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(1) Background: We investigated the detrimental and protective effects of short-, medium, and long-term treatment with different doses of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) during the aging process. (2) Methods: Rats were treated for 15, 30, and 60 weeks with 1, 3, 10, and 30 J of PBMT-sMF or a placebo control. In addition, eight young rats were not subjected to any procedure or treatment and were euthanized at six weeks old. Skin, muscle, bone, kidney, liver, and blood samples were analyzed. (3) Results: No differences between the groups in the morphology of the skin, muscle, and bone was observed. Glutamic pyruvic transaminase levels were increased in the placebo group after 30 and 60 weeks. Glutamic oxaloacetic transaminase levels were also increased in the placebo group after 30 weeks. An increase in creatinine in the PBMT-sMF 3, 10, and 30 J groups compared with that in the young control group was observed. No significant difference in urea levels between the groups was noted. Vascular endothelial growth factor increased in the PBMT-sMF 10 and 30 J groups after 15 weeks of treatment and in the PBMT-sMF 3 J after 60 weeks. Finally, vascular endothelial growth factor decreased in the PBMT-sMF 30 J group after 30 weeks of treatment. (4) Conclusions: PBMT-sMF did not have detrimental effects on the skin, muscle, bone, kidney, or liver after short-, medium-, and long-term treatments in aging rats. In addition, PBMT-sMF may have protective effects on the muscle tissue in aging rats after short- and long-term treatment. [ABSTRACT FROM AUTHOR]

This paper presents the development and application of an optical fiber-embedded tendon based on biomimetic multifunctional structures. The tendon was fabricated using a thermocure resin (polyurethane) and the three optical fibers with one fiber Bragg grating (FBG) inscribed in each fiber. The first step in the FBG-integrated artificial tendon analysis is the mechanical properties assessment through stress–strain curves, which indicated the customization of the proposed device, since it is possible to tailor the Young's modulus and strain limit of the tendon as a function of the integrated optical fibers, where the coated and uncoated fibers lead to differences in both parameters, i.e., strain limits and Young's modulus. Then, the artificial tendon integrated with FBG sensors undergoes three types of characterization, which assesses the influence of temperature, single-axis strain, and curvature. Results show similarities in the temperature responses in all analyzed FBGs, where the variations are related to the heterogeneity on the polyurethane matrix distribution. In contrast, the FBGs embedded in the tendon presented a reduction in the strain sensitivity when compared with the bare FBGs (i.e., without the integration in the artificial tendon). Such results demonstrated a reduction in the sensitivity as high as 77% when compared with the bare FBGs, which is related to strain field distributions in the FBGs when embedded in the tendon. In addition, the curvature tests indicated variations in both optical power and wavelength shift, where both parameters are used on the angle estimation using the proposed multifunctional artificial tendon. To that extent, root mean squared error of around 3.25° is obtained when both spectral features are considered. Therefore, the proposed approach indicates a suitable method for the development of smart structures in which the multifunctional capability of the device leads to the possibility of using not only as a structural element in tendon-driven actuators and devices, but also as a sensor element for the different structures. [ABSTRACT FROM AUTHOR]

To review the effects of photobiomodulation therapy (PBMT) on pain intensity and disability in people with plantar fasciitis (PF) when compared with control conditions, other interventions, and adjunct therapies. Systematic searches were conducted in five database randomized controlled trials (RCT). We only included randomized controlled trials (RCTs) in adults with PF that compared PBMT to placebo, as well as RCTs that compared PBMT to other interventions; and as an adjunct to other therapies. The methodological quality and certainty were assessed through PEDro Scale and GRADE approach, respectively. The data of comparison were pooled and a meta-analysis was conducted when possible. Nineteen RCTs involving 1089 participants were included in this review. PBMT alone (MD = − 22.02 [− 35.21 to − 8.83]) or with exercise (MD = − 21.84 [− 26.14 to − 17.54]) improved pain intensity in short-term treatment. PBMT was superior to (extracorporeal shock wave therapy) EWST for relief of pain (MD = − 20.94 [− 32.74 to − 9.13]). In the follow-up, PBMT plus exercise had a superior to exercise therapy alone (MD = − 18.42 [− 26.48 to − 10.36]). PBMT may be superior to (ultrasound therapeutic) UST in medium- and long-term follow-ups for disability, but can be not clinically relevant. There is uncertainty that PBMT is capable of promoting improvement in disability. PBMT when used with adjuvant therapy does not enhance outcomes of interest. PBMT improves pain intensity with or without exercise. PBMT has been shown to be superior to ESWT for pain relief, but not superior to other interventions for pain intensity and disability. The evidence does not support PBMT as an adjunct to other electrotherapeutic modalities. [ABSTRACT FROM AUTHOR]

This paper presents the development and signal analysis of surface plasmon resonance (SPR)-based sensors in D-shaped polymer optical fibers (POFs). A gold-palladium (Au-Pd) coating was applied to the D-shaped region to obtain the SPR signal in the transmitted spectrum of the POFs, where different samples were fabricated using the same methods and parameters. In this case, the transmitted spectra of three sets of samples were compared, which indicated variations in the SPR signature that can influence the sensors' application and reproducibility. Then, the intensity of and wavelength shift in the SPR signals were analyzed as a function of the refractive index variation, where it was possible to observe differences in the sensors' sensitivities and the linearity of the different samples. In this regard, additional features, namely the area below the curve and the peak amplitude of the fast Fourier transform (FFT) applied to the transmitted spectra, were used to enhance the sensors' accuracy and precision. To verify the use of such additional features in the sensor analysis, an unsupervised approach based on k-means clustering was used considering a single dataset with the results of all the sensors. The results showed clustering with the number of different refractive indices tested, which motivated the use of these features (intensity, wavelength, area and FFT amplitude) in the refractive index assessment. In this context, random forest was the supervised algorithm with the smallest root mean squared error (RMSE) among the algorithms tested, where an RMSE of 0.0057 was obtained considering all the datasets. For the analysis of each sensor (considering the three sets of sensor samples), the mean RMSE using random forest applied to the multifeature approach returned relative errors below 9%, considering the entire tested range of refractive index variation. [ABSTRACT FROM AUTHOR]

This paper presents the development, analysis, and application of chirped fiber Bragg gratings (CFBGs) for dynamic and static measurements of beams of different materials in the single-cantilever configuration. In this case, the beams were numerically analyzed using the finite-element method (FEM) for the assessment of the natural frequencies and vibration modes of the beam for the dynamic analysis of the structural element. Furthermore, the static numerical analysis was performed using a load at the free end of the beam, where the maximum strain and its distribution along the beam were analyzed, especially in the region at which the FBG was positioned. The experimental evaluation of the proposed CFBG sensor was performed in static conditions for forces from 0 to 50 N (in 10 N steps) applied at the free end of the beam, whereas the dynamic evaluation was performed by means of positioning an unbalanced motor at the end of the beam, which was excited at 16 Hz, 65 Hz, 100 Hz, and 131 Hz. The results showed the feasibility of the proposed device for the simultaneous assessment of the force and strain distribution along the CFBG region using the wavelength shift and the full-width at half-maximum (FWHM), respectively. In these cases, the determination coefficients of the spectral features as a function of the force and strain distribution were higher than 0.99 in all analyzed cases, where a potential resolution of 0.25 N was obtained on the force assessment. In the dynamic tests, the frequency spectrum of the sensor responses indicated a frequency peak at the excited frequency in all analyzed cases. Therefore, the proposed sensor device is a suitable option to extend the performance of sensors for structural health assessment, since it is possible to simultaneously measure different parameters in dynamic and static conditions using only one sensor device, which, due to its multiplexing capabilities, can be integrated with additional optical fiber sensors for the complete shape reconstruction with millimeter-range spatial resolution. [ABSTRACT FROM AUTHOR]

This paper presents the development and sensor applications of 3D-printed polymer optical fibers (POFs) using commercially available filaments. The well-known intensity variation sensor was developed using this fiber for temperature and curvature sensing, where the results indicate a linear response in the curvature analysis, with a coefficient of determination (R 2 ) of 0.97 and sensitivity of 4.407 × 10 − 4 mW/ ∘ , whereas the temperature response was fitted to an R 2 of 0.956 with a sensitivity of 5.718 × 10 − 3 mW/ ∘ C. Then, the POF was used in the development of a modal interferometer by splicing the POF in-between two single-mode fibers (SMFs), which result in a single-mode-multimode-single-mode (SMS) configuration. The such interferometer was tested for temperature and axial strain responses, where the temperature response presented a linear trend R 2 of around 0.98 with a sensitivity of −78.8 pm/ ∘ C. The negative value of the sensitivity is related to the negative thermo-optic coefficient commonly obtained in POFs. Furthermore, the strain response of the SMS interferometer showed a high sensitivity (9.5 pm/ μ ϵ ) with a quadratic behavior in which the R 2 of around 0.99 was obtained. Therefore, the proposed approach is a low-cost, environmentally friendly and straightforward method for the production of highly sensitive optical fiber sensors. [ABSTRACT FROM AUTHOR]

This clinical trial aims to provide evidence about the effectiveness of the Pilates method on stress urinary incontinence (SUI), as well as to elucidate the effects of photobiomodulation therapy associated with static magnetic field (PBMT/sMF) alone or associated with the Pilates Method on Pelvic floor muscle (PFM) in women affected by SUI. For that, a three-arm, parallel randomized, double-blinded, placebo-controlled trial was conducted (NCT05096936). We recruited thirty-three women diagnosed with SUI, randomly allocated to three groups: placebo PBMT/sMF plus method Pilates, PBMT/sMF active plus method Pilates and only PBMT/sMF active. The evaluation consisted of anamnesis and physical examination, muscle strength, completion of the ICIQ-SF questionnaire, and urinary loss. The evaluation of muscle strength and filling the ICIQ-SF were performed on the first and last days, while the Pad test was applied in baseline, one month, two months, and three months of intervention. We observed an increase in strength (p < 0.01), tone (p < 0.01), and quality of life (p < 0.01), in addition to a decrease in urinary lost (p < 0.01) for all groups comparing the pre and post-intervention. The PBMT/sMF alone, the Pilates, and the combination of the two therapies proved to be effective in improving the signs and symptoms of women with SUI. [ABSTRACT FROM AUTHOR]

This paper presents the development and application of a multiplexed intensity variation-based sensor system for multiplane shape reconstruction. The sensor is based on a polymer optical fiber (POF) with sequential lateral sections coupled with a flexible light-emitting diode (LED) belt. The optical source modulation enables the development of 30 independent sensors using one photodetector, where the sensor system is embedded in polydimethylsiloxane (PDMS) resin in two configurations. Configuration 1 is a continuous PDMS layer applied in the interface between the flexible LED belt and the POF, whereas Configuration 2 comprises a 20 mm length PDMS layer only on each lateral section and LED region. The finite element method (FEM) is employed for the strain distribution evaluation in different conditions, including the strain distribution on the sensor system subjected to momentums in roll, pitch and yaw conditions. The experimental results of pressure application at 30 regions for each configuration indicated a higher sensitivity of Configuration 1 (83.58 a.u./kPa) when compared with Configuration 2 (40.06 a.u./kPa). However, Configuration 2 presented the smallest cross-sensitivity between sequential sensors (0.94 a.u./kPa against 45.5 a.u./kPa of Configuration 1). Then, the possibility of real-time loading condition monitoring and shape reconstruction is evaluated using Configuration 1 subjected to momentums in roll, pitch and yaw, as well as mechanical waves applied on the sensor structure. The strain distribution on the sensor presented the same pattern as the one obtained in the simulations, and the real-time response of each sensor was obtained for each case. In addition, the possibility of real-time loading condition estimation is analyzed using the k-means algorithm (an unsupervised machine learning approach) for the clusterization of data regarding the loading condition. The comparison between the predicted results and the real ones shows a 90.55% success rate. Thus, the proposed sensor device is a feasible alternative for integrated sensing in movement analysis, structural health monitoring submitted to dynamic loading and robotics for the assessment of the robot structure. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the mechanical properties of different polymer optical fibers (POFs) at ultraviolet (UV) radiation conditions. Cyclic transparent optical polymer (CYTOP) and polymethyl methacrylate (PMMA) optical fibers are used in these analyses. In this case, the fiber samples are irradiated at the same wavelength, pulse time and energy conditions for different times, namely, 10 s, 1 min, 2 min and 3 min. The samples are tested in tensile tests and dynamic mechanical thermal analysis (DMTA) to infer the variation in the static and dynamic properties of such fibers as a function of the UV radiation condition. Furthermore, reference samples of each fiber (without UV radiation) are tested for comparison purposes. The results show a lower UV resistance of PMMA fibers, i.e., higher variation in the material features in static conditions (Young's modulus variation of 0.65 GPa). In addition, CYTOP fiber (material known for its high UV resistance related to its optical properties) also presented Young's modulus variation of around 0.38 GPa. The reason for this reduction in the moduli is related to possible localized annealing due to thermal effects when the fibers are subjected to UV radiation. The dynamic results also indicated a higher variation in the PMMA fibers storage modulus, which is around 30% higher than the variations in the CYTOP fibers when different radiation conditions are analyzed. However, CYTOP fibers show a smaller operational temperature range and higher variation in the storage modulus as a function of the temperature when compared with PMMA fibers. In contrast, PMMA fibers show higher variations in their material properties when subjected to oscillatory loads at different frequency conditions. Thus, the results obtained in this work can be used as guidelines for the influence of UV radiation in POFs not only for the material choice, but also on the limitations of UV radiation in the fabrication of the grating as well as in sensor applications at UV radiation conditions. [ABSTRACT FROM AUTHOR]

This paper presents the development, analysis and application of a fiber Bragg grating (FBG) array for two-dimensional (2D) shape reconstruction in a cantilever beam. The structural elements made of Pinus wood and Nylon 6.0 were numerically analyzed using the finite element method for the strain distribution when constant loading is applied at the free end of the beam. In addition, the temperature compensation method is proposed to decouple the temperature cross-sensitivity in the deflection analysis. In this case, the temperature sensitivities of all sensing elements of the 5-FBG array were obtained. An additional FBG was encapsulated in a silicone mold for increased sensitivity and positioned in the clamping point in which deflection was negligible. Temperature compensation was achieved considering the temperature measured by the silicone-embedded FBG (sensitivity of 27.78 pm/°C) and the sensitivity of all five FBGs of the deflection-sensing array (9.14 pm/°C ± 0.33 pm/°C). In the deflection experiments, the sensors presented a high linearity, in which a determination coefficient (R2) higher than 0.995 was obtained in all of the analyzed cases. Furthermore, the 2D shape construction using the proposed sensor approach resulted in the elastic line estimation for all analyzed beams, where the experimental results were in agreement with the theoretical and numerical analysis with a R2 higher than 0.99 in all of the analyzed cases. Therefore, the proposed sensor array is a feasible approach for real-time shape reconstruction of structural elements with the advantages related to the possibility of direct embedment in the measured structure. [ABSTRACT FROM AUTHOR]

Oxidative stress induced by exercise has been a research field in constant growth, due to its relationship with the processes of fatigue, decreased production of muscle strength, and its ability to cause damage to the cell. In this context, photobiomodulation therapy (PBMT) has emerged as a resource capable of improving performance, while reducing muscle fatigue and muscle damage. To analyze the effects of PBMT about exercise-induced oxidative stress and compare with placebo therapy. Data Sources: Databases such as PubMed, EMBASE, CINAHL, CENTRAL, PeDro, and Virtual Health Library, which include Lilacs, Medline, and SciELO, were searched to find published studies. Study Selection: There was no year or language restriction; randomized clinical trials with healthy subjects that compared the application (before or after exercise) of PBMT to placebo therapy were included. Study Design: Systematic review with meta-analysis. Level of Evidence: 1. Data Extraction: Data on the characteristics of the volunteers, study design, intervention parameters, exercise protocol and oxidative stress biomarkers were extracted. The risk of bias and the certainty of the evidence were assessed using the PEDro scale and the GRADE system, respectively. Results: Eight studies (n = 140 participants) were eligible for this review, with moderate to excellent methodological quality. In particular, PBMT was able to reduce damage to lipids post exercise (SMD = −0.72, CI 95% −1.42 to −0.02, I2 = 77%, p = 0.04) and proteins (SMD = −0.41, CI 95% −0.65 to −0.16, I2 = 0%, p = 0.001) until 72 h and 96 h, respectively. In addition, it increased the activity of SOD enzymes (SMD = 0.54, CI 95% 0.07 to 1.02, I2 = 42%, p = 0.02) post exercise, 48 and 96 h after irradiation. However, PBMT did not increase CAT activity (MD = 0.18 CI 95% −0.56 to 0.91, I2 = 79%, p = 0.64) post exercise. We did not find any difference in TAC or GPx biomarkers. Conclusion: Low to moderate certainty evidence shows that PBMT is a resource that can reduce oxidative damage and increase enzymatic antioxidant activity post exercise. We found evidence to support that one session of PBMT can modulate the redox metabolism. [ABSTRACT FROM AUTHOR]

We present results for the disturbance location characterization of Transmission-Reflection Analysis (TRA)-based sensors using three different optical fibers doped with dielectric nanoparticles (DNP). Different DNPs ($SrO$ , $CaO$ and $MgO$) lead to different sensors’ performance due to the composition-dependent properties. Fibers doped with bigger DNPs lead to higher Rayleigh backscattering attenuation, which unable the use of larger fiber length. Alternatively, fibers with smaller DNPs presented spatial resolution (SR) of $0.2~cm$ with signal-to-noise ratio (SNR) of $32~dB$ for $150~cm$ -along fiber under test. In some fibers, the high attenuation led to a negligible backscattering power variation. The results obtained in this work indicate the feasibility of using DNP fibers in sensors applications in which the different compounds can be selected or even optimized considering the demands for each application such SNR, SR, dynamic range and sensitivity. [ABSTRACT FROM AUTHOR]

This letter presents a method of measuring the strain during rapid maxillary expansion (RME) using fiber Bragg grating (FBG) sensors. The activation of the central jackscrew of the Hyrax expander provides the forces required to expand the maxilla that are transmitted to the teeth by a metallic wire. The strain resulted from the opening forces was measured by a FBG sensor bonded to the posterior arm of the appliance. A proof of concept is shown using a 3D printed maxillary model of the biomechanical structure of a human maxilla, in which the appliance was mounted. The sensor was able to measure static and dynamic events, such as the strain accumulation and viscoelastic strain patterns. An increase in the strain is observed as the number of activations increases. A fast decrease in the strain between activations was also observed. In spite of using a plastic model with viscoelastic properties, this decrease may be related to limitations of the central jackscrew. The instrumentation of the Hyrax expanders using FBG sensors assists in clinical studies on the biomechanics and the efficiency of RME. Different expanders can be compared using the present sensor, and tests on their components, especially the central jackscrew, contributes to improvements or new procedures on such treatments. [ABSTRACT FROM AUTHOR]

This paper presented the force and displacement analyses of a diaphragm-embedded fiber Bragg grating (FBG) sensor. In the first step, a numerical analysis (via finite element method) was performed considering linear elastic materials, where there is a linear variation on the strain in the optical fiber for both displacement and force (or pressure). In the second step, the experimental analysis was performed using two approaches: (i) controlling the displacement applied in the diaphragm-embedded FBG (while the force is also measured). (ii) Controlling the force applied in the sensor (also with the measurement of the displacement). Results showed reflected optical power variations and wavelength shift following the application of displacement and force. The sensitivities of both wavelength shift and optical power were different (and non-proportional) when displacement and force were compared. However, a higher correlation, determination coefficient (R2) of 0.998, was obtained in the analysis of the wavelength shift as a function of the displacement, which indicated that the strain transmission in the optical fiber is directly related to the strain in the diaphragm, whereas the force has an indirect relation with the strain and depends on the material features. Then, the possibility of simultaneous estimation of force and displacement was investigated, where the linear relation of both parameters (displacement and force) with the wavelength shift and the optical power were obtained in a limited range of displacement and force. In this range, root mean squared errors of 0.37 N and 0.05 mm were obtained for force and displacement, respectively. In addition, the force variation with a step displacement input also shows the possibility of using the proposed FBG device for the characterization of the materials' viscoelastic features such as phase delay, creep, and stress relaxation, which can be employed for in situ characterization of different viscoelastic materials. [ABSTRACT FROM AUTHOR]

Background: Both physical activity and low-level laser therapy (LLLT) can reduce knee osteoarthritis (KOA) inflammation. We conducted a randomized clinical trial to investigate the short- and long-term effectiveness of LLLT combined with strength training in persons with KOA. Methods: Fifty participants were randomly divided in two groups, one with LLLT plus strength training (n = 26) and one with placebo LLLT plus strength training (n = 24). LLLT and strength training were performed triweekly for 3 and 8 weeks, respectively. In the laser group, 3 joules 904 nm wavelength laser was applied to fifteen points (45 joules) per knee per session. Patient-reported outcomes, physical tests, and ultrasonography assessments were performed at baseline and 3, 8, 26, and 52 weeks after initial LLLT or placebo therapy. The primary outcomes were pain on movement, at rest, at night (Visual Analogue Scale), and globally (Knee injury and Osteoarthritis Outcome Score (KOOS) subscale). Parametric data were assessed with analysis of variance using Šidák's correction. Results: There were no significant between-group differences in the primary outcomes. However, in the laser group there was a significantly reduced number of participants using analgesic and non-steroidal anti-inflammatory drugs and increased performance in the sit-to-stand test versus placebo-control at week 52. The joint line pain pressure threshold (PPT) improved more in the placebo group than in the laser group, but only significantly at week 8. No other significant treatment effects were present. However, pain on movement and joint line PPT were worse in the placebo group at baseline, and therefore, it had more room for improvement. The short-term percentage of improvement in the placebo group was much higher than in similar trials. Conclusions: Pain was reduced substantially in both groups. LLLT seemed to provide a positive add-on effect in the follow-up period in terms of reduced pain medication usage and increased performance in the sit-to-stand test. [ABSTRACT FROM AUTHOR]

Sensing technologies using optical fibers have been studied and applied since the 1970s in oil and gas, industrial, medical, aerospace, and civil areas. Detecting ultrasound acoustic waves through fiber-optic hydrophone (FOH) sensors can be one solution for continuous measurement of volumes inside production tanks used by these industries. This work presents an FOH system composed of two optical fiber coils made with commercial single mode fiber (SMF) working in the sensor head of a Michelson's interferometer (MI) supported by an active stabilization mechanism that drives another optical coil wound around a piezoelectric actuator (PZT) in the reference arm to mitigate external mechanical and thermal noise from the environment. A 1000 mL glass graduated cylinder filled with water is used as a test tank, inside which the sensor head and an ultrasound source are placed. For detection, amplitudes and phases are measured, and machine learning algorithms predict their respective liquid volumes. The acoustic waves create patterns electronically detected with resolution of 1 mL and sensitivity of 340 mrad/mL and 70 mvolts/mL. The nonlinear behavior of both measurands requires classification, distance metrics, and regression algorithms to define an adequate model. The results show the system can determine liquid volumes with an accuracy of 99.4% using a k-nearest neighbors (k-NN) classification with one neighbor and Manhattan's distance. Moreover, Gaussian process regression using rational quadratic metrics presented a root mean squared error (RMSE) of 0.211 mL. [ABSTRACT FROM AUTHOR]

This letter presents the development and application of a multimaterial polymer optical fiber (POF) for temperature and force sensing. The POF is fabricated from the well-known polymethyl methacrylate (PMMA) through a conventional extrusion method combined with the Polycaprolactone (PCL), a biodegradable material with low melting point, which is thermally molded into the PMMA. In this approach, the high customizability enables the development of two configurations: (i) one input, one output (configuration 1); (ii) one input, two outputs (configuration 2). An advantageous feature of the PCL is its transmittance increase as a function of the temperature, which is confirmed via spectrophotometry at different temperatures. In the experimental analysis, the configuration 1 is used in the temperature tests and demonstrates a high linearity (coefficient of determination of 0.981) and resolution below 1°C, whereas its temperature limit is around 55°C. Configuration 2 is tested in simultaneous variations of temperature and transverse force, resulting in relative force insensitivity in temperatures below 40°C, whereas an optical power attenuation as a function of the applied force is found in temperatures around 55°C. Thus, the proposed approach shows a novel, flexible and customized technique for POF multimaterial fabrication, which can be employed not only on sensors applications, but also in the development of optical components based in POFs. [ABSTRACT FROM AUTHOR]

Photobiomodulation therapy (PBMT) has been used to treat patients with chronic neck and/or shoulder pain. However, it is unknown whether the concurrent use of PBMT and static magnetic field (PBMT-sMF) also has positive effects in these patients. The aim of this study was to investigate the effects of PBMT-sMF versus placebo on pain intensity, range of motion (ROM) and treatment satisfaction in patients with chronic nonspecific neck and/or shoulder pain. A randomized controlled trial, with blinded assessors, therapists and patients was carried out. Seventy-two patients with chronic nonspecific neck and/or shoulder pain were randomized to either active PBMT-sMF (n = 36) or placebo PBMT-sMF (n = 36). Patients were treated twice weekly, over 3 weeks. Primary outcome was pain intensity, measured 15 min after the last treatment session and at 24-, 48-, 72-h, and 7-days after the last treatment. Secondary outcomes were ROM, patient' treatment satisfaction, and adverse effects. PBMT-sMF was able to reduce pain intensity in all time points tested compared to placebo (p < 0.05). There was no difference between groups in the secondary outcomes (p > 0.05). Our results suggest that PBMT-sMF is better than placebo to reduce pain in patients with chronic nonspecific neck and/or shoulder pain at short-term. [ABSTRACT FROM AUTHOR]

The purpose of this study is to compare the effect of photobiomodulation therapy (PBMT) and cryotherapy (CRT) on muscle recovery outcomes. These searches were performed in PubMed, PEDro, CENTRAL, and VHL (which includes the Lilacs, Medline, and SciELO database) from inception to June 2021. We included randomized clinical trials involved healthy human volunteers (> 18 years) underwent an intervention of PBMT and CRT, when used in both isolated form post-exercise. Standardized mean differences (SMD) or mean difference (MD) with 95% confidence interval were calculated and pooled in a meta-analysis for synthesis. The risk of bias and quality of evidence were assessed through Cochrane risk-of-bias tool and GRADE system. Four articles (66 participants) with a high to low risk of bias were included. The certainty of evidence was classified as moderate to very low. PBMT was estimated to improve the muscle strength (SMD = 1.73, CI 95% 1.33 to 2.13, I2 = 27%, p < 0.00001), reduce delayed onset muscle soreness (MD: − 25.69%, CI 95% − 34.42 to − 16.97, I2 = 89%, p < 0.00001), and lower the concentration of biomarkers of muscle damage (SMD = − 1.48, CI 95% − 1.93 to − 1.03, I2 = 76%, p < 0,00,001) when compared with CRT. There was no difference in oxidative stress and inflammatory levels. Based on our findings, the use of PBMT in muscle recovery after high-intensity exercise appears to be beneficial, provides a clinically important effect, and seems to be the best option when compared to CRT. [ABSTRACT FROM AUTHOR]

This paper proposes an optical fiber sensor system based on the strain rosette strategy to monitor the stress-strain state on the surface of a robotic manipulator tool. Three Fiber Bragg Grating (FBG) sensors are positioned according to a deformation rosette configuration within a slot in two 3D printed claws. The equations based on elasticity theory to obtain the stress-strain state from the sensors data are developed and a methodology using an auxiliary temperature sensor to prevent cross-sensitivity and to avoid measurement errors is proposed. The characterization tests show a highly linear behavior in terms of sensitivity to strain (R2 = 0.996 for the linear regression of the means) and to temperature variation (lower R2 between FBGs equal to 0.9868). From the compression tests, it is possible to conclude that the dynamic range of the sensors is adequate to the load capacity of the claws. Grip tests with different objects were performed on the manipulator to verify the system’s feasibility in real-time applications. Finally, from the data processing of the experiments on the robot, it is possible to apply failure criteria and shows that the grip structure is not at risk during the tests. [ABSTRACT FROM AUTHOR]

Smart textiles are novel solutions for remote healthcare monitoring which involve non-invasive sensors-integrated clothing. Polymer optical fiber (POF) sensors have attractive features for smart textile technology, and combined with Artificial Intelligence (AI) algorithms increase the potential of intelligent decision-making. This paper presents the development of a fully portable photonic smart garment with 30 multiplexed POF sensors combined with AI algorithms to evaluate the system ability on the activity classification of multiple subjects. Six daily activities are evaluated: standing, sitting, squatting, up-and-down arms, walking and running. A k-nearest neighbors classifier is employed and results from 10 trials of all volunteers presented an accuracy of 94.00 (0.14)%. To achieve an optimal amount of sensors, the principal component analysis is used for one volunteer and results showed an accuracy of 98.14 (0.31)% using 10 sensors, 1.82% lower than using 30 sensors. Cadence and breathing rate were estimated and compared to the data from an inertial measurement unit located on the garment back and the highest error was 2.22%. Shoulder flexion/extension was also evaluated. The proposed approach presented feasibility for activity recognition and movement-related parameters extraction, leading to a system fully optimized, including the number of sensors and wireless communication, for Healthcare 4.0. [ABSTRACT FROM AUTHOR]

In this paper, the experimental analysis of different assembly configurations for diaphragm-embedded optical fiber sensors is proposed. A fiber Bragg grating (FBG) is embedded in a nitrile rubber diaphragm, which is positioned in different front and back supports. The difference between such supports is their contact angles with the diaphragm, which leads to differences in the strain applied in the FBG prior to the sensor application. This prestrain condition in the diaphragm influences the sensor’s performance in terms of sensitivity, linearity and hysteresis. To that extent, there are 8 different configuration angles, namely 0°, 1.5°, 3.8°, 6.8°, 9.0°, 11.3°, 13.5° and 15°. The diaphragm-embedded FBG is positioned at each configuration and pressure is transversely applied on the diaphragm region (which transmits strain to the optical fiber) at constant temperature conditions. Results show a relation between the configuration angle and the sensor performance, where sensitivity and linearity presented opposite behaviors, i.e., lower angles (especially the 0° angle) lead to high linearity with a coefficient of determination (R2) of 0.992, whereas higher angles resulted in higher sensitivity with the highest sensitivity value of 13.26 pm/kPa. In contrast, the sensor hysteresis showed a peak value of 6.7% at 9.0° angle with hysteresis decrease in angles higher and lower than 9.0°. The smallest hysteresis of 0.2% is obtained at 1.5°. The obtained results can be used as a guideline on the development of diaphragm-embedded sensors with the additional degree of freedom from the possibility of customizing the diaphragm assembly configuration to achieve predefined performance parameters. [ABSTRACT FROM AUTHOR]

This paper presents a development of the smart garment instrumented with polymer optical fiber (POF) sensors to identify the impact location during a perturbation protocol for balance assessment. The sensor system installed on the smart garment consists of 30 multiplexed sensors, and each sensor is composed of a light-emitting diode (LED) coupled to a lateral cut in the POF. The sensor’s responses are acquired by four photodetectors and the data processing is made by a microcontroller. Two tests were performed to characterize the system. First, forces were applied on each sensor using a reference force sensor to characterize their sensitivities. Second, several perturbations on predefined body areas were performed. A technique based on the sensors’ responses is proposed to identify impacts. Finally, the proposed system was applied on a perturbation protocol to assess the human balance under an instability condition. Results of the first test showed different sensor sensitivities due to differences provoked by the manufacturing process, and the sensors were normalized. Results of the second test showed the ability of identifying the impact region by using the impact location identification technique. Furthermore, results of the perturbation protocol showed the feasibility of the proposed system in the balance assessment, in which the identified impact regions combined with the trunk angles obtained by an inertial measurement unit (IMU) improved the balance assessment. The proposed system is portable, low cost, with simple signal processing and ease of implementation, with possibility of scalability, in which can be adapted for other impact detection protocols. [ABSTRACT FROM AUTHOR]

Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds during the proliferation phase in rats with a hypoproteic diet. Rats were randomized to one of the following groups (n = 10 per group): (i) injured normoproteic (25% protein) not subjected to PBMT; (ii) injured normoproteic who received PBMT; (iii) injured hypoproteic (8% protein) not subjected to PBMT; and (iv) injured hypoproteic who received PBMT. Rats were submitted to skin wounds and then treated with PBMT (low-level laser therapy: 660 nm, 50 mW, 1.07 W/cm2, 0.028 cm2, 72 J/cm2, 2 J). Analyses were performed at 7 and 14 days of follow-up: semi-quantitative histopathologic analysis, collagen type I and III expressions, immunohistochemical marking for matrix metalloproteinases-3 (MMP-3) and (matrix metalloproteinases-9) MMP-9, and mechanical resistance test. There were significant differences between the normoproteic groups and their respective treated groups (p < 0.05), as well as to treated and untreated hypoproteic groups in histopathologic analysis semi-quantitatively and immunohistochemistry for MMP-3 and 9, in which PBMT was able to decrease immunostaining. Moreover, there was a decrease in collagen deposition with the statistical difference (p < 0.05) for both collagen types III and I. In conclusion, PBMT application was proved effective in the treatment of cutaneous wounds in rats submitted to a hypoproteic diet. These alterations were more salient in the proliferation stage with the reduction of metalloproteinases providing better mechanical resistance of the injured area in the remodeling phase with an intensification of type I collagen. [ABSTRACT FROM AUTHOR]

The whole world experienced in the last decades a continuous change in the age pyramid related to the population aging, where there is an increase in the elderly population (over 65 years) when compared with other age groups [1]. Such demographic change is not essentially an issue, since it demonstrates that the life expectancy is increasing, directly related to many advances in medicine, public health and biotechnology as well as social and economic developments that allow access for the general population to health treatments [1]. The population aging in conjunction with chronic diseases, where some of them are also age-related, leads to some clinical conditions that can affect human health such as osteoarthritis, rheumatoid arthritis, Alzheimer's disease, Parkinson's disease and weakness of the skeletal muscles [2]. These clinical conditions can lead to different types of disabilities, and the most common type is locomotion impairment, which occurs with nearly 14% of the world population [3] and represents around 1 billion people. As locomotor impairment harms work performance, activities of daily living and independence in the community, there is a necessity for continuous treatment of the different conditions that result in locomotor impairments. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to investigate the effects of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) on the length of intensive care unit (ICU) stay and mortality rate of severe COVID-19 patients requiring invasive mechanical ventilation and assess its role in preserving respiratory muscles and modulating inflammatory processes. Patients and Methods: We conducted a prospectively registered, triple-blinded, randomized, placebo-controlled trial of PBMT-sMF in severe COVID-19 ICU patients requiring invasive mechanical ventilation. Patients were randomly assigned to receive either PBMT-sMF or a placebo daily throughout their ICU stay. The primary outcome was length of ICU stay, defined by either discharge or death. The secondary outcomes were survival rate, diaphragm muscle function, and the changes in blood parameters, ventilatory parameters, and arterial blood gases. Results: Thirty patients were included and equally randomized into the two groups. There were no significant differences in the length of ICU stay (mean difference, MD = − 6.80; 95% CI = − 18.71 to 5.11) between the groups. Among the secondary outcomes, significant differences were observed in diaphragm thickness, fraction of inspired oxygen, partial pressure of oxygen/fraction of inspired oxygen ratio, C-reactive protein levels, lymphocyte count, and hemoglobin (p < 0.05). Conclusion: Among severe COVID-19 patients requiring invasive mechanical ventilation, the length of ICU stay was not significantly different between the PBMT-sMF and placebo groups. In contrast, PBMT-sMF was significantly associated with reduced diaphragm atrophy, improved ventilatory parameters and lymphocyte count, and decreased C-reactive protein levels and hemoglobin count. Trial Registration Number (Clinical Trials.gov): NCT04386694. [ABSTRACT FROM AUTHOR]

This paper presents the development and the performance analysis of a force sensor using a novel high stretchable polymer optical fiber (POF) fabricated using the light polymerization spinning (LPS) fiber. The system consists of an LPS-POF fiber encapsulated in a flexible material polydimethylsiloxane (PDMS), in addition to a light source and a photodetector. The sensor was characterized by using a commercial 3-axis force sensor K3D60a ±500N/VA (ME Systeme, Germany). Since the LPS-POF and PDMS are viscoelastic materials, tests with loading and unloading cycles were performed to evaluate the sensor response. A viscoelasticity compensation model was proposed to decrease the errors and the sensor phase delay provoked by the viscoelastic behavior. In addition, the LPS-POF force sensor was applied on two different applications, as a gait perturbation system for balance assessment and as a walking cane for gait assistance. Results showed that proposed sensor presents a linear response, with determinant coefficient (R2) of 0.9974, and high sensitivity (S = 40N/V). However, the unload time presented high phase delay and errors, corroborating the viscoelastic behavior. Compensated response presented lower hysteresis, leading to a decrease of the root mean square error (RMSE) of approximately 65%. Moreover, numerical integration was used as performance metric for the results of both applications and presented a decrease of 48% in the first application and up to 46% in the second application when used viscoelasticity compensation. The proposed sensor is small and versatile for different applications, and presents simple fabrication, data acquisition and processing. [ABSTRACT FROM AUTHOR]

In this article, we thoroughly discuss many aspects of diaphragm-embedded optical fiber sensors covering industrial, robotics and medical applications: from the modeling to field applications, which also include sensor fabrication (such as interferometers, grating-based sensors, intensity variation sensors) in standard and specialty optical fibers, diaphragm and optical fiber materials thermal and mechanical characterizations. The operation limits of the sensors, interrogation techniques and the measurement possibilities that such sensors provide are also discussed. We expect that this review and tutorial provide valuable information regarding the optical fiber sensor approach, material selection and sensor assembly for the development of diaphragm-embedded optical fiber sensors. [ABSTRACT FROM AUTHOR]

Motivated by its high toxicity and presence on many industrial processes, in this work, a hydrogen sulphide (H2S) gas detector was developed. The construction of the device was accomplished by taking advantage of both silica optical fiber and the potentialities of gold nanoparticles, where the physics for the plasmon resonance on localized surface are exploited. The localized surface plasmon resonance occurs in gold nanoparticles and has strong influence when the free electrons of gold suffer external perturbation. In this case, strong bonding energy between the gold element and sulfur was the main basis for the operation principle of the developed colorimetric detector. In the process of nanoparticles adhesion, polyvinyl alcohol was used on the interface between the fiber and the nanoparticles. The developed detector has the ability of detecting H2S levels in the range of 0.4 to 2.0 ppm, at room temperature. Different experiments were carried out to verify the behavior of the nanoparticle concentration at the detection limit of the gas. Thus, the proposed detector has many applications in different industrial processes and environments considering the numerous accidents caused by H2S inhalation with fatal victims already registered around the world. [ABSTRACT FROM AUTHOR]

Computing performance and hardware integrity are tightly linked to adequate thermal management in datacenters. In addition, a large share of its electricity bills comes from cooling systems, so there is a pressing need for enhanced thermal management systems. This paper proposes a fiber Bragg grating (FBG) quasi-distributed sensing device as an alternative to electronic sensors. The main focus is to demonstrate that a FBG-based solution allows thermal measurement at critical non-monitored regions (blind spots) within a server in an acquisition rate of 1 Hz, with thermal sensitivity of 8.757 pm/°C, a thermal resolution smaller than 1 °C and spatial resolution and multiplexing needed to monitoring diverse blind spots where there is virtually no room for adapting conventional sensors. In addition, we also monitor spots where there are already internal sensors next to them (referential spots), such as central processing unit (CPU) and graphics processing unit (GPU). As a result, a simple FBG sensor calibration technique is proposed using those referential spots. The technique proposed can be scaled out to monitor a large number of elements across large areas in a datacenter environment, since quasi-distributed FBG sensing signal can be transmitted over longer optical fibers than those employed in optical distributed temperature systems (DTS). [ABSTRACT FROM AUTHOR]

This study evaluated the effect of photobiomodulation therapy (PBMt) before or after a high-intensity resistance exercise (RE) session on muscle oxidative stress. Female Wistar rats were assigned to one of the following groups: Sham (non-exercised, undergoing placebo-PBMt); NLRE (exercised, undergoing placebo-PBMt); PBMt + RE (pre-exercise PBMt); RE + PBMt (post-exercise PBMt). The RE comprised four climbs bearing the maximum load with a 2 min rest between each climb. An 830-nm aluminum gallium arsenide diode laser (100 mW; 0.028 cm2; 3.57 mW/cm2; 142.8 J/cm2; 4 J; Photon Laser III, DMC, São Paulo, Brazil) was applied 60 s before or after RE in gastrocnemius muscles. Analyses were performed at 24 h after RE: lipoperoxidation using malondialdehyde (MDA) and protein oxidation (OP) on Western blot. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity were spectrophotometrically assessed. Nitric oxide (NO) level was determined by the Griess reaction. The MDA and OP levels were significantly higher in the NLRE group. Increased OP was prevented in all PBMt groups; however, increased MDA was prevented only in the RE + PBMT group. The RE + PBMt group had higher SOD activity compared to all other groups. A higher GPx activity was observed only in the PBMT + RE compared to Sham group, and CAT activity was reduced by RE, without PBMt effect. NO levels were unchanged with RE or PBMt. Therefore, PBMt application after a RE section has a more potent antioxidant effect than previous PBMt. Rats submitted to post-RE PBMt illustrated prevention of increased lipoperoxidation and protein oxidation as well as increased SOD activity. The photobiomodulation can attenuate oxidative stress induced by resistance exercise. A more evident benefit shows to be obtained with the application after exercise, in which it has increased the activity of superoxide dismustase. [ABSTRACT FROM AUTHOR]

This paper presents the development of a thermal measurement system for density, specific heat capacity and thermal conductivity in fluids. Due to toxic and flammable environment often found in oil industry, Fiber Bragg Gratings (FBGs) were used in the sensor development, which consists in a diaphragm-embedded FBG, to estimate density, and a FBG temperature sensor, to estimate specific heat and thermal conductivity. The diaphragm system, with sensitivity of 0.025 nm/kPa, was employed for density measurements in water, diesel and crude oil, becoming a feasible option for density estimation in fluids. The temperature sensor, with sensitivity of 11.5 pm/°C, was used to propose a method to estimate specific heat and thermal conductivity. The method uses the quantity of heat equation to estimate specific heat, then, density and specific heat to estimate thermal conductivity. To validate the method, it was presented three setups based in an acrylic tank, a Becker and a test tube. The tests were performed with water, mineral oil and kryo 51 oil. In addition the proposed system can be integrated in order to realize simultaneous measurements of density, specific heat and thermal conductivity with the same structure. [ABSTRACT FROM AUTHOR]

The knee flexion-extension angle is an important variable to be monitored in various clinical scenarios, for example, during physical rehabilitation assessment. The purpose of this work is to develop and validate a sensor fusion system based on a knee sleeve for monitoring of physical therapy. The system consists of merging data from two inertial measurement units (IMUs) and an intensity-variation based Polymer Optical Fiber (POF) curvature sensor using a quaternion-based Multiplicative Extended Kalman Filter (MEKF). The proposed data fusion method is magnetometer-free and deals with sensors’ uncertainties through reliability intervals defined during gait. Walking trials were performed by twelve healthy participants using our knee sleeve system and results were validated against a gold standard motion capture system. Additionally, a comparison with other three knee angle estimation methods, which are exclusively based on IMUs, was carried out. The proposed system presented better performance (mean RMSE $< $ 3.3 $^\circ$ , LFM coefficients, $a_1$ = 0.99 $\pm$ 0.04, $a_0$ = 0.70 $\pm$ 2.29, $R^2$ = 0.98 $\pm$ 0.01 and $\rho _C$ $>$ 0.99) when compared to the other evaluated methods. Experimental results demonstrate the usability and feasibility of our system to estimate knee motion with high accuracy, repeatability, and reproducibility. This wearable system may be suitable for motion assessment in rehabilitation labs in future studies. [ABSTRACT FROM AUTHOR]

Background: Photobiomodulation therapy with static magnetic field (PBMT/sMF) stands out for being a non-pharmacological resource with bioenergetic effects capable of accelerating muscle recovery, delaying muscle fatigue and potentiate gains in different training protocols. In recent years, blood flow restriction (BFR) associated with low load exercise (20-30% 1RM/MVC) has demonstrated positive effects on muscle performance. However, the effects of PBMT/sMF combined with BFR training are still unknown. Objective: Verify the effects of PBMT/sMF associated with BFR training and compared with high load training (HLT) in the muscle strength, muscle damage, inflammation, and the oxidative stress. Methods: This are a protocol of a randomized, double-blind, placebo-controlled clinical trial. The participants will be healthy men between the ages of 18 to 40 years, with no practice in upper limb strength training in the previous three months. The voluntaries will be randomly divided into four groups: (1) PBMT/sMF + BFR; (2) PBMT/sMF + HLT; (3) placebo + BFR; (4) placebo + HLT. The PBMT/sMF will be applied immediately before strengthening protocol (4 sets x 20 repetitions of elbow flexion). The BFR groups will undergo to exercise with low load (30% of MVC), while the HLT groups will performed the same protocol with 80 % of MVC. The primary outcome will be muscle strength, measured in baseline, fourth, eighth week of training and detraining period. The secondary outcomes include measured the fatigue resistance, arm circumference, muscle damage, inflammatory and oxidative stress levels in one session, during, after intervention and detraining. Discuss: This trial will elucidate the effects of PBMT/sMF when when used in association with BFR training or HLT. [ABSTRACT FROM AUTHOR]

This study presents the development and validation of a fibre Bragg gratings (FBGs)‐based sensor system for the assessment of strain in the midpalatal suture in subjects using rapid palatal expanders (RPEs). The ex‐vivo experiments were made by means of positioning two RPEs in a porcine palatal region. The RPEs used were the Hyrax, a tooth‐borne expander and MARPE (microimplant‐assisted rapid palatal expansion), a bone‐borne expander. In order to define the regions in the palatal region for the sensors positioning, a finite‐element analysis was performed in a porcine head subjected to the loadings caused by an RPE. In addition, a strain transfer model was used to obtain a correction coefficient that approximates the strain estimated by the FBG to the actual strain in the structure under shear and normal stress. Results show high linearity in the sensors characterisation tests with the advantages of compactness, intrinsic safe operation and multiplexing capabilities of FBGs. In the RPE analysis, a higher strain was estimated in the anterior region, which is in accordance with the simulation and previously reported results, where MARPE showed a higher strain (with an exponential pattern) than Hyrax as the number of activations increase. [ABSTRACT FROM AUTHOR]

This paper reports the first microstructured solid-core fiber drawn from a 3D-printed preform and the first fiber Bragg gratings inscribed in a fiber of this type. The presented fiber is made of polycarbonate and displays single-mode behavior. The fiber attenuation was the lowest reported so far for a POF drawn from a 3D-printed preform across a broad range of wavelengths. In addition, extensive fiber characterization results are presented and discussed including: fiber attenuation, mode simulations, dynamic thermomechanical analysis and thermo-optic coefficient. Fiber Bragg gratings are successfully inscribed in the produced fiber using three different lasers: a continuous wave helium-cadmium laser, a pulsed femtosecond frequency doubled ytterbium laser and ultra-violet nanosecond krypton fluoride laser. Mechanical testing of the fiber showed that the 3D printing approach did not introduce any unexpected or undesirable characteristics. [ABSTRACT FROM AUTHOR]

Background: The optimal time-response window for photobiomodulation therapy (PBMT) using low-level laser therapy (LLLT) and/or light emitting diodes therapy (LEDT) combined with static magnetic fields (sMF) before physical activity still was not fully investigated. The aim of the present study was to investigate the better of four time-response windows for PBMT combined with sMF (PBMT-sMF) use before exercise in humans. Methods: A prospectively registered, randomized, triple-blinded (volunteers, therapists and assessors) placebo-controlled trial was carried out. Sixty healthy untrained male subjects were randomly allocated to six experimental groups (n = 10 per group): PBMT-sMF 5 mins, PBMT-sMF 3 h, PBMT-sMF 6 h, PBMT-sMF 1-day, placebo, and control. The control group performed all procedures, however did not receive any kind of intervention. PBMT-sMF active or PBMT-sMF placebo was applied precisely in different time points after baseline MVC test to ensure that both MVC tests and eccentric exercise protocol would occur at the same hour of the day in all groups. Then, after five minutes, 3 h, 6 h or 1-day (24 h) of PBMT-sMF treatment (active or placebo) the eccentric exercise protocol was performed. The primary outcome was peak torque obtained from maximum voluntary contraction (MVC). The secondary outcomes were creatine kinase (CK), and delayed onset muscle soreness (DOMS). The primary and secondary outcomes were measured at baseline, immediately after, 1 h, 24 h and 48 h after the eccentric exercise protocol. Results: Sixty patients were randomized and analyzed to each sequence. The outcomes in absolute values show that all active PBMT-sMF groups increased (p < 0.05) MVC from immediately after to 1 h after eccentric exercise, and decreased (p < 0.05) CK activity at all time points. However, PBMT-sMF 5 mins, 3 h and 6 h groups showed better results in MVC and CK analysis from 24 h to 48 h, and also to DOMS (p < 0.05) at all time points. Participants did not report any adverse events. Conclusions: PBMT-sMF can be used from 5 min to 6 h before exercise, and the effects can last up to 54 h after treatment. However, the effects start to decrease when a 1-day (24 h) time-response window is used. Trial registration: NCT03420391. Registered 05 February 2018. [ABSTRACT FROM AUTHOR]

Objective: To compare the effects of photobiomodulation therapy (PBMT) and pharmacological therapy (glucocorticoids and non-steroidal anti-inflammatory drugs) applied alone and in different combinations in mdx mice. Methods: The animals were randomized and divided into seven experimental groups treated with placebo, PBMT, prednisone, non-steroidal anti-inflammatory drug (NSAIDs), PBMT plus prednisone and PBMT plus NSAID. Wild type animals were used as control. All treatments were performed during 14 consecutive weeks. Muscular morphology, protein expression of dystrophin and functional performance were assessed at the end of the last treatment. Results: Both treatments with prednisone and PBMT applied alone or combined, were effective in preserving muscular morphology. In addition, the treatments with PBMT (p = 0.0005), PBMT plus prednisone (p = 0.0048) and PBMT plus NSAID (p = 0.0021) increased dystrophin gene expression compared to placebo-control group. However, in the functional performance the PBMT presented better results compared to glucocorticoids (p<0.0001). In contrast, the use of NSAIDs did not appear to add benefits to skeletal muscle tissue in mdx mice. Conclusion: We believe that the promising and optimistic results about the PBMT in skeletal muscle of mdx mice may in the future contribute to this therapy to be considered a safe alternative for patients with Duchenne Muscular Dystrophy (DMD) in a washout period (between treatment periods with glucocorticoids), allowing them to remain receiving effective and safe treatment in this period, avoiding at this way periods without administration of any treatment. [ABSTRACT FROM AUTHOR]

Identify the optimal energy delivered with a single application of the combination of photobiomodulation therapy (PBMT) combining different light sources (low-level laser therapy-LLLT and light emitting diode therapy-LEDT) and static magnetic field (sMF) in order to determine the acute effects on functional mobility of stroke survivors. Was conducted a randomized, placebo-controlled, crossover, triple-blind, clinical trial (RCT). Twelve patients were recruited, however ten concluded the study, they were randomly treated with four PBMT/sMF energies (sham-0 J, 10 J, 30 J, and 50 J per site irradiated), with 1-week interval washout between treatments. PBMT/sMF were administered after the pre-intervention (baseline) evaluation and the total energy delivered per site at each treatment was determined based on the results of the randomization procedure. PBMT/sMF were administered in direct contact with the skin and applied with slight pressure to nine sites on the knee extensors, six sites on the knee flexors, and two sites on the plantar flexors' muscles in both lower limbs (bilaterally). The primary outcome measure was the 6-min walk test (6MWT) and the secondary outcome was the Timed Up and Go (TUG) test. Significant improvements were found in the 6MWT test using a total energy of 30 J per site compared with sham (0 J) (p < 0.05) and compared with the baseline evaluation (p < 0.01). And in the TUG test significant improvements were also found using a total energy per site of 30 J per site compared to sham (0 J) and baseline (p < 0.05). PBMT with different light sources (laser and LEDs) and wavelengths in combination with sMF with a total energy per site of 30 J has positive acute effects on functional mobility in stroke survivors. [ABSTRACT FROM AUTHOR]

This letter presents the development and characterization of a Fabry-Perot interferometer (FPI) for the detection of dissolved ammonia. The FPI cavity is obtained by the alignment of two single mode fibers (SMFs), where a mixture of ultraviolet (UV) curable resin and Oxazine 170 perchlorate is positioned in the gap between both SMFs. The sensor operation principle is based on the chemical reaction between the dissolved ammonia and the Oxazine 170 perchlorate. Such reaction leads to the refractive index variation in the FPI cavity, which results in a wavelength shift of the reflected spectrum. The water absorption and temperature effects in the sensor response are characterized. Such characterizations demonstrate that a good sensor performance is achieved when it is submerged in aqueous solutions for about one hour (to enable the water absorption) and at controlled temperature conditions. Then, the FPI sensor is submerged in ammonia solutions with concentrations ranging from 0 to 700 ppb (in 100 ppb steps). Results show a reversibility of the proposed sensor and a high sensitivity of 4.3 pm/ppb (4.3 nm/ppm). Thus, the proposed sensor can be used on the detection of low concentrations of ammonia (in a sub-ppm range) with one of the highest reported sensitivities of ammonia sensors, which makes it suitable for water quality monitoring.This letter presents the development and characterization of a Fabry-Perot interferometer (FPI) for the detection of dissolved ammonia. The FPI cavity is obtained by the alignment of two single mode fibers (SMFs), where a mixture of ultraviolet (UV) curable resin and Oxazine 170 perchlorate is positioned in the gap between both SMFs. The sensor operation principle is based on the chemical reaction between the dissolved ammonia and the Oxazine 170 perchlorate. Such reaction leads to the refractive index variation in the FPI cavity, which results in a wavelength shift of the reflected spectrum. The water absorption and temperature effects in the sensor response are characterized. Such characterizations demonstrate that a good sensor performance is achieved when it is submerged in aqueous solutions for about one hour (to enable the water absorption) and at controlled temperature conditions. Then, the FPI sensor is submerged in ammonia solutions with concentrations ranging from 0 to 700 ppb (in 100 ppb steps). Results show a reversibility of the proposed sensor and a high sensitivity of 4.3 pm/ppb (4.3 nm/ppm). Thus, the proposed sensor can be used on the detection of low concentrations of ammonia (in a sub-ppm range) with one of the highest reported sensitivities of ammonia sensors, which makes it suitable for water quality monitoring. [ABSTRACT FROM AUTHOR]

This letter presents the development and thermal and mechanical considerations of sensing elements using different diaphragm materials which are embedded in optical fiber Bragg gratings (FBGs). Diaphragms made of polyurethane, polydimethylsiloxane (PDMS) and nitrile rubber were fabricated, and all of them with embedded FBGs. Tensile tests were performed in each material, showing the lower Young’s modulus of the PDMS (0.8 MPa), which is orders of magnitude lower than the ones of polyurethane (2.0 MPa) and nitrile rubber (362.2 MPa). Moreover, the highest strain limit was obtained in the PDMS diaphragm (24.5%). These results indicated the potential for higher pressure sensitivity of the PDMS, which was confirmed in the pressure characterization tests (pressure sensitivity of 1.4 nm/kPa). In addition, temperature tests indicated a higher sensitivity of the nitrile rubber, which presented a sensitivity of 49.8 pm/°C. Considering applications in which there are simultaneous variation of pressure and temperature, the nitrile presented a cross-sensitivity of 0.01 nm kPa−1°C−1 which is the lowest among the materials tested, indicating the possibility of obtaining the mitigation of temperature influence in the pressure response. It is also worth noting that the highest measurement range was obtained in the nitrile rubber diaphragm with linear responses in the range of pressures up to 3 kPa. [ABSTRACT FROM AUTHOR]

We present the development and application of an angular movement sensor based on Fabry-Perot interferometer (FPI) in series with a fiber Bragg grating (FBG) inscribed in cyclic transparent optical polymer (CYTOP) using a femtosecond laser. The FPI was fabricated with UV-curable resin between the CYTOP and a silica pigtail, which provides flexibility and the possibility in situ fabrication. In this case, the FPI is an edge-filter for the FBG response, which presents both wavelength shift and optical power attenuation as the bending angle increases. A dynamic compensator for the material’s viscoelastic response resulted in a six-fold reduction in the sensor’s transient response error. The FPI-POFBG angular movement sensor was validated in knee angle monitoring during gait cycles, where the sensor presented errors as low as 2.5°. This is a low-cost sensor with high flexibility on fabrication and with the capacity of following subtle angle variations, as the ones commonly occurred in gait cycles. [ABSTRACT FROM AUTHOR]