The Spatial Filter of Cardiac Magnetic Signals
|Course||Control Theory and Control Engineering|
|Keywords||Cardiac magnetic field Spatial filtering Fast Fourier Transform Wavelet Transform|
The heart is extremely complex physiological system. To diagnose heart disease by detecting the signal of the surface magnetic field of the human heart is a new development of science and technology in recent years. Cardiac electromagnetic field theory and the MCG signal processing aspects of the research has been a lot of national attention. Currently, using a superconducting quantum interference device detects the magnetic field of the heart signal weak, vulnerable to all kinds of noise interference in the detection process. In addition to the need to consider the conventional time-based signal filtering, the impact of environmental noise distribution of 36 points on the surface of human pleural space by the attention of scholars at home and abroad, the problem has some theoretical significance and application value. In this thesis, the magnetic field detection data of human heart, cardiac magnetic field source model based on two different spatial filtering methods, the main research. The papers completed work are as follows: 1. Reading of the literature on the basis of the analysis of the characteristics of the signal and the ambient noise of MCG MCG signal, the heart field measurement data spatial filtering. 2. The establishment of a single magnetic dipole model-based spatial filtering algorithm. The spatial filtering effect of different intensity noise is added to the signal of the magnetic field generated by the theoretical model, and calculate the signal-to-noise ratio and the goodness of fit, verify the validity of the the MCG signal space filtering method. 3. On the basis of the single magnetic dipole model to study the spatial filtering algorithm based on wavelet transform. The heart of the magnetic field generated by the use of theoretical graph model signal, to compare the results of three different wavelet transform spatial filtering. Simulation results show that the order Sym wavelet spatial filtering effect is better. 4. Filtering method to expand the space of a single moment to the time domain, spatial filtering algorithm of continuous-time cardiac magnetic measurement data. The computer simulation results demonstrate the effectiveness of this method. 5. Written using MATLAB the MCG signal spatial filtering program modules. Including spatial filtering of a single moment, continuous-time spatial filtering, and the function of the heart magnetic signal of the multi-channel signal processing and signal analysis with theoretical models of cardiac magnetic detection signal. 6. Verify the basis of the mathematical model of the single magnetic dipole, with the cardiac magnetic field information analysis software research computing and positioning of a variety of cardiac magnetic field source model, and the results were analyzed.