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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Integrated Optical Fibre — Investigating the Vibrational Response using Optical Frequency Domain Reflectometry
摘要： Integrated Optical Fibre (IOF) is a new technology in integrated optics using flame hydrolysis deposition to permanently attach an optical fibre onto a silicon substrate. This approach combines the low losses of optical fibre with the mechanical integrity of an integrated planar platform. By attaching the fibre with high quality optical glass we create devices that transform the packaging of fibres for sensing applications removing any use of glues, epoxies, adhesives and making it suitable for harsh environments such as aerospace. The binding medium itself can also be used for its optical properties. Aerospace environments are demanding, both for temperature range (-50 to +120 °C), but also for vibration and shock. In this work we are investigating a technique for monitoring the vibration sensitivity and damage points of the IOF under typical structural vibration conditions. In particular, here we report the use of Optical Frequency Domain Reflectometry (OFDR), which can reveal spectral and spatial information of features within a fibre such as Fibre Bragg Gratings (FBGs). This is of particular interest when applied to structural health monitoring, distributed strain and temperature sensing.
关键词： Optical Frequency Domain Reflectometry,vibration sensitivity,structural health monitoring,Integrated Optical Fibre,Fibre Bragg Gratings
更新于2025-09-12 10:27:22
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Machine Learning-Based Classification of the Health State of Mice Colon in Cancer Study from Confocal Laser Endomicroscopy
摘要： In this article, we address the problem of the classification of the health state of the colon’s wall of mice, possibly injured by cancer with machine learning approaches. This problem is essential for translational research on cancer and is a priori challenging since the amount of data is usually limited in all preclinical studies for practical and ethical reasons. Three states considered including cancer, health, and inflammatory on tissues. Fully automated machine learning-based methods are proposed, including deep learning, transfer learning, and shallow learning with SVM. These methods addressed different training strategies corresponding to clinical questions such as the automatic clinical state prediction on unseen data using a pre-trained model, or in an alternative setting, real-time estimation of the clinical state of individual tissue samples during the examination. Experimental results show the best performance of 99.93% correct recognition rate obtained for the second strategy as well as the performance of 98.49% which were achieved for the more difficult first case.
关键词： classification,confocal laser endomicroscopy,machine learning,cancer study,health state,mice colon
更新于2025-09-12 10:27:22
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Direct measurement of the concurrence of hybrid entangled state based on parity check measurements
摘要： Employing data from the population census in 2010 and the 1% population sample survey in 2015, this paper examines the health status of China’s elderly including urban–rural differences and gender gaps in their health. In addition, sampling surveys from 1994 and 2004 are used to analyze the changes in the health status of the elderly since 1994. The results show that the health status of the urban elderly remained stable, but that of the rural elderly improved between the years 2010 and 2015. The health status of older males was generally better than that of older females. The health status of middle-aged elderly improved, but that of the oldest-old declined among male groups. The prevalence of disability of the elderly declined between 1994 and 2015, but the developmental pattern of disability changed in this period.
关键词： Disability,Self-reported health,Health status of the elderly
更新于2025-09-11 14:15:04
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Infrared- Thermometer-Based Detection of Optical Fiber Breakage in Structure
摘要： We show that infrared thermometry can be exploited to detect breakage points of optical fibers embedded in structures. This method has such advantages as real-time operation, cost efficiency, and visual display on site.
关键词： infrared thermometry,carbon fiber-reinforced plastics,structural health monitoring
更新于2025-09-11 14:15:04
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Nanomaterial‐Enabled Flexible and Stretchable Sensing Systems: Processing, Integration, and Applications
摘要： Nanomaterial-enabled flexible and stretchable electronics have seen tremendous progress in recent years, evolving from single sensors to integrated sensing systems. Compared with nanomaterial-enabled sensors with a single function, integration of multiple sensors is conducive to comprehensive monitoring of personal health and environment, intelligent human–machine interfaces, and realistic imitation of human skin in robotics and prosthetics. Integration of sensors with other functional components promotes real-world applications of the sensing systems. Here, an overview of the design and integration strategies and manufacturing techniques for such sensing systems is given. Then, representative nanomaterial-enabled flexible and stretchable sensing systems are presented. Following that, representative applications in personal health, fitness tracking, electronic skins, artificial nervous systems, and human–machine interactions are provided. To conclude, perspectives on the challenges and opportunities in this burgeoning field are considered.
关键词： sensing systems,human-machine interfaces,nanomaterials,Flexible electronics,health monitoring,stretchable electronics
更新于2025-09-11 14:15:04
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Flexible graphene photodetectors for wearable fitness monitoring
摘要： Wearable health and wellness trackers based on optical detection are promising candidates for public health uses due to their noninvasive tracking of vital health signs. However, so far, the use of rigid technologies hindered the ultimate performance and form factor of the wearable. Here, we demonstrate a new class of flexible and transparent wearables based on graphene sensitized with semiconducting quantum dots (GQD). We show several prototype wearable devices that are able to monitor vital health signs noninvasively, including heart rate, arterial oxygen saturation (SpO2), and respiratory rate. Operation with ambient light is demonstrated, offering low-power consumption. Moreover, using heterogeneous integration of a flexible ultraviolet (UV)–sensitive photodetector with a near-field communication circuit board allows wireless communication and power transfer between the photodetectors and a smartphone, offering battery-free operation. This technology paves the way toward seamlessly integrated wearables, and empowers the user through wireless probing of the UV index.
关键词： flexible graphene photodetectors,quantum dots,wearable fitness monitoring,UV index,health signs monitoring
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Functionalized Carbon Reinforcement Structures with Optical Fibre Sensors for Carbon Concrete Composites
摘要： Here we present our latest efforts in the development of functionalized carbon reinforcement structures (FCSs). FCSs are textile based carbon structures that are functionalized with optical fibre sensors and are designed for the reinforcement as well as structural health monitoring (SHM) of concrete composites. A schematic of a FCS is shown in Fig. 1a. In this example, the FCS contains an optical glass fibre to measure distributed strain profile using the Optical Frequency Domain Reflectometry (OFDR) technique as well as two Fibre Bragg Grating (FBG) sensors to determine local strain and strain direction. The fabrication technique to manufacture FCS has been developed at the Saxon Textile Research Institute (STFI) in Chemnitz, Germany, and the fabrication of the FCS involve embroidering of the carbon fibre filaments and optical glass fibres simultaneously on a polyvinyl alcohol (PVA) nonwoven substrate [1]. PVA was chosen as an embroider substrate since it can be easily removed by dissolving it in hot water and the dissolved PVA further stabilizes the FCS. A manufactured FCS that is embedded in a custom-made concrete block in order to evaluate the sensor performance of the FCS is illustrated in Fig. 1b. After the concrete was set, the concrete blocks containing the FCS were installed in a three point bending test rig (Fig. 1c) and the load transfer from the concrete to the FCS was observed using the integrated optical fibre sensors. In Fig. 1d, the response of the FBG sensor inside the FCS in response to the applied load is illustrated for three consecutive load cycles. As can be seen, the FBG sensor is able to detect the load cycles with a sensitivity of 0.44 nm/% as well as a relatively low hysteresis of 0.011% [2]. Moreover, as indicated in Fig. 1e, four strain peaks were detected using the OFDR during the three point bending test. The four strain peaks results from the integration of the optical fibre in a meander shape (see Fig. 1a) and thus the same optical glass fibre experiences along its length the same load at four different positions. Furthermore, the different magnitudes of the four strain peaks at different time stamps corresponds to the increase in applied load when the concrete block was subjected to the three point bending test [2]. Therefore, the experiments verify that the developed FCS can be applied to monitor spatial strain profiles with a relatively high sensitivity and low hysteresis.
关键词： functionalized carbon reinforcement structures,OFDR,FBG,optical fibre sensors,structural health monitoring,carbon concrete composites
更新于2025-09-11 14:15:04
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A review on state of health estimation for lithium ion batteries in photovoltaic systems
摘要： Enhancing state of health (SOH) estimation accuracy and robustness for battery systems in photovoltaic (PV) systems is a feasible way to improve system performance and economics. Nevertheless, the SOH is not directly measurable and affected by a number of factors, therefore its estimation is challenging. Plenty of SOH estimation methods have been proposed for different applications, but little evaluation and discussion have been made for the SOH estimation for battery management systems in PV systems. In this paper, SOH estimation methods are categorised according to the signals that are used to extract the health indicator. Most methods are based on voltage characteristics while other signals such as temperature, ultrasound and force are also promising for SOH estimation. For each method, the basic theory, advantages and drawbacks are introduced and discussed. Then, a thorough comparison among the existing methods is conducted to provide readers with a comprehensive understanding of the development of the SOH estimation. Finally, key issues and suggestions on the SOH estimation are discussed to give novel insights to researchers and engineers.
关键词： State of health,Photovoltaic system,Battery management system,Lithium ion battery
更新于2025-09-11 14:15:04
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Femtosecond Laser Inscribed Sapphire Fiber Bragg Grating for High Temperature and Strain Sensing
摘要： In this paper, a sapphire fiber Bragg grating (SFBG) is fabricated by femtosecond (fs) laser line-by-line scanning method. A third-order fiber Bragg grating is obtained in a single crystal sapphire fiber with a diameter of 60 μm. Compared to the SFBG written by point-by-point method, the SFBG written by the line-by-line method has a higher reflectivity and grating with about 15% reflectivity is achieved when the track length is about 40 μm. The temperature sensing characteristics of this SFBG from room temperature to 1600°C are studied, and the temperature sensitivity of SFBG is 34.96 pm/°C from 1000°C to 1600°C. The strain characteristics are also tested at the temperature of 26°C, 500°C, 1000°C and 1600°C, and the strain sensitivities are 1.42 pm/με, 1.42pm/με, 1.44 pm/με and 1.45 pm/με, respectively. These characteristics show that this SFBG has potential applications in harsh environment structural health monitoring.
关键词： structural health monitoring,femtosecond laser,line-by-line scanning,Sapphire fiber Bragg grating
更新于2025-09-11 14:15:04
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A nonlinear ultrasonic method for real-time bolt looseness monitoring using PZT transducer–enabled vibro-acoustic modulation
摘要： A real-time nonlinear ultrasonic method based on vibro-acoustic modulation is applied to monitor early bolt looseness quantitatively by using piezoceramic transducers. In addition to the ability to detect the early bolt looseness, a major contribution is that we replaced the shaker, which is commonly used in a vibro-acoustic modulation method, by a permanently installed and low-cost lead zirconate titanate patch. In vibro-acoustic modulation, when stimulating two input waves with distinctive frequencies, namely the high-frequency probing wave and the low-frequency pumping wave, the high-frequency probing wave will be modulated by the low-frequency pumping wave to generate sidebands in terms of bolt looseness. Thus, the influence of low-frequency voltage amplitudes on the modulation results, which is ambiguous in previous research, is also analyzed in this article. The results of experiment demonstrated that the lead zirconate titanate–enabled vibro-acoustic modulation method is reliable and easy to implement to identify the bolt looseness continuously and quantitatively. In addition, low-frequency amplitudes of actuating voltage should be selected in a reasonable range. Finally, we compared the vibro-acoustic modulation method with the time-reversal method based on the linear ultrasonic theory, and the result illustrates that vibro-acoustic modulation method has better performance in monitoring the early bolt looseness.
关键词： structural health monitoring,time-reversal,lead zirconate titanate transducers,Bolt looseness,vibro-acoustic modulation,nonlinear ultrasonic
更新于2025-09-11 14:15:04