Body Movements Research Articles

Dome structure nonwoven-based dual-mode pressure-humidity sensor: Enhancing sensitivity and breathability for human health monitoring

In the field of health monitoring and electronic skin, flexible wearable sensors have attracted considerable research interest. However, preparing a flexible multifunctional sensor that simultaneously possesses a rapid response time, stability, reliability, high breathability, as well as high sensitivity remains a significant challenge. Herein, a flexible pressure-humidity dual-mode sensor based on nonwoven fabrics is developed in this study, using hydroentangled nonwoven fabric with graphene oxide/carbon nanotube composite as the sensing layer and polyester plain nonwoven fabric with carbon nanotube printed interdigitated electrodes as the electrode layer. The sensor exhibits high permeability (649.2 mm/s), high sensitivity (2.72 kPa−1), wide sensing range (0–220 kPa), fast response/recovery time (24.4 /73.3 ms), and low detection limit (2.79 Pa). In addition, the sensor exhibits excellent cyclic stability (15,000 cycles) and can detect both weak body movements (pulses, swallowing) as well as large deformational movements (joint movements). Furthermore, the sensing layer of the sensor responds quickly to different humidity levels, which can be used to monitor humidity in real time, and human breathing and speech can be monitored by placing it inside a mask. This high-performance flexible pressure-humidity dual-mode sensor shows promising potential for applications in health monitoring and respiratory monitoring.

ZIF-67 Assists ultra-high piezoelectric output based on PVDF flexible nanogenerator

As smart electronics and self-powered devices continue to evolve, the emergence of piezoelectric polymers has sparked significant research interest. In this pioneering project, we have successfully synthesized ZIF-67 particles/tetrabutylammonium hexafluorophosphate (TBAHP)/polyvinylidene fluoride (PVDF) tree-like nanofiber structures for the first time, which was characterized by a large number of branching nanofibers (down to 5 nm) and a uniform diameter trunk fiber (about 400 nm). And the synergistic interaction between these two distinct additives yields exceptional multifunctional properties. By optimizing the quantities of ZIF-67 and TBAHP, we enhanced the β-phase content and piezoelectric performance of PVDF through diameter refinement, interface coupling enhancement, and the introduction of a micro-capacitance mechanism. Notably, the improvements surpassed those achieved with a single additive. Specifically, the piezoelectric energy harvester fabricated using TBAHP/PVDF-TLNMs doped with 0.5 wt% ZIF-67 exhibited an output current of 4.25 μA and a peak voltage of 17.32 V, marking an increase of approximately 1187 % and 831 %, respectively, over pure PVDF nanofiber membranes. Furthermore, the device demonstrated sensitivity to motor movements and effectively harvested energy from diverse bodily motions.

Blends of polydimethylsiloxane-based polyurethane and poly (propylene glycol)-based polyurethane with co-continuous structures: Morphology evolution, synergistic effects and application in strain sensors

Blending is an effective way to improve properties of rubbers and develop new materials, so more than 75 % of the rubber consumption in the world is rubber blend. However, blending of thermoplastic elastomers has not yet been emphasized, and few successful examples have been reported. The main challenge for blend systems is compatibility of two components. Herein, a series of (polydimethylsiloxane-based PU)-g-(poly (propylene glycol)-based PU) ((PDMS-PU)-g-(PPG-PU)) graft copolymers with different graft chain lengths and hard segment contents (HSC) were synthesized and utilized as compatibilizers of PDMS-PU/PPG-PU blends. The influence of the structure of compatibilizers on the morphology of blends was investigated, and the compatibilization mechanism was proposed. With the solubilization, the phase structure of blends transforms from “droplet-in-matrix” morphologies to co-continuous ones, and the average size of PPG-PU dispersed phase decreases from 3.5 ± 0.45 μm to 230 ± 60 nm. This is the first time that thermoplastic PDMS-PU/PPG-PU blends with co-continuous structures have been successfully prepared. The properties of blends exhibit synergistic effects. For example, they show high tensile strength of PPG-PU in mechanical properties and unique properties of PDMS in dynamic mechanical properties, weather resistance, water resistance and biocompatibility. In addition, strain sensors were fabricated by introducing carbon nanotubes (CNTs) into the blends, which demonstrated remarkable sensing capability for diverse human body motions.

Cardiac Time Intervals under Motion Using Bimodal Chest E-Tattoos and Multistage Processing.

We present a thin, soft, and chest conformable bimodal sensor, known as the chest e-tattoo, coupled with an advanced signal processing framework to accurately identify various cardiac events, and thereby extract cardiac time intervals even during body motion. We built a wireless electronic tattoo that features synchronous electrocardiography (ECG) and seismocardiography (SCG). The SCG measures chest vibrations due to heartbeat, providing information on cardiovascular health that is complementary to the ECG. However, the efficacy of the SCG is compromised by motion-induced artifacts. The slim and stretchy design of the e-tattoo allows it to be strategically placed near the xiphoid process, facilitating high-quality monitoring of the ECG and SCG for increased signal quality. Nine participants were measured during walking and cycling. We propose a multistage signal processing framework, integrating an adaptive Normalized Least Mean Squares (NLMS) filter, ensemble averaging, and Empirical Mode Decomposition (EMD), together named the FAD framework, to accurately extract cardiac time intervals (CTIs).

Sensory augmentation for a rapid motor task in a multisensory environment.

Sensory substitution and augmentation systems (SSASy) seek to either replace or enhance existing sensory skills by providing a new route to access information about the world. Tests of such systems have largely been limited to untimed, unisensory tasks. To test the use of a SSASy for rapid, ballistic motor actions in a multisensory environment. Participants played a stripped-down version of air hockey in virtual reality with motion controls (Oculus Touch). They were trained to use a simple SASSy (novel audio cue) for the puck's location. They were tested on ability to strike an oncoming puck with the SASSy, degraded vision, or both. Participants coordinated vision and the SSASy to strike the target with their hand more consistently than with the best single cue alone, t(13) = 9.16, p <.001, Cohen's d = 2.448. People can adapt flexibly to using a SSASy in tasks that require tightly timed, precise, and rapid body movements. SSASys can augment and coordinate with existing sensorimotor skills rather than being limited to replacement use cases - in particular, there is potential scope for treating moderate vision loss. These findings point to the potential for augmenting human abilities, not only for static perceptual judgments, but in rapid and demanding perceptual-motor tasks.

The Physics and Mathematics of Ziplining

We study the kinematic and dynamic characteristics of body motion along an inclined hanging cable in the approximation of its masslessness and inextensibility. It is shown that in this case, the motion of the suspended body occurs along an inclined ellipse, the foci of which are the cable attachment points. Herewith, at any given moment, the net tension force of the cable is perpendicular to the instantaneous velocity of the body. Besides, the tension force is a dynamic characteristic of the cable and increases as the body descends along with the increase in the speed. There is also a sharp increase in the tension at the end of the trajectory, which is explained by a decrease in its radius of curvature.

Evolutionary Cognitive Enhancement: Stimulating Whole-Body Problem-Solving Capacities

AbstractThis article argues that understanding the primary functions of cognitive processes in our evolutionary past can help to develop effective cognitive enhancement methods. The adaptive problems our ancestors faced forged interconnected cognitive and motor mechanisms supporting various movement-based problem-solving processes. However, the physical and social challenges these cognitive-motor capacities originally evolved to address are no longer prevalent in modern societies. Consequently, many adaptive problem-solving mechanisms linked to a wide range of body movements are often underused and insufficiently developed in modern contexts, contributing to age-related cognitive decline. From this view, and considering current cognitive enhancement techniques such as cognitive training, neurostimulation, physical exercise, and combined cognitive and physical training, the present article introduces an evolutionary-inspired cognitive enhancement framework. This framework advocates for developing strategies and training methods that stimulate our evolved cognitive-motor adaptations. In particular, therapeutic interventions should incorporate adaptive problems and whole-body movement solutions into modern technologies and computer-based tasks.

Characterisation of the Rigid Body Vibration Spectra of Road Transport Vehicles

ABSTRACTFor decades, numerous attempts at re‐creating realistic (vertical) vibrations that purport to represent typical conditions during road transport have been proposed and published. This has and continues to result in a significant number of target power density spectra (PDS) for use in laboratory simulation of vibrations despite the fact that the underlying parameters that influence the vibrations (road surface unevenness and vehicle dynamics) remain largely unchanged. This paper seeks to address this situation by analysing published and measured PDS (129 in total) from a variety of vehicles and road types with the aim of establishing typical PDS. Through the analysis of the frequency of the first natural mode of these PDS, it was found that there exist five typical response PDS (three for steel leaf suspension and two for air ride suspension) that can be considered as representative vibration response PDS for road transport in general. These representative PDS were matched with a two degree‐of‐freedom quarter‐car model representing the heave response of the rigid body motion of the vehicles. The analysis suggests that the higher frequency content of the measured data is not related to rigid body motion but emanates from drivetrain and, in some cases, structural vibrations. These usually comprise numerous harmonics of fixed and varying frequencies as well as transients. As these vibrations are impossible to classify based on vehicle type, it is recommended that the five quarter‐car representative spectral models proposed in this paper—namely, for steel leaf spring suspended vehicles with heavy, moderate and light loads and air ride type vehicles with heavy and light loads—be used for laboratory simulation for the purpose of evaluating the vibration resistance of products and packaged systems. It is suggested that, for most packaged product, this is sufficient to test their ability to survive road transport vibrations. These will yield more realistic vibrations than those endorsed by standards organisations and should have a positive impact on the optimisation of packaging designs and a corresponding reduction in packaging waste. Finally, the need for further work aimed at developing methods to identify and extract fixed and varying discrete frequency vibration as well as transient vibrations was identified.

Enhancing output performance of triboelectric nanogenerators with ZnFe2O4 nanoparticles in biodegradable polylactic acid for sustainable energy harvesting

ABSTRACT The development of triboelectric nanogenerators (TENGs) using sustainable materials addresses the global electronic waste issue. This research focuses on fabricating a TENG device with biodegradable polylactic acid (PLA) as the tribopositive material and polytetrafluoroethylene (PTFE) as the tribonegative material. ZnFe2O4 nanoparticles are incorporated into the PLA matrix to enhance surface charge density and synthesised via a simple combustion method. PLA-ZnFe2O4 composite films were prepared by solvent casting with varying nanofiller content (0.25, 0.45, 0.65, and 0.85 g). Prepared composites were characterised by Powder X-ray Diffraction (PXRD) for crystalline nature and phase purity, Fourier Transform Infrared Spectroscopy (FTIR) for vibrational analysis, and Scanning Electron Microscopy (SEM) for surface morphology. The inclusion of ZnFe2O4 nanoparticles improves TENG output performance, with a maximum output voltage of 18.4 V and a current of 1.57 µA observed for a PLA (poly(lactic acid)) composite with 39.39% nanoparticle content. Electrical studies on the optimised device show successful charging of various capacitors and powering 20 LEDs and a calculator. Body movements like walking and jumping were also tested to measure voltage and current outputs. These findings highlight new possibilities for developing smart, self-powered electronic devices.

Validity and reliability of the Pain Assessment in Impaired Cognition 15 (PAIC15) observation scale in persons with aphasia

BackgroundThe use of self-report pain scales in persons with aphasia can be challenging due to communication and cognitive problems, while for assessing pain self-report pain is considered the gold standard (Harrison RA, Field TS. Post stroke pain: identification, assessment, and therapy. Cerebrovasc Dis. 2015;39(3–4):190–201.). An observational scale may be used as an alternative. This study examines the validity and reliability of the observational Pain Assessment in Impaired Cognition (PAIC15) scale in persons with aphasia.MethodsPersons with aphasia were observed during rest and transfer by two observers using the PAIC15. The PAIC15 comprises 15 items covering the three domains of facial expressions, body movements, and vocalizations. When able, the participant completed four self-report pain scales after each observation. The observations were repeated within one week. For criterion validity, correlations between the PAIC15 and self-report pain scales were calculated and for construct validity, three hypotheses were tested. Reliability was determined by assessing internal consistency, and intra- and interobserver agreement.ResultsPAIC15 observations were obtained for 71 persons (mean age 75.5 years) with aphasia. Fair positive correlations (rest: 0.35–0.50; transfer: 0.38–0.43) were reported between PAIC15 and almost all self-report pain scales. Results show that significantly more pain was observed in persons with aphasia during transfer than during rest. No differences were found for observed pain between persons with aphasia who use pain medication and those without, or persons who have joint diseases compared to those without. Results showed acceptable internal consistency. Intra- and interobserver agreement was high for most PAIC15 items, particularly for the domains body movements and vocalizations during rest and transfer.ConclusionsRecognition of pain in persons aphasia using the PAIC15 showed mixed yet promising results.

Strong and anti-swelling nanofibrous hydrogel composites inspired by biological tissue for amphibious motion sensors.

Conductive hydrogel-based sensors are increasingly favored for flexible electronics due to their skin-like characteristics. However, conventional hydrogels suffer from significant swelling in humid environments and poor mechanical properties which largely restrict their applications in wearable electronic devices, especially for underwater sensing. Herein, drawing inspiration from the extracellular matrix (ECM) structure, a TPU-PVAc@AgNPs/MXene nanofibrous hydrogel composite (TPAMH) with excellent mechanical robustness and anti-swelling properties is developed. The TPAMH nanofibrous hydrogel composite is created by integrating the silver nanoparticles (AgNPs) and MXene nanosheets into an interwoven network comprising of stiff TPU nanofibers as the fibril scaffold and formic acid-crosslinked PVA hydrogel fibers as the elastic matrix (PVAc). Benefiting from the unique ECM structure, the obtained nanofibrous hydrogel composites exhibit exceptional tensile strength (4.47 MPa), remarkable elongation at break (621%), excellent anti-swelling properties, and high detection sensitivity (maximum gauge factor = 105.02), which are sufficient to monitor body motions in both air and water environments effectively. They can detect large strain movements of fingers, elbows, wrists, and knees, as well as small strain physiological signals such as frown, smile, and pulse beats, with high accuracy. Particularly noteworthy is their ability to accurately identify underwater multidirectional motions and facilitate underwater smart alarms using Morse code.

Mechanically Induced Motor Tremors Disrupt the Perception of Time.

Contemporary research has begun to show a strong relationship between movements and the perception of time. More specifically, concurrent movements serve to both bias and enhance time estimates. To explain these effects, we recently proposed a mechanism by which movements provide a secondary channel for estimating duration that is combined optimally with sensory estimates. However, a critical test of this framework is that by introducing "noise" into movements, sensory estimates of time should similarly become noisier. To accomplish this, we had human participants move a robotic arm while estimating intervals of time in either auditory or visual modalities (n = 24, ea.). Crucially, we introduced an artificial "tremor" in the arm while subjects were moving, that varied across three levels of amplitude (1-3 N) or frequency (4-12 Hz). The results of both experiments revealed that increasing the frequency of the tremor led to noisier estimates of duration. Further, the effect of noise varied with the base precision of the interval, such that a naturally less precise timing (i.e., visual) was more influenced by the tremor than a naturally more precise modality (i.e., auditory). To explain these findings, we fit the data with a recently developed drift-diffusion model of perceptual decision-making, in which the momentary, within-trial variance was allowed to vary across conditions. Here, we found that the model could recapitulate the observed findings, further supporting the theory that movements influence perception directly. Overall, our findings support the proposed framework, and demonstrate the utility of inducing motor noise via artificial tremors.

Knowing where to go: Spatial memory guides eye and body movements in a naturalistic visual search task.

Most research on visual search has used simple tasks presented on a computer screen. However, in natural situations visual search almost always involves eye, head, and body movements in a three-dimensional (3D) environment. The different constraints imposed by these two types of search tasks might explain some of the discrepancies in our understanding concerning the use of memory resources and the role of contextual objects during search. To explore this issue, we analyzed a visual search task performed in an immersive virtual reality apartment. Participants searched for a series of geometric 3D objects while eye movements and head coordinates were recorded. Participants explored the apartment to locate target objects whose location and visibility were manipulated. For objects with reliable locations, we found that repeated searches led to a decrease in search time and number of fixations and to a reduction of errors. Searching for those objects that had been visible in previous trials but were only tested at the end of the experiment was also easier than finding objects for the first time, indicating incidental learning of context. More importantly, we found that body movements showed changes that reflected memory for target location: trajectories were shorter and movement velocities were higher, but only for those objects that had been searched for multiple times. We conclude that memory of 3D space and target location is a critical component of visual search and also modifies movement kinematics. In natural search, memory is used to optimize movement control and reduce energetic costs.

Visuomotor prediction during action planning in the human frontoparietal cortex and cerebellum.

The concept of forward models in the brain, classically applied to describing on-line motor control, can in principle be extended to action planning, i.e. assuming forward sensory predictions are issued during the mere preparation of movements. To test this idea, we combined a delayed movement task with a virtual reality based manipulation of visuomotor congruence during functional magnetic resonance imaging. Participants executed simple hand movements after a delay. During the delay, two aspects of the upcoming movement could be cued: the movement type and the visuomotor mapping (i.e. congruence of executed hand movements and visual movement feedback by a glove-controlled virtual hand). Frontoparietal areas showed increased delay period activity when preparing pre-specified movements (cued > uncued). The cerebellum showed increased activity during the preparation for incongruent > congruent visuomotor mappings. The left anterior intraparietal sulcus showed an interaction effect, responding most strongly when a pre-specified (cued) movement was prepared under expected visuomotor incongruence. These results suggest that motor planning entails a forward prediction of visual body movement feedback, which can be adjusted in anticipation of nonstandard visuomotor mappings, and which is likely computed by the cerebellum and integrated with state estimates for (planned) control in the anterior intraparietal sulcus.

Energy-Harvesting Device Based on Lead-Free Perovskite

This research investigates the solid-state synthesis of lead-free (K, Na)0.5NbO3 ceramics to improve the performance of triboelectric nanogenerators (TENGs) for energy-harvesting applications. The TENGs have developed as potential devices for converting mechanical energy into electrical energy. However, traditional TENG materials frequently include lead, which raises environmental and health problems. To overcome this issue, lead-free ceramics were examined as alternative materials with superior properties. In this work, a TENG was fabricated using potassium sodium niobate (KNN) ceramics as one triboelectric layer, Kapton as the other triboelectric layer, and a flexible substrate. The aim was to create TENGs with improved performance and environmental sustainability. The output performance of the TENG was estimated to be 70 V and 1100 nA. The TENG was further used to charge capacitors, light up an LED, and harvest energy from various body motions.

Development of a body movement detection system to avoid re-exposure during radiography.

During the radiographic examination of the chest and bones in hospitals, communicating and maintaining posture is difficult for some patients, and movement before or during X-ray irradiation may necessitate re-exposure owing to body wobbling movements or breathing movements. To prevent the need for re-exposure during radiography and to determine the exposure timing, a body movement detection system that considers breathing movements was developed in this study. The posture of a patient was monitored using an RGB camera. The acquired video data was analyzed to detect body movement using either an inter-frame difference method or an optical flow estimation method. The performance of the system was evaluated by detecting the body and breathing movements during positioning. Consequently, the inter-frame difference method detected 179.8-1222.2pixels during body movements, and the optical flow estimation method confirmed that the feature points moved by 5.5-26.6mm (4.2-20.3pixels). When detecting breathing movements, 82-585pixels were detected by the inter-frame difference method, and the optical flow estimation method showed that the feature points moved by 5.2mm (2-4pixels). Therefore, the proposed method can detect body movements during radiography to prevent re-exposure due to body wobble and breathing movements. For healthcare providers, it will lead to reduce not only concerns about patient exposure but also unnecessary radiographic workload.

Fetal Outcome Evaluation in High-risk Term Pregnancy Using Biophysical Profile at a Tertiary Hospital in Anambra State, Nigeria

Introduction: A high-risk pregnancy is defined as a pregnancy in which there is a significant probability of an adverse maternal or fetal outcome that is more than the incidence of that outcome in the general population. Aim: To determine the usefulness of biophysical profile evaluation in women with high-risk term pregnancies. Methods: Biophysical profile (BPP) parameters were used to evaluate 160 high-risk women with term pregnancies. Results: All the participants had normal amniotic fluid index values [AFI] of 8.1-24.0cm. Most of the participants 115 (71.9%) showed good BPP scores. Outcome at delivery was as follows; fetal distress [presence 8.9%, absence 91.1%], stillbirth = none, admission into the intensive care unit (ICU) [Yes 2.0%, No 88%], meconium staining [Yes 8.2%, Clear 91.8%], birth weight [&lt; 2.5kg = 5.7%, &gt; 2.5kg = 94.3%]. APGAR score at 1 minute [&lt;7 = 5.1%, &gt;7 = 94.9%] while at 5 minutes [&lt;7 = 3.2%, &gt; 7= 96.8%]. The commonest mode of delivery was vaginal 84 (52.8%). The association between gross body movement, fetal breathing movement, and fetal outcome was not statistically significant p &gt; 0.05. Conclusion: BPP parameters were found to be associated with fetal outcomes.

Sternalis muscle, a rare anatomical variation with clinical implications

Abstract The sternalis muscle is a rare variant of the anterior chest wall musculature. Although its frequency in general population worldwide has been reported from 2% to 8%, its prevalence depends on regions and populations. The aim of this paper is to describe one of the first cases of sternalis muscle found in Central Europe. An anterior chest wall of 64-year-old white male was dissected during a regular anatomy class at Department of Human Anatomy. A right unilateral sternalis muscle was revealed and described. The unilateral sternalis muscle laid between the pectoral and the superficial thoracic fascia. The muscle was long and wide. In addition, it had a massive tendon. According to the Snosek et al. Classification, it was a “simple unilateral” type. This report presents another case of the sternalis muscle among humans. Although the sternalis muscle serves a minor role in body movement, its occurrence gives several clinical implications. The awareness of variability in the thoracic region is important during diagnostic and treatment processes or in surgical operation planning.

Computational biomechanics for a standing human body: Modal analysis and simulation.

We develop computational mechanical modeling and methods for the analysis and simulation of the motions of a human body. This type of work is crucial in many aspects of human life, ranging from comfort in riding, the motion of aged persons, sports performance and injuries, and many ergonomic issues. A prevailing approach for human motion studies is through lumped parameter models containing discrete masses for the parts of the human body with empirically determined spring, mass, damping coefficients. Such models have been effective to some extent; however, a much more faithful modeling method is to model the human body as it is, namely, as a continuum. We present this approach, and for comparison, we choose two digital CAD models of mannequins for a standing human body, one from the versatile software package LS-DYNA and another from open resources with some of our own adaptations. Our basic view in this paper is to regard human motion as a perturbation and vibration from an equilibrium position which is upright standing. A linear elastodynamic model is chosen for modal analysis, but a full nonlinear viscoelastoplastic extension is possible for full-body simulation. The motion and vibration of these two mannequin models is analyzed by modal analysis, where the normal vibration modes are determined. LS-DYNA is used as the supercomputing and simulation platform. Four sets of low-frequency modes are tabulated, discussed, visualized, and compared. Higher frequency modes are also selectively displayed. We have found that these modes of motion and vibration form intrinsic basic modes of biomechanical motion of the human body. This view is supported by our finding of the upright walking motion as a low-frequency mode in modal analysis. Such a "walking mode" shows the in-phase and out-of-phase movements between the legs and arms on the left and right sides of a human body, implying that this walking motion is spontaneous, likely not requiring any directives from the brain. Dynamic motions of CAD mannequins are also simulated by drop tests for comparisons and the validity of the models is discussed through Fourier frequency analysis. All computed modes of motion are collected in several sets of video animations for ease of visualization. Samples of LS-DYNA computer codes are also included for possible use by other researchers.

Physical Activity in Pregnancy: The Role of Exercise in Promoting Maternal and Fetal Health

Introduction and Objective: There is no doubt that engaging in regular physical activity is beneficial for individuals of all ages. Pregnancy is a special time of life for most women. This period presents a unique opportunity for them to improve their lifestyle choices and adopt healthier habits such as exercise. The aim of this article is to find out if regular physical activity during pregnancy has a positive impact for both the mother and the baby.Review and Methods: Review and summary of available studies and meta-analyses found in open-access formats on Google Scholar and PubMed.State of Knowledge: The WHO defines physical activity as any bodily movement requiring energy expenditure, including during leisure, transport, work, and domestic activities. Regular exercise reduces the risk of noncommunicable diseases (NCDs) and poor health outcomes, while sedentary behavior contributes to this and burdens healthcare systems. For pregnant and postpartum women, physical movement decreases the risk of various complications, with no negative effects on birthweight or stillbirth risk. Conclusions: Studies show that physical activity decreased risk of pre-eclampsia, gestational hypertension, gestational diabetes, excessive gestational weight gain, delivery complications, postpartum depression and newborn complications.