Amplitude Parameters Research Articles

Asymmetric Cyclic Controlled Quantum Teleportation via Multiple-Qubit Entangled State in a Noisy Environment

In this paper, by using eleven entangled quantum states as a quantum channel, we propose a cyclic and asymmetric novel protocol for four participants in which both Alice and Bob can transmit two-qubit states, and Charlie can transmit three-qubit states with the assistance of the supervisor David, who provides a guarantee for communication security. This protocol is based on GHZ state measurement (GHZ), single-qubit measurement (SM), and unitary operations (UO) to implement the communication task. The analysis demonstrates that the success probability of the proposed protocol can reach 100%. Furthermore, considering that in actual production environments, it is difficult to avoid the occurrence of noise in quantum channels, this paper also analyzes the changes in fidelity in four types of noisy scenarios: bit-flip noise, phase-flip noise, bit-phase-flip noise, and depolarizing noise. Showing that communication quality only depends on the amplitude parameters of the initial state and decoherence rate. Additionally, we give a comparison with previous similar schemes in terms of achieved method and intrinsic efficiency, which illustrates the superiority of our protocol. Finally, in response to the vulnerability of quantum channels to external attacks, a security analysis was conducted, and corresponding defensive measures were proposed.

Experimental investigation of the influence of surface topographic parameters on fluid leakage through static metallic seals

Purpose The purpose of this paper is to monitor leakage in the static sealing interface, using three-dimensional and two-dimensional surface topography parameters as indicators. Design/methodology/approach This study involved developing a test rig for examining fluid leakage in metallic seals. Leakage of water through the interface of the metallic valve and valve seats was measured. The analysis focused on the combined effect of roughness, waviness and form error of metallic seal surfaces on leakage, with a detailed emphasis on the significance of form errors through harmonic analysis. Findings The findings suggest that three-dimensional or areal surface texture parameters have more predictive control over leakage compared to two-dimensional or profile parameters, as they provide information about micro-leak channels in all directions. Moreover, it was observed that average amplitude parameters of surface topography, particularly the form error of metallic valves, are strongly correlated with leakage values compared with the roughness and waviness of the contact surface. In addition, the leakage in metallic seals is profoundly influenced by lower-order harmonics, with a corresponding increase as the average undulation number of the flatness profile rises. Originality/value This research contributes to the understanding of the relationship between surface topography and sealing performance, particularly in metallic seals. By emphasizing the importance of form errors and using advanced surface texture analysis techniques, the study offers insights that can aid in optimizing the design and performance of static seals in industrial applications. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0186/

CFD-based simulation of the hydrodynamics of steady-state gas–liquid in ultrasonically oscillating microreactors

Ultrasound-driven microbubble oscillation in a microchannel is commonly used in mixing and mass transfer, and its steady-state mechanisms are complex. This study proposes an acoustic streaming steady-state model for the oscillation between two microbubbles driven by ultrasound in a square microchannel (150 × 150 μm2). The breathing mode and shape oscillation mode of the bubble cap were experimentally analyzed at an ultrasound frequency of 97.5 kHz, and the flow patterns of liquid slugs were found to be completely opposite. A two-dimensional numerical model of the two microbubble oscillations was developed from a new perspective of steady state. The correctness of the model was verified by comparing the 2 μm diameter polystyrene tracer flow field with the simulation results. The steady-state flow field was analyzed in terms of ultrasound amplitude, shape, size, and liquid property parameters. The streaming velocity was found to be directly proportional to the square of the microbubble amplitude. When the bubble cap became more hydrophilic and sharper, the mixing effect improved. In particular, it was found that the microbubbles had the most intense disturbance to the fluid when the distance between the two microbubbles was twice the channel width.

Clinical Application of Micro-Movement of Head by Vibraimage for Psychological Traits Study

The authors have conducted various research studies in medical care, anti-aging, psychosomatic medicine, health, and sports. The VibraImage project has recently begun. Using a 70-second video of the subject’s eye, face, and head, the micro-movement and vibration parameters of frequency and amplitude are determined. The vestibulo-ocular reflex (VOR) is involved in the mechanism. These data can suggest mental attractiveness or charm. The obtained results include 10 items: aggression, stress, tension, suspicion, stability, leadership, vitality, self-control, inhibition, and nervousness. The most attractive person is referred to as a “charismatic” person, and the project is therefore named the “charisma judge evaluation.

Study on the effect mechanism of vibration excitation parameters on bolt loosening based on an implicit monitoring method

This study focuses on investigating the mechanism of bolt loosening under harmonic vibration. An implicit monitoring method of bolt loosening based on strain detection is proposed. By conducting simulations on a PCB (Printed Circuit Board) structure with fastening bolts base on the implicit method, a three-stage peculiarity for bolt loosening is established under harmonic vibration. Under different tightening torques, distinct effecting trends of the two excitation parameters of excitation amplitudes and frequencies on the strain response are indicated comprehensively. The comprehensive effect mechanism of the excitation amplitudes and frequencies on bolt loosening is investigated, and the results reveal that when the tightening torque is small, the excitation amplitude has a main impact on the strain RMS, while when the tightening torque is larger, the excitation frequency plays a major role. A bolt loosening peculiarity based on strain monitoring is provided for different excitation frequencies, amplitudes accompanied with different tightening torques under harmonic vibration. In practical application, the RMS value of the strain response of the monitored point is calculated and then compared with the three-stage loosening peculiarity to determine whether the bolt is loosen or not. The simulation analysis and test verification on a four-bolt connection structure are conducted based on the implicit method under harmonic vibration, and the good consistency is shown. Valuable insights for the detection and prevention of bolt loosening are provided, which have important engineering reference significance.

Particulate Flow of a Viscous Fluid Driven by a Torsionally Oscillating Disk

Abstract A novel hydrodynamic model is used to study oscillatory flow of a particle-laden fluid driven by a torsionally oscillating disk. The present model is featured by a modified form of Navier–Stokes equations which is conceptually different than existing related models and enjoys relatively concise mathematical formulation. Explicit expressions are derived for the radial, azimuthal and axial velocities using the method of power series expansions of small amplitude parameter, and the derived solutions reduce to Rosenblat's earlier results for a clear fluid driven by a torsionally oscillating disk in the absence of suspended particles. The implications of the present results to dusty gases are discussed in detail with particular interest in the effects of suspended particles on the decay indexes and wavelengths of the induced oscillatory velocity fields. The results obtained in this work can be used to quantify the effects of suspended particles on particulate flow driven by a torsionally oscillating disk.

Detection of Diffusion Interlayers in Dissimilar Welded Joints in Processing Pipelines by Acoustic Emission Method

The paper considers the neural network application to detect microstructure defects in dissimilar welded joints using the acoustic emission (AE) method. The peculiarity of the proposed approach is that defect detection is carried out taking into account a priori information about the properties of the AE source and the acoustic waveguide parameters of the testing structure. Industrial process pipelines with dissimilar welded joints were studied as the testing object, and diffusion interlayers formed in fusion zones of welded joints were considered microstructure defects. The simulation of AE signals was carried out using a hybrid method: the signal waveform was determined based on a finite element model, while the amplitudes of AE hits were determined based on a physical experiment on mechanical testing of dissimilar welded joints. Measurement data from industrial process pipelines were used as noise realizations. As a result, a data sample was formed that considered the parameters of the AE source and the parameters of the acoustic waveguide with realistic noise parameters and a signal-to-noise ratio. The proposed method allows for a more accurate determination of the waveform, spectrum, and amplitude parameters of the AE signal. Greater certainty in the useful signal parameters allows for achieving a more accurate and reliable classification result. When using a backpropagation neural network, a percentage of correct classification of more than 90% was obtained for a data set in which the signal-to-noise ratio was less than (−5 dB) in 90% of cases.

Prior-guided restoration of intense local specular highlight in fringe projection profilometry images

This paper presents a novel prior-guided restoration method, to our knowledge, aimed at removing and recovering intense local specular highlight in fringe projection profilometry (FPP) images of specular objects. Local reflections, caused by the direct reflection of the projector on smooth surfaces, often saturate pixel intensities, posing a significant obstacle to 3D shape reconstruction. The proposed method combines sinusoidal fringe projection principles with improved fitting techniques. By analyzing fringe patterns in non-highlight regions, the constant and amplitude parameters of the fringes are determined by non-highlight regions. For the critical initial phase parameter, the continuity of highlight regions and the fixed relative geometry between the projector and object are leveraged, which enables an iterative calculation strategy that progressively estimates fringe intensity within specular regions. The results show a seamless integration of the restored fringe data with the original non-highlight information, ensuring global consistency and continuity. 3D measurement experiments demonstrate effective restoration of morphological distortions and filling of point cloud holes.

Multi-objective optimization of the design parameters in longitudinal corrugated tubes to improve crashworthiness performance

Longitudinal corrugated tubes (LCTs) are among the structures of interest to designers, because of their ability to improve the weaknesses of conventional simple tubes by reducing the maximum crushing force (Fmax) and providing a controllable and predictable force-displacement curve during energy absorption. In this study using finite element (FE) simulations, the effect of design parameters of LCTs, i.e., amplitude and number of folds on the crashworthiness criteria, in different deformation modes has been investigated. Crushing parameters of some simple and corrugated tubes have been examined experimentally to validate the FE simulations. Results of 400 FE models, revealed some geometries in LCTs that, in addition to reducing Fmax, can increase the specific energy absorption (SEA) compared to the simple tubes. Most of these geometries deform under compressive axial loading in the N-mode region. Using multi-objective optimization, specification of the optimal LCT, including number of folds and their amplitudes were determined. Then the optimal LCT was made by the ring-forming method and compared with the simple tube experimentally. The optimized LCT was experimentally evaluated and results showed that it can reduce Fmax by 27.2% and increase SEA by 21.6% compared to the simple tube. The lower SEA of the LCTs is usually considered as a disadvantage for the LCTs compared to the simple tubes, which is violated in this research. Optimized LCT may be a new idea for aerospace applications as crash-resistant structures.

Non-invasive assessment of left ventricular hemodynamic forces in hypertrophic cardiomyopathy

Abstract Background Hemodynamic force (HDF) analysis allows non-invasive measurement of intraventricular pressure gradients, portraying cyclic spatial-temporal interaction between blood and tissues. Impaired HDFs have been implicated in early detecting of adverse cardiac remodelling and treatment response in various cardiovascular disorders, providing insights into cardiac physiology not offered by traditional cardiovascular imaging (1). Mainly explored in heart failure, HDF analysis has not been previously applied to hypertrophic cardiomyopathy (HCM). Purpose To investigate differences in systo-diastolic function in HCM patients compared to healthy controls using HDF analysis. Methods Forty patients with HCM diagnosis (20 obstructive and 20 non-obstructive) were retrospectively evaluated in comparison with 22 healthy controls. Left ventricular (LV) HDFs were derived from routine transthoracic apical 4-, 2- and 3-chamber views using a dedicated software. Apical-basal HDF curves were generated, where positive deflections represent forces directed from the LV apex to the base, whilst negative ones are directed toward the apex. Amplitude and timing parameters were derived, the latter indexed to total cardiac cycle duration. Results Table 1 shows the demographic, clinical and echocardiographic characteristics of HCM compared to controls. Patients with HCM were older, had a slower heart rate due to treatment with beta-blockers, and showed hypercontractility, as expressed by higher LV ejection fraction. Compared to controls, HCM patients showed reduced LV longitudinal force, i.e. the force during the whole cardiac cycle (4.17% [2.36-5.52] vs. 6.01% [4.73-7.78], p=0.002), shorter time interval to systolic peak (0.15 [0.12-0.16] vs. 0.19 [0.17-0.20], p <0.001), and shorter duration of LV impulse (0.29 [0.27-0.32] vs. 0.34 [0.32-0.37], p <0.001) (Figure 1). However, no differences in terms of systolic force peak (p=0.283) or LV impulse intensity (p=0.689) were detected. During the transition between systole and diastole, LV suction (i.e. the interval including late systolic deceleration and early diastolic suction) was significantly longer (0.26 [0.22-0.29] vs. 0.23 [0.21-0.25], p=0.023) but less pronounced (6.30% [4.56-8.44] vs. 8.72% [6.71-12.59], p=0.005), likely reflecting a relaxation impairment from the very beginning of diastole. Such impairment was maintained during early diastolic filling, where the amplitude of the positive deceleration flow force was severely reduced in HCM compared to controls (2.98% [1.98-4.58] vs. 7.11% [4.55-8.72], p <0.001). Conclusions HDF analysis in HCM patients revealed unique systolic and diastolic changes reflecting faster LV contraction during systole and slower and weaker LV forces during diastole. This analysis deepens our understanding of HCM mechanic abnormalities and may help assess response to innovative treatment options.

Intrinsic steady-state pattern of mouse cardiac electrophysiology: analysis using a characterized quantitative electrocardiogram strategy

To explore the intrinsic steady-state electrophysiological properties of mouse heart under physiological conditions by high-resolution quantitative analysis. Twenty-two young adult C57BL/6 mice with a 1:1 male-to-female ratio were used. The limbs of the mice were fixed without anesthesia, and electrocardiographic waveforms, including characteristic P-waves, R-waves, and ST-waves, were recorded using a sensitive 12-lead electrophysiological recorder (ECGsqa) under spontaneous breathing. LabScribe software was used to extract and quantify high-resolution time course and amplitude parameters within a single cardiac cycle from the V3 precordial lead. Pearson correlation test combined with simple linear regression was used to generate a scatter plot of ECG parameter fitting. The common and unique correlation parameters were separately identified by joint associations for profiling the quantitative association network. ECGsqa analysis identified and quantified 14 characteristic ECG parameters, 28.6% of which showed statistical differences between the groups. Compared to male mice, female mice exhibited higher amplitudes and velocities of R and ST waves. Among the 51 association pairs identified in primary association analysis, 47.1% were positively correlated, including shared (29.2%), male-specific (29.2%), and female-specific (41.7%) association groups. Second-order clustering of the association pairs revealed that the amplituderate association pairs of each waveform voltage in both male and female mouse hearts were strongly correlated. The male mice showed an atrioventricular interconnection pattern, while the female mice showed a unique atrial conduction system quality dependence. The distribution network characteristics of the association groups showed that sex-specific and common correlation sets formed a certain series pattern. We discovered a novel intrinsic correlation network of cardiac electrophysiological traits in male and female mice, which reveals the key internal quantitative characteristics and gender difference of both atrial and ventricular conduction systems.

Joint Prediction of Sea Clutter Amplitude Distribution Based on a One-Dimensional Convolutional Neural Network with Multi-Task Learning

Accurate modeling of sea clutter amplitude distribution plays a crucial role in enhancing the performance of marine radar. Due to variations in radar system parameters and oceanic environmental factors, sea clutter amplitude distribution exhibits multiple distribution types. Focusing solely on a single type of amplitude prediction lacks the necessary flexibility in practical applications. Therefore, based on the measured X-band radar sea clutter data from Yantai, China in 2022, this paper proposes a multi-task one-dimensional convolutional neural network (MT1DCNN) and designs a dedicated input feature set for the joint prediction of the type and parameters of sea clutter amplitude distribution. The results indicate that the MT1DCNN model achieves an F1 score of 97.4% for classifying sea clutter amplitude distribution types under HH polarization and a root-mean-square error (RMSE) of 0.746 for amplitude distribution parameter prediction. Under VV polarization, the F1 score is 96.74% and the RMSE is 1.071. By learning the associations between sea clutter amplitude distribution types and parameters, the model’s predictions become more accurate and reliable, providing significant technical support for maritime target detection.

Identification of prospective oil-bearing areas in the peripheral parts of productive horizons U-12 and U-13 of the Zhetybai field

Background: To date, a comprehensive range of scientific, geological exploration, and appraisal work has been conducted at the Zhetybai field. The overall structural map of the field has been relatively well established. However, several critical issues remain insufficiently studied or entirely unexplored. Based on the results of seismic exploration (3D common depth point method) and additional appraisal work, peripheral (edge) zones of the field structure have been identified, including its cross-faults, as well as transverse flexures and longitudinal faults on the southern wing of the structure, which require further investigation. Aim: To further study the field structure, identify new potential hydrocarbon areas in the peripheral parts of the field, and assess the oil potential of the U-12 and U-13 horizons in the Zhetybai field. Materials and methods: This study involved a qualitative assessment of the informativeness of seismic attributes, analysis of reflection geometry (configuration), dynamic amplitude parameters, continuity of frequency, and other indicators. The analysis of reflection characteristics, in conjunction with all available data, primarily geophysical survey data, allowed for hypothesizing sedimentary conditions and obtaining acceptable lithological assessments. Results: The evaluation wells J-1, J-2, and J-3, drilled in 2023-2024 in the peripheral parts beyond the approved boundary of hydrocarbon-bearing horizons U-12 and U-13, yielded positive results. The productivity of the new reservoir was also confirmed by newly drilled production wells 5333, 5652, and 5367. Conclusion: To further study the structure of the Zhetybai field and identify new potential hydrocarbon-bearing areas in the peripheral parts, as well as structural uplifts and sandstone bodies of horizons U-12 and U-13, evaluation wells J-1, J-2, and J-3 were drilled. The detailed identification of sandstone bodies allows for the prediction of prospective areas not covered by drilling. The positive results from drilling evaluation wells have refined the geological structure of horizons U-12 and U-13 and confirmed the productivity of the peripheral parts of the reservoirs.

Assessment of Sacculocollic and Vestibulomasseteric Reflex Pathways in Individuals With Migraine and Vestibular Migraine.

The study's objective was to evaluate the functioning of sacculocollic and vestibulomasseteric reflex pathways in individuals with vestibular migraine and migraine. Seventy-five participants aged 18-50 years were selected for the study. Participants were divided into three groups. Group 1 consisted of 25 healthy individuals, Group 2 consisted of 25 migraine individuals, and Group 3 consisted of 25 individuals with vestibular migraine. Cervical vestibular-evoked myogenic potential (cVEMP) and masseter vestibular-evoked myogenic potential (mVEMP) were recorded using a 500-Hz tone burst stimulus presented at 125 dB peSPL for all participants. The cVEMP test results showed a delayed p13 and n23 latency for both migraine and vestibular migraine individuals when compared to healthy individuals. Also, the amplitude of the p13-n23 peak was reduced compared to healthy individuals in both migraine and vestibular migraine. Similarly, the mVEMP test results showed a delayed p11 and n21 latency for both migraine and vestibular migraine individuals. No difference was observed in the amplitude of the p11-n21 peak complex between the three groups. Spearman's rho correlation revealed no significant (p > .05) correlation between cervical and masseter VEMP latency and amplitude parameters between healthy, migraine, and vestibular migraine individuals. The results of the study are suggestive of the pathology of the sacullocollic and vestibulomasseteric reflex pathways in individuals with migraine and vestibular migraine. Individuals with migraine and vestibular migraine should undergo a detailed vestibular evaluation.

A Study of Stochastic Low-frequency Variability for Galactic O-type Stars

In order to explore how the ubiquitous stochastic low-frequency (SLF) variability of O-type stars is related to various stellar characteristics, we compiled a sample of 150 O-type stars observed via ground-based spectroscopic surveys, alongside photometric data obtained from the Transiting Exoplanet Survey Satellite (TESS). We analyzed 298 light curves obtained from TESS Sectors 1–65 for the stars in our sample. Leveraging the spectroscopic parameters, we used Bonnsai to determine masses, radii, fractional main-sequence ages, and mass-loss rates for stars of our sample. Subsequently, we identified possible correlations between the fitted parameters of SLF variability and stellar properties. Our analysis unveiled four significant correlations between the amplitude and stellar parameters, including mass, radius, fractional main-sequence ages, and mass-loss rate. For stars with ≳30 M ⊙, we observed a decrease in characteristic frequency and steepness with increasing radius. Finally, we compared various physical processes that may account for the SLF variability with our results. The observed SLF variability may arise from the combined effects of the iron convection zone (FeCZ) and internal gravity waves (IGWs), with IGWs potentially more dominant in the early stages of stellar evolution, and the contribution of FeCZ becoming more significant as stars evolve. Meanwhile, our results indicate that the SLF variability of O-type stars bears certain signatures of the line-driven wind instability and granulation.

Mapping Guaranteed Positive Secret Key Rates for Continuous Variable Quantum Key Distribution.

The standard way to measure the performance of existing continuous variable quantum key distribution (CVQKD) protocols is by using the achievable secret key rate (SKR) with respect to one parameter while keeping all other parameters constant. However, this atomistic method requires many individual parameter analyses while overlooking the co-dependence of other parameters. In this work, a numerical tool is developed for comparing different CVQKD protocols while taking into account the simultaneous effects of multiple CVQKD parameters on the capability of protocols to produce positive SKRs. Using the transmittance, excess noise, and modulation amplitude parameter space, regions of positive SKR are identified to compare three discrete modulated (DM) CVQKD protocols. The results show that the M-QAM protocol outperforms the M-APSK and M-PSK protocols and that there is a non-linear increase in the capability to produce positive SKRs as the number of coherent states used for a protocol increases. The tool developed is beneficial for choosing the optimum protocol in unstable channels, such as free space, where the transmittance and excess noise fluctuate, providing a more holistic assessment of a protocol's capability to produce positive SKRs.

Effect of ultrasonic radiation on the organization and mechanical properties of laser-melted Ni-based WC coatings

In this paper, laser cladding technology and ultrasonic radiation technology are combined to eliminate defects such as cracks and porosity in the coating. Firstly, the influence of the ultrasonic amplitude parameter on the macroscopic morphology and microstructure of the coating was investigated, and the dissolution law of WC was analyzed. It was found that under ultrasonic radiation with an amplitude of 14 μm, the surface of the coating was smoother and the average grain size was 16.52 μm2, which was reduced by 66.47 % compared to that of the coating without applied ultrasonic. Secondly, the effect of the ultrasonic radiation process on the mechanical properties of the coating was analyzed by comparative experiments. The results showed that when the amplitude of ultrasound was 14 μm, the number of cracks in the coating was effectively reduced, the amount of wear was reduced by 96.49 %, and the average microhardness value was 510.92 HV0.025, which was a relative increase of 28.10 %. Finally, the longitudinal residual stress of the coating was measured and the residual stress at the bottom of the coating was reduced by 95.31 % at an amplitude of 14 μm.

3D reconstruction of vocal fold dynamics with laser high-speed videoendoscopy in children.

The objective of this study is to evaluate three-dimensional vertical motion of the superior surface of the vocal folds in vivo in (a) typically developing children as a function of vocal frequency variations and (b) a child with vocal nodules. A custom developed laser endoscope coupled with high-speed videoendoscopy was used to obtain 3D parameters from 2 healthy children, one child with vocal nodules, and 23 vocally healthy adults (females = 11, males = 12). Parameters of amplitude (mm), maximum opening/closing velocity (mm/s), and mean opening/closing velocity (mm/s) were computed for the lateral and vertical vibratory motion along the anterior, middle, and posterior sections of the vocal folds were computed. We provide for the first time, absolute measurements of vertical amplitude and maximum/ mean velocity during the opening and closing phases, in vivo in children. Overall, the vertical motion was larger in vocally normal children compared with the lateral motion, especially along the visible posterior section of the vocal folds and during low pitch phonation. The opening phase dynamics were consistently large along the posterior section in the child with vocal nodules. The study findings establish the feasibility of capturing 3D motion in a clinical setting and provide proof of concept for the application of the proposed 3D laser in the pediatric population. Future large sample size studies are needed to establish the diagnostic potential of examining the closing phase vertical motion to evaluate vibratory development in children with normal voice and investigating the opening phase vertical motion in children with nodules. N/A.

Measuring the Pupillary Light Reflex Using Portable Instruments in Applied Settings.

The early components of the pupillary light reflex (PLR) are governed by the parasympathetic nervous system. The use of cheap, portable pupillometry devices may allow for the testing of parasympathetic-system health in field settings. We examined the reliability of two portable instruments for measuring the PLR and their sensitivity to individual differences known to modulate the PLR. Parameters of the PLR were measured in a community sample (N = 108) in a variety of field settings. Measurements were taken using a commercial pupillometer (NeuroLight, IDMED) and an iPhone using the Reflex Pro PLR analyser (Brightlamp). The parameters of baseline pupil diameter, constriction latency, amplitude and relative amplitude of constriction, and constriction velocity were measured. Individual differences related to age, levels of anxiety, and post-traumatic stress disorder (PTSD) symptomology were assessed. Some measures could not be attained using the iPhone under these field conditions. The reliability of the measures was high, save for the measurement of contraction latency which was particularly unreliable for the iPhone system. The parameters of the PLR showed the same internal relationships as those established in laboratory-based measurements. Age was negatively correlated with all the reliable PLR parameters for both systems. Effects of anxiety and PTSD symptomology were also apparent. The study demonstrated that a hand-held portable infrared pupillometer can be used successfully to measure the PLR parameters under field settings and can be used to examine individual differences. This may allow these devices to be used in workplaces, sports fields, roadsides, etc., to examine parasympathetic activity where needed.

The Effects of Functional Electrical Stimulation Cycling on Muscle Spasticity in Individuals with Spinal Cord Injury: A Systematic Review

Objectives: To evaluate the effects of functional electrical stimulation (FES) cycling on muscle spasticity in individuals with spinal cord injury (SCI) and provide recommendations for optimal FES cycling parameters to treat muscle spasticity. Method: In this systematic review, database searches of CINAHL, MEDLINE (Ovid), PEDro, PubMed, and Scopus were conducted to identify relevant studies published up to June 2023. Studies were screened for eligibility. Those that included an FES cycling intervention, an outcome measure of spasticity, and were available in full-text English were included. Two independent reviewers extracted the data and appraised the literature via the Crowe Critical Appraisal Tool (CCAT). Results: Of the 1782 studies identified, 16 satisfied the criteria for this review. Two-hundred and three participants were included, aged 7 to 80 years old. Ten studies identified a reduction in spasticity following FES cycling via objective or subjective outcome measures. Methodological quality was variable, with CCAT scores ranging from 19/40 (48%) to 35/40 (88%). National Health and Medical Research Council hierarchy levels ranged from II to IV. Conclusion: Evidence for the effectiveness of FES cycling to reduce muscle spasticity remains inconclusive. Long-term effects on spasticity were evident in moderate- to high-quality studies where FES cycling was conducted for 60 minutes, three times per week for 16 weeks. Additional research with larger sample sizes is warranted to confirm these findings. Further clarification of the optimal parameters of FES frequency, amplitude, and pulse width to reduce spasticity is required.