Design And Implementation Of Fetal Heart Rate Detection System Based On Smartphone

With the implementation of two-child fertility policy, intensive monitoring before delivery for pregnant women becomes more and more important to promote aristo genesis. Fetal heart rate is an important indicator of the fetal monitoring process, which can reflect the physiological state of the fetal heart. Most of the household ultrasonic Doppler fetal heart rate detecting instruments on the market are large in size with high power consumption. Apart from the above, the MCU used by those instruments are weak properties and the accuracy and stability of traditional autocorrelation algorithm to calculate fetal heart rate are poor. It cannot meet real-time requirements for fetal monitoring.In this paper to solve the above problems, a kind of fetal heart rate detection system based on smart phone is designed, which mainly consists of two parts; one is ultrasonic Doppler hardware detection terminal, responsible for collecting ultrasonic data, the other is smartphone, responsible for detecting fetal heart rate. This system is smaller in size with lower power consumption, and has better accuracy and stability than the traditional. Especially, for solving the problem that ultrasonic Doppler frequency shift signal is susceptible to be interfered severely, active signal endpoint detection module is designed in this paper to eliminate the interference signal cause by probe, guarantying system stability and shortening the detection delay. In addition, an improved auto correlation algorithm is proposed, which overcome the shortcomings of the traditional autocorrelation algorithm so that it has better performances in accuracy and stability. At the same time, the new algorithm reduces the computational complexity.The pregnant women can do self-testing at home using this fetal heart rate detection system and share fetal heart rate data in Internet, so that the doctor can grasp the health status of the fetus timely, which is of great significance to protect the safety of pregnant women and the fetus.