胎儿心率监测是一种有效评估胎儿当前健康状况的重要参考依据。为了可以快速准确地获取胎儿心率,该文提出一种基于非负盲分离的胎儿心率检测方法。该方法首先对采集得到的腹壁信号进行预处理,平稳小波变换后重构出母亲心电信号;接着,采用相减法去除母亲心电信号,再把剩下含有噪声的胎儿心电信号通过时频变换得到 Born- Jordan分布;最后,利用非负矩阵分解得到胎儿心电的特征信号,检测其R波位置求得胎儿瞬时心率。实验结果表明,该方法可以快速、准确有效地获得胎儿地瞬时心率数据。
Fetal heart rate monitoring is an important reference to evaluate the current health condition of the fetus. In order to obtain fetal heart rate rapidly and exactly, this paper proposed a method to detect fetal heart rate based on non-negative blind source separation. First of all, the abdominal composite signal was preprocessed. Next, we adopted stationary wavelet transform and reconstructed the maternal ECG signal, removed maternal ECG signal by subtraction. Then, through the time-frequency transform, we got the Born-Jordan distribution of fetal ECG signal with noise. Last, based on the non-negative matrix decomposition to get the clear FECG characteristic signal, through detecting the fetal signal position of R wave we could calculate instantaneous heart rate. The experimental results show that the method can effectively and correctly calculate fetal instantaneous heart rate.