X射线管灯丝发射特性曲线的拟合算法

Fitting Algorithm of the Filament Emission Characteristic Curve for X-Ray Tube

X射线管灯丝发射特性曲线是X射线管的重要参数,在发生器里储存当前使用的X射线管灯丝发射特性曲线,X射线曝光准备时就可以将灯丝电流加载到预定的值,以实现快速曝光。X射线管灯丝发射特性曲线的储存方式有数据表格式和曲线方程式,前者获取速度快但储存容量大,而后者是相反的特点,但是以目前计算机的速度,使用曲线方程式来进行存储已经可以满足实际需求。本文采用VB软件界面,对X射线管灯丝发射特性曲线以描点的方式采样,再利用最小二乘法进行曲线拟合,以获得灯丝发射特性曲线,为发生器提供X射线管灯丝加热电流参数值。

As one of the important parameters of the X-ray tube, the filament emission characteristic curve used currently shall be stored in the generator, and then the filament current can be loaded to a predetermined value when the X-ray exposure is prepared. There are two methods to store the curve in the generator： data table format and curve equation method. The former has rapid access to the data and more storage space; and the latter is just opposite. Under the high calculating speed of the modern computers, the generator has adequate speed to acquire the data from the curve equation. This paper uses the VB software interface, and sample the filament emission curve of X-ray tube by point-by-point manner, then applies linear least-squares method to perform curve fitting. Finally, the filament emission characteristic curve is acquired so as to provide the value of X-ray tube filament heating current for the generator.