一种用于检测胎儿心率的改进自相关算法

Improved Auto-Correlation Algorithm for Doppler Fetal Heart Rate Detection

在分析传统自相关算法的基础上,提出了一种改进的自相关算法.该算法通过自适应控制,实时调整控制因子,使自相关函数随时延的衰减程度在不同的胎心率值下不同,始终保证自相关函数最大周期峰值在第一周期处,有效地克服了传统算法在超声多普勒胎儿心率检测时易造成心率加倍或减半的误判现象.对该算法进行了优化,使得计算量减少为原来的18%,速度提高了近6倍,同时由于除去了大量不与心率值对应的点,降低了干扰信号对心率值的影响.

Analyzing the traditional auto-correlation algorithms, an improved method is presented, where the adaptive control is adopted to realize a real-time adjustment for control factor, thus the attenuation of auto-correlation function at any time extension varies with different fetal heart rate. It consistently ensures that the largest cycle peak is in the first cycle of correlation function to effectively eliminate the misjudgments due to doubling and halving in the detection of Doppler fetal heart rate with the traditional methods. In the optimized algorithm, the computation is reduced to 18% of the original, and the computing rate is accelerated 6 times Simultaneously, the influence of interference signals on heart rate is greatly weakened by removing the un-corresponding values.