Demographic changes and increasing air pollution entail that monitoring of respiratory parameters is in the focus of research.In this study, two customary inertial measurement units (IMUs) are used to measure the breathing rate by using quaternions.One IMU was located ventral, and BNC skt - SMA skt one was located dorsal on the thorax with a belt.The relative angle between the quaternion of each IMU was calculated and compared to the respiratory frequency obtained by a spirometer, which was used as a reference.
A frequency analysis of both signals showed that the obtained respiratory rates vary slightly (less than 0.2/min) between the two systems.The introduced belt can analyse the respiratory rate and Earphone Board Set can be used for surveillance tasks in clinical settings.