Optical fiber sensor with optical power feed

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Optical fiber sensor is promising to use in biomedical application. Has many advantages, i.e., it is small, free from electro-magnetic interference, safe for electric hazard and cheep. The aim of this study was to develop and evaluate optical fiber sensor and actuators.1) Heart and respiratory rates minitor by photo plethysmographyA simultaneous monitoring system for heart and respiratory rates has been developed by combined photo-plethysmography (PPG) and signal acquisition of wavelet transform. PPG signal which includes both heart and respiratory synchronous components was measured at a finger with a fiber-optic reflectance-mode PPG set-up. Different level of wavelet function was achieved to distinguish heart and respiratory signals from the PPG signal. The accuracy of the new instrument is comparable with existing methods for heart and respiratory rate monitoring.2) Tissue motion artifact in laser Doppler blood flow signalThe tissue matrix is continuously in motion under the influen … More ce of forces generated by the circulatory and respiratory systems. The hypothesis raised in this paper is whether the motion of tissue matrix grenerates an error signal in laser Doppler recordings that is misinterpreted as solely a blood flow signal. Measurements of skin motion in the forearm have been performed at 3 sites and the corresponding spectra have been compared with blood flow spectra recorded with the laser Doppler method. The two types of spectra overlap each other indicating that motion induced signals can be interpreted as a blood flow signal. The blood flow contribution from tissue motion varies strongly with the particular site under study.3) Reflection spectroscopy for the assessment of UV induced erythemaReflection spectroscopy was applied to broad spectrum light was transmitted to the tissue under syudy via optical fiber. A part of scattered light was received another set of potical fibers. The diffuse reflection spectrum was calculated and changes in the spectrum following erythema was described. From the preliminary study, the slop of the spectrum in the rane 580-600 nm can be classified the normal and erythematous skin surface. The results in 15 subjects showed a linear increase in the slope in the range between 580-600 nm.4) Optical power-feedWe have developed an optical power feed system using high-power laser and solar cell. The power of laser light illuminated solar cell via optical fiber. We could obtained enough power to operate very low-powered circuit less than 10 mW.We need further investigation for improving the energy efficiency. Less