Based On The Research And Implementation Of Embedded Integrated Fetal Heart Rate Meter

Fetal heart rate is the key information for analyzing fetal status during pregnancy.The integrated ultrasonic Doppler fetal heart rate meter on the market uses a dual-chip probe to collect fetal heart signals by synchronizing sending and receiving signals.Due to structural reasons,the connection line between the probe and the signal processing integrated circuit is long and the cost is high.In order to solve the problem of split fetal heart rate meter,this paper designs and implements an integrated fetal heart rate meter based on embedded system,which has short connection line between probe and signal processing circuit and low production cost.Firstly,the ultrasonic pulse frequency of the integrated fetal heart rate meter was determined by studying the theory of fetal heart detection.Based on time-frequency analysis,the echo signal of fetal heart was preprocessed by software,and the empirical mode EMD decomposition algorithm was improved to combine it with autocorrelation algorithm to better extract fetal heart cycle signal and calculate fetal heart rate.Secondly,according to the functional requirements of the fetal heart rate meter,the hardware system of the integrated fetal heart rate meter is designed.The domestic 32-bit CS32F030 chip is used as the microcontroller,and the peripheral hardware circuit is built according to the specific functions to realize the modular design.The specific modules include: Power module,ARM control module,signal acquisition and demodulation module,filter circuit,audio module,touch button module,switch button and voltage detection module,etc.Then,MDK software was used to design the functions of each module of the integrated fetal heart rate meter,including key processing module,heart rate numerical calculation,energy intensity detection and volume output modules,realizing the real-time fetal heart rate and average fetal heart rate numerical display,heart rate abnormal flashing warning,fetal heart energy intensity detection and key control page and volume.Based on QT and Py Charm,GUI design was carried out to convert fetal heart data into fetal heart signal time-domain diagram,which assisted in optimizing adaptive autocorrelation detection algorithm and amplitude threshold filtering algorithm.Finally,the fetal heart simulator was used for testing and clinical trials.The experimental results show that the integrated fetal heart rate meter not only has a large measuring range,the test is suitable for the long pregnancy,the sensitivity and accuracy of fetal heart rate detection meet the requirements.