小于5cm肺癌5野调强和容积调强放疗的剂量比较

目的 :比较肺部<5cm病灶5野调强放射治疗(5-field intensity modulated radiotherapy,5F-IMRT),容积调强放射治疗(volume modulated arc therapy,VMAT)立体定向放射治疗(stereotactic body radiotherapy, SBRT)计划的剂量参数,观察两种放疗设计方法在计划靶区和正常组织剂量。方法 :对收治的56例(共68个病灶)采用大分割立体定向放射治疗肺部<5cm病灶,设计处方计划靶区剂量的SBRT计划(IMRT和VMAT),处方剂量500cGy*10fx包括95%PTV,对两种计划的适形度指数(conformity index,CI)、均匀指数(homogeneity index,HI)、全肺平均剂量以及肺V_5,V_(10),V_(20),V_(30),以及串联器官脊髓、食管最大受量进行比较。结果 :5F-IMRT与VMAT计划的PTVmax, PTVDmean和PTVmin差异无统计学意义。靶区CI和HI值比较VMAT均优于5F-IMRT。全肺V_5和全肺平均受量比较,VMAT显著低于5F-IMRT,组间差异有统计学意义,而V_(10),V_(20)和V_(30)两种方式差异无统计学意义。两种放疗计划患侧肺受量V_5,V_(10),V_(20),V_(30)和患侧肺平均剂量值差异无统计学意义。健侧肺组织V_5值VMAT显著低于5F-IMRT,差异有统计学意义,V_(10),V_(20),V_(30),健侧肺平均肺剂量差异无统计学意义。食管和脊髓最高剂量差异无统计学意义。结论:5F-IMRT和VMAT计划可满足临床要求,VMAT计划的靶区适形度更优。对于小体积肺癌病灶,综合考虑可优先选择VMAT。     

剂量引导实时验证系统KylinRay-DGRT的研发及验证

FDS团队发展了剂量引导实时验证系统KylinRay-DGRT,该系统集射野透射影像采集、射野透射剂量标定、三维剂量重建、剂量评价、计划重优化等功能于一体,可进行强度和三维剂量验证,并引导物理师对放疗计划进行精确修正,从而有效地保证病人受照剂量的精准性。本文对KylinRay-DGRT的总体设计和关键技术方法进行了介绍;采用美国医学物理学家协会(AAPM)TG119号报告中的"模拟C形靶区"测试例题对KylinRay-DGRT进行正确性测试举例,结果表明KylinRay-DGRT重建的剂量与参考TPS计算的计划剂量,以及实测剂量的符合率达到94.8%以上;采用头颈部肿瘤病例对KylinRay-DGRT进行了临床验证,结果表明KylinRay-DGRT重建的剂量满足临床要求。     

肝癌四维CT放疗计划设计方式探讨

目的 :通过与标准流程制作的4D放疗计划剂量分布对比分析,探讨四维计划设计过程简化可行性。方法 :选取原发性肝癌患者10例,每例患者都采用两种方案进行4D放疗计划设计,分别定义为准4D计划和4D计划。两种方案基于相同的4D轮廓勾画方式、射野方向和处方剂量,准4D计划在参考时相上进行布野及射野优化,而4D计划在各个时相上各自进行优化,然后变形叠加到参考时相。最终对比分析两种方案的剂量差异。结果 :在肝癌危及器官保护和处方剂量提升方面,4D计划都略优于准4D计划,但无统计学意义差异。结论 :临床应用肝癌的四维放射治疗技术,可以对4D计划优化过程进行部分简化,提高该技术临床应用的可操作性。但对于个别呼吸幅度较大或靶区与危及器官结构相对复杂患者,需要后续研究中进一步探讨。     

三维适形放疗联合FOLFOX治疗直肠癌的临床效果观察

目的:探讨术前三维适形放疗联合FOLFOX方案治疗直肠癌的临床疗效及治疗安全性。方法 :选取2008年2月~2012年1月在我科治疗而且病理证实为局部晚期直肠癌患者65例,随机分为适形放疗加化疗组(观察组)35例,常规放疗加化疗组(对照组)30例,观察并比较两组的临床疗效和不良反应情况。结果 :两组总有效率(CR+PR)分别是63.3%和82.9%。术前肿瘤分期明显降低,治疗后原诊断为T 3期的35例患者中6例降为T 1期,13例降为T 2期,16例仍为T 3期;其侵犯淋巴结均有缩小,其中12例转阴。对照组放射性膀胱炎、皮肤反应和放射性直肠炎的发生率高于观察组(P<0.05)。结论 :术前三维适形放疗联合FOLFOX方案化疗治疗局部晚期直肠癌的安全有效的方法,值得临床应用。     

核通放疗计划系统临床应用总结及问题对策

本文简要介绍核通放射治疗计划系统Oncentra MasterPlan3.3的临床应用,分析该TPS在实际应用中的优缺点,并针对系统速度慢、易死机以及剂量稳定性差等相关问题提出合理实用的解决方案。     

Delaunay三角剖分在放射治疗计划轮廓线重建中的应用

靶器官与关键器官二维轮廓线序列的三维重建,是三维放射治疗计划系统（3 dimension therapy planning system,3D-TPS）的重要组成部分,它能帮助计划者以任意视角获取病人内部组织和病变体的大小、位置、形状等三维空间信息.本文在回顾3D Delaunay三角剖分的定义、性质和基本算法的基础上,运用可视化类库Visualization Toolkit（VTK）中封装的3D Delaunay类,编程实现了脊柱和肿瘤二维轮廓线序列的三维重建.结果表明,Delaunay三角剖分方法具有稳定、耗时少、内存占用量小等优点,对轮廓线点集的数据三维分布没有特殊限制等优点.     

肿瘤放射治疗下患者生命体征多区域实时同步监测方法的探讨

本文旨在讨论肿瘤放射治疗下患者生命体征的实时同步监测方法。放射治疗是一种非常有效的肿瘤治疗方法，约70%的恶性肿瘤患者需要采用放射治疗，但是在治疗过程中，患者的生命体征需要被严密监测以确保治疗的安全性和有效性。针对放射治疗中患者安全监护系统的不完善，本文构建全方位放射治疗患者安全监护系统，加强对放射治疗中患者的监控观察。安全监护系统采用基于血氧饱和度信号的呼吸率检测技术，用血氧探头测量患者的血氧饱和度、脉率、呼吸率等重要的生命体征信息，并传输至中央监护系统，在医技工作站跨区域实时同步显示，保障了患者在放射治疗环境下的生命安全监测。     

两种子野分割算法在直肠癌术后调强放疗计划中的剂量学对比

目的探讨XIO5.0制订直肠癌术后调强放疗计划时,SlidingWnd(SL)和SmartSequence(SM)两种子野分割算法的区别.方法选取本放疗中心行直肠癌术后放疗的患者19例,分别采用SL、SM子野分割算法制订IMRT计划,并按分割算法分成PSL组和PSM组,比较两组IMRT计划的靶区、危及器官剂量分布、机器跳数、总子野数和治疗时间.结果两组IMRT计划均符合临床剂量要求,两组计划的靶区和危及器官剂量分布均未见明显区别(P>0.05),PSM组机器跳数、总子野数和治疗时间分别比PSL组少26%、32%、16%,且有显著性差异(P<0.05).结论制订直肠癌术后调强计划时,相对于SL子野分割算法,SM子野分割算法可以减少子野数和机器跳数,节约治疗时间,建议优先选择.     

SIEMENS PRIMUS M医用直线加速器性能质控QA与使用评价

探讨医用电子直线加速器检测中的使用方法和临床应用体会,并评价其性能的优缺点。直线加速器的机械精度和剂量的稳定性在使用中会出现偏差,通过前指针法和两维剂量仪对加速器的机械精度和剂量参数进行定期检测,是对放射治疗计划有效实施的有利保证。依据国家放射卫生防护相关的标准及规定的方法、国家(卫生部)确认的医用电子直线加速器的性能质控和安全性评价QA检测方法,测量了SIEMENS PRIMUS M医用电子直线加速器的主要技术指标和QA内容。每周治疗前由放疗物理工程师按照国家(卫生部)质量保证规程对直线加速器进行周检,该医用直线加速器符合国家相关标准的要求。     

术前放疗与术后放疗治疗软组织肉瘤的效果和并发症

目的 :分析术前放疗和术后放疗对软组织肉瘤患者的临床效果及并发症的影响,为治疗方案的制定提供参考依据。方法 :选择我院2010年6月至2015年6月期间收治的114例确诊为软组织肉瘤的患者,采用随机数字发将所有患者平均分为术前组57例和术后组57例,所有患者均采用常规扩大根治手术切除术,前组患者手术前给予照射总剂量为30 Gy的放射治疗,共治疗2周;术后组患者于手术后1～3周后开始放射治疗,照射总剂量为50 Gy,共治疗5周,如果患者术后有残留肿瘤灶,则增加照射剂量至60～70 Gy。结果 :术前组患者的3年生存率显著高于术后组,3年转移复发率均明显低于术后组,差异具有统计学意义(P<0.05);术前组患者的伤口愈合延迟的发生率均显著高于术后组患者,但皮肤毒性反应和关节功能障碍等并发症发生率显著低于术后组,差异均具有统计学意义(P<0.05)。结论 :术前放疗对于软组织肉瘤患者较术后放疗能够获得更高的3年生存率,减少患者术后3年的转移率和复发率,但术前放疗的患者伤口并发症发生风险高,皮肤毒性反应的发生率低,临床上应全面评估患者病情,根据肿瘤灶的大小和部位选择合适的放疗时机,以提高患者的治疗效果和安全性。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.