This paper presents the design of a novel periodic macrobending hetero-core fiber optic sensor embedded in textile for respiratory movements’ analysis. We report on several different designs based on textiles which have different loop periodicity and configuration of optical fiber types. In all experiments, the changes of textile elongation are measured during breathing movements. In order to demonstrate the superiority of the proposed sensor, experiments were done on a macrobending sensor constructed from 62.5-50-62.5 hetero-core fiber and a macrobending sensor constructed from 62.5/125 μm multi-mode fiber having different loops. Experimental results show that the sensitivity of the proposed macrobending sensor constructed using hetero-core optical fiber is much higher than the sensor constructed from plain multi-mode optical fiber. It is also shown that, the sensitivity of the sensor increases as the number of loops is increased. On the other hand, several experiments were performed for periodic macrobending sensors having different bending radius by changing the lengths of loops amplitude and period. We demonstrate that the sensors tested on different patients’ morphology can successfully sense respiratory movements.
In this paper, a novel design of microbending hetero-core fiber optic sensor for force and location sensing is proposed, and potential applications to home security systems are discussed. Force and location detection is done by using two different microbending fiber optic sensors. The main idea is, we have two unknowns, two different fibers, and two simultaneous intensity measurements. In order to demonstrate the location detection of the microbending fiber optic sensor, changes in the light intensity are examined with different force locations and forces magnitudes on the microbending fiber optic sensor. Several experiments are performed for different microbend sensors by varying periodicity, corrugation size, thickness of plates, and the configuration of optical fiber type. All experiments were done on a microbending sensor constructed from 62,5/125 μm multimode fibers and a microbending sensor constructed from 62,5-50-62,5/125 μm hetero-core fiber. For each case, the output light intensity is measured as a function of applied force. The characteristics of hysteresis, repeatability and location comparison are examined for each combination of microbending fiber optic sensors. Experimental results show that the sensitivity of the proposed microbending sensor constructed using hetero-core optical fiber having loops is the highest.