Adaptive Estimation of Low Frequency Noise in Impedance Cardiography

Adaptive systems are employed in the cancelation of noises and estimation of periodic and quasi periodic signals. Amongst these signals are the electrocardiogram (ECG),impedance cardiography, brain evoked potentials and modulated signals in telecommunication applications. In this paper we study the behaviour of the weights of the LMS algorithm when used to estimate the coefficients of the discrete Fourier transform (DFT) of a signal under influence of low frequencies. It uses a reference signal, closely related to the respiratory artifact, obtained by a least-squares approximation based B-spline fitting on the contaminated imedence cardiogram in synchronism with the respiratory phases. We show theoretically that low frequency noise affects the estimation of the weights at higher frequencies. The simulation results obtained are in agreement with theoetical results. KeywordsAdaptive algorithms, LMS algorithm, Low frequency noise. . African Journal of Computing & ICT Reference Format F.E. Ekpenyonga & D.T. Chinyio (2013 Web Designers Guide on Development Technologies: An Evaluation Approach. Afr J. of Comp & ICTs. Vol 6, No. 1. Pp 173-179