scholarly journals POF Smart Carpet: A Multiplexed Polymer Optical Fiber-Embedded Smart Carpet for Gait Analysis

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3356 ◽  
Author(s):  
Leticia M. Avellar ◽  
Arnaldo G. Leal-Junior ◽  
Camilo A. R. Diaz ◽  
Carlos Marques ◽  
Anselmo Frizera
Keyword(s):  
Optical Fiber ◽  
Gait Analysis ◽  
Light Emitting Diode ◽  
Reaction Force ◽  
Intensity Variation ◽  
Light Sources ◽  
Polymer Optical Fiber ◽  
Double Support ◽  
Spatio Temporal ◽  
Stance Duration

This paper presents the development of a smart carpet based on polymer optical fiber (POF) for ground reaction force (GRF) and spatio-temporal gait parameter assessment. The proposed carpet has 20 intensity variation-based sensors on one fiber with two photodetectors for acquisition, each one for the response of 10 closer sensors. The used multiplexing technique is based on side-coupling between the light sources and POF lateral sections in which one light-emitting diode (LED) is activated at a time, sequentially. Three tests were performed, two for sensor characterization and one for validation of the smart carpet, where the first test consisted of the application of calibrated weights on the top of each sensor for force characterization. In the second test, the foot was positioned on predefined points distributed on the carpet, where a mean relative error of 2.9% was obtained. Results of the walking tests on the proposed POF-embedded smart carpet showed the possibility of estimating the GRF and spatio-temporal gait parameters (step and stride lengths, cadence, and stance duration). The obtained results make possible the identification of gait events (stance and swing phases) as well as the stance duration and double support periods. The proposed carpet is a low-cost and reliable tool for gait analysis in different applications.

scholarly journals Polymer Optical Fiber-Based Integrated Instrumentation in a Robot-Assisted Rehabilitation Smart Environment: A Proof of Concept

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3199
Author(s):  
Arnaldo Leal-Junior ◽  
Leticia Avellar ◽  
Jonathan Jaimes ◽  
Camilo Díaz ◽  
Wilian dos Santos ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Gait Analysis ◽  
Low Cost ◽  
Wearable Sensors ◽  
Intensity Variation ◽  
Physiological Parameter ◽  
Clinical Environment ◽  
Polymer Optical Fiber ◽  
Robot Assisted ◽  
Flexion Extension

Advances in robotic systems for rehabilitation purposes have led to the development of specialized robot-assisted rehabilitation clinics. In addition, advantageous features of polymer optical fiber (POF) sensors such as light weight, multiplexing capabilities, electromagnetic field immunity and flexibility have resulted in the widespread use of POF sensors in many areas. Considering this background, this paper presents an integrated POF intensity variation-based sensor system for the instrumentation of different devices. We consider different scenarios for physical rehabilitation, resembling a clinic for robot-assisted rehabilitation. Thus, a multiplexing technique for POF intensity variation-based sensors was applied in which an orthosis for flexion/extension movement, a modular exoskeleton for gait assistance and a treadmill were instrumented with POF angle and force sensors, where all the sensors were integrated in the same POF system. In addition, wearable sensors for gait analysis and physiological parameter monitoring were also proposed and applied in gait exercises. The results show the feasibility of the sensors and methods proposed, where, after the characterization of each sensor, the system was implemented with three volunteers: one for the orthosis on the flexion/extension movements, one for the exoskeleton for gait assistance and the other for the free gait analysis using the proposed wearable POF sensors. To the authors’ best knowledge, this is the first time that optical fiber sensors have been used as a multiplexed and integrated solution for the simultaneous assessment of different robotic devices and rehabilitation protocols, where such an approach results in a compact, fully integrated and low-cost system, which can be readily employed in any clinical environment.

Recent Progress in Polymer Optical Fiber Light Sources and Fiber Bragg Gratings

2017 ◽  
Vol 23 (2) ◽  
pp. 252-262 ◽  
Author(s):  
Julien Bonefacino ◽  
Xin Cheng ◽  
Ming-Leung Vincent Tse ◽  
Hwa-Yaw Tam
Keyword(s):  
Optical Fiber ◽  
Recent Progress ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Light Sources ◽  
Polymer Optical Fiber

Multiplexing technique for quasi-distributed sensors arrays in polymer optical fiber intensity variation-based sensors

2019 ◽  
Vol 111 ◽  
pp. 81-88 ◽  
Author(s):  
Arnaldo G. Leal-Junior ◽  
Camilo R. Díaz ◽  
Carlos Marques ◽  
Maria José Pontes ◽  
Anselmo Frizera
Keyword(s):  
Optical Fiber ◽  
Intensity Variation ◽  
Polymer Optical Fiber ◽  
Distributed Sensors

scholarly journals Transformable Warning Clothing for Children with Active Light Sources

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Anna Studzińska ◽  
Iwona Frydrych ◽  
Krzysztof Łężak
Keyword(s):  
Optical Fiber ◽  
Research Methodology ◽  
Technological Development ◽  
Point Of View ◽  
Light Sources ◽  
Light Elements ◽  
Traffic Light ◽  
Polymer Optical Fiber ◽  
The Road ◽  
On The Road

AbstractWarning clothing for children should meet several requirements in the field of safety and functionalities. Technical and technological development has brought many different benefits. One of them are active light sources that can be used to improve the visibility of the user of given clothing products in situations, where the risk of being invisible is high. Therefore, the transformable clothing with the use of side emitting polymer optical fiber increases the child visibility in the traffic compared to the situation, when the safety was guaranteed only by reflective materials. The scientific problem to be solved was the design of transformable clothing, followed by the integration of traffic light systems with transformable children's clothing, which should increase the child's safety on the road. Transformability, as a feature of the product, should not interfere with the child's visibility. At a later stage of work, visioility tests on the transformable children's clothing set prototype were carried out according to the proposed research methodology. The visibility of system has been assessed both from the point of view of the arrangement of traffic light elements as well as their optoelectronic parameters, such as illuminance, the color of the optical fiber cover, and so on.

RGB wavelength multiplexer based on polycarbonate multicore polymer optical fiber

2021 ◽  
Vol 61 ◽  
pp. 102441
Author(s):  
Bar Gelkop ◽  
Linoy Aichnboim ◽  
Dror Malka
Keyword(s):  
Optical Fiber ◽  
Polymer Optical Fiber

scholarly journals A 40 Mb/s VLC System Reusing an Existing Large LED Panel in an Indoor Office Environment

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1697
Author(s):  
Xicong Li ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvánovec ◽  
Paul Anthony Haigh
Keyword(s):  
Modulation Depth ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Data Communication ◽  
Experimental System ◽  
Digital Signal ◽  
Visible Light Communication ◽  
Cost Driver ◽  
Limiting Factors ◽  
Light Sources

With advances in solid-state lighting, visible light communication (VLC) has emerged as a promising technology to enhance existing light-emitting diode (LED)-based lighting infrastructure by adding data communication capabilities to the illumination functionality. The last decade has witnessed the evolution of the VLC concept through global standardisation and product launches. Deploying VLC systems typically requires replacing existing light sources with new luminaires that are equipped with data communication functionality. To save the investment, it is clearly desirable to make the most of the existing illumination systems. This paper investigates the feasibility of adding data communication functionality to the existing lighting infrastructure. We do this by designing an experimental system in an indoor environment based on an off-the-shelf LED panel typically used in office environments, with the dimensions of 60 × 60 cm2. With minor modifications, the VLC function is implemented, and all of the modules of the LED panel are fully reused. A data rate of 40 Mb/s is supported at a distance of up to 2 m while using the multi-band carrierless amplitude and phase (CAP) modulation. Two main limiting factors for achieving higher data rates are observed. The first factor is the limited bandwidth of the LED string inside the panel. The second is the flicker due to the residual ripple of the bias current that is generated by the panel’s driver. Flicker is introduced by the low-cost driver, which provides bias currents that fluctuate in the low frequency range (less than several kilohertz). This significantly reduces the transmitter’s modulation depth. Concurrently, the driver can also introduce an effect that is similar to baseline wander at the receiver if the flicker is not completely filtered out. We also proposed a solution based on digital signal processing (DSP) to mitigate the flicker issue at the receiver side and its effectiveness has been confirmed.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

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