Natural Motion Research Articles

On fertility of female population of large-scale industrial agglomeration of cities of the Irkutsk Oblast

The article considers the most important demographic indicator of natural movement of population - the natality. The dynamics of age-specific fertility of female population residing industrial highly urbanized areas of the region is demonstrated. The increase of total fertility was established. The dynamics of common and standardized coefficients of age-specific fertility of female population revealed process of aging (motherhood). However, the cleared, accurate net-coefficient of population reproduction indicates that positive dynamics of general, age-specific fertility ensures only simple character of population reproduction in city of Angarsk. The population of cities of Irkutsk and Shelekhov remains in narrowed character of population reproduction. The special coefficients of fertility make it possible to obtain accurate age-specific qualitative characteristic of fertility of female population and to forecast demographic situation in the region.

Wearable Loop Sensors for Knee Flexion Monitoring: Dynamic Measurements on Human Subjects.

Goals: We have recently introduced a new class of wearable loop sensors for joint flexion monitoring that overcomes limitations in the state-of-the-art. Our previous studies reported a proof-of-concept on a cylindrical phantom limb, under static scenarios and with a rigid sensor. In this work, we evaluate our sensors, for the first time, on human subjects, under dynamic scenarios, using a flexible textile-based prototype tethered to a network analyzer. An untethered version is also presented and validated on phantoms, aiming towards a fully wearable design. Methods: Three dynamic activities (walking, brisk walking, and full flexion/extension, all performed in place) are used to validate the tethered sensor on ten (10) adults. The untethered sensor is validated upon a cylindrical phantom that is bent manually at random speed. A calibration mechanism is developed to derive the sensor-measured angles. These angles are then compared to gold-standard angles simultaneously captured by a light detection and ranging (LiDAR) depth camera using root mean square error (RMSE) and Pearson's correlation coefficient as metrics. Results: We find excellent correlation (≥ 0.981) to gold-standard angles. The sensor achieves an RMSE of 4.463° ± 1.266° for walking, 5.541° ± 2.082° for brisk walking, 3.657° ± 1.815° for full flexion/extension activities, and 0.670° ± 0.366° for the phantom bending test. Conclusion: The tethered sensor achieves similar to slightly higher RMSE as compared to other wearable flexion sensors on human subjects, while the untethered version achieves excellent RMSE on the phantom model. Concurrently, our sensors are reliable over time and injury-safe, and do not obstruct natural movement. Our results set the ground for future improvements in angular resolution and for realizing fully wearable designs, while maintaining the abovementioned advantages over the state-of-the-art.

Рождаемость и смертность населения Удмуртии в 1930-е гг.

The aim of the study was to examine the birth rate and mortality in Udmurtia in the 1930s. To date, almost no one has studied this topic. The objectives of the study include studying the reproduction rates of the population of Udmurtia and identifying factors influencing the dynamics of changes, as well as comparing the birth rate and mortality of the population of Udmurtia and the RSFSR/USSR. The scientific novelty lies in the fact that a large volume of previously unpublished materials is introduced into scientific discourse, a significant gap in Russian history is filled. The sources were mainly unpublished materials of the natural movement of the Statistical Office and office records of the health authorities of Udmurtia. The results of the study showed that the birth rate in Udmurtia was much higher than in the European part of the Soviet Union, especially in the first half of the 1930s. The main reasons for this are the national specifics of the region (a significant part of the population is Udmurts with increased birth rates), lower educational level of women, and a higher proportion of villagers. In turn, in the village of Udmurtia, the birth rate was higher than in cities (except 1937). In the second half of the decade, the birth rate in the republic decreased, approaching the all-Union indicator. It fell due to higher rates of urbanization, the spread of abortion, the famine of 1936 due to large-scale crop failure, which was as significant as in 1932/33. The mortality rate in Udmurtia was also much higher (except for 1933) than the all-Union one. The high mortality rate of the entire population was mainly due to significant morbidity, among the main causes of death exogenous. Mortality increased sharply during the hunger years. The thencurrent level of medical care was unsatisfactory. The shortage of medical workers was acute; their qualifications often raised questions. The allocated funds were not enough for the purchase of medicines and the necessary equipment. In the second half of the 1930s, the difference in mortality rates in the USSR and Udmurtia slightly decreased. Total mortality was greatly influenced by infant mortality. Its share was extremely high and it decreased very slowly throughout the 1930s. In the first place among the causes of infant mortality were gastrointestinal diseases due to poor nutrition. In the second place were congenital weakness and premature birth. They, in turn, were explained by the difficult working conditions of women in the workplace, as well as by the high percentage of mothers with syphilis, which was almost never detected or treated during pregnancy. In the third place were lung diseases caused by crowding and the spread of rickets due to a lack of vitamins. With a few exceptions, the natural population growth in Udmurtia was more significant than in the European part of the USSR. In addition, it was positive all these years, even in 1933.

Prosthetic hand for phocomelia patients with enhanced pain management using EMG signal processing and biofeedback control system

Denoising is an essential step in data mining. It makes an effort to remove noise from the picture without sacrificing any of the important elements. The primary method utilized in this project to assess the effectiveness of phocomelia images is Kmeans clustering. The PSNR and MSE values of the denoised image are computed. In the end, the best technique for denoising medical images is chosen based on the PSNR values from the collection of patient data necessary for the fitting of upper limb devices. Using image processing, the bone health of phocomelia patients are evaluated and specific information extracted from MRI scans. Electromyography (EMG) sensors pick up electrical impulses, convert them into hand movements that the user wants, and flex the muscles in the residual limb directly below the elbow. The same muscles that enable hand function in humans are also felt by the system using microcontrollers. Through the integration of sophisticated sensor technologies with responsive prosthetic design idea, this newly developed technique enhances feedback from the proprioceptive system for patients with phocomelia, hence promoting natural movement and improving functional outcomes. As a result, it provides phocomelia patients a special method for acquiring superior result from biofeedback system.

A Novel Passive Occupational Shoulder Exoskeleton With Adjustable Peak Assistive Torque Angle For Overhead Tasks.

Overhead tasks are a primary inducement to work-related musculoskeletal disorders. Aiming to reduce shoulder physical loads, passive shoulder exoskeletons are increasingly prevalent in the industry due to their lightweight, affordability, and effectiveness. However, they can only handle specific tasks and struggle to balance compactness with a sufficient range of motion effectively. We proposed a novel passive occupational shoulder exoskeleton designed to handle various overhead tasks at different arm elevation angles, ensuring sufficient ROM while maintaining compactness. By formulating kinematic models and simulations, an ergonomic shoulder structure was developed. Then, we presented a torque generator equipped with an adjustable peak assistive torque angle to switch between low and high assistance phases through a passive clutch mechanism. Ten healthy participants were recruited to validate its functionality by performing the screwing task. Measured range of motion results demonstrated that the exoskeleton can ensure a sufficient ROM in both sagittal (164°) and horizontal (158°) flexion/extension movements. The experimental results of the screwing task showed that the exoskeleton could reduce muscle activation (up to 49.6%), perceived effort and frustration, and provide an improved user experience (scored 79.7 out of 100). These results indicate that the proposed exoskeleton can guarantee natural movements and provide efficient assistance during overhead work, and thus have the potential to reduce the risk of musculoskeletal disorders. The proposed exoskeleton provides insights into multi-task adaptability and efficient assistance, highlighting the potential for expanding the application of exoskeletons.

A Novel Low-Pressure Robotic Glove Based on CT-Optimized Finger Joint Kinematic Model for Long-Term Rehabilitation of Stroke Patients.

Wearing robotic gloves has become increasingly crucial for hand rehabilitation in stroke patients. However, traditional robotic gloves can exert additional pressure on the hand, such as prolonged use leading to poor blood circulation and muscle stiffness. To address these concerns, this work analyzes the finger kinematic model based on computerized tomography (CT) images of human hands, and designs a low-pressure robotic glove that conforms to finger kinematic characteristics. Firstly, physiological data on finger joint flexion and extension were collected through CT scans. The equivalent rotation centers of finger joints were obtained using the SURF and RANSAC algorithms. Furthermore, the trajectory of finger joint end and the correlation equation of finger joint motion were fitted, and a comprehensive finger kinematic model was established. Based on this finger kinematic model, a novel under-actuated exoskeleton mechanism was designed using a human-machine integration approach. The novel robotic glove fully aligns with the equivalent rotation centers and natural motion trajectories of the fingers, exerting minimal and evenly distributed dynamic pressure on the fingers, with a theoretical static pressure value of zero. Experiments involving gripping everyday objects demonstrated that the novel robotic glove significantly reduces the overall pressure on the fingers during grasping compared to the pneumatic glove and the traditional exoskeleton robotic glove. It is suitable for long-term use by stroke patients for rehabilitation training.

Designing and Analyzing In-Place Motor Tasks in Virtual Reality With Goal Functions.

Goal functions make virtual goal-oriented motor tasks easier to analyze and manipulate by explicitly linking movement to outcome. However, they have only been used to study constrained (e.g., planar) upper limb movements. We present a design framework for integrating goal functions with unconstrained postural and upper limb movements in a virtual reality (VR) device. VR tasks designed with the framework can mimic unconstrained natural motions and thus train a range of functional movements yet remain analytically tractable. We created three in-place VR motor tasks: a bow-and-arrow, a reach-and-strike, and a punching bag task. Each task was adjusted to subject-specific workspace limits and anthropometrics. We studied the effects of 3 days of practice and 3 reach/lean distances on task performance in 12 healthy adults. Subjects performed all tasks on day 1 with moderate proficiency and improved with practice at all reach/lean distances. Task-specific results showed that performance decreased and movement variability increased near the edge of the reaching workspace; viewing angles and the imperfect depth cues in VR likely led to biases in performance and practice could attenuate the former effect; in reach-and-strike, subjects learned movement patterns similar to those seen in a real-world striking sport. These results show that our framework can deliver tasks useful for analyzing and training motor performance and can guide future in-place motor training. Post-hoc, we demonstrated the feasibility of generalizable methods that adjust required movement speeds and task difficulty for impaired populations.

Control of Dynamic Biped Walking Robot

The objective of this article is to present control algorithms of biped dynamic walking robot. A mathematical model of the walking robot is compiled. The construction of the robot is based on minimalist design principles - absolutely solid body with two legs. Analytical dependencies between six coordinates of the body, coordinates of the left and right legs and absolute coordinates of the feet are defined. The block diagram of control system is presented. Differential equations of walking are compiled. The dynamic stability of biped walking robot near the required trajectory is provided by discrete control of the parameters: «when and where to put foot». To define these parameters, it is proposed to use an inverted mathematical pendulum as an ideal mechanism. Its linearized differential equations allow present the feet coordinates according to the measured initial and final parameters (at the begging and at the end of the step). The article paid particular attention to results of such control method with various walking modes. The coordinates of the robot body, its velocities and accelerations, angles of rotation were investigated. Calculations confirmed the small deviations of the proposed model of walking from the ideal one. The developed methodology allows improve the construction and control system of biped dynamic walking robots at the design stage. Some of the tasks, it can be used: design machines simulating human walking, with high speed and maneuverability, with point feet and synchronized with natural uncontrolled movements.

The role of street network metrics in shaping distance distributions in a residential neighbourhood

Walkability studies often rely on physical proximity metrics for destination accessibility. However, some recent studies argue that configuration (topological) distance provides a more accurate reflection of the actual distances experienced by individuals. This study therefore aims to test the extent to which an association exists between network-metric proximity to several destinations and two main measures of space syntax – integration and choice – in a dendriform network structure such as Putrajaya city (Malaysia). Using GIS, multiple buffer-service areas were generated around each housing unit (N = 2,392). Interpolation and space syntax analyses were conducted to assess metric and topological distance at local and global levels for each buffer. The statistical analysis showed that distances to commercial areas, transportation and average distances to all destinations were strongly affected by the syntactical properties of the neighbourhood. Moreover, global measures were more powerful in detecting metric-distance changes compared to local measures. Aligned with natural movement theory, these results support the idea that the spatial properties of urban form have a significant impact on distance distributions within residential settings, specifically distances to commercial areas. Therefore, policies that promote mixed-use development, especially in areas with good transportation access, should consider the impact of syntactical accessibility of the network.

Thermal characterization and ventilation assessment of a battery-caged laying hen housing in the humid tropic climate.

The indoor climate to which livestock are exposed is a critical factor influencing their performance and productivity. Elevated air temperature and relative humidity could result in heat stress for laying hens. This situation results in severe adverse effects such as weight loss and mortality. Egg fertility and hatchability are also impacted. Consequently, a study was carried out in a naturally ventilated battery-caged laying hen house to measure climatic variables (air temperature, relative humidity and air velocity). The degree of heat stress was assessed using the temperature-humidity index (THI), and the index of temperature and air velocity (ITV) was also evaluated. According to the results obtained, birds reared within the study building would spend most of their productive life under stressful thermal conditions, which could significantly hamper their performance. The air velocity was below 1.0 ms-1 for most of the internal part of the housing, meaning natural air movement at the location was insufficient to provide a suitable environment for the birds. A high THI was recorded for nearly the entire study period. This high THI could indicate high relative humidity about air temperature. The observed ITV values (ITV > 25) suggest that birds throughout the building could be perpetually uncomfortable. The thermal and velocity profile within the structure could further be assessed numerically using computational fluid dynamics. This would enable engineers to make modifications to improve living conditions within the building.

Естественное движение населения Коми АССР в 1946–1959 годах

The paper deals with the natural movement of the population of the Komi ASSR in 1946-1959. The post-war period was the most pronounced stage of the demographic transition in the republic. The problems of statistical accounting of the population movement in the post-war years are considered. The dynamics of absolute and relative indicators of fertility, mortality, marriage and divorce are analyzed. The influence of gender, age, nationality and type of settlement on the intensity of natural population movement is estimated. The transformation of the structure of causes of mortality, including infant mortality, is considered. Territorial differences in indicators of natural population movement at the level of urban settlements and Village Soviets are revealed.

Design, control and evaluation of a treadmill-based Pelvic Exoskeleton (PeXo) with self-paced walking mode

Most gait rehabilitation exoskeletons focus only on assisting lower limb motions. However, the pelvis plays an essential role in overground ambulation. This calls for the need of gait training devices that allow full control and assistance of user’s pelvis to improve gait rehabilitation therapies of stroke survivors. This paper presents a new pelvic assistance treadmill-based exoskeleton (PeXo) for gait rehabilitation. The system includes a total of 5 actively controlled Degrees of Freedom (DOFs), plus a passive one, in order to provide all DOFs of the human pelvis. The paper describes the mechatronic design and haptic control of PeXo, and introduces a newly developed self-paced walking mode where the user can control walking speed at his/her will. The system was evaluated by means of a pilot study with a stroke survivor. Results showed PeXo can be used safely and reliably during walking activities, allowing for the natural motion of the pelvis with reduced interaction forces. However, the use of the platform reduced user’s Range of Motion at the pelvis and lower limb joints, whereas lower limb’s muscle activity increased to compensate the disturbances introduced by the platform. Nevertheless, the user reported a positive feedback when using the system, suggesting potential and promising advantages of PeXo that should be explored in a larger study in the future.

«Цифровой двойник» населения Арктики в демографических исследованиях и управлении развитием территорий

The article considers “digital twins” of the population as a tool for socio-demographic research and territorial management. The experience of creating digital twins of the population and interactive web-sites devoted to demographic issues is systematized. A methodology for creating a digital twin of the Arctic population is proposed, based on three methodological principles: consideration of the hierarchy of territories, spatial representation of data, and combining demographic statistics with new digital data sources. The author has developed the Digital twin of the Arctic population — an interactive website (dashboard) containing detailed data on the Arctic population, including municipal and settlement levels. It includes demographic statistics, census results and data from digital platforms. The Digital twin of the Arctic population covers such issues as the size, dynamics and composition of the population, resettlement, natural and migration movement, labor and employment, transport movements, science and education, and the impact of the pandemic on demographic processes. Tools of ranking, multivariate analysis, clustering and forecasting of indicator values are implemented for researchers. From the viewpoint of state and municipal management, the main interest is the demographic profiles of regions and territories, reflecting up-to-date information about the demographic situation. Using the Digital twin of the Arctic population, the author draws conclusions about the spatial patterns of the demographic development of the Russian Arctic.

Portable markerless hand motion capture system for determining the grasps performed in activities of daily living

ABSTRACT Upper-limb prostheses are either too expensive for many consumers or have a greatly simplified choice of actions. This research aims to enable an improvement to the quality of life for recipients of these devices by providing an understanding of how we use our hands in modern everyday life. To achieve this a taxonomy of grasps used in activities of daily living has been created. A portable motion capture system was developed to collect data. Thirteen participants’ hand movements were recorded (totalling 62 hours and 10 minutes of data). From these data, 38 and 22 grasps were observed from the left and right hands, respectively. The portable system effectively captured natural hand motions, which formed an updated taxonomy of grasps.

Research on the progress of neurorehabilitation

With the intensification of global aging problems, the incidence of central nervous system diseases such as stroke is getting higher and higher. At the same time, the number of disabled people has also increased. Amputation and neurological diseases are important causes of disability, and neurorehabilitation is an important method for restoring the nervous function and autonomous movement ability of the disabled. At present, neurorehabilitation methods commonly used in clinical treatment mainly include: wearing prosthetic limbs, functional electrical stimulation (FES) therapy, rehabilitation robots, and so on. The prosthetic limb refers to an artificial device used to replace the function of a lost limb. Many advanced technologies are being used to improve the motion control of prosthetics to achieve natural movement. FES is a technique that can improve physiological function or treat diseases by stimulating nerves or tissues through current, and has become one of the important means to promote nerve regeneration and restore motor function. Rehabilitation robots are the equipment that uses mechanical devices and advanced control technology to assist rehabilitation treatment and functional recovery. This article mainly discusses the current research progresses of prosthetic limbs, EFS and rehabilitation robots, so as to promote the development of neurorehabilitation.

Contrariety and Complementarity: Reading Spinoza’s Intersubjective Holism of Ideas with Aristotle’s Two Accounts of Motion

Do minds and ideas connect, interact, or even depend on each other, and if so, how exactly do they connect and interact? How to conceive of the mode and process of minds and ideas being in a network and connected in some way, that is, being intersubjective or social? Martin Lenz’s study Socializing Minds (2022) convincingly shows that, contrary to widespread opinion in philosophy of mind, at least some early modern philosophers, here Spinoza, Locke, and Hume, actually give a positive answer to the first question and present models that respond to the second question, thus, addressing what Lenz proposes to call ‘the contact problem’ and repudiating the idea that mentalism is necessarily bound to individualism. In this comment, I focus on a detail in Lenz’s reconstruction of Spinoza’s ‘metaphysical model’ of intersubjectivity of minds, namely the Aristotelian physical dynamism that would underlie Spinoza’s idea of the interaction of minds. While I agree that Spinoza’s model of the interaction of minds refers to the Aristotelian conception of motion, I argue that the guiding principle in natural motion is best understood not only in terms of contrariety but also in terms of complementarity. A closer reading of Aristotle’s theory of motion (kinēsis, metabolē) identifies two approaches to natural motion, one based on contrary principles, the other on complementary principles or powers (dynameis; potentiae). I suggest conceiving them as two sources for modelling natural motion and thus as two resources for a kinetic modelling of intersubjectivity and sociality. Admittedly, my proposal goes beyond Spinoza’s model of ideas in contact, and probably beyond Lenz's interpretation of that model, but it might enrich the imagination of the socialising of minds and ideas from a kinetic point of view, which, at least as I understand it, is precisely what Spinoza and Lenz thrive on.

Human-network regions as effective geographic units for disease mitigation

Susceptibility to infectious diseases such as COVID-19 depends on how those diseases spread. Many studies have examined the decrease in COVID-19 spread due to reduction in travel. However, less is known about how much functional geographic regions, which capture natural movements and social interactions, limit the spread of COVID-19. To determine boundaries between functional regions, we apply community-detection algorithms to large networks of mobility and social-media connections to construct geographic regions that reflect natural human movement and relationships at the county level in the coterminous United States. We measure COVID-19 case counts, case rates, and case-rate variations across adjacent counties and examine how often COVID-19 crosses the boundaries of these functional regions. We find that regions that we construct using GPS-trace networks and especially commute networks have the lowest COVID-19 case rates along the boundaries, so these regions may reflect natural partitions in COVID-19 transmission. Conversely, regions that we construct from geolocated Facebook friendships and Twitter connections yield less effective partitions. Our analysis reveals that regions that are derived from movement flows are more appropriate geographic units than states for making policy decisions about opening areas for activity, assessing vulnerability of populations, and allocating resources. Our insights are also relevant for policy decisions and public messaging in future emergency situations.

Characterizing ramp events in floating offshore wind power through a fully coupled electrical-mechanical mathematical model

Floating Offshore Wind Turbines (FOWTs) exhibit a noteworthy nonlinear low-frequency dynamic response during rated and higher wind-wave scenarios, leading to a substantial exacerbation of its power characteristics, power stability, and wind energy forecast reliability. This study develops a fully coupled FOWT model to investigate the impact of wind and wave loads on wind power ramp events (WPREs), which integrates mechanical and electrical factors, including a spar buoy FOWT with generator, converter, and aero-hydro-servo-elastic (AHSE) dynamics. Results indicate that the floating structure enables periodic and significant WPREs of FOWTs, as wave load and platform natural motion causing low and ultra-low frequency response. In contrast to bottom-fixed offshore wind turbines (OWT), FOWTs exhibit a supplementary decline in rated power output ranging from 7.9 % to 40.5 % during WPREs. Moreover, ramp peak mainly depends on the aerodynamic loads, but become sensitive to wave loads characterized by wave heights over 2.52 m. FOWT power performance is highly unstable within the rated wind speed range, under WPREs within ultra short time period, resulting in failure to meet grid standards, emphasizing the external need for targeted power compensation and power signal processing. Overall, this study highlights the importance of pitch motion and wave load impact for WPRE study of FOWTs.

Best Practices for Research in Virtual and Augmented Reality in Dermatology

Virtual reality (VR) and augmented reality (AR) technologies have advanced rapidly in recent years. These cutting-edge technologies provide dermatology researchers, educators, proceduralists, and patients with opportunities in new scientific horizons. VR is a technology that facilitates immersive human experiences by allowing users to connect with various simulated environments through natural head and hand movements, whereas AR supplements a user's perception of their real environment with virtual elements. Despite technological advancements, there is limited literature on the methodological steps for conducting rigorous VR and AR research in dermatology. Effective storyboarding, user-driven design, and interdisciplinary teamwork play a central role in ensuring that VR/AR applications meet the specific needs of dermatology clinical and research teams. We present a step-by-step approach for their design, team composition, and evaluation in dermatology research, medical education, procedures, and habit formation strategies. We also discuss current VR and AR dermatology applications and the importance of ethical and safety considerations in deploying this new technology.

Touch‐Enabled Self‐Powered Elastomeric Keypad for Mapping Human Input and an Emergency Alert via Triboelectric Effect

The demand for smart, flexible electronics and wearable devices has been increasing rapidly, thereby making the user comfortable by bridging the gap between humans and machines. Herein, groundbreaking research in the field of wearable triboelectric nanogenerators (TENGs) and their innovative applications are presented by exploring a novel silicone elastomer‐based TENG. Different approaches involve the creation of wearable flexion and ring sensors for harvesting biomechanical energy from the natural finger joint motions and for sensing finger movements, wherein the silicone film acts as triboelectric negative material and human skin acts as the positive material. Additionally, the article describes the development of a touch keypad comprising 12 silicone film‐based TENG devices arranged in a 3 × 4 keypad array. Each keypress results in triboelectrification, converting mechanical energy into electrical power. Integrating an Arduino microcontroller and a graphical user interface provides user‐friendly and interactive functionality for recognizing and visualizing keypresses. Most notably, the article introduces the novel concept of an emergency alarm system, the “global emergency tracker system,” employing the 12‐keypad array. Users can trigger security alerts by pressing specific key patterns, such as “SOS” or “911.” This work showcases the potential of TENGs in wearable technology, human–machine interfaces, and security systems, pushing the boundaries of energy harvesting and practical applications in diverse fields. The combination of materials, device designs, and applications highlights the innovative nature of this research, promising advancements in sustainable energy generation and personal safety.