Separating Heart Sounds from Lung Sounds - Accurate Diagnosis of Respiratory Disease Depends on Understanding Noises

This study reviews the adaptive methods of canceling heart sounds from lung sounds that have been investigated over approximately 20 years. Filtering techniques are categorized as linear adaptive filters and filters employing time-frequency based methods. Several filtering schemes are outlined within these two categories. Methods of heart sound localization are indicated in conjunction with the studies of heart-sound cancellation. Details such as digitization parameters, the location of heart and lung sound recordings, and the number of subjects used in each study. Since a primary objective of respiratory sound research is bring about improvements to monitoring and diagnosis of respiratory disease, the potential usefulness of any method for filtering heart sounds from lung sounds rests on its ability to perform in a clinical setting