Search Results (212)

Humanoid robots operating near humans require short protective reaction times in physical human–robot interaction (pHRI). Safety standards distinguish between quasi-static and transient contact. This paper quantifies the reaction timing of a compliant pneumatic artificial muscle (PAM) mechanism under controlled preload conditions. Measurements were performed at 10 N, 50 N, and 100 N preload using synchronised load-cell force, PAM pressure, actuator position, and force-sensitive resistor (FSR) signals. Reaction timing was evaluated relative to the FSR-defined contact onset, at which the controller issued the pressure-release command. The force trace reached its first post-contact peak within 15–20 ms after onset, while the pressure peak occurred within 5–15 ms. A 90% recovery of the post-contact force excursion was achieved within 40–50 ms, whereas the corresponding pressure excursion required 155–180 ms. These timing results quantify reaction latency in PAM-actuated humanoid joints and support multi-modal sensing for robust onset localisation and mitigation monitoring in both ISO/TS 15066 contact types. Full article

Accurate impact localization on spacecraft structural panels subjected to contact loading by on-orbit servicing robots is critical for real-time structural health monitoring (SHM), yet remains challenging due to heterogeneous elastic wave propagation in complex aluminum structures with stiffener ribs and bonded joints. Conventional Received Signal Strength Indicator (RSSI)-based weighted centroid methods rely on fixed path-loss exponents that cannot accommodate spatially varying wave attenuation, resulting in position-dependent localization errors that worsen significantly near structural discontinuities. This paper proposes a Crow Search Algorithm (CSA)-optimized adaptive weighted centroid algorithm using distributed Fiber Bragg Grating (FBG) sensors, featuring three principal innovations: (i) a novel FBG wavelength-shift-to-RSSI amplitude mapping derived from elastic wave attenuation theory, bridging optical fiber sensing with centroid localization; (ii) per-event online weight optimization via CSA that adapts sensor contributions to each individual impact’s strain-wave signature; and (iii) a multi-objective fitness function simultaneously optimizing localization accuracy, noise robustness, and temporal consistency. The proposed method is validated across 200 impact events distributed over five representative positions on a 1 m³ Al6061 satellite-like structure with 64 FBG sensors (8 × 8 grid, 125 mm pitch), under three Gaussian noise levels (σ = 1%, 3%, 5% of signal RMS), and benchmarked against classical weighted centroid (WC), PSO-WC, GA-WC, DE-WC, and GWO-WC using paired t-tests (p < 0.01). CSA-WC achieves a mean localization error of 4.63 mm—an 83.29% improvement over classical WC and the lowest error among all five compared algorithms—with an average computation time of 0.14 s per event, satisfying real-time monitoring requirements. Full article

Flexible piezoresistive sensors are often vulnerable to modal ambiguity and bending-induced drift, both of which can obscure true pressure and strain signals under practical operation. Here, we address these limitations by suppressing bending sensitivity at the device level and disambiguating tactile modes at the algorithmic level. We propose and fabricate a Ti₃C₂T_x/graphene oxide (GO) sandwich sensor in which the conductive network is positioned near the neutral axis, thereby ensuring that bending induces negligible axial strain in the active layer. In contrast, out-of-plane pressing enlarges microcontacts, while in-plane stretching disrupts percolation pathways. We develop a composite-beam model to quantify neutral-axis alignment and the resultant bending immunity, realize the device via a straightforward casting process, and systematically characterize its electromechanical response under bending, pressing, nail pressing, and stretching. To further reduce modal ambiguity and improve tactile recognition, a lightweight one-dimensional convolutional neural network (1D-CNN) was introduced to classify temporal resistance signals from the sensor. Experimental results showed that the 1D-CNN achieved a high classification accuracy of 98.52% under flat-state training and testing conditions, and maintained 96.67% accuracy when evaluated on bending-state samples, demonstrating strong robustness against bending-induced interference. Together, the neutral-axis device architecture and the learning-based inference pipeline deliver high sensitivity to pressing and stretching while markedly suppressing the response to bending, thereby enabling wrist-worn pulse monitoring, soft-robotic joint sensing, and plantar pressure insoles. Full article

Background: Adolescent idiopathic scoliosis (AIS) is often associated with central nervous system disorders and deficits in sensorimotor function. While the Schroth method is a common clinical intervention, research evidence regarding its effectiveness in enhancing sensorimotor control remains limited. This study aimed to evaluate the impact of the Schroth method on sensorimotor control and quality of life (QoL) in AIS patients. Methods: Sixty female participants (mean age 13.4 years) with Cobb angles between 10° and 45° were divided into an intervention group (n = 30), receiving Schroth exercises and bracing for 10 weeks, and a control group (n = 30), receiving bracing alone. Outcome measures included static and dynamic balance, spine lateral flexion joint position sense (JPS), upper-limb functional proprioception, and the GR-BSSQ Brace questionnaire. Results: Statistical analysis using two-way mixed ANOVA revealed significant Group × Time interactions across several parameters. The Schroth group showed significant improvements in static and dynamic balance, with ellipse area reduction (p = 0.005) and reduced Fukuda test distance (p = 0.007), respectively. Significant enhancements were noted in spine lateral flexion JPS (Bilateral p = 0.008) and upper-limb proprioception (Bilateral p = 0.000). Furthermore, the intervention group reported a significant improvement in QoL scores compared to the control (p = 0.000). Conclusions: The findings demonstrate that the Schroth method was associated with enhanced sensorimotor control, supporting its use as a targeted approach to improve functional outcomes in individuals with AIS. These results highlight the clinical value of the method, beyond spinal curve correction. Full article

With the development of 6G communication technology, Space–Air–Ground Integrated Networks (SAGINs) have become critical infrastructure for global intelligent collaborative computing. However, federated learning deployment in SAGINs faces three severe challenges: the high dynamics of satellite orbital motion, node resource heterogeneity, and privacy vulnerabilities in data transmission. This paper proposes an adaptive compressed sensing differential privacy federated learning framework based on orbital spatiotemporal characteristics. First, we design orbital periodicity-driven time-varying sparse sensing matrices that dynamically adjust compression strategies according to satellite orbital positions, achieving intelligent communication efficiency optimization. Second, we propose an orbital predictability-based privacy budget temporal allocation mechanism and perform differential privacy noise injection in the compressed domain, establishing a compression–privacy joint optimization algorithm. Furthermore, we construct an energy–communication–privacy ternary collaborative mechanism that achieves multi-objective dynamic balance through model predictive control. Finally, we design reinforcement learning-based dynamic routing scheduling and hierarchical aggregation strategies to effectively handle the time-varying characteristics of network topology. Simulation experiments demonstrate that compared to existing methods, the proposed approach achieves 3–12% improvement in model accuracy and 30–50% enhancement in communication efficiency while maintaining differential privacy protection with dynamic privacy budget $\epsilon \in [0.1,10.0]$ and compression ratio $\rho \in [0.2,0.8]$. Unlike static compressed sensing approaches that ignore orbital periodicity, the proposed orbital-driven time-varying sensing matrices reduce reconstruction error by up to 19.4% compared to fixed-matrix baselines, validating the synergistic effectiveness of integrating orbital spatiotemporal characteristics with federated learning in 6G SAGIN deployments. The framework assumes reliable orbital propagation via SGP4/SDP4 models and does not account for Doppler frequency shifts or inter-satellite link handover delays; future extensions include scalability to mega-constellations and integration of quantum-resistant privacy mechanisms. Full article

Production profiling is essential for optimizing production strategies in oil and gas wells. Conventional production logging tools provide only discrete, time-limited measurements and face operational challenges in long or complex horizontal wells. Distributed fiber-optic sensing (DTS/DAS) enables continuous, full-wellbore monitoring but each sensing modality has limitations when used alone: DTS interpretation is influenced by wellbore disturbances and thermal hysteresis, while DAS acoustic energy does not always correspond to actual inflow zones. This study proposes a joint interpretation method integrating DTS-based temperature inversion with DAS frequency-band energy and apparent velocity analysis. DTS data are processed using a coupled wellbore–formation heat-transfer model to obtain segmental flow rates, while DAS data are analyzed using short-time Fourier transform, cross-correlation, and Hough transform to extract positive and negative apparent velocities indicating fluid migration directions. Field results show that high-production intervals at 4126–4486 m correlate with positive apparent velocities, whereas medium-/low-production and shut-in stages exhibit persistent negative velocities linked to backflow and reinjection. The combined interpretation effectively distinguishes reservoir inflow from wellbore flow by jointly constraining thermal response and flow direction, thereby reducing uncertainties associated with single-method analysis. Full article

Background: Upper-limb performance in handball depends on accurate shoulder sensorimotor control under high loads and fatigue. This study examined between-cohort differences associated with concentric versus eccentric exercise-induced fatigue in shoulder proprioception, kinesthesia, functional stability, and isometric force output in professional male handball players. Methods: This was a retrospective, quasi-experimental (non-randomized) between-cohort comparison of two previously collected cohorts who completed either a concentric (n = 46) or eccentric (n = 33) fatigue protocol, with pre- and post-fatigue assessments of joint repositioning sense (absolute angular error, AAE), threshold to detection of passive movement (TTDPM), Y Balance Test Upper Quarter (YBT-UQ), and the Athletic Shoulder (ASH) test. Results: Fatigue significantly increased AAE across all tested angles (Time: all p < 0.001), with a contraction-specific effect at end-range internal rotation (IR45°), where AAE increased more after concentric than eccentric fatigue (Time × Fatigue Type: p = 0.017; Δ = +1.34° (+61.8%) vs. +0.20° (+7.4%)). TTDPM increased after fatigue (p = 0.001) with no interaction (p = 0.968). YBT-UQ performance decreased after fatigue for all dominant-limb outcomes and for non-dominant inferolateral, superolateral, and composite scores (all p ≤ 0.018), but not for non-dominant anteromedial reach (p = 0.986); no Time × Fatigue Type interactions were detected for YBT-UQ outcomes (all p > 0.05). ASH force output decreased across all positions and both limbs (all p ≤ 0.002), with the dominant-limb Y position showing a greater decline following eccentric fatigue (Time × Fatigue Type: p = 0.030; e.g., ASH Y dominant Δ = −0.49 (−4.6%) vs. −1.43 N·kg⁻¹ (−13.3%)). Conclusions: Exercise-induced fatigue impairs shoulder sensorimotor function and upper-limb performance in handball. Contraction-mode differences were small and task-specific in this between-cohort comparison, emerging primarily at end-range proprioception and selected isometric strength positions. These findings may inform the design of training programs that emphasize fatigue-resistant sensorimotor control and end-range strength, while causal inferences regarding contraction mode are not warranted given the non-randomized design. Full article

Background: Patellofemoral pain syndrome (PFPS) is a common musculoskeletal disorder that involves various biomechanical factors, including the altered positioning of the patella, weakness of the lower extremity muscles, delayed activation of the vastus medialis muscle, and excessive pronation of the foot. Although the short- and long-term effects of external support among the recommended conservative treatment methods for PFPS have been examined, there remains a lack of consensus regarding their impacts. This study was conducted to investigate the immediate effects of braces and rigid taping applied to control pain on proprioception, functional status, and balance in patients with PFPS, and to compare these outcomes with normative values obtained from healthy individuals. Methods: The study included 18 patients with PFPS and 18 healthy individuals who met the inclusion criteria. Through randomization of the intervention sequence, patients were evaluated under conditions of rigid taping, support, or without any support. Their pain levels before and after the application were assessed using the Visual Analog Scale; their functional status was evaluated with the Kujala Patellofemoral Scoring, the 10-Step Up Test, and the Squat; their balance performance was measured using the Y-Balance Test and the Single Leg Stance Test; and their proprioception was assessed with the Joint Position Sense Test. Results: It has been determined that rigid taping and bracing have similar effects in the immediate management of pain, proprioception, functional status, and balance issues in patients with PFPS. The interventions were observed to bring patients’ static balance and proprioception parameters closer to the values seen in healthy individuals. Conclusions: Rigid taping and bracing are both effective interventions in the management of PFPS, offering benefits such as pain relief, prevention of proprioceptive deficits, mitigation of balance impairments, and enhancement of functional outcomes. The selection of the most appropriate modality should be based on the individual patient’s characteristics and tolerance levels. Full article

(1) Background: Prosocial behaviour serves as a crucial indicator of mental health development among preschool children. This study aimed to reveal the path through which family cohesion affects prosocial behaviour in Chinese preschoolers, while exploring the potential roles of parent–child relationships and parenting sense of competence in this relationship; (2) Methods: The questionnaire method was used, with 515 parents of preschool children from Southwest China participating in this survey (115 fathers, 400 mothers; Mage = 34.37, SD = 5.31). (3) Results: The key findings of the study are as follows: 1. Family cohesion exerted a direct and positive significant effect on the prosocial behaviour of preschoolers such that strong family cohesion effectively promoted children’s prosocial behaviour; 2. Parent–child relationships and a sense of competence in terms of parenting played a joint mediating role in the relationship between family cohesion and preschooler’s prosocial behaviour. Specifically, strong family cohesion enhanced the quality of parent–child relationships, which in turn improved parents’ parenting sense of competence, ultimately facilitating the development of prosocial behaviour in preschool children; 3. Further propensity score-matching analysis revealed that the influence of family cohesion on the prosocial behaviour of preschoolers varies by parent, with parenting sense of competence being significant among fathers and parent–child relationships being significant among mothers. (4) Conclusions: In educational practice, greater attention should be paid to the role of fathers in Chinese family education, especially regarding their parenting capabilities and experiences. Additionally, it is essential to encourage Chinese fathers to actively fulfil their parenting duties and responsibilities. Full article

Remote sensing-based landslide segmentation is of great significance for geological hazard assessment and post-disaster rescue. Existing convolutional neural network methods, constrained by the inherent limitations of spatial convolution, tend to lose high-frequency edge details during deep semantic extraction, while frequency-domain analysis, although capable of globally preserving high-frequency components, struggles to perceive local multi-scale features. The lack of an effective synergistic mechanism between them makes it difficult for networks to balance regional integrity and boundary precision. To address these issues, this paper proposes the Geometric Context and Frequency Domain Fusion Network (GCF-Net), which achieves explicit edge enhancement through a three-stage progressive framework. First, the Pyramid Lightweight Fusion (PGF) block is proposed to aggregate multi-scale context and provide rich hierarchical features for subsequent stages. Second, the Geometric Context and Frequency Domain Fusion (GCF) module is designed, where the frequency-domain branch generates dynamic high-frequency masks via the Fourier transform to locate boundary positions, while the spatial branch models foreground–background relationships to understand boundary semantics, with both branches fused through an adaptive gating mechanism. Finally, Edge-aware Detail Consistency Improvement (EDCI) module is designed to balance boundary preservation and noise suppression based on edge confidence, achieving adaptive output refinement. Under the joint supervision of Focal loss, Dice loss, and Edge loss, experiments on the mixed dataset and LMHLD dataset demonstrate that GCF-Net achieves OAs of 96.42% and 96.71%, respectively. Ablation experiments and visualization results further validate the effectiveness of each module and the significant improvement in boundary segmentation. Full article

Contactless text entry is increasingly important in immersive and constrained computing environments, yet most vision-based approaches rely on character-level recognition or key localization, which are fragile under monocular sensing. This study investigates the feasibility of recognizing natural QWERTY typing motions directly at the word level using only a single RGB camera, under a fixed single-user and single-camera configuration. We propose a word-level contactless typing framework that models each word as a distinctive spatiotemporal finger motion pattern derived from hand joint trajectories. Typing motions are temporally segmented, and direction-aware finger displacements are accumulated to construct compact motion representations that are relatively insensitive to absolute hand position and typing duration within the evaluated setup. Each word is represented by multiple motion prototypes that are incrementally updated through online learning with a trial-delayed adaptation protocol. Experiments with vocabularies of up to 200 words show that the proposed approach progressively learns and recalls word-level motion patterns through repeated interaction, achieving stable recognition performance within the tested configuration at realistic typing speeds. Additional evaluations demonstrate that learned motion representations can transfer from physical keyboards to flat-surface typing within the same experimental setting, even when tactile feedback and visual layout cues are reduced. These results support the feasibility of reframing contactless typing as a word-level motion recall problem, and suggest its potential role as a complementary component to character-centric camera-based input methods under constrained monocular sensing. Full article

Background/Objectives: Mechanical neutrality has long been regarded as the principal alignment target in total knee arthroplasty (TKA). However, radiographic neutrality does not necessarily reflect physiological morphology or patient perception. This study aimed to evaluate one-week postoperative patient-perceived lower-limb straightness after unrestricted kinematic alignment (KA) TKA and to examine its relationship with radiographic alignment parameters and functional findings. Methods: A total of 175 patients (203 knees) who underwent unrestricted KA-TKA were retrospectively reviewed. Pre- and postoperative radiographs, clinical assessments, and a study-specific, non-validated questionnaire were analyzed one week postoperatively. Patient perception of straightness was assessed using the Straightness Visual Analog Scale (S-VAS) and the Straightness Satisfaction Visual Analog Scale (SS-VAS). Radiographic parameters included the hip–knee–ankle angle (HKAA), the medial proximal tibial angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), the joint line convergence angle (JLCA), and Coronal Plane Alignment of the Knee (CPAK) patterns. Correlative analyses between VAS scores and radiographic and clinical parameters were examined. Results: Preoperatively, 85% of knees were perceived as bowed, and all were reported as straight after surgery. Among knees not perceived as bowed preoperatively, 60% were newly perceived as straight postoperatively, while 40% remained perceived as straight. Postoperative satisfaction was high (S-VAS 88.9 ± 11.6; SS-VAS 92.3 ± 12.9). Associations between S-VAS/SS-VAS and HKAA were weak but statistically significant, whereas both showed moderate positive correlations with postoperative knee extension (S-VAS r = 0.54; SS-VAS r = 0.59). Conclusions: At one week after surgery, patients tended to perceive lower-limb straightness as being associated with restoration of physiological morphology and improved knee extension rather than with radiographic mechanical neutrality. Patient-perceived straightness reflects an individualized and natural sense of limb alignment (“inherent straightness”) and should be interpreted as an exploratory, patient-centered concept based on an early postoperative test, supporting a personalized framework for alignment evaluation in unrestricted KA-TKA. Full article

Background: Proprioceptive deficits, commonly quantified as joint position sense error (JPSE), are frequently reported in musculoskeletal conditions. Articular manual therapy may influence afferent input and sensorimotor integration. This review synthesised the effects of joint mobilization and/or high-velocity low-amplitude (HVLA) thrust manipulation on quantitative proprioception outcomes in humans. Methods: PubMed, Scopus, CINAHL, and MEDLINE Complete were searched (from inception to November 2025) for randomized or sham-controlled trials assessing proprioception after eligible articular manual therapy. Searches were limited to English-language publications. Risk of bias was assessed using Risk of Bias 2 (RoB 2). Random-effects meta-analysis (Hedges’ g) was conducted when outcomes and time points were comparable; pooling was possible for only one outcome/time-point comparison. Certainty of evidence was assessed using GRADE. Results: Database searches yielded 483 records; after duplicate removal, 371 records were screened. Eighteen full-text articles were assessed for eligibility, of which 11 were excluded, resulting in seven randomized clinical trials (2018–2025; total n = 350) evaluating spinal or peripheral mobilization/manipulation. No eligible randomized or sham-controlled trials meeting the prespecified criteria were identified before 2018. In chronic mechanical neck pain, cervical thrust manipulation improved cervical JPSE versus sham with large partial eta-squared effects (η²p = 0.23–0.36). Cervical mobilization improved left rotation JPSE (4.15 → 1.65° vs. 4.01→3.74°). In patellofemoral pain, lumbopelvic manipulation produced immediate reductions in knee JPSE at 60° (6.58 → 4.48° vs. 5.91 → 6.05°). Only one outcome/time-point was suitable for meta-analysis (knee JPSE at 60° flexion in patellofemoral pain; two trials), showing no statistically significant pooled effect (Hedges’ g = −0.21, 95% CI −1.36 to 0.94; I² ≈ 83%). Remaining outcomes could not be pooled due to heterogeneity and incompatible reporting. Conclusions: Evidence from seven randomized trials indicates that articular manual therapy (mobilization and/or HVLA thrust manipulation) can improve quantitative proprioceptive outcomes immediately post-intervention, particularly JPSE in neck and patellofemoral pain; however, effects are condition- and outcome-specific, and confidence is limited by heterogeneity and the predominance of narrative synthesis with sparse poolable data. Future adequately powered trials should standardize proprioception protocols, include longer follow-up, and report data to enable robust meta-analysis. Full article

Functional ankle instability (FAI) is a common consequence of lateral ankle sprains, characterized by impaired sensorimotor control. While orthoses and localized vibration have shown individual benefits for FAI, their combined application in a wearable device has not been previously investigated. This pilot randomized trial compared the effects of a vibrotactile foot orthosis (VFO) and a vibrotactile ankle orthosis (VAO) on joint position sense (JPS) and postural control in individuals with FAI. Sixteen participants were randomized to receive either a VFO or a VAO, both delivering 30–50 Hz pulsed vibration in 20 min sessions, three times a week, for two weeks. Outcome measures included joint position sense (JPS) error (°), center of pressure (COP) velocity (mm/s), the Star Excursion Balance Test (SEBT), and the Six-Meter Hop Test (SMHT), which were assessed pre-intervention, immediately post-intervention, and after two weeks of use. The analysis showed a statistically significant interaction between time and intervention group for JPS error (p = 0.02, η² = 0.42). Specifically, the VFO group improved JPS significantly more than VAO at two weeks follow-up (MD = −1.75°, p = 0.005, d = −1.68). Both groups significantly reduced in anteroposterior COP velocity after two weeks (VFO: MD = 1, p = 0.003, d = 1.47; VAO: MD = 1.39, p ˂ 0.001, d = 2.05) with no between-group differences. No changes were observed in the SEBT or SMHT. Plantar-based vibrotactile stimulation was more effective than ankle-based stimulation in enhancing proprioceptive acuity in individuals with FAI. Both interventions improved static postural stability, supporting the potential of integrated vibrotactile orthoses in FAI rehabilitation. No major practical issues were reported during the intervention. Two participants experienced minor discomfort related to the electronic housing bulk in the first week, which was resolved by week two. No further complaints regarding device weight or usability were observed. Full article

Joint acidosis is increasingly recognized as an important determinant of cellular behavior in osteoarthritis (OA). Declines in extracellular pH (pHe) occur across cartilage, meniscus, synovium, and subchondral bone, where they influence inflammation, matrix turnover, and pain. Among proton-sensing G protein-coupled receptors, GPR68 responds to the acidic pH range characteristic of human OA joints. The receptor is activated between pH 6.8 and 7.0, couples to Gq/PLC-MAPK, cAMP-CREB, G12/13-RhoA-ROCK signaling pathways, and is expressed most prominently in articular cartilage, with additional expression reported in synovium, bone, vasculature, and some neuronal populations. These pathways regulate transcriptional programs relevant to cartilage stress responses, inflammation, and matrix turnover. GPR68 expression is increased in human OA cartilage and aligns with regions of active matrix turnover. We previously reported that pharmacologic activation of GPR68 suppresses IL1β-induced MMP13 expression in human chondrocytes under acidic conditions, indicating that increased GPR68 expression may represent a microenvironment-responsive, potentially adaptive signaling response rather than a driver of cartilage degeneration. Evidence from intestinal, stromal, and vascular models demonstrates that GPR68 integrates pH changes with inflammatory and mechanical cues, providing mechanistic context, although these effects have not been directly established in most joint tissues. Small-molecule modulators, including the positive allosteric agonist Ogerin and the inhibitor Ogremorphin, illustrate the tractability of GPR68 as a drug target, although no GPR68-directed therapies have yet been evaluated in preclinical models of OA. Collectively, current data support GPR68 as a functionally relevant proton sensor within the acidic OA joint microenvironment. Full article