Study On Signal Detection And Analysis Of Impedance Cardiography

With the rapid development of society, life rhythm and lifestyle changes, phenomenon ofpopulation aging, cardiovascular diseases become the greatest threat to human health. Today,cardiovascular diseases seriously affected the quality of people lives. In the face of a highincidence of cardiovascular disease, a comprehensive evaluation of cardiac function, makeprospective warning to cardiovascular disease have very important practical significance. Ithas important research significance and clinical value. But the technology is restricted becausethe signal is weak, and especially interfered by lung impedance.Impedance Cardiogram (ICG) is a non-invasive method to evaluate cardiovascularfunction. ICG evaluate cardiac function from the aspect of hemodynamic as a cardiac functionevaluation parameter. It has important research significance and clinical value. But thetechnology is restricted because the signal is weak, and especially interfered by lungimpedance. This article proposed a synchronous acquisition and processing method of ICGand ECG based on the characteristics of ICG. First of all, build acquisition system of ICG andcooperation ECG based on the four-electrode method. Secondly, analysis of noise andspectrum of thorax impedance signal. Design the ICG extraction method based on wavelettransform. Obtain feature points in first-order differential signal, combined with calibration ofECG. Complete calculation of heart function parameters. Aiming at the effects of lung to thethorax impedance, this paper designed four kinds of condition: natural breath, hold breath,breathing rate10times/min, breathing rate,6times/min. Collected the thorax impedance andECG signal of32subjects in four breathing condition,256sets of data in total. Finally theexperimental results show that the thorax impedance completely accords with the setting ofexperiment scheme. It verifies the reliability of the signal acquisition method. Cardiac functionparameters are in the normal range, to verify the accuracy of impedance signal extraction andthe algorithm of feature point extraction. This study shows that the feasibility of system inaccurate, objective and comprehensive analysis of cardiac function, but also lay the foundationfor further expanding the experimental samples and research.