Search Results (52)

This study investigates the effects of heart rate and arm tremor on performance in elite archery, using non-contact physiological monitoring from real Olympic competition footage. A total of 50 video segments were extracted from publicly available international broadcasts, comprising athletes of various backgrounds. From these, heart rate signals were estimated via remote photoplethysmography (rPPG) from facial regions, and micro-movements were quantified from right and left arm regions using feature point tracking. Ordinal logistic regression was employed to evaluate the relationship between biometric variables and archery scores (10, 9, ≤8 points). Results showed that elevated heart rate ($\beta$ = −0.1166; $p<$ 0.001) and greater right-arm movement ($\beta$ = −6.1747; p = 0.008) were significantly associated with lower scores. Athletes scoring 10 points exhibited significantly lower heart rate ($p<$ 0.001) and reduced right-arm tremor (p = 0.010) compared to others. These findings support the hypothesis that physiological arousal and biomechanical instability impair performance, and they further demonstrate the feasibility of contactless monitoring in real competition environments. The proposed method enables objective, in-game performance evaluation and supports the development of personalized training systems for precision sports. Full article

This study investigates how Iyengar yoga postures influence autonomic nervous system (ANS) activity by analyzing multimodal physiological signals collected via wearable sensors. The goal was to explore whether subtle postural variations elicit measurable autonomic responses and to identify which sensor features most effectively capture these changes. Participants performed a sequence of yoga poses while wearing synchronized sensors measuring electrodermal activity (EDA), heart rate variability, skin temperature, and motion. Interpretable machine learning models, including linear classifiers, were trained to distinguish physiological states and rank feature relevance. The results revealed that even minor postural adjustments led to significant shifts in ANS markers, with phasic EDA and RR interval features showing heightened sensitivity. Surprisingly, micro-movements captured via accelerometry and transient electrodermal reactivity, specifically EDA peak-to-RMS ratios, emerged as dominant contributors to classification performance. These findings suggest that small-scale kinematic and autonomic shifts, which are often overlooked, play a central role in the physiological effects of yoga. The study demonstrates that wearable sensor analytics can decode a more nuanced and granular physiological profile of mind–body practices than traditionally appreciated, offering a foundation for precision-tailored biofeedback systems and advancing objective approaches to yoga-based interventions. Full article

Adaptors, self-touching movements that supposedly lack communicative significance, have often been overlooked by researchers focusing on co-speech gestures. A significant complication in their study arises from the somewhat ambiguous definition of adaptors. Examples of these movements include self-manipulations like scratching a leg, bringing a hand to the mouth or head, and fidgeting, nervous tics, and micro hand or finger movements. Research rooted in psychology indicates a link between adaptors and negative emotional states. However, psycholinguistic approaches suggest that these movements might be related to the communicative task. This study analyzes adaptors in forty Cantonese speakers of English as a second language in monologues and dialogues in face-to-face and online contexts, revealing that adaptors serve functions beyond emotional expression. Our data indicate that adaptors might have cognitive functions. We also identify micro-movements, flutter-like adaptors or “flutters” for short, that may have interactive functions conveying engagement. These findings challenge the traditional view of adaptors as purely non-communicative. Participants’ self-reports corroborate these interpretations, highlighting the complexity and individual variability in adaptor use. This study advocates for the inclusion of adaptors in gesture analysis, which may enrich understanding of gesture–speech integration and cognitive and emotional processes in communication. Full article

Fatigue failure of overhead line conductors made of AlMgSi alloys is much more complex than fatigue failure of a single wire. The main difference lies in the fretting phenomenon, which is a significant mechanism initiating fatigue damage. It is generated because of micro-movements between individual wires or outer wires and overhead line fittings. Such movements are mainly caused by aeolian vibrations, which lead to degradation of wire surface, initiation of microcracks, and premature failure of multiple wires. Research based on laboratory experiments and modeling studies simulating real operating conditions made it possible not only to identify the mechanisms leading to failure but also to assess the impact of working conditions on their evolution. According to the obtained results, properly selected heat treatment parameters influence both the mass decrease of the wires and number of cycles to failure due to fretting fatigue. Further development of materials, protective coatings, and methods of durability prediction will reduce the impact of fretting on fatigue failure and thus increase the reliability of power lines. Full article

Aim: The aim of this preliminary study was to explore the visual attention in children with ADHD using eye-tracking, and to identify a relevant quantitative proxy of their attentional control. Methods: Twenty-two children diagnosed with ADHD (aged 7 to 12 years) and their 24 sex-, age-matched control participants with typical development performed a visual sustained-fixation task using an eye-tracker. Fixation stability was estimated by calculating the bivariate contour ellipse area (BCEA) as a continuous index of gaze dispersion during the task. Results: Children with ADHD showed a significantly higher BCEA than control participants (p < 0.001), reflecting their increased gaze instability. The impairment in gaze fixation persisted even in the absence of visual distractors, suggesting intrinsic attentional dysregulation in ADHD. Conclusions: Our results provide preliminary evidence that eye-tracking coupled with BCEA analysis, provides a sensitive and non-invasive tool for quantifying visual attentional resources of children with ADHD. If replicated and extended, the increased use of gaze instability as an indicator of visual attention in children could have a major impact in clinical settings to assist clinicians. This analysis focuses on overall gaze dispersion rather than fine eye micro-movements such as microsaccades. Full article

Electromagnetic articulography is a technique developed for recording three-dimensional movements. It is based on magnetic induction, where small currents are induced in miniature receiver coils acting as motion sensors by means of electromagnetic fields generated by transmitter coils. This technology has been applied in dental research to record mandibular movements during mastication, Posselt’s envelope of motion, and micromovements of dental prostheses. The AG501 electromagnetic articulograph (Carstens Medizinelektronik GmbH, Bovenden, Germany) provides a Head Correction (HC) procedure to eliminate head movement, which requires the reference sensors to be firmly attached to the subject’s head. If the sensors shift during the recordings, it becomes necessary to reposition them and repeat the head correction procedure. The aim of this study was to develop a 3D-printed helmet to securely fix the reference sensors to the head of a subject in the context of performing a series of recordings involving the mastication of 36 foods and the execution of Posselt’s envelope of motion. The number of HCs required was recorded for a group using the helmet and for a control group in which the sensors were attached to the subject’s head using tissue adhesive. A total of 29 recordings were conducted with and without the helmet. Without the helmet 44 HCs were required; on the other hand, with the helmet 36 HCs were required. On average, 1.5 HCs were required per session without the helmet and 1.2 HCs with the helmet, showing a non-significant difference (p < 0.05). A reduction in the number of HCs required per session was observed. However, more than one HC was still needed to complete a session. This could be addressed in future research by designing a series of helmets that adapt to different head sizes. Full article

Critical components in support structures for wind turbines, flange joints, are fundamental to ensure the structural integrity of mechanical assemblies under varying operational conditions. This paper investigates the structural performance of L-type flange joints, focusing on the influence of bolt grades and bolt pretension through a finite element analysis (FEA) study of its key performance indicators, including stress distribution, deformation, and force–displacement behaviors. This paper studies two high-strength bolt grades, Grade 10.9 and Grade 12.9, and two main steps—first, bolt pretension and, second, external loading (tower shell tensile load)—to investigate the influence on joint reliability and safety margins. The novelty of this study lies in its specific focus on static axial loading conditions, unlike the existing literature that emphasizes fatigue or dynamic loads. Results show that the specimen carrying a higher bolt grade (12.9) has 18% more ultimate load carrying capacity than the specimen with a lower bolt grade (10.9). Increased pretension increases the stability of the joint and reduces the micro-movements between A and B (on model specimen), but could result in material fatigue if over-pretensioned. Comparative analysis of the different bolt grades has provided practical guidance on material selection and bolt pretension in L-type flange joints for wind turbine support structures. The findings of this work offer insights into the proper design of robust flange connections for high-demand applications by highlighting a balance among material properties, bolt pretension, and operational conditions, while also proposing optimized pretension and material recommendations validated against classical analytical models. Full article

Introduction: Median sternotomy carries post-surgical risks like sternal instability, requiring careful monitoring. Ultrasonography provides a real-time, quantitative assessment of sternal micromovements and has emerged as a promising tool for clinical evaluation. However, its reliability for assessing sternal micromovements post-surgery remains unclear. This study evaluated the inter-rater, intra-rater, and test–retest reliability of ultrasound performed by physiotherapists. Methods: Ultrasound was used to measure the distance between sternal edges in sternotomized patients along the X-axis and Y-axis. Measurements were taken under a resting position, during cough, and in two supine-to-sitting postural transitions (one using a rotational modality and the other with an individual device). Real-time ultrasound imaging acquisition was followed by off-line data elaboration. Assessments were conducted by multiple physiotherapists after a brief training period. Reliability was determined using intraclass correlation coefficients (ICCs), along with the standard error of measurement (SEM) and minimum detectable change (MDC90). ICC values > 0.75 were classified as excellent. Results: A total of 33 subjects with median sternotomy were included (5 women, age 66 ± 7 years). All reliability measurements (24 total) were rated as excellent in each condition examined, with intra-rater ICCs exceeding 0.90, except for on the X-axis during the postural transition using the individual device for supine-to-sitting. SEM values ranged from 0.23 to 0.64 mm, while MDC90 values ranged from 0.54 to 1.50 mm. Conclusions: Ultrasound demonstrated excellent reliability for assessing sternal micromotions when performed by physiotherapists with brief training. Given its reliability, cost-effectiveness, and ease of use, ultrasound sternal micromotions assessment could be integrated into post-surgical rehabilitation to enhance patient care. Full article

Artistic masterpieces are mostly collected in museums located in the center of urban areas, which are prone to heavy traffic. Traffic-induced vibrations can represent a significant hazard for museum objects, due to the repeated nature of the excitation and the brittle, pre-damaged condition of the artifacts. This is the case of the Sarcophagus of the Spouses, displayed at the National Etruscan Museum of Villa Giulia in Rome. Vibrations on the floor of the room are measured by means of velocimeters, highlighting substantial vertical amplitudes and recommending the design of an isolation system. For its design, the dynamic identification of the statue is essential, but the use of contact or laser sensors is ruled out. Therefore, a recent technique that magnifies the micromovements present in digital videos is used and the procedure is validated with respect to constructions where the dynamic identification was available in the literature. In the case of the Sarcophagus, identified frequencies are satisfactorily compared with those of a finite element model. The recognition of the dynamic characteristics shows the method’s potential while using inexpensive devices. Because costs for cultural heritage protection are usually very high, this simple and contactless dynamic identification technique represents an important step forward. Full article

This study aimed to utilize finite element analysis (FEA) to evaluate the primary stability of Cyroth dental implants (AoN Implants Srl, Grisignano di Zocco, Italy) under various biomechanical conditions, including different implant inclinations (0°, 15°, and 20°) and bone densities (D3 and D4). By comparing these results with those obtained from in vitro tests on polyurethane blocks, the study sought to determine whether FEA could provide stability information more quickly and efficiently than in vitro methods. The research involved correlating dental implant micro-mobility with the implant stability quotient (ISQ) using FEA to simulate the mechanical behavior of implants and the surrounding bone tissue. Additionally, the study assessed the error in ISQ value detection by comparing FEA results with in vitro tests on polyurethane blocks conducted under the same experimental conditions. Both the FEA simulations and in vitro experiments demonstrated similar trends in ISQ values. For the D3 bone block simulated by FEA, the difference from the in vitro test was only 1.27%, while for the D2 bone, the difference was 2.86%. The findings also indicated that ISQ increases with implant inclination and that bone quality significantly affects primary stability, with ISQ decreasing as bone density diminishes. Overall, this study showed that ISQ evaluation for dental implants can be effectively performed through FEA, particularly by examining micro-movements. The results indicated that FEA and in vitro polyurethane testing yielded comparable outcomes, with FEA providing a faster and more cost-effective means of assessing ISQ across various clinical scenarios compared to in vitro testing. Full article

One main research area of the Competence Centre for Tribology is so-called standstill marks (SSMs) at roller bearings that occur if the bearing is exposed to vibrations or performs just micromovements. SSMs obtained from experiments are usually photographed, evaluated and manually categorized into six classes. An internal project has now investigated the extent to which this evaluation can be automated and objectified. Images of standstill marks were classified using convolutional neural networks that were implemented with the deep learning library Pytorch. With basic convolutional neural networks, an accuracy of 70.19% for the classification of all six classes and 83.65% for the classification of pairwise classes was achieved. Classification accuracies were improved by image augmentation and transfer learning with pre-trained convolutional neural networks. Overall, an accuracy of 83.65% for the classification of all six standstill mark classes and 91.35% for the classification of pairwise classes was achieved. Since 16 individual marks are generated per test run in a typical quasi standstill test (QSST) of the CCT and the deviation in the prediction of the classification is a maximum of one school grade, the accuracy achieved is already sufficient to carry out a reliable and objective evaluation of the markings. Full article

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of non-Hodgkin lymphomas, with mycosis fungoides and Sézary syndrome being the two common subtypes. Despite the substantial improvement in early-stage diagnosis and treatments, some patients still progress to the advanced stage with an elusive underpinning mechanism. While this unsubstantiated disease mechanism coupled with diverse clinical outcomes poses challenges in disease management, emerging evidence has implicated the tumor microenvironment in the disease process, thus revealing a promising therapeutic potential of targeting the tumor microenvironment. Notably, malignant T cells can shape their microenvironment to dampen antitumor immunity, leading to Th2-dominated responses that promote tumor progression. This is largely orchestrated by alterations in cytokines expression patterns, genetic dysregulations, inhibitory effects of immune checkpoint molecules, and immunosuppressive cells. Herein, the recent insights into the determining factors in the CTCL tumor microenvironment that support their progression have been highlighted. Also, recent advances in strategies to target the CTCL tumor micromovement with the rationale of improving treatment efficacy have been discussed. Full article

This paper designs a minimal neural network (NN)-based model-free control structure for the fast, accurate trajectory tracking of robotic arms, crucial for large movements, velocities, and accelerations. Trajectory tracking requires an accurate dynamic model or aggressive feedback. However, such models are hard to obtain due to nonlinearities and uncertainties, especially in low-cost, 3D-printed robotic arms. A recently proposed model-free architecture has used an NN for the dynamic compensation of a proportional derivative controller, but the minimal requirements and optimal conditions remain unclear, leading to overly complex architectures. This study aims to identify these requirements and design a minimal NN-based model-free control structure for trajectory tracking. Two architectures are compared, one NN per joint (INN) and one global NN (GNN), each tested on two serial robotic arms in simulations and real scenarios. The results show that the architecture reduces tracking errors (RMSE < 2°). The INN is accurate for decoupled joint dynamics and requires fewer training data than the GNN. A table summarizes the design process. Future works will apply this control structure to low-cost robotic arms and micro-movements. Full article

The noninvasive measurement and sensing of vital bio signs, such as respiration and cardiopulmonary parameters, has become an essential part of the evaluation of a patient’s physiological condition. The demand for new technologies that facilitate remote and noninvasive techniques for such measurements continues to grow. While previous research has made strides in the continuous monitoring of vital bio signs using lasers, this paper introduces a novel technique for remote noncontact measurements based on radio frequencies. Unlike laser-based methods, this innovative approach offers the advantage of penetrating through walls and tissues, enabling the measurement of respiration and heart rate. Our method, diverging from traditional radar systems, introduces a unique sensing concept that enables the detection of micro-movements in all directions, including those parallel to the antenna surface. The main goal of this work is to present a novel, simple, and cost-effective measurement tool capable of indicating changes in a subject’s condition. By leveraging the unique properties of radio frequencies, this technique allows for the noninvasive monitoring of vital bio signs without the need for physical contact or invasive procedures. Moreover, the ability to penetrate barriers such as walls and tissues opens new possibilities for remote monitoring in various settings, including home healthcare, hospital environments, and even search and rescue operations. In order to validate the effectiveness of this technique, a series of experiments were conducted using a prototype device. The results demonstrated the feasibility of accurately measuring respiration patterns and heart rate remotely, showcasing the potential for real-time monitoring of a patient’s physiological parameters. Furthermore, the simplicity and low-cost nature of the proposed measurement tool make it accessible to a wide range of users, including healthcare professionals, caregivers, and individuals seeking to monitor their own health. Full article

Edentulism can generate negative impacts on self-esteem, interpersonal relationships, and oral functions. Removable prostheses are commonly used for tooth replacement, but they may cause discomfort due to micromovements during mastication. Objective and quantifiable methods are needed to evaluate these micromovements. A pilot study was conducted to determine the micromovements in removable prostheses during mastication using a 3D electromagnetic articulography (EMA-3D) system. One elderly participant wearing lower removable prostheses and an upper total well-fitting removable prosthesis was studied. The EMA-3D system was used to record movements in three spatial planes. Peanuts were given as test food, and the participant was instructed to chew normally while recordings were carried out until feeling the need to swallow. Analyses of the upper total prosthesis show micromovements ranging from 0.63 ± 0.11 to 1.02 ± 0.13 mm. During simultaneous analyses of the upper prosthesis and lower partial prosthesis, interference was not observed. This pilot study demonstrated the feasibility of using the EMA-3D system to evaluate micromovements in removable prostheses during mastication. Further research is needed to evaluate a larger sample and assess the clinical implications of these micromovements. Full article