Low-cost fiber specklegram sensor for noncontact continuous patient monitoring

Different low-cost approaches based on fiber specklegram sensors are employed to measure the physiological activity of patients lying in bed. This study is conducted over 20 volunteers to measure the movement and heart rate (HR) using two different sensor designs placed at two different bed locations. Three different processing methods are developed and tested in order to extract useful information from the measured data. The results suggest that a stretched fiber optic configuration under the head of the person lying in bed is the optimal configuration to detect HR and motion, nonetheless the other tested possibilities also exhibit remarkably good performances. On the other hand, the three proposed processing methods also achieve a good precision in the HR detection. The sensor implementation is simple, not requiring any special conditions, and it provides robust performance. This leads to the conclusion that fiber specklegram technology is a feasible method to be used in real situations for heartbeat and movement monitoring.