A wavelet method for local activity identification in fractionated electrograms

A new method is presented, that uses wavelets in order to suppress distal activity and produce an estimate of the membrane current. It can improve current clinical techniques of electrogram interpretation, minimizing physician time required to manually mark activation time estimates and localize infarcted tissue. Spatial and temporal information are combined. The input is an array of electrograms positioned on grid-points of a rectangular grid. No assumption is required about the propagation velocity or grid-size. The output is an array of estimates of the membrane current. Wavelet transform is performed for all signals. For each time step and each scale, the common spatial component is rejected. Signals are reconstructed from the wavelet coefficients. As a post-processing step, activation times are calculated from the current estimates using time-based criteria. Extracellular potentials are calculated from the current estimates and compared with the experimental ones