scholarly journals Fiber-Optic Based Smart Textiles for Real-Time Monitoring of Breathing Rate

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3408
Author(s):  
Aizhan Issatayeva ◽  
Aidana Beisenova ◽  
Daniele Tosi ◽  
Carlo Molardi
Keyword(s):  
Optical Fibers ◽  
Mobile Application ◽  
Fiber Optic ◽  
Breathing Pattern ◽  
Wavelength Shift ◽  
Biophysical Parameters ◽  
Integrated Optical ◽  
Respiratory Behavior ◽  
Fbg Sensors ◽  
Widespread Interest

Wearable light textiles are gaining widespread interest in application for measurement and monitoring of biophysical parameters. Fiber optic sensors, in particular Bragg Grating (FBG) sensors, can be a competitive method for monitoring of respiratory behavior for chest and abdomen regions since the sensors are able to convert physical movement into wavelength shift. This study aims to show the performance of elastic belts with integrated optical fibers during the breathing activities done by two volunteers. Additionally, the work aims to determine how the positions of the volunteers affect the breathing pattern detected by optical fibers. As a reference, commercial mobile application for sensing vibration is used. The obtained results show that the FBGs are able to detect chest and abdomen movements during breathing and consequently reconstruct the breathing pattern. The accuracy of the results varies for two volunteers but remains consistent.

scholarly journals Femtosecond-Laser-Assisted Fabrication of Radiation-Resistant Fiber Bragg Grating Sensors

2022 ◽  
Vol 12 (2) ◽  
pp. 886
Author(s):  
Hun-Kook Choi ◽  
Young-Jun Jung ◽  
Bong-Ahn Yu ◽  
Jae-Hee Sung ◽  
Ik-Bu Sohn ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Fiber Bragg Grating ◽  
Optical Fibers ◽  
Coming Out ◽  
Single Mode ◽  
Femtosecond Laser Irradiation ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Radiation Resistant ◽  
Fbg Sensors

This paper demonstrates the fabrication of radiation-resistant fiber Bragg grating (FBG) sensors using infrared femtosecond laser irradiation. FBG sensors were written inside acrylate-coated fluorine-doped single-mode specialty optical fibers. We detected the Bragg resonance at 1542 nm. By controlling the irradiation conditions, we improved the signal strength coming out from the FBG sensors. A significant reduction in the Bragg wavelength shift was detected in the fabricated FBG sensors for a radiation dose up to 105 gray, indicating excellent radiation resistance capabilities. We also characterized the temperature sensitivity of the radiation-resistant FBG sensors and detected outstanding performance.

Integrated Fiber Optic Sensors For Nondestructive Characterization Of Concrete Structures

1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Optical Fiber Sensor ◽  
Fiber Optic Sensors ◽  
Fiber Sensors ◽  
Fully Integrated ◽  
Integrated Optical ◽  
Concrete Elements

ABSTRACTIt is possible to monitor the initiation and progress of various mechanical or environmentally induced perturbations in concrete elements by way of fully integrated optical fiber sensors. Geometric adaptability and ease by which optical fibers can be embedded within concrete elements has led to the development of a number of innovative applications for concrete elements. This article is intended for a brief introduction into the theories, principles, and applications of fiber optic sensors as they pertain to applications in concrete.. However, due to the fact that the transduction mechanism in optical fibers is invariant of the materials employed, the principles introduced here also correspond to other structural materials. The only application related differences among various materials pertain to sensitivity and choice of optical fiber sensor types.

Abstract 17300: Development and Ex Vivo Validation of Novel Force-Sensing Neo-Tendons for Measuring Chordae Tendineae Tension in the Mitral Valve Apparatus Using Optical Fibers With Embedded Bragg Gratings

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Michael J Paulsen ◽  
Jung Hwa Bae ◽  
Annabel M Imbrie-Moore ◽  
Hanjay Wang ◽  
Camille E Hironaka ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Optical Fibers ◽  
Ex Vivo ◽  
Rate Of Change ◽  
Force Sensing ◽  
Wavelength Shift ◽  
Spatial Period ◽  
High Fidelity ◽  
Chordae Tendineae ◽  
Fbg Sensors

Introduction: Very few technologies exist that can provide quantitative data on forces within the mitral valve apparatus. Marker based strain measurements can be performed, but chordae heterogeneity limits utility. Foil-based strain sensors have also been described, but tend to be bulky, limiting the number of chordae that can be measured. Hypothesis: We hypothesize that the use of Fiber Bragg Grating (FBG) sensors—optical strain gauges made of 125 μ m diameter silica fibers— can overcome the critical limitations of previous methods of measuring chordae tendineae forces. Methods: Using FBG sensors, we created a force-sensing neochord that would mimic the natural shape and movement of native chordae tendineae. FBG sensors reflect a specific wavelength of light depending on the spatial period of gratings - when a force is applied, the gratings move relative to one another, changing the reflected light (Fig 1A). This wavelength shift is directly proportional to the force applied. The FBG sensors were housed in a protective sheath fashioned from the outer coil of a 0.025" Amplatz Extra-Stiff guidewire, and attached to the chordae using GoreTex suture (Fig 1B). The function of the force-sensing neochordae were validated in a 3D printed left heart simulator. Results: FBG sensors provided high-fidelity force measurements of mitral valve chordae tendineae at a temporal resolution of 1000 Hz. As ventricular pressures increased, such as in the hypertensive condition, forces on the chordae also increased (Fig 1C). The resolution of FBG sensors allow for increased accuracy of not only chordae tension, but also the rate of change of force (dF/dt) - a parameter critical to determining likelihood of leaflet rupture. Conclusions: FBG sensors are a viable, durable, and high-fidelity technology that can be effectively used to measure mitral valve chordae forces and overcome limitations of other such technologies.

High-voltage monitoring by the fiber-optic recirculating measuring system

2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov
Keyword(s):  
Optical Fibers ◽  
High Voltage ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Electric Power Industry ◽  
Measuring System ◽  
Voltage Range ◽  
External Electromagnetic Fields ◽  
Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

MODELING OF FIBER-OPTIC COMMUNICATION CHANNEL FOR QUANTUM CRYPTOGRAPHIC SYSTEMS

2019 ◽  
pp. 90-95
Author(s):  
V. A. Minaev ◽  
I. D. Korolev ◽  
O. A. Kulish ◽  
A. V. Mazin
Keyword(s):  
Information Transmission ◽  
Information Transfer ◽  
Fiber Optic ◽  
Single Photon ◽  
Optical Devices ◽  
Energy Losses ◽  
Integrated Optical ◽  
Integrated Optical Devices ◽  
Fiber Optic Communication ◽  
Optic Communication

The existing methods of information delivery to the strategic and tactical management of many government agencies are expensive, not always reliable and efficient. Therefore, quantum cryptographic systems (QCS) have been actively developed in recent years. However, there are problems with the use of the QCS associated with the reliability of information transfer. First, the existing fiber-optic communication channels (FOCC) are not designed to transmit single-photon signals, which leads to the complexity of their cryptographic protection. The second is insufficiently methodically developed calculation of energy losses and errors in the evaluation of the characteristics of information transfer in FOCC QCS. In article the analysis of the energy loss factors in the classical fiber-optic channel is carried out and the additive loss formula is discussed in detail. Then we consider the fiber-optic channel of quantum information transmission with the use of integrated optical devices. The additive formula of optical losses in such a channel is discussed. The features of losses in integrated optical devices are shown. The features of quantum cryptographic system of information transmission are considered. As a result, the model of FOCC QCS taking into account energy losses is presented, which allows competently in theoretical terms and visualize the passage of information through modern quantum cryptographically secure telecommunications while providing control in government structures.

scholarly journals Sensing, Actuation, and Control of the SmartX Prototype Morphing Wing in the Wind Tunnel

Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 107
Author(s):  
Nakash Nazeer ◽  
Xuerui Wang ◽  
Roger M. Groves
Keyword(s):  
Wind Tunnel ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Experimental Testing ◽  
Single Mode ◽  
Fiber Optic Sensor ◽  
Sensor Data ◽  
Random Errors ◽  
Morphing Wing ◽  
Actuator Dynamics

This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of each of the morphing modules. The deflection estimation is carried out by interrogating optical fibers that are bonded on to the wing’s inner surface. A novel application is demonstrated using this method that utilizes the least amount of sensors for load monitoring purposes. The fiber optic sensor data is used to measure the deflections of the modules in the wind tunnel using a multi-modal fiber optic sensing approach and is compared to the deflections estimated by the actuators. Each module is probed by single-mode optical fibers that contain just four grating sensors and consider both bending and torsional deformations. The fiber optic method in this work combines the principles of hybrid interferometry and FBG spectral sensing. The analysis involves an initial calibration procedure outside the wind tunnel followed by experimental testing in the wind tunnel. This method is shown to experimentally achieve an accuracy of 2.8 mm deflection with an error of 9%. The error sources, including actuator dynamics, random errors, and nonlinear mechanical backlash, are identified and discussed.

scholarly journals Novel Bloch wave excitation platform based on few-layer photonic crystal deposited on D-shaped optical fiber

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esteban Gonzalez-Valencia ◽  
Ignacio Del Villar ◽  
Pedro Torres
Keyword(s):  
Optical Fibers ◽  
High Performance ◽  
Light Propagation ◽  
Fiber Optic ◽  
Layer Structure ◽  
Optical Network ◽  
Building Blocks ◽  
Bloch Wave ◽  
Nanophotonic Devices ◽  
Wide Range

AbstractWith the goal of ultimate control over the light propagation, photonic crystals currently represent the primary building blocks for novel nanophotonic devices. Bloch surface waves (BSWs) in periodic dielectric multilayer structures with a surface defect is a well-known phenomenon, which implies new opportunities for controlling the light propagation and has many applications in the physical and biological science. However, most of the reported structures based on BSWs require depositing a large number of alternating layers or exploiting a large refractive index (RI) contrast between the materials constituting the multilayer structure, thereby increasing the complexity and costs of manufacturing. The combination of fiber–optic-based platforms with nanotechnology is opening the opportunity for the development of high-performance photonic devices that enhance the light-matter interaction in a strong way compared to other optical platforms. Here, we report a BSW-supporting platform that uses geometrically modified commercial optical fibers such as D-shaped optical fibers, where a few-layer structure is deposited on its flat surface using metal oxides with a moderate difference in RI. In this novel fiber optic platform, BSWs are excited through the evanescent field of the core-guided fundamental mode, which indicates that the structure proposed here can be used as a sensing probe, along with other intrinsic properties of fiber optic sensors, as lightness, multiplexing capacity and easiness of integration in an optical network. As a demonstration, fiber optic BSW excitation is shown to be suitable for measuring RI variations. The designed structure is easy to manufacture and could be adapted to a wide range of applications in the fields of telecommunications, environment, health, and material characterization.

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