Due to the interference of blood pulse and muscle stretching,the heart movements detected by B-type ultrasonic contain functional and non-functional motions,therefore,the motional curve of heart obtained by this way cannot exactly reveal heart' 8 function. In this article,the contour of left ventricle in a short axis was firstly extracted using the modified Canny algorithm and the gray searching algorithm in radial direction as auxiliary. Non-functional movements were obtained using the movement extracting method based on Fourier descriptors,as well as the method of mass center and inertia axis,and finally removed from the compound motion. As a result,the cardiac motional curve obtained using this method eliminated the phenomena of multi line,shift excursion and being smooth. It showed that the modified sampling directional lines accurately tracked the movements on a certain position in heart at any moment,and the cardiac motional curve did not shift with the movement of non-functional,and the characteristics point was remained. Compared with the original method,the proposed motional curve of heart movement accurately reflected the functional movement at a certain place in the heart.%由于受到血液的冲击和周围肌肉的牵拉,B超探测到的心脏运动包含了功能性和非功能性两种运动,由此获得的心动波形图不能准确反映心脏的功能.首先采用改进的Canny算法并辅以改进的径向灰度搜索算法提取左心室短轴轮廓,然后使用基于傅里叶描述子的运动提取方法和质心主轴法获取心脏的非功能性运动,并从复合运动中剔除非功能性运动.基于该方法得到的心动曲线消除了心动波形图中的多线、偏移和被平滑等现象,经修正后的采样方向线能够跟随心脏特定结构的各方向平移,没有出现心动曲线随非功能运动位移和特征点失落等情况,可更准确地反映心脏结构特定部位的功能性运动.
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