Noise cancellation on mitral valve Doppler signal with IIR digital filter using harmony search algorithm

In this paper, a filter design approach which uses the harmony search algorithm for additive white Gaussian noise cancellation through an infinite impulse response digital filter, is described. In the digital filter design, a mitral valve Doppler signal and a 4^th degree infinite impulse response digital filter were used. In order to improve the design, additive white Gaussian noise was added to the mitral valve Doppler signal at different values of signal to noise ratio which were selected as -4dB, +4dB, -2dB and +2dB. As a result, four different infinite impulse response digital filters were designed at different noise levels using the harmony search algorithm and their performances were compared with each other.