基于最小二乘法的X线球管管电流校准优化方法  

Optimization method of X-ray bulb tube current calibration based on least square fitting

作　　者：杜凡宇 蒋曦贤 邓岚之 冯小洁 DU Fanyu;JIANG Xixian;DENG Lanzhi;FENG Xiaojie(School of Medical Imaging,North Sichuan Medical College,Nanchong 637000,China)

机构地区：[1]川北医学院医学影像学院,四川南充637000

出　　处：《中国医学物理学杂志》2023年第4期456-462,共7页Chinese Journal of Medical Physics

基　　金：南充市市校科技战略合作项目(20SXQT0139);川北医学院校级科研发展青年项目(CBY20QAY04)。

摘　　要：医疗X线类设备球管中电流漂移问题会影响影像构建质量和患者检查的准确性,工程中一般采用人为多次测量校准,准确度低且成本花费巨大。本研究提出通过控制变量的方法测绘出新、旧球管的灯丝特性曲线,根据管电流多项式的变化规律,采用Matlab最小二乘法多项式拟合方法,利用实测的少数点值和多项式分段平移方法对球管所有曝光点的灯丝电流以及灯丝曲线多项式进行推算校准,减少了人为测量次数,降低了人工成本和人为测量平均误差。通过康达C臂X线光机KD-C5000实验验证表明,此方法可节约75%的管电流校准时间,能将原来20%的平均误差降低到2%左右。The problem of tube current drift in the bulb of medical X-ray equipment affects the quality of image construction and the accuracy of patient examinations,and is generally calibrated by multiple human measurements in engineering,which is low in accuracy and high cost.Herein,it is proposed to map the filament characteristic curves of the new and old tubes by controlling variables.According to the change law of tube current polynomials,the Matlab least square polynomial fitting approach is adopted,and the filament current of all exposure points of the spherical tube and the polynomials are calculated and calibrated using the measured tube current of a few exposure points of the spherical tube and the polynomial piecewise translation method,which reduces the frequency of human measurements,labor costs and the average error of human measurements.Through the experimental verification of KD-C5000 of Kangda C-arm,it is showed that the method can save about 75%of the tube current calibration time,and can effectively reduce the average error from the original 20%to about 2%.

关 键 词：最小二乘法 X线球管 管电流 多项式拟合 分段平移 

分 类 号：R318[医药卫生—生物医学工程] TP[医药卫生—基础医学]