Performance of Fourier versus Wavelet analysis for magnetocardiograms using a SQUID-acquisition system

A lately developed clinical investigation method for the diagnosis of heart disease, the magnetocardiogram (MCG) is described in this paper. Sensitive sensors based on Superconducting Quantum Interference Devices (SQUID), developed at IPHT-Jena, Germany are used for the acquisition of reliable data. MCGs are sensitive to magnetic interferences and procedures in order to enhance the signal-to-noise ratio have to be developed. The paper aims at the comparison of the performance of Fourier versus Wavelet analysis applied to the input signal in order to enable the choice of the optimal processing technique for MCGs, advantages and drawbacks of each procedure being shown. A wavelet based baseline drift correction method and a denoising technique for the reduction of the biological noise of MCGs have been developed and compared to the Fourier based filtering procedure from IPHT-Jena.