ASEPTIC: Aided system for event-based phonocardiographic telediagnosis with integrated compression

A general purpose system for telediagnosis of the valvular condition of the heart by analysing the phonocardiographic (PCG) signals generated by the heart is presented in this article. The system includes two main parts: a processing stage and a compression stage. The first one is arranged as a modular hierarchical structure with different abstraction levels, and performs a complete analysis of the PCG from the acquisition to the final diagnosis, following an event-based methodology. Analysis does not use auxiliary signals like ECG or pulse. The compression stage includes a lossy compression wavelet-based method with optimized parameters for an efficient transmission and storing of PCG signals. Results show a high degree of cardiac cycles in which all the events have been correctly delimited and identified, 91.27% and 65.65% for non-murmurs and for murmurs recordings, respectively, and compression rates between 2.6 and 5.6 times higher than the OGG Vorbis compression method.