基于加权平均的胎心率提取算法

Arithmetic on fetal heart rate based on weighted mean

为解决胎心率从胎心音信号中提取并计算的问题,分析这一提取并计算的特点,综合考虑胎心音信号到达孕妇腹部传感器后极弱,和受到噪声和干扰的影响、胎心率直接计算法误差较大、时间加窗法时延过长且效率低3个因素,提出基于加权平均的胎心率提取算法。该算法将窗内自动加权平均且窗外指数加权平均修正,对窗内操作得到的胎心率加以限制,使实时系统输出结果更稳定。实验结果表明,基于加权平均的胎心率提取算法消除了窗内错检和漏检,可以提供实时稳定的输出,性能优于直接计算法和时间加窗法。

To solve the problem that the fetal heart rate is extracted and calculated from the fetal heart sound signal,the characteristics of this extraction and calculation were analyzed,and the fetal heart sound signal was considered to be extremely weak after reaching the pregnant woman’s abdominal sensor,and was affected by noise and interference.The fetal heart rate direct calculation method has large error,the delay of the time windowing method is too long and the method efficiency is low,a fetal heart rate extraction algorithm based on weighted average was proposed.The weighted average in the window and the outer-index exponential weighted average were automatically adjusted and the fetal heart rate obtained by the operation in the window was limited,so that the output of the real-time system was more stable.The experimental results show that the proposed method eliminates the error detection and missed detection in the window,and can provide real-time stable output.Its performance is better than that of the direct calculation method and the time windowing method.