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基于盆腔MRI图像的新型直肠腔内施源器的设计与评价
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作者 程天 廉清杰 +3 位作者 彭冉 孙海涛 曲昂 王皓 《中华放射肿瘤学杂志》 CSCD 北大核心 2024年第11期1042-1048,共7页
目的设计并评价一种新型弧形多通道直肠腔内施源器,以增强对直肠中上段肿瘤的剂量覆盖并降低对直肠壁的压强。方法回顾性分析2022年7月至2022年8月北京大学第三医院200例中国无直肠病变人群盆腔MRI图像,基于图像数据设计并制造了具有人... 目的设计并评价一种新型弧形多通道直肠腔内施源器,以增强对直肠中上段肿瘤的剂量覆盖并降低对直肠壁的压强。方法回顾性分析2022年7月至2022年8月北京大学第三医院200例中国无直肠病变人群盆腔MRI图像,基于图像数据设计并制造了具有人群一般特征的直肠体模与硬软两类材质的新型弧形施源器。对比常规直筒施源器和两种新型弧形施源器对体模直肠壁的形变、最大压强与稳定压强,以及GTV的D_(90%)、D_(100%)、V_(100%)、V_(150%)、V_(200%)和危及器官的D_(2 cm^(3))、D_(1 cm^(3))、D_(0.1 cm^(3))。采用方差分析或Kruskal-Wallis H检验比较三组施源器差异,Dunnett多重比较检验进行配对比较。结果硬软两类材质的新型弧形施源器造成体模肠壁的形变均较小。硬质弧形施源器和软质弧形施源器对直肠壁的最大压强分别为(0.606±0.182)kPa、(0.481±0.229)kPa,稳定压强分别为(0.207±0.137)kPa、(0.055±0.097)kPa,均显著小于直筒施源器(P<0.001、<0.001,P=0.024、<0.001),降幅达到或接近50%。在确保靶区剂量的前提下,硬质弧形施源器和软质弧形施源器设计计划中的危及器官的D 2_(cm^(3))、D_(1 cm^(3))、D_(0.1 cm^(3))比直筒施源器显著降低(均为P<0.001)。结论新型弧形多通道直肠腔内施源器可显著降低直肠壁压强和形变,同时能在不牺牲靶区剂量覆盖的情况下降低危及器官的剂量,有一定的治疗优势。 展开更多
关键词 直肠肿瘤 近距离放射疗法 施源器 多通道 适形设计
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Joint adaptive waveform and baseline range design for bistatic radar 被引量:2
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作者 王璐璐 王宏强 +1 位作者 程永强 秦玉亮 《Journal of Central South University》 SCIE EI CAS 2014年第6期2262-2272,共11页
The problems of joint adaptive waveform design and baseline range design for bistatic radar to maximize the practical radar resolution were considered.Distinguishing from the conventional ambiguity function(AF)-based ... The problems of joint adaptive waveform design and baseline range design for bistatic radar to maximize the practical radar resolution were considered.Distinguishing from the conventional ambiguity function(AF)-based resolution which is only related with the transmitted waveform and bistatic geometry and could be regarded as the potential resolution of a bistatic radar system,the practical resolution involves the effect of waveform,signal-to-noise ratio(SNR)as well as the measurement model.Thus,it is more practical and will have further significant application in target detection and tracking.The constraint optimization procedure of joint adaptive waveform design and baseline range design for maximizing the practical resolution of bistatic radar system under dynamic target scenario was devised.Simulation results show that the range and velocity resolution are enhanced according to the adaptive waveform and bistatic radar configuration. 展开更多
关键词 ambiguity function (AF) adaptive waveform design bistatic radar baseline range design RESOLUTION
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Liquid-level sensor based on tapered chirped fiber grating
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作者 DONG XiaoWei LIU WenKai ZHAO RuiFeng 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第2期471-474,共4页
An optic-fiber liquid-level sensor based on tapered chirped grating was proposed and demonstrated experimentally.With a properly designed column buoy hung to chain wheel,the liquid-level variation was converted to axi... An optic-fiber liquid-level sensor based on tapered chirped grating was proposed and demonstrated experimentally.With a properly designed column buoy hung to chain wheel,the liquid-level variation was converted to axial strain,which made the reflection spectrum of the tapered chirped grating narrowed or broadened correspondingly.And a high-sensitive liquid-level sensor was obtained by monitoring the bandwidth variation of the tapered chirped grating.Compared with traditional absolute wavelength or power detection,this special monitoring technique based on bandwidth modulation makes the liquid-level sensor insensitive to spatially uniform temperature variations and power fluctuations from down-lead or light source. 展开更多
关键词 liquid-level sensor chirped fiber grating tapered fiber
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