Supporting prolonged COPD monitoring using an application for mobile devices.

COPD (chronic obstructive pulmonary disease) is the most frequent form of chronic respiratory disease. During the progress of this disease, phases of aggravation of pulmonary function (exacerbations) can occur, which reduce the quality of life. Clinical experience shows that single investigations are insufficient. Therefore a prolonged monitoring is required to recognize an exacerbation early. This home monitoring will involve a quick respiratory test and a related application for Android, iOS and Windows phones. This rapid test transmits the relevant pulmonary parameters, converted in an Extensible Markup Language file to the smartphone. The application will analyze the incoming data to evaluate the current health status of the patient. Additionally the data will be transferred to the virtual control point (server) and stored in a database. If critical values are detected, the server will send a notification to prior defined relatives and doctors. A connection to a Hospital Information System will be possible through an included Health Level 7 interface. This offers an improved site-independent patient care. The project is planned to be in development until 2016.

Estimation of respiratory flow by means of normal lung sound.

The respiratory flow is a good indicator of sleep-related breathing disorders. Common praxis is to use a pneumotachograph as the golden standard for flow measurement. However, it does not have to be necessarily the best possible test device for long-term condition, because the device is very uncomfortable and rarely suitable for measurement during sleep. A computer-based method to determine the respiratory flow, called ThorAKUSTIK, yielded a highly positive correlation between the calculated flow out of the tracheal breath sound and a measured flow signal. In order to avoid noise interference due to a breath-mask or a pneumotachograph, in this study we applied the ThorAKUSTIK-method to lung sound which was measured at the back of 18 subjects and investigated the correlation between the calculated flow and the measured flow by a pneumotachograph. The new method showed a highly positive correlation (r = 0.89 and 0.90). Additionally we examined the use of an accelerometer signal to distinguish between inspiration and expiration. In this case we got high correlation coefficients of r = 0.87 and 0.88 between the calculated and measured airflow as well.