Quantification of nasal respiratory flow by tracheal sound analysis

Abstract

By now the pneumotachograph is the gold standard for quantitative measurement of the respiratory flow. However, for continuous quantitative monitoring of airflow or measuring flow within non-invasive ventilated patients an ideal solu-tion is still missing. In this study we made an attempt to detect the nasal breathing with our newly developed system of measurement. This method allows the detection of nasal airflow by means of a sensor, which is placed on the trachea. In 20 pulmonary healthy male subjects the airflow was measured by a pneumotachograph. At the same time tracheal breathing sounds were recorded by a sensor placed paralaryngeal. Using a newly developed analysis system, tracheal breathing sounds can be transformed and the real respiratory flow curve can be calculated. For inspiration, as well as expiration, the estimated airflow showed a highly significant correlation (pearson correlation coefficient, r = 0.89 up to 0.92 with p< 0.01). The presented method is still being tested but has the potential to be ap-plicable in polysomnography. © 2012 by Walter de Gruyter Berlin Boston.