Summary: 1006 IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 44, NO. 10, OCTOBER 1997
Interference Cancellation in Respiratory Sounds
via a Multiresolution Joint Time-Delay
and Signal-Estimation Scheme
Sonia Charleston, Mahmood R. Azimi-Sadjadi,* Senior Member, IEEE, and Ramon Gonz´alez-Camarena
Abstract--This paper is concerned with the problem of cancel-
lation of heart sounds from the acquired respiratory sounds using
a new joint time-delay and signal-estimation (JTDSE) procedure.
Multiresolution discrete wavelet transform (DWT) is first applied
to decompose the signals into several subbands. To accurately
separate the heart sounds from the acquired respiratory sounds,
time-delay estimation (TDE) is performed iteratively in each
subband using two adaptation mechanisms that minimize the
sum of squared errors between these signals. The time delay
is updated using a nonlinear adaptation, namely the Leven-
berg­Marquardt (LM) algorithm, while the function of the other
adaptive system--which uses the block fast transversal filter
(BFTF)--is to minimize the mean squared error between the
outputs of the delay estimator and the adaptive filter. The
proposed methodology possesses a number of key benefits such

Source: Azimi-Sadjadi, Mahmood R. - Department of Electrical and Computer Engineering, Colorado State University

Collections: Computer Technologies and Information Sciences