Search Results (2,078)

Assistive bathing for the elderly and disabled presents significant challenges regarding caregiver workload and safety. This paper presents the design and verification of a multi-module integrated intelligent bathing assistance system. The system automates the entire bathing sequence through four coordinated modules: a robotic scrubbing unit, a climate-controlled cabin, a passive multifunctional wheelchair, and a multi-degree-of-freedom transfer device. A key innovation is the wheelchair’s passive design with an automated docking mechanism, ensuring safety in wet environments. Unlike existing commercial solutions and the existing literature, which primarily focus on fragmented, singular functionalities (such as transfer-only devices or fixed-spray cabins), the core advantage of the developed system lies in its holistic integration of safe physical transfer, adaptive robotic scrubbing, and microenvironment control into a seamless, unified architecture. Employing a modular and ergonomic approach, the system executes a predefined 12-step automated workflow. Experimental validation demonstrates an average bathing time of 16.6 min and a quantifiable 69.8% reduction in caregiver workload, confirming the system’s high efficiency and practical utility in alleviating caregiver burden. Full article

Background: In horses, standing arthroscopy offers a valuable alternative to general anesthesia for the reduction of anesthetic-associated risks, and provides improved visualization in joints where access is facilitated by weightbearing. These techniques are particularly advantageous for patients with increased anesthetic risk or financial limitations. To the authors’ knowledge, the removal of osteochondral fragments from the distal interphalangeal joint in a standing, sedated horse using small-diameter arthroscopic equipment has not been previously reported. Case Presentation: A 7-year-old American Quarter Horse–Thoroughbred cross presented on referral for treatment of osteochondral fragmentation in the right fore distal interphalangeal joint. A standing arthroscopic approach to the distal interphalangeal joint was performed. In a weight-bearing position, debridement of the dorsal osteochondral fragments from the second and third phalanx was successfully completed, using a 2 mm NanoNeedle scope and 3.2 mm high-flow 10- degree cannula (Arthrex^®). At one year follow-up, the horse had returned to competition and was sound at veterinary examination. Conclusion: This case demonstrates the feasibility of standing NanoNeedle arthroscopy of the equine coffin joint with improved maneuverability, surgical ergonomics, and reduced iatrogenic injury compared to a standard rigid arthroscope. The successful execution of this technique effectively expands our collection of standing arthroscopic procedures in the equine patient. Full article

Prolonged sitting with poor posture is associated with musculoskeletal disorders, reduced productivity, and long-term health risks. Many existing posture monitoring systems predominantly rely on single-modality sensing, such as pressure or vision-based approaches, limiting their ability to capture both static alignment and dynamic micro-movements. This study proposes a multimodal smart-skin system integrating pressure, temperature, and vibration sensors for sitting posture recognition. A total of 42 sensors distributed across 14 anatomical locations were deployed, generating 15,037 samples collected over three independent sessions to evaluate cross-session temporal generalization across nine posture classes under controlled experimental conditions. Two deep learning architectures—Temporal Convolutional Networks with Attention (TCN + Attn) and Convolutional Neural Network–Long Short-Term Memory (CNN − LSTM)—were compared under Leave-One-Session-Out (LOSO) cross-validation. TCN + Attn achieved 85.23% LOSO accuracy, outperforming CNN − LSTM by 2.56 percentage points while reducing training time by 36.7% and inference latency by 33.9%. Ablation analysis revealed that temperature sensing was the most discriminative unimodal modality (71.5% accuracy), and full multimodal fusion improved LOSO accuracy by 22.93% compared to pressure-only configurations. These results demonstrate the feasibility of multimodal smart-skin sensing combined with temporal convolutional modeling for cross-session posture recognition and indicate potential for efficient real-time, privacy-preserving ergonomic monitoring. This study should be interpreted as a controlled, single-subject proof-of-concept, and further validation in multi-subject and real-world environments is required to establish broader generalizability. Full article

Background/Objectives: This study aimed to examine how interpupillary distance (IPD) influences motor and sensory binocular vision functions at distance and near, and to examine associations between different motor and sensory binocular vision functions. Methods: A descriptive cross-sectional study was performed involving 100 random participants of both genders, aged 20 to 38 years. Optically corrected and non-strabismic participants were selected from King Saud University, Riyadh, Saudi Arabia between June 2024 and June 2025. Distance and near IPD were assessed with a pupillometer. Motor binocular functions included horizontal phoria using the von Graefe technique and near point of convergence (NPC). Sensory binocular vision was assessed using crossed and uncrossed TNO and Random-dot E stereopsis tests at near and distance respectively. Statistical analysis was conducted using SPSS version 26 (p ≤ 0.05). Results: IPD and phoria were not significantly associated at distance or near. However, moderate and significant correlations were found between IPD (distance and near) and NPC. Significant correlations were also found between IPD and both crossed and uncrossed stereopsis at distance, but correlations were weak or non-significant at near. A strong correlation was observed between NPC and stereopsis at distance. Conclusions: As interpupillary distance (IPD)increases, near point of convergence (NPC) receded, and stereopsis at distance declined, suggesting that anatomical variation influences binocular vision primarily at distance. Full article

Indoor environmental quality (IEQ) significantly impacts people’s comfort, health, and productivity in buildings, and modern green rating systems are primarily focused on energy efficiency rather than the direct user experience. This paper analyses the relationship between IEQ and the perceived quality of life (QoL) of certified and conventional office buildings in Malaysia using a mixed-methods design. The questionnaires were completed by 162 employees working in four open-plan offices: two were certified under the Green Building Index (GBI) established in Malaysia, and two were traditional. This was supplemented by 14 semi-structured interviews and 2 focus groups. The factors of IEQ were divided into ambient, designed, and behavioral environments. It was statistically determined that behavioral factors, such as visual privacy, personalization, ergonomics, and control, exhibited the strongest correlations with overall QoL, compared to ambient factors such as air quality or thermal comfort. Green buildings performed better in terms of daylighting and esthetics than conventional buildings, though they did not always deliver higher occupant satisfaction. The results indicate that current green certification frameworks pay insufficient attention to occupant-centered aspects. The proposed research adds a validated IEQ-QoL framework that predicts the incorporation of subjective user experience into building performance indicators, which can be important for certification reform, post-occupancy evaluation (POE), and human-centered sustainable design approaches. Full article

Low back pain associated with exposure to whole-body vibration (WBV) is common among agricultural workers, and seated posture significantly affects health outcomes from WBV exposure. Current posture assessment methods rely on manual observation or body-worn sensors, which are labor-intensive and impractical for continuous monitoring. We developed a machine learning approach to classify seated posture using force sensors and accelerometers integrated into a vibration sensing seat pad for use in agricultural machinery, avoiding the need for body-worn sensors. Twenty-four participants were exposed to WBV in different upper body postures while seat pad force and acceleration data were recorded. We compared four machine learning architectures: Logistic Regression, Random Forest, Support Vector Machine, and Recurrent Neural Network with Gated Recurrent Unit (GRU). The GRU architecture substantially outperformed baseline models, achieving 89% accuracy (weighted F1 = 0.89) in classifying forward and backward leaning postures. To our knowledge, this study demonstrates the first application of machine learning to classify seated postures from seat pad force measurements during WBV exposure. Temporal modeling with an 18 s window proved essential for accurate classification, enabling non-invasive, continuous posture monitoring. Full article

Background/Objectives: Low back pain (LBP) is one of the most common musculoskeletal conditions globally and a leading cause of disability. University populations may be particularly vulnerable due to prolonged sitting, academic stress, and frequently suboptimal ergonomics, especially in rapidly expanding higher education systems such as those in Saudi Arabia. This systematic review and meta-analysis aimed to synthesize evidence on the prevalence of LBP among university attendants in Saudi Arabia and to quantify its associations with key demographic and environmental risk factors. Methods: We systematically reviewed observational studies reporting LBP prevalence and/or risk factors among university students and faculty in Saudi Arabia published in English, following Cochrane methodological guidance and PRISMA 2020 reporting recommendations. The protocol was prospectively registered in PROSPERO (CRD420250654048). We searched PubMed, Embase and CINAHL from inception to February 2025. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Joanna Briggs Institute checklist for analytical cross-sectional studies. Random effects meta-analyses were used to pool prevalence estimates across recall periods, regions, populations, and measurement tools, and to calculate pooled odds ratios (ORs) for age, sex, smoking, family history of LBP, and college seating conditions. Heterogeneity, subgroup, and sensitivity analyses were undertaken. Results: Thirteen cross-sectional studies were included. The overall pooled prevalence of LBP was 57% (95% confidence interval [CI] approximately 43–71), with substantial heterogeneity. Prevalence varied by recall period, region, population group, and measurement instrument; pooled prevalence was 58% among students and 50% among faculty. Increasing age (OR 1.17, 95% CI 1.01–1.34) and poor college seating conditions (OR 1.42, 95% CI 1.07–1.76) were significantly associated with LBP. Male gender, smoking, and family history showed non-significant pooled effects. These estimates are limited by substantial between-study heterogeneity, variable measurement tools, and exclusively cross-sectional designs, which restrict causal inference. Conclusions: LBP is prevalent among university attendants in Saudi Arabia, affecting both students and faculty. The consistent associations with age and seating ergonomics highlight the need for ergonomic classroom redesign and age-sensitive preventive strategies. Future work should adopt standardized LBP measures and longitudinal designs to clarify causal pathways and evaluate targeted interventions. Funding: This work was supported by the Deanship of Graduate Studies and Scientific Research at Jouf University (grant DGSSR-2026-NF-01-002). Full article

This study investigates the dripping and leakage problem in kitchenware known as the “teapot effect” through a multidisciplinary experimental approach encompassing fluid mechanics, material science, and ergonomic design. Unlike previous studies confined to idealized geometries and single-fluid analyses, this work systematically examines 32 distinct spout geometries from commercially available teapots, coffee pots, and milk jugs under realistic operating conditions. Experiments were performed using three fluids with contrasting rheological properties: boiling black tea, cow’s milk, and Turkish coffee on a precision rotating platform operating at quasi-static (1°/s) to isolate surface tension, gravitational, and geometric effects from inertial forces. Three quantitative parameters were measured for each specimen: capillary dome angle, teapot effect angle range, and optimum pouring angle. Results demonstrate that spout tip geometry is the dominant controlling parameter. Thin-lipped elliptical cross-sections effectively suppressed dripping, whereas triangular and wide curved geometries produced the teapot effect across broad pouring angle ranges reaching up to 70°. A spout outlet extension length of 4–5 mm combined with a spout tip radius below 4 mm was found necessary and sufficient for clean flow separation. Furthermore, suspended particles and proteins in milk and Turkish coffee were shown to intensify the teapot effect by disrupting contact line dynamics at the spout tip. These findings provide quantitative design thresholds directly applicable to industrial kitchenware development. Full article

Background: Work-related musculoskeletal disorders (WMSDs) are prevalent among orthopaedic surgeons as a result of prolonged exposure to non-neutral postures and forceful manual tasks during surgery. Although working height is a key determinant of trunk and upper-limb posture, the systematic evaluation of ergonomic working-height recommendations in orthopaedic surgery remains limited. Methods: A simulated left total knee arthroplasty (TKA) was divided into twelve critical surgical steps and analysed across four commonly used surgeon positions (A–D). Two conditions were compared: uncorrected working height (N) and working height corrected according to Canadian Centre for Occupational Health and Safety (CCOHS) recommendations (C). Joint angles were measured from standardized photographs using Kinovea software, and postural load was quantified with the Rapid Entire Body Assessment (REBA) method. Two trained evaluators conducted three independent assessments, yielding 288 REBA scores. Results: Mean REBA scores decreased across all surgeon positions following ergonomic correction, with statistically significant reductions observed in positions A, B, and D. When pooled across all position–step combinations (n = 48), the mean reduction was 0.92 REBA points (95% CI 0.50–1.33; p < 0.001). Notably, 27 of the 48 position–step comparisons exceeded the minimal detectable change threshold. The largest reductions occurred during force-intensive surgical steps, including bone cutting, drilling, and implant impaction. Conclusions: Adjusting working height in accordance with CCOHS ergonomic recommendations reduces surgeons’ postural load during TKA. These findings support the integration of evidence-based ergonomic adjustments into routine orthopaedic surgical practice. Full article

Vascular remodeling driven by the phenotypic switching of vascular smooth muscle cells (VSMCs) poses a significant health risk to astronauts during long-duration spaceflight. While the morphological and molecular changes are well recognized, the underlying metabolic drivers and potential translational countermeasures remain elusive. To investigate the metabolic determinants of VSMCs phenotypic switching, human aortic smooth muscle cells (HASMCs) were subjected to cyclic mechanical stretch, an in vitro model offering indirect mechanistic insights into mechanical loading conditions relevant to spaceflight-associated hemodynamic alterations. An integrated approach combining quantitative proteomics, flux analysis (Seahorse), and functional assays (cell cycle, wound healing, transwell) was used to characterize the accompanying metabolic and phenotypic alterations. Molecular mechanisms were assessed using immunoprecipitation, protein crosslinking, and immunofluorescence. Mechanical stretch triggered a contractile-to-synthetic phenotypic switch in HASMCs, accompanied by a shift from oxidative phosphorylation to aerobic glycolysis. Pyruvate kinase M2 (PKM2) was identified as a central metabolic regulator of this process, its silencing reversed the pro-synthetic phenotype. Notably, lactate, a glycolytic product, was found to exert a self-limiting feedback signal. Exogenous lactate suppressed the synthetic switch in associated with increased PKM2 lactylation. Further analysis indicated that PKM2 lactylation was associated with enhanced stability of its active tetrameric conformation, which was associated with a metabolic shift toward oxidative phosphorylation and restored expression of contractile markers. Although specific lactylation sites on PKM2 were not identified in this study, and direct causality between lactylation and tetramerization remains to be established, these findings identify a previously unrecognized association. This study reveals a novel metabolic regulatory mechanism in which lactate correlates with the suppression of synthetic switching of VSMCs, linked to PKM2 lactylation and tetramer stabilization. The observed lactate-PKM2 axis represents a candidate metabolic node associated with VSMCs phenotype regulation and offers a potential therapeutic target for modulating vascular remodeling. Upon direct validation under relevant conditions in future studies, this mechanism may inform the development of novel therapeutic strategies for managing vascular adaptation during long-duration spaceflight and other aerospace-related physiological challenges. Full article

Work-related shoulder disorders during overhead assembly represent a persistent occupational challenge. We evaluated a quasi-direct-drive (QDD) active upper-limb exoskeleton during simulated overhead work, providing simultaneous metabolic, electromyographic, and kinematic assessment of QDD actuation under static and dynamic conditions. Seven healthy males completed within-subject comparisons of without-exoskeleton (WO) and with-exoskeleton (WE) conditions during dynamic screwing (5 min) and static holding (2.5 min, 3 kg). During static holding, the exoskeleton achieved substantial shoulder offloading (Upper Trapezius: −68.2%, 6/6 participants, p = 0.031, d = 3.61; Anterior Deltoid: −43.6%) and improved postural stability (32–41% variability reduction). However, metabolic cost increased during both static (+57.2%) and dynamic (+30.6%) tasks, while movement smoothness degraded. These findings extend prior task-dependent exoskeleton observations to QDD actuation, revealing that intrinsic backdrivability does not eliminate whole-body energy penalties from device mass. The exoskeleton exhibits task-dependent effectiveness: potentially suitable for prolonged static overhead holding but not currently recommended for dynamic assembly without mass reduction and control refinement. Full article

Tactile somatosensory comfort is a critical factor in ergonomics research, particularly in designing assistive robots for geriatric care. Despite its importance, existing studies lack comprehensive comfort models tailored for optimizing system control in such applications. This study addresses this gap by introducing the first derivation of a tactile somatosensory comfort model that integrates Stevens’ law with the energy transfer function, establishing a link between physical stimuli and psychological responses. Through experimental data collection and parameter fitting, a quantitative relationship between comfort and psychological responses was established, facilitating the development of a novel optimal control model. The model parameters were fitted using the Physics-Informed Neural Networks (PINNs) algorithm, while the optimal scrubbing parameters for force (1.68 N) and velocity (36.47 mm/s) were determined via the Particle Swarm Optimization (PSO) algorithm. Validation experiments involving 20 participants, which monitored physiological parameters such as heart rate variability (HRV), confirmed the model’s effectiveness in enhancing comfort while ensuring robustness and generalizability. These findings contribute a novel theoretical framework for modelling and applying tactile somatosensory comfort, providing valuable insights for future research and development. Full article

The mandatory introduction of tethered caps on plastic beverage bottles under European Directive (EU) 2019/904 aims to reduce plastic litter and improve the collection efficiency of packaging waste. This regulatory change introduced a packaging design modification that directly affects consumer interaction. Consumer acceptance of this packaging innovation, however, remains uncertain. Drawing on research suggesting that product experience is shaped not only by physical interaction but also by expectations and value-based framing, this study examines whether the environmental intent of tethered caps is reflected in consumer perceptions over time. We analyze changes in consumer attitudes toward tethered caps before and after the legal obligation came into force, based on survey data collected in 2024 and 2025. Results indicate that overall consumer perceptions remained predominantly negative in both years, with a slight increase in negative responses following mandatory implementation. Although reported awareness of single-use plastic issues was higher in 2025, this did not correspond to improved evaluations of usability. Skepticism regarding the actual impact on waste reduction, along with ergonomic concerns and discomfort during drinking, were consistently identified as key barriers to acceptance. Socio-demographic analysis showed that age and employment status significantly influenced attitudes, whereas gender and place of residence did not. Contrary to expectations, younger respondents showed a shift toward more negative perceptions after implementation. Overall, the results suggest that the EU Single-Use Plastics Directive, although primarily aimed at achieving positive environmental outcomes, did not produce a comparable effect on consumer perception, as the environmental rationale did not significantly increase the acceptability of the tethered cap among users. This highlights the limits to value-based acceptance of sustainability-driven packaging measures and underscores the importance of integrating user-centered evaluation into regulatory design and communication strategies. These insights contribute to the broader discussion on the effectiveness of regulatory packaging interventions in the beverage sector. Full article

Computed tomography (CT)-guided procedures require close proximity to the CT gantry or patient, increasing occupational exposure to scattered radiation. Even though radiation-protective equipment is commonly used, the optimization of CT fluoroscopic techniques remains important. Partial-angle CT (PACT) employs a limited exposure angle, producing cumulative scattered radiation distributions that vary with the selected angle and are difficult to estimate in advance. I aimed to develop an augmented reality (AR)-based visualization method for cumulative scattered radiation distributions during PACT and to evaluate its ergonomic feasibility as a proof of concept for occupational exposure reduction. An AR display system was developed to overlay cumulative scattered radiation distributions onto physical space using AR glasses. Workload was assessed using the NASA Task Load Index (NASA-TLX), and usability was assessed using the System Usability Scale (SUS). Compared with non-virtual conditions using radiation-protective glasses alone, AR-assisted visualization was associated with increased perceived workload, and usability scores were lower than those reported in previous AR studies. These findings indicate that, for AR display systems to support occupational exposure reduction, perceived task demands must be comparable to conventional protection strategies. Further improvements in visualization methods, user familiarity with AR environments, and ergonomic optimization are required to facilitate clinical implementation. Full article

Background: Work at heights is a high-risk occupational activity, with falls being a leading cause of fatal accidents in construction and industrial maintenance. Conventional safety training often does not fully prepare workers for real-world hazards. Immersive virtual reality (IVR) has emerged as a promising training tool, providing controlled and realistic simulations of hazardous scenarios. This hypothesis-generating pilot study evaluates the feasibility and effectiveness of IVR in enhancing practical skills, safety perception, and physiological responses during work-at-height training. Methods: This controlled trial will recruit first-time trainees from the National Learning Service (SENA) of Colombia. Participants will be assigned to an intervention group, receiving IVR training before field-based practical sessions, or a control group, receiving standard theoretical instruction. Outcomes include practical skill acquisition, ergonomic risk, cognitive performance, and physiological responses, including heart rate variability measured with validated devices. Assessments will be performed using standardized tools, and data will be analyzed with repeated-measures ANOVA and regression models to compare groups. Conclusions: By integrating practical, cognitive, ergonomic, and physiological measures, this study will provide evidence on whether IVR improves the effectiveness of work-at-height training beyond conventional methods. Findings may inform future strategies to enhance occupational safety training in high-risk work environments. Full article