Two-Dimensinal Signal Warping (2DSW) provides a general framework for analysing beat-to-beat changes in ECG waveform and can be utilized for accurately tracking changes in common features of interest, e.g. the P, QRS or QT intervals or amplitude related information. The algorithm first generates a template beat based on ensemble averaging of relatively noise-free beats (template construction). Features of interest are annotated on the template in a semi-automated fashion. The template is then adapted to each waveform under consideration, exploiting 2DSW. In brief, a 2D mesh of warping points is superimposed on the template beat. These warping points are sequentially shifted in x- and y-directions, minimizing the Euclidean distance between segments of the template and the waveform. From the optimally adapted template, changes in annotated features can be tracked from beat to beat, providing the foundation for studying ECG variability.
Own work
Martin Schmidt