background: the basic requirements for monitoring anesthetized patients during surgery are assessing cardiac and respiratory function. esophageal stethoscopes have been developed for this purpose, but these devices may not provide clear heart and lung sound due to existence of various noises in operating rooms. in addition, the stethoscope is not applicable for continues monitoring, and it is u...

Background: The basic requirements for monitoring anesthetized patients during surgery are assessing cardiac and respiratory function. Esophageal stethoscopes have been developed for this purpose, but these devices may not provide clear heart and lung sound due to existence of various noises in operating rooms. In addition, the stethoscope is not applicable for continues monitoring, and it is u...

INTRODUCTION Automated mapping of lung sound distribution is a novel area of interest currently investigated in mechanically ventilated, critically ill patients. The objective of the present study was to assess changes in thoracic sound distribution resulting from changes in positive end-expiratory pressure (PEEP). Repeatability of automated lung sound measurements was also evaluated. METHODS...

This study investigates the problems associated with lung sound recognition under noisy conditions. Firstly, the effects of noise on the lung sound feature representation and the classification performance are analyzed. Two kinds of feature representations, autoregressive and mel-frequency cepstral coefficients, are used to characterize the lung sound signals. Dynamic time warping is used to ca...

For diagnosis of lung disease, lung sound auscultation plays an important role. Lung sound provides important information regarding underlying condition of lungs. Advances in the field of signal processing have led to development of automated tools for diagnosis of respiratory diseases using lung sound. This paper investigates the previous work undertaken by various researchers on automated res...

The transpulmonary speed of sound input at the mouth has been shown to vary with lung volume. To avoid the disadvantages that exist in certain clinical situations in inputting sound at the mouth, we input sound in the supraclavicular space of 21 healthy volunteers to determine whether similar information on the relationship of sound speed to lung volume could be obtained. We measured the transi...

During the recording time of lung sound (LS) signals from the chest wall of a subject, there is always heart sound (HS) signal interfering with it. This obscures the features of lung sound signals and creates confusion on pathological states, if any, of the lungs. A novel method based on empirical mode decomposition (EMD) technique is proposed in this paper for reducing the undesired heart soun...