Heart and lung sound separation using periodic source extraction method

In this paper a novel algorithm for blind source extraction of quasi-periodic signals is developed. It is assumed that the cycle frequencies of the sources are known a priori. Necessary and sufficient conditions are introduced and Jacobi method for diagonalization of complex matrices is used to find the solution. A warping method is also introduced to adjust the cycle frequencies in the signals with time varying periods. The proposed algorithm is applied to simulated data and mixtures of heart and lung sounds, and effectiveness and performance of the algorithm are verified.