Unobtrusive monitoring of human vital functions based on speckle interferometry with plastic optical fiberPodbreznik, Peter (Avtor) Đonlagić, Denis (Avtor) Lešnik, Dejan (Avtor) Cigale, Boris (Avtor) Zazula, Damjan (Avtor) plastic optical fiberspeckle interferometryunobtrusive monitoringheartbeat detectionrespiration detectionphase-shift methodwavelet transformIn this paper, a speckle interferometer with a plastic optical fiber system is reported for unobtrusive monitoring of heartbeat and respiration. The sensor consists of a laser diode butt-coupled to the plastic optical fiber, whose exit face projects speckle patterns onto a linear optical sensor array, which leads to a simple and cost-effective construction. Speckle images are acquired in a sequence and transformed into a 1D signal by using a phase-shifting method. Band-pass filtering and Morlet-wavelet-based multiresolutional approaches were used to analyze signals for the detection of cardiac and respiratory activities, respectively. Ten young, healthy persons participated in system testing, by lying supine on a mattress with embedded plastic optical fiber. Experimental results show the proposed system and detection algorithms are highly efficient. Sensitivities of 99.4 0.6% and 95.3 3%, precisions of 98.8 1.5% and 97.9 2.3%, and mean delays between interferometric detections and corresponding referential signals of 116.6 55.5ms and 1299.2 437.3 ms were computed for heartbeat and respiration, respectively.20132015-07-10 12:39:58Delo ni kategorizirano50442sl