On the pole stability of rational approximation

Abstract. In this paper we investigated the stability of the system parameters of the adaptive rational transformation, i.e. how specific perturbation of the inverse poles affects the approximation error. We provided some estimations and sufficient confidence intervals on the perturbation of the absolute values of the inverse poles with respect to the approximation error. The research was motivated by biomedical (primarily ECG) signal processing problems, where the results may be utilized to improve the approximation and representation techniques.