Improvement of level-crossing reconstruction of potential maps by use of a priori information

The authors refine the approach for simplification of the body surface potential mapping (BSPM) acquisition system, which is based on partial measurements of level-crossing (LC) data. The algorithm is based on a combination of the optimal signal representation by the K-L transform and the theory of projections onto a convex set. A training set consisting of 200 subjects has been used for calculating a basis of decomposition functions. The reconstructions have been performed on LC measurements of BSPMs from a test set of 80 subjects, with similarly distributed pathologies. By incorporating a priori information about the underlying electrophysiological nature of the electrocardiogram (ECG) signals, the reconstruction error was decreased from an average of 120 mu V root mean square (RMS) for the whole test set, to about 100 mu V.<
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