Low-Cost Interrogation Technique for Dynamic Measurements with FBG-Based Devices

Díaz, Camilo A. R.; Leitão, Cátia; Marques, Carlos; Domingues, M. Fátima; Alberto, Nélia; Pontes, Maria José; Frizera, Anselmo; Ribeiro, Moisés R. N.; André, Paulo; Antunes, Paulo

doi:10.3390/s17102414

Cited by 63 publications

(34 citation statements)

References 35 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fiber Bragg gratings are commonly used optical fiber sensors for measuring temperature and/or mechanical strain. Though, the excessive cost of the interrogation systems is the most significant obstacle for their large commercial application [74].…”

Section: Fiber Optic-based Sensorsmentioning

confidence: 99%

Ballistocardiogram signal processing: a review

Sadek

Biswas

Abdulrazak

2019

Health Inf Sci Syst

126

View full text Add to dashboard Cite

There are several algorithms for analyzing and interpreting cardiorespiratory signals obtained from in-bed based sensors. In sum, these algorithms can be broadly grouped into three categories: time-domain algorithms, frequency-domain algorithms, and wavelet-domain algorithms. A summary of these algorithms is given below to highlight which category of algorithms will be used in our analysis. First, time-domain algorithms are mainly focused on detecting local maxima or local minima using a moving window, and therefore finding the interval between the dominant J-peaks of ballistocardiogram signal. However, this approach has many limitations because of the nonlinear and nonstationary behavior of the ballistocardiogram signal. The implication is that the ballistocardiogram signal does not display consistent J-peaks, which can usually be the case for overnight, in-home monitoring, particularly with frail elderly. Additionally, its accuracy will be undoubtedly affected by motion artifacts. Second, frequency-domain algorithms do not provide information about interbeat intervals. Nevertheless, they can provide information about heart rate variability. This is usually done by taking the fast Fourier transform or the inverse Fourier transform of the logarithm of the estimated spectrum, i.e., cepstrum of the signal using a sliding window. Thereafter, the dominant frequency is obtained in a particular frequency range. The limit of these algorithms is that the peak in the spectrum may get wider and multiple peaks may appear, which might cause a problem in measuring the vital signs. At last, the objective of wavelet-domain algorithms is to decompose the signal into different components, hence the component which shows an agreement with the vital signs can be selected. In other words, the selected component contains only information about the heart cycles or respiratory cycles, respectively. Interbeat intervals can be found easily by applying a simple peak detector. An empirical mode decomposition is an alternative approach to wavelet decomposition, and it is also a very suitable approach to cope with nonlinear and nonstationary signals such as cardiorespiratory signals. Apart from the above-mentioned algorithms, machine learning approaches have been implemented for measuring heartbeats. However, manual labeling of training data is a restricting property. Furthermore, the training step should be repeated whenever the data collection protocol has been changed.

show abstract

Section: Fiber Optic-based Sensorsmentioning

confidence: 99%

Ballistocardiogram signal processing: a review

Sadek

Biswas

Abdulrazak

2019

Health Inf Sci Syst

126

View full text Add to dashboard Cite

show abstract

“…Whether the transducer is not fed (ε = ε 0 ), the Bragg wavelength shift depends mainly on temperature effects. Since the temperature variations occurs at very low frequency when compared with strain variations (which occurs from 100 Hz to 800 Hz in the current work), the temperature cross-sensitivity can be neglected or filtered by a high-pass filter [12].…”

Section: Fbg-based Iotof: a Fully Passive Optical Architecturementioning

confidence: 99%

“…On the other hand, the technique of edge-filtering is vulnerable to optical power fluctuations. Therefore, parameters such as bandwidth and visibility of the filter, excursion of Bragg wavelength shift, and sensitivity of the receiver need to be into account to improve the signal to noise ratio [12]. In the electrical path of Figure 2a, signals are amplified by the operational amplifiers (OP-AMPs) in a transimpedance configuration and then acquired by a multichannel analog-to-digital converter (ADC) module to reach the data receiver.…”

Section: Fbg-based Iotof: a Fully Passive Optical Architecturementioning

confidence: 99%

“…Following, the FBG was pre-stressed (strain, ε = ε 0 ) and glued on its left side to other anchorage point, after removing the fiber acrylate protection in order to improve its adhesion. The FBG was recorded with the same specification as reported in [12].…”

Section: Acoustic-to-optical Modulementioning

confidence: 99%

“…In the current work, we proposed a cost-effective modulation scheme composed by a fiber Bragg grating (FBG) mechanically driven by an acoustic signal containing the IoT information. FBGs have been broadly used in the sensing field such as overhead transmission line wire sag monitoring [8], liquid level monitoring [9], temperature [10], strain [11], and acceleration [12]. In this approach, we focused on the use of the FBG not as a sensor but rather as a modulator, which allows encoding the IoT device's information directly into wavelength shifting.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

IoToF: A Long-Reach Fully Passive Low-Rate Upstream PHY for IoT over Fiber

et al. 2019

Self Cite

View full text Add to dashboard Cite

Internet of things (IoT) devices heavily rely on wireless connectivity. There are intrinsic overlooked limitations such as reach, availability, security and safety vulnerabilities closely associated with wireless solutions. Wired connectivity is the alternative to tackle those issues, and optical fibers directly connecting IoT devices could provide them unique features such as huge bandwidth, long reach, signal integrity and high security grade for the transmitted information. Nevertheless, it can be prohibitive for IoT devices which are power hungry and have costly electrical-to-optical conversions. In this paper, first, a niche is identified for IoT over fiber (IoToF) based on fully passive optical solutions for long reach upstream of low data rate optical connectivity over dark fibers. Then, we proposed, implemented and characterized a prototype physical connectivity (PHY) based on fiber Bragg grating (FBG) low-cost acousto-optic modulation at IoT devices and respective optical edge-filtering as wavelength discriminator at the receiver. Finally, we performed an experimental demonstration of upstream data communication based on simple M-ary frequency-shift keying (FSK), with baud rate of 300 bps transmitted over 30 km range. In terms of data rate and reach for niche applications, IoToF can outperform traditional wireless technologies, such as Sigfox or LoRa. IoToF will enable monitoring urban areas with scarce and polluted spectrum, industrial areas requiring intrinsic safety, and upstreaming data from IoT devices in remote locations with unfavorable wireless propagation but with dark fibers available.

show abstract

Sensing Applications of Polymer Optical Fiber Fuse

Leal‐Junior

Marques

Lee

et al. 2021

Advanced Photonics Research

Self Cite

View full text Add to dashboard Cite

This article presents a review of the fuse effect in polymer optical fibers (POFs) and its sensing applications. First, the propagation mechanisms and the characteristics of the POF fuse are discussed, showing that its optical threshold power and propagation velocity are much lower than those of silica fiber fuse. In addition, it is shown that the main unique advantages of the POF fuse are its capability of transmitting optical signal as well as the electrical conductivity of the carbonized oscillatory path created in the fiber core. The physical properties of the fused POF are also described, such as its higher elasticity and stability to external effects. Subsequently, some applications of fused POFs are reviewed, such as temperature, strain, force, and angle sensors with higher sensitivity and stabler operation than those of nonfused POF‐based sensors. Finally, future perspectives on fused POF‐based sensing are discussed, where the magnetic field sensitivity plays an important role in implementing the optical devices. Thus, the unique features of fused POFs can provide a new paradigm for the fuse effect in optical fibers, in which the effect can be intentionally ignited for fabrication of novel in‐fiber devices and sensors with extended capabilities.

show abstract

Low-Cost Interrogation Technique for Dynamic Measurements with FBG-Based Devices

Cited by 63 publications

References 35 publications

Ballistocardiogram signal processing: a review

Ballistocardiogram signal processing: a review

IoToF: A Long-Reach Fully Passive Low-Rate Upstream PHY for IoT over Fiber

Sensing Applications of Polymer Optical Fiber Fuse

Contact Info

Product

Resources

About