Charleston, S., authorAzimi-Sadjadi, Mahmood R., authorIEEE, publisher2007-01-032007-01-031996Charlston, S. and M. R. Azimi-Sadjadi, Reduced Order Kalman Filtering for the Enhancement of Respiratory Sounds, IEEE Transactions on Biomedical Engineering 43, no. 4 (April 1996): 421-424.Charleston, S. and M. R. Azimi-Sadjadi, Correction to "Reduced Order Kalman Filtering for the Enhancement of Respiratory Sounds", IEEE Transactions on Biomedical Engineering 43, no. 6 (June 1996): 668.http://hdl.handle.net/10217/67876Correction included.In the processing and analysis of respiratory sounds, heart sounds present the main source of interference. This paper is concerned with the problem of cancellation of the heart sounds using a reduced order Kalman filter (ROKF). To facilitate the estimation of the respiratory sounds, an autoregressive (AR) model is fitted to heart signal information present in the segments of the acquired signal which are free of respiratory sounds. The state-space equations necessary for the ROKF are then established considering the respiratory sound as a colored additive process in the observation equation. This scheme does not require a time alignment procedure as with the adaptive filtering-based schemes. The scheme is applied to several synthesized signals with different signal-to-interference ratios (SIR) and the results are presented.born digitalarticleseng©1996 IEEE.Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text