollow focused ultrasound transducer blood vessels
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The experimental study of the calibration of the focus ultrasonic transducer on its picture
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作者 侯珍秀 赵永平 +4 位作者 黄乃华 陈新亮 张丽莉 罗建伟 金长善 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第2期139-142,共4页
The shape and size of the energy transducer’s focus decide the constitution of the cure project using HIFU (High intensity focused ultrasound). The parameter of the focus will be different when the structure of the t... The shape and size of the energy transducer’s focus decide the constitution of the cure project using HIFU (High intensity focused ultrasound). The parameter of the focus will be different when the structure of the transducer is different, so we must calibrate each of them. This paper represents calibration principle and method of focal territory in a high-power ultrasonic focus transducer. The experiment is performed on our designed multiple wafer concave focus probe and HIFU apparatus, using 1010 nylon and pork as the target range. It can be seen that the geometric center and focal territory acoustic field center cannot match together. When using nylon as the target, the distributed curves and theoretical curves are a better match. Therefore, the method and principle of calibration here is constructive for the calibration on pictures of other types of HIFU apparatus. 展开更多
关键词 ultrasonic wave the focus ultrasonic transducer FOCUS CALIBRATION HIFU
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Photoacoustic microscopy by scanning mirror-based synthetic aperture focusing technique 被引量:3
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作者 蔡德 李忠飞 陈松良 《Chinese Optics Letters》 SCIE EI CAS CSCD 2015年第10期45-48,共4页
Photoacoustic imaging with a synthetic aperture focusing technique(SAFT) is an effective method to improve the lateral resolution for out-of-focus regions in scanning microscopy systems, which commonly require a dec... Photoacoustic imaging with a synthetic aperture focusing technique(SAFT) is an effective method to improve the lateral resolution for out-of-focus regions in scanning microscopy systems, which commonly require a decent motorized scanning stage for a lateral scan of a transducer to obtain a cross-sectional image. In this study, we propose and test a photoacoustic imaging system with a scanning mirror-based SAFT(SM-SAFT) for simple and fast data acquisition, without the need for a physical scan of the transducer. Photoacoustic images of hair phantoms acquired by SM-SAFT are demonstrated, serving as a proof-of-concept experiment to show the feasibility and potential of the proposed approach. 展开更多
关键词 mirror aperture focusing transducer serving scanned proof scanner sectional applying
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