Comparitive Study of Different IIR Filter for Denoising Lung Sound

摘要

Pulmonary sounds carry important information relevant to pathology and the physiology of the respiratory system of a human body. The clinical environment where doctors listen to the patient's lung sound is generally not quite and can affect the clarity of audible lung sound. This can cause the dependency of diagnosis on the availability of such noisy sound to make correct diagnosis unattainable. This paper aims to classify four different IIR filters namely Butterworth, Chebyshev 1, Chebyshev 2, and Elliptic, to grade them on the grounds of different characteristics attained by their performance. In this study Signal to Noise Ratio, Energy of Signal, Entropy of Signal, Computational time and Percentage-Root-Mean-Square-Difference (PRD) are the five parameters which is used to evaluate the performance of all four IIR filters. The result analysis of the experiment of this study implies that the Butterworth filter displays superior performance in abolishing different noises.