Comparison of respiratory rate estimation based on tracheal sounds versus a capnograph.

The objective was to compare the accuracy of estimations of respiratory rate (RR), based on tracheal sounds, with simultaneous estimations from a capnograph, using as a common reference a pneumotachometer. Five subjects without pulmonary diseases were enrolled. Tracheal sounds were acquired using a contact piezoelectric sensor placed on the subject's throat and analyzed using a combined investigation of the sound envelope and frequency content.

Estimation of respiratory rate and heart rate during treadmill tests using acoustic sensor.

The objective was to test the robustness of an acoustic method to estimate respiratory rates (RR) during treadmill test. The accuracy was assessed by the comparison with simultaneous estimates from a capnograph, using as a common reference a pneumotachometer. Eight subjects without any pulmonary disease were enrolled.

Automated extraction of aortic and pulmonary components of the second heart sound for the estimation of pulmonary artery pressure.

The second heart sound, S2, is generally believed to be comprised of aortic (A2) and pulmonary (P2) components. Previously, the normalized splitting interval (NSI) between the A2 and P2 components has been shown to be proportional to the pulmonary artery pressure (PAP). A set of fully automated algorithms based on adaptive modeling of A2/P2 components using chirplets were developed to provide real-time estimates of PAP.

Monitoring respiratory rate based on tracheal sounds. First experiences.

The objective was to develop a non-invasive method for continuously monitoring respiratory rate (RR) based on tracheal sounds. 25 volunteers and 36 patients with chronic pulmonary diseases were enrolled in a clinical study. Tracheal sounds were acquired using a contact piezoelectric sensor placed on the examinee's throat and analyzed using a combined investigation of the sound envelope and frequency content.