Abstract

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

Author(s):: DU Fanyu; JIANG Xixian; DENG Lanzhi; FENG Xiaojie; School of Medical Imaging, North Sichuan Medical College, Nanchong 637000, China

Keywords:: Keywords: least square method X-ray bulb tube tube current polynomial fitting piecewise translation

Abstract:: Abstract: 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%.