Heart rate and respiration rate detection by optical fiber mattress using statistical classification spectrum analysis

Physiological monitoring systems have been widely used for the collection of key physio-logical parameters such as heart and respiration rates. However, conventional monitoring systems rely on electrodes or bandages which are not well accepted by subjects due to the requirements of direct contacts with their skins. In this paper, a new physiological monitoring system without the direct contacts with hu-man skins was proposed, where physiological movements of subjects were translated into micro bends of optical fibers. More specifically, the movements due to blood pumping were used as the inputs of the system and variations of light intensities of optical fibers were used as the outputs, which were further processed to obtain heart and respiration rates. In data analysis, adaptive regulations and statistical classifications were used to address potential concerns of individual differences and body interferences. The physiological monitoring systems developed in this study were used to quantify heart and reparation rates for healthy volunteers. Experimental results included 1) the heart rates of 40-150bpm and respiration rates of 10-20bpm for individual differences; 2)the heart rates of the mean error 1.60±0.98 beats per minute (bpm), 1.94±0.83bpm, 1.24±0.59bpm, 1.06±0.62 bpm contract to polar beat device in same individuals at four different posture contacts and mean error 1.09±0.96bpm, 1.44±0.99bpm, 1.78±0.94bpm at three different breathing states. Furthermore, the results based on this system were validated by conventional counterparts relying on skin-contacting electrodes where comparable results of 0.26±2.80 bpm in 95% confidence intervals (± 1.96SD) vs. Philips sure-signs of the VM6 medical monitor for heart rates and 0.41 ± 1.49 bpm in 95% confidence intervals (± 1.96SD) vs. ECG-derived Respiratory(EDR) for respiration rates were reported. It is indicated that the developed system has nice performances and can be senselessly used under complex environments.