Research On Electrocardiograph Signal Collection System Based On USB And Wavelet Transform

With the fast development of computer technique, the computer application in medical realm gains more and more attention. So the research of new generation of medical monitor equipments is more and more payed attention to by lots of research departments and factories. The high-speed serial bus (USB2.0 technique) is already rather mature and has been the standard configuration to most computers. Applying the USB2.0 technique, we can develop many new kinds of analysis equipments. They are plug-and-play, small scaled and very easy used. Now a lot of medical equipments can be concentratedly used only in big hospitals, if more and more medical instruments can be used widely in small ones, even in families, it will be of great importance to improve people's health level.A digital electrocardiograph based on USB2.0 communication is designed in the dissertation to explore a high-speed and convenient scheme about medical physiology signal collection. And then make some software processing of the collected electrocardiograph signal and thus set the foundation for special digital medical monitor equipments.In the dissertation, the standard I-lead electrocardiogram measurement is explained detailedly and then the digital electrocardiograph design scheme is discussed. It takes singlechip as the control kernel and uses USB2.0 interface and high-speed A/D conversion to realize high-speed data transmission. Next, the design flow is given in detail. According to the characteristic of electrocardiograph signal, the way of using wavelet transform to eliminate noise and using smoothing filter to eliminate baseline drift is adopted in the dissertation. Then the principle of threshold denoising is discussed and the design of smoothing filter is given. At last, the simulation is made using Matlab on the electrocardiograph signal stored in PC which is collected by digital electrocardiograph. The results show that threshold denoising and smoothing filter based on wavelet transform achieve the good expectation. The sampling and USB communication part of this digital electrocardiograph can cooperate with other corresponding sensors, such as blood pressure sensor, brain wave sensor and so on, in order to realize the digital medical treatment.