基于体外标志物的放疗患者位移监测方法  

Displacement Monitoring for Radiotherapy Patients Using in Vitro Markers

作　　者：王妍璐 何枫 侯再红 靖旭 程乙轮 Wang Yanlu;He Feng;Hou Zaihong;Jing Xu;Cheng Yilun(Key Laboratory of Atmospheric Optics,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,Anhui,China;University of Science and Technology of China,Hefei 230026,Anhui,China;Advanced Laser Technology Laboratory of Anhui Province,Hefei 230037,Anhui,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所中国科学院大气光学重点实验室,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026 [3]先进激光技术安徽省实验室,安徽合肥230037

出　　处：《激光与光电子学进展》2023年第2期298-305,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(41405014)。

摘　　要：为提高放疗的治疗精度,需要实时监测放疗中患者病灶区域的位移。针对放疗过程中患者体表被热塑膜遮挡的特点,通过标志物的材质、形状等设计,最大限度地减少热塑膜遮挡对标志物定位精度的影响。首先根据标志物的颜色特征分割出热塑膜遮挡下的标志物并用凸包算法计算标志物的外轮廓;其次采用改进的最小二乘椭圆拟合算法拟合标志物外轮廓上的点并定位标志物;最后,基于标志物的位置特征匹配标志物并计算患者的位移值。通过搭建模拟实验平台多次实验,验证了该方法测量患者位移的精度是0.2 mm,帧频可以达到30 Hz,可以满足放疗中位移监测的实时性和精度要求。To improve the accuracy of radiotherapy,it is necessary to monitor the displacement of the patient's focus area in real time during radiotherapy.Considering that the surface of the patient's body is blocked by the thermoplastic film used during radiotherapy,the material and shape of the marker were designed to minimize the impact of this thermoplastic film on the positioning accuracy of the marker.First,the markers covered by the thermoplastic film were segmented according to their color characteristics;thereafter,the convex hull algorithm was employed to calculate the outer contour of the markers.Next,the improved least squares ellipse fitting algorithm was adopted to fit the points on the outer contour of the markers and locate the markers.Lastly,based on the location of the markers,features were matched to the markers,and the patient's displacement value was thus calculated.Based on a simulation experiment platform and multiple experiments,this method for measuring patient displacement achieves an accuracy of 0.2 mm,with frame rates of up to 30 Hz.Thus,this approach can meet the requirements of real-time and accurate displacement monitoring in radiotherapy.

关 键 词：医用光学与生物技术 图像处理 位移监测 体外标志物 最小二乘椭圆拟合 精确放疗 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]