Compression of magnetocardiograms using the Discrete Wavelet Transform

The paper presents a compression algorithm based on wavelets applied to magnetocardiograms (MCG). MCGs are a newly developed tool for diagnosis of heart diseases, which enable recording of data using sensitive contactless transducers based on Superconductive Interference Devices (SQUID). The acquisition system presented has been developed at the Institute of Photonic Technology (IPHT) in Jena, Germany and several processing techniques based on wavelets have been tested. Wireless technology allows nowadays a remote monitoring of data, and compression techniques have to be developed to enable the storage and handling of a significant quantity of data. A compression technique based on the Discrete Wavelet Transform has been proposed, optimized and its performance evaluated. The method takes into consideration parameters of the input MCG, being thus adaptive. The influence of several features of the algorithm, like mother wavelets, number of vanishing moments, number of decomposition levels, are tested so as to optimize the performances. Results are provided for comparison with other results reported in literature.