The Study Of Fetal Instantaneous Heart Rate Detection Method

Based on the security of maternal and fetal safety, a long time ago, people have already begun to study fetal heart rate monitoring and the fetal heart electronic monitoring system also has been widely used in clinical fetal monitoring. We know that one of the most important indicators of fetal heart monitoring is the instantaneous heart rate of the fetus. It is well known that the fetus in the body of the mother, it is impossible to directly measure fetal heart rate, therefore, there are two ways to calculate the instantaneous heart rate of the fetus, the first approach is to obtain the instantaneous heart rate of the fetus by processing the fetal ECG signal acquired by the ECG signal collector and using the corresponding algorithm; the second approach is to obtain the instantaneous heart rate of the fetus by processing the fetal heart sounds signal collected by ultrasonic Doppler instrument and using the corresponding algorithm. This paper puts forward effective methods for fetal heart sound signal and the fetal ECG signal to calculate the fetal instantaneous heart rate. Therefore, the method of fetal instantaneous heart rate detection can quickly and easily calculate the instantaneous heart rate of the fetus, and better serve the clinical fetal monitoring.The work of this paper is:(1) Introduces the theory background knowledge of the study on the detection of fetal instantaneous heart rate. Mainly introduces the basic idea of Shannon envelope algorithm, rectangle window short-time energy algorithm and improved template matching algorithm.(2) This paper proposes a new algorithm of fetal instantaneous heart rate detection based on Shannon envelope. The basic steps are:firstly, preprocessing, the heart sound signal is filtered through Butterworth low-pass filter and normalized amplitude; secondly, calculating the Shannon envelope curve; finally, the instantaneous heart rate of the fetus can be obtained by the corresponding conversion.(3) This paper proposes a new method of fetal instantaneous heart rate detection based on short-time average energy. The basic steps are:firstly, the choice of window function and the length of the window function; secondly, the peak detection and positioning of the processed signal; finally, using the finite difference method to calculate the values of neighboring points, and calculating the fetal instantaneous heart rate.(4) An improved template matching method for fetal instantaneous heart rate detection is proposed. The basic steps are:firstly separated from the mixed fetal ECG signal; secondly, the fetal ECG R wave location; the difference and adjacent interval, calculate the instantaneous heart rate of fetal movement by the corresponding conversion.(5) Comprehensive analysis of practical significance and future outlook of the three new methods.