基于DM6446的数字X光机自动曝光控制系统设计和实现

Automatic Exposure Control System Design and Implementation of Digital X-ray machine Based on DM6446

X射线摄影为诊断提供了有力依据,但对病人造成辐射伤害,所以曝光剂量的控制尤为重要,自动曝光控制可以采用较小的曝光剂量得到符合诊断要求的图像。本文基于双核TMS320DM6446达芬奇嵌入式平台,设计了数字X光机自动曝光控制系统,通过预曝光图像分割、提取ROI特征参数,采用多ROI自适应调整多曝光参数。并且对算法代码进行优化和x DM封装,使其易于移植并且满足实时要求。通过DM6446平台运行和Matlab仿真模拟表明,该方法能够从较模糊的预曝光图像中提取出ROI,自适应调整曝光参数,曝光成像质量高且降低了曝光剂量,提高了数字X光机曝光准确性和曝光效率。

X ray photography provides a strong basis for medical diagnosis, but it causes radiation damage to the patient, so it become important to control the exposure dose. Automatic exposure control can obtain the image that accord with the standard of diagnosis with a smaller exposure dose. In this study, dual-core TMS320DM6446 Da- Vinci embedded platform were chosen to design the automatic exposure control system of digital X ray machine. The pre-exposure image were fi rstly segmented to extract feature parameters in the region of interest（ROI）, and then multi- exposure parameters were received through an adaptive adjustment of multi ROI. Meanwhile the algorithm code was optimized and the x DM was packaged which make it easy to transplant and satisfy the real-time requirement. The results based on DM6446 platform operation and the Matlab simulation show that, the ROI can be extracted from a fuzzy pre-exposure image, via adaptive adjusting the exposure parameters, a high exposure imaging quality and a reduced exposure dose was obtained, digital X ray exposure accuracy and exposure effi ciency was improved.