A Research Of Wireless Fetal ECG Monitoring Technology Based On Embedded Web Server

As people’s emphasis on health and the pursuit of eugenics, the health of the fetus during pregnancy is more and more important. The fetal heart rate monitoring can effectively reflect fetal hypoxia and other abnormal conditions. Timely treatment can reduce the risk of fetal death when gestation or delivery. Getting fetal heart rate from fetal electrocardiogram has advantages of accuracy, stability and safety.Using indirect method to get fetal ECG can reduce operation risk and overcome the limitation of time. The focus of it is how to get fetal ECG from abdomen ECG with large value of amplitude of mother ECG and other noises. Currently, the fashion of medical facility is miniature and household. This dissertation aimed to give a research of a wireless fetal ECG monitoring method based on embedded web server. This project can avoid inconvenience and danger of pregnant women when going to the hospital, and it doesn’t need any cable compared with the traditional equipment. Date collection and data processing will be done in embedded device, and device management and data maintenance will be done on PC or smart phone with the help of web server and WLAN. User can start or stop measurement and get measurement result with web browser. Main works in this dissertation are listed as follows.(1) A method for getting fetal ECG from abdomen ECG is given to get fetal heart rate. The first step is abdominal ECG pre-processing. Noises could be removed by using filter. Mother ECG and fetal ECG remain after filtering. The second step is locating R-wave of mother ECG with method of wavelet transform modulus maxima. So that every mother ECG period is confirmed. Then using coherent averaging method to get template of mother ECG and joining them beat by beat. The third step is obtaining fetal ECG by subtracting the reconstructed mother ECG from the filtered abdomen ECG. R-waves of Fetal ECG can be located with same method, and fetal heart rate can be easily gotten at this time. Analyzing 60 abdomen ECG recordings using this method, a good result is gotten with R-wave accurate rate 91.7%, MSEHR 6.8 bpm and MSE_RR 7.6ms. The result indicates that this method has a high feasibility.(2) Give a research of how an embedded web server works and how it is realized. Explore operating system, server software, database, server side scripting language which is necessary for setting up web server. Compile and configure the web server software, Lighttpd in Linux. Set up operating environment of PHP and configure PHP in web server. Set up database environment SQLite. All the softwares and configuration above are transplant to Linux in development board.(3) Implement the management system using PHP script which inserted in HTML. The PHP script achieves logic, database interaction, data management and function realization. The management system has four main functions. Login is to realize the authentication with web browser. Device operation is to start or stop measurement by using controls on webs and to get status from device. Data management is to operate measured date like querying, deleting and downloading. Information management is to insert or update user information or login information. Finally, design test plan and test cases, which are used to finish software testing.