Natural Motion Research Articles

Confinement effects within the seismic design of reinforced concrete frames: reliability assessment and comparison

The current Italian code “NTC2018” and Eurocode “EC8” provide specific design requirements in terms of flexural overstrength factors for reinforced concrete (RC) buildings in seismic areas. This study proposes to improve the design methodology by including explicitly the confinement effects within the seismic design of a new regular RC frame due to their influence on the capacity design principles (at structural and member level). Specifically, the seismic performance of a RC frame designed according to codes is compared, in reliability terms, with the one of the same frame designed including the concrete confinement effects. Moreover, a comparison between three constitutive models for confined concrete is performed. Selecting L’Aquila (Italy) as reference site, the two design methodologies combined with the three confinement models are numerically implemented. Scaling 30 non-frequent natural ground motions to increasing seismic intensity measures, according to the site seismic hazard, non-linear incremental dynamic analyses (IDAs) have been developed. Assuming the interstory drift indices as engineering demand parameters, the peak responses have been fitted through log-normal distributions to define IDA curves. Subsequently, appropriate limit state thresholds have been adopted to define the seismic fragility curves. Finally, through the convolution integral and Poisson model, the seismic reliability curves have been derived showing the importance of the proposed design methodology. In fact, for the frame under investigation, the seismic performance strongly improves in terms of ductility respecting all the reliability objective levels if the confinement effects are explicitly considered in the seismic design. Furthermore, the different confinement models provide similar results when the proposed seismic design is adopted, implying a reduction of the model uncertainty.

Design of a Compliant Sternum Prosthesis for Improving Respiratory Dynamics

This study presents a novel approach to sternum prosthesis design, aiming to address the limitations of the current solutions by employing compliant mechanisms. The research focuses on developing a prosthetic design capable of generating lifting movements on ribs during breathing. First, a videogrammetry experimental test and virtual simulations were conducted to ascertain the vertical forces applied to each sternum joint. Subsequently, a compliant mechanism design was initiated, involving optimization and finite element analysis (FEM). A comprehensive kinematic performance analysis was performed to evaluate the prosthetic design. The results indicate that the obtained displacements of each rib closely align with those reported in the existing literature, demonstrating the effectiveness of the proposed solution. In conclusion, the developed sternum prosthesis exhibits the capability to recover approximately 56% of the ribs’ natural movements, highlighting its potential as an innovative and promising solution in the field of chest prosthetics.

Toward a disruptive, minimally invasive small finger joint implant concept: Cellular and molecular interactions with materials in vivo

Osteoarthritis (OA) poses significant therapeutic challenges, particularly OA that affects the hand. Currently available treatment strategies are often limited in terms of their efficacy in managing pain, regulating invasiveness, and restoring joint function. The APRICOTⓇ implant system developed by Aurora Medical Ltd (Chichester, UK) introduces a minimally invasive, bone-conserving approach for treating hand OA (https://apricot-project.eu/). By utilizing polycarbonate urethane (PCU), this implant incorporates a caterpillar track-inspired design to promote the restoration of natural movement to the joint. Surface modifications of PCU have been proposed for the biological fixation of the implant. This study investigated the biocompatibility of PCU alone or in combination with two surface modifications, namely dopamine-carboxymethylcellulose (dCMC) and calcium-phosphate (CaP) coatings. In a rat soft tissue model, native and CaP-coated PCU foils did not increase cellular migration or cytotoxicity at the implant–soft tissue interface after 3 d, showing gene expression of proinflammatory cytokines similar to that in non-implanted sham sites. However, dCMC induced an amplified initial inflammatory response that was characterized by increased chemotaxis and cytotoxicity, as well as pronounced gene activation of proinflammatory macrophages and neoangiogenesis. By 21 d, inflammation subsided in all the groups, allowing for implant encapsulation. In a rat bone model, 6 d and 28 d after release of the periosteum, all implant types were adapted to the bone surface with a surrounding fibrous capsule and no protracted inflammatory response was observed. These findings demonstrated the biocompatibility of native and CaP-coated PCU foils as components of APRICOTⓇ implants. Statement of significanceHand osteoarthritis treatments require materials that minimize irritation of the delicate finger joints. Differing from existing treatments, the APRICOTⓇ implant leverages polycarbonate urethane (PCU) for minimally invasive joint replacement. This interdisciplinary, preclinical study investigated the biocompatibility of thin polycarbonate urethane (PCU) foils and their surface modifications with calcium-phosphate (CaP) or dopamine-carboxymethylcellulose (dCMC). Cellular and morphological analyses revealed that both native and Ca-P coated PCU elicit transient inflammation, similar to sham sites, and a thin fibrous encapsulation in soft tissues and on bone surfaces. However, dCMC surface modification amplified initial chemotaxis and cytotoxicity, with pronounced activation of proinflammatory and neoangiogenesis genes. Therefore, native and CaP-coated PCU possess sought-for biocompatible properties, crucial for patient safety and performance of APRICOTⓇ implant.

Cyborg insect repeatable self-righting locomotion assistance using bio-inspired 3D printed artificial limb

Cyborg insects have emerged as a promising solution for rescue missions, owing to their distinctive and advantageous mobility characteristics. These insects are outfitted with electronic backpacks affixed to their anatomical structures, which endow them with imperative communication, sensing, and control capabilities essential for effecting survivor retrieval. Nevertheless, the attachment of supplementary loads to the insect’s body can exert adverse effects on their intrinsic self-righting locomotion when confronted with fall or shock scenarios. To address this challenge, the present study introduces a bio-inspired 3D-printed artificial limb that serves to facilitate the maneuverability of cyborg insects amidst unpredictable conditions. Drawing inspiration from the natural self-righting motion exhibited by Coccinellidae, we have successfully identified a solution that can be transferred to the electronic backpack utilized by G. portentosa. Incorporation of the bio-inspired artificial wing-like limb has notably enabled the cyborg insect to achieve a remarkable tilting angle of 112°, thereby significantly amplifying the success ratio of self-righting under conditions closely emulating those prevalent in disaster areas. Moreover, we have replicated the expansion and contraction kinematics to ensure seamless motion progression within confined spaces. Importantly, the fabricated device proffered in this study has been meticulously designed for facile reproducibility employing commonly available tools, thereby serving as an inspirational catalyst for fellow researchers engaged in the advancement of 3D-printed limb development aimed at expanding the functional capacities of cyborg insects.

Black hair technologies at the “post-natural” turn

ABSTRACT Manipulation of the hair is one of the lesser theorized technologies through which Black diasporic subjects have carved space for their existence, expressed aspirations, and posed dissent against a social world reliant upon their dehumanization. In response to this forum's call to elevate mediated epistemologies about Black women, we offer focused consideration of Black hair as a technology of collective expansion that resists essentialism and begins to theorize a digital, post-natural turn. The practices tied to Black hair, from the development of styling tools and products (physical technologies) to technologies of touch via digital practices (i.e., the digits or fingers) such as greasing, braiding, washing, combing, and otherwise working hair, are central to how Black women create digital (here meaning: online) content and navigate scrutinization. We consider the complications of these technological and digital practices by considering the simultaneous neoliberal and liberatory undergirding of the Digital Natural Black Hair Movement and a very recent tech-forward turn toward what we call the “post-natural” that eschews the implicit essentialism of earlier natural hair moments. Taking the “sacred” foray into the haircare industry by megastar Beyoncé as a case study, we outline facets (and aspirations) of the post-natural digital re-branding of Black hair.

Microspace regulation inspired by water permeation phenomenon for the preparation of high-conductivity composite films with efficient electromagnetic shielding performance

Conductive polymers, integral to advancements in wearable devices, energy storage, healthcare and more, are crafted by integrating polymers with conductive elements like carbon substances, metals, and their particles. Drawing inspiration from natural water movement, this study introduces a method for crafting high-performance conductive composite films. This technique involves regulating the microstructure space of GaIn-based polymers under the mechanical pressure, where the fluid metal improves the internal microstructure gaps of the material. The presence of hydroxyl/carboxyl groups within the polymer enables the bonding with Ga3+ ions from the liquid metal (LM), securing them in place. This innovative process significantly boosts the material's electrical and thermal conductivity, as well as its mechanical integrity. This methodology has been successfully applied to enhance the attributes of GaIn-based composite films, utilizing nanocellulose fibers, chitosan nanofibers, and Kevlar-29 fibers as foundational materials. To demonstrate the method's effectiveness, a durable, highly thermally and electrically conductive GaIn-based MXene/nanocellulose composite film was developed and investigated in detail. This film showcased remarkable electromagnetic shielding with a high SSE/t value of 7718.91 dB cm2 g−1, and its performance mechanism was detailed through finite element analysis. Notably, the inclusion of GaIn endowed the film with excellent opto-electro-thermal conversion and heat-responsive deformation capabilities, highlighting its suitability for smart applications. Therefore, this research establishes a versatile approach for designing conductive films by merging liquid metal with polymers, potentially setting the stage for the creation of highly conductive composites in future.

GazeSwitch: Automatic Eye-Head Mode Switching for Optimised Hands-Free Pointing

This paper contributes GazeSwitch, an ML-based technique that optimises the real-time switching between eye and head modes for fast and precise hands-free pointing. GazeSwitch reduces false positives from natural head movements and efficiently detects head gestures for input, resulting in an effective hands-free and adaptive technique for interaction. We conducted two user studies to evaluate its performance and user experience. Comparative analyses with baseline switching techniques, Eye+Head Pinpointing (manual) and BimodalGaze (threshold-based) revealed several trade-offs. We found that GazeSwitch provides a natural and effortless experience but trades off control and stability compared to manual mode switching, and requires less head movement compared to BimodalGaze. This work demonstrates the effectiveness of machine learning approach to learn and adapt to patterns in head movement, allowing us to better leverage the synergistic relation between eye and head input modalities for interaction in mixed and extended reality.

Learning Crowd Motion Dynamics with Crowds

Reinforcement Learning (RL) has become a popular framework for learning desired behaviors for computational agents in graphics and games. In a multi-agent crowd, one major goal is for agents to avoid collisions while navigating in a dynamic environment. Another goal is to simulate natural-looking crowds, which is difficult to define due to the ambiguity as to what is a natural crowd motion. We introduce a novel methodology for simulating crowds, which learns most-preferred crowd simulation behaviors from crowd-sourced votes via Bayesian optimization. Our method uses deep reinforcement learning for simulating crowds, where crowdsourcing is used to select policy hyper-parameters. Training agents with such parameters results in a crowd simulation that is preferred to users. We demonstrate our method's robustness in multiple scenarios and metrics, where we show it is superior compared to alternate policies and prior work.

Relationship between natural muscle oscillation frequency and lower limb muscle performance during instrumented sit-to-stand and stand-to-sit movements on a novel device in sedentary subjects

BackgroundDespite the significance of muscle oscillation frequency, previous research has not established a correlation with muscle performance due to the challenges of applying resistance without altering natural motion during functional tests. Research questionWhat is the correlation between muscle oscillation frequency and lower limb muscle strength, power, and work during an instrumented sit-to-stand and stand-to- sit (iSTS-TS) task among sedentary subjects? MethodsIn a cross-sectional study, the oscillation frequency of the gastrocnemius medialis (GM), biceps femoralis (BF), and vastus medialis (VM) muscles in both the dominant (D) and non-dominant (ND) legs was assessed with a handheld myotonometer in 34 sedentary individuals before performing the iSTS-TS task. ResultsIn the isokinetic mode, no significant correlations were found. In the isotonic mode, the BF muscle oscillation frequency in the D and ND legs exhibited significant positive correlations with peak force, peak power, and work during sitting down, as well as peak power and work during standing up. Positive correlations were observed in both legs between the GM oscillation frequency and sitting down peak force and work. Additionally, significant positive correlation was found with standing up work in the D leg. Muscle oscillation frequency of the VM exhibited a positive correlation with sitting down peak force in the ND leg. SignificanceDue to a greater number of correlations found, it is advisable to use the isotonic mode when assessing muscle oscillation frequency in relation to muscle performance during functional iSTS-TS tasks in sedentary subjects.

Understanding the vulnerability of skeleton-based Human Activity Recognition via black-box attack

Human Activity Recognition (HAR) has been employed in a wide range of applications, e.g. self-driving cars, where safety and lives are at stake. Recently, the robustness of skeleton-based HAR methods have been questioned due to their vulnerability to adversarial attacks. However, the proposed attacks require the full-knowledge of the attacked classifier, which is overly restrictive. In this paper, we show such threats indeed exist, even when the attacker only has access to the input/output of the model. To this end, we propose the very first black-box adversarial attack approach in skeleton-based HAR called BASAR. BASAR explores the interplay between the classification boundary and the natural motion manifold. To our best knowledge, this is the first time data manifold is introduced in adversarial attacks on time series. Via BASAR, we find on-manifold adversarial samples are extremely deceitful and rather common in skeletal motions, in contrast to the common belief that adversarial samples only exist off-manifold. Through exhaustive evaluation, we show that BASAR can deliver successful attacks across classifiers, datasets, and attack modes. By attack, BASAR helps identify the potential causes of the model vulnerability and provides insights on possible improvements. Finally, to mitigate the newly identified threat, we propose a new adversarial training approach by leveraging the sophisticated distributions of on/off-manifold adversarial samples, called mixed manifold-based adversarial training (MMAT). MMAT can successfully help defend against adversarial attacks without compromising classification accuracy.

Footwear-Based Assistive Technology for Lower Limb Amputees

Men and women with lower limb amputations struggle with managing the balance between prosthesis alignment and shoe heel rise. A novel prosthetic ankle-feet system is being developed to support a wider range of footwear options for men and women with lower limb amputations. Each rigid foot is customized to fit the footwear of choice and can be rapidly attached to (or released from) an ankle unit which remains attached to the prosthesis. The proposed system consists of two key components: a transmitter shoe and a receiver shoe. The transmitter shoe is worn on the intact limb and is equipped with sensors, including accelerometers and gyroscopes to capture the wearer's ankle movements accurately. These sensor data are wirelessly transmitted to the receiver shoe worn on the amputated limb, which houses actuators, such as stepper motors, to replicate the natural ankle movements. The hypothesis was that the orientation of the roll-over shapes of these systems would be altered with even small changes in shoe heel height. Seven prosthetic ankle-foot systems were mechanically loaded to determine their roll-over shapes while using a no-heel shoe and a low-heel shoe. This system was developed specifically to allow users the ability to switch between shoes of different heel heights (i.e., it is a heel-height-adjustable system). Additional loading trials were performed with the heel-height-adjustable system in which the ankle alignment was altered to accommodate the change in heel height between shoes.

How to teach a puppet to sing: exploring posthuman perspectives on the ‘natural’ voice alongside The Walk (2021)

ABSTRACT In this article I explore the construct of the ‘natural’ voice within the context of the natural voice movement, before invoking perspectives on voice from the posthumanities and D/deaf studies in discussion of The Walk, a performance between a puppet, a natural voice choir, a refugee choir and a large audience that occurred in London in October 2021. Methodologically, this paper is an attempt at ‘thinking with theory’ (Jackson, Alecia Youngblood, and Lisa A. Mazzei. 2017. “Thinking with Theory: A New Analytic for Qualitative Inquiry.” In The SAGE Handbook of Qualitative Research, edited by N. K. Denzin, and Y. Lincoln, 717–737. Sage) – specifically thinking voice alongside theoretical stimuli from the posthumanities through the doing of ethnography – in the hope of provoking useful flights of thought in relation to the practice and study of music education and community music. I conclude by considering my personal rationale for engaging with the posthumanities as a means of researching community singing within the natural voice movement. A protean version of this article was presented as a paper-presentation at the Grieg Research School in Bergen, Norway in 2022.

Application of the RADEC Learning Model through the Experimental Method on Students' Critical Thinking Ability in Natural Science Learning Animal Movement Organ Material Class V SDN 13 Singkawang

This research aims to: 1) To describe the differences between the RADEC learning model through the experimental method on the critical thinking abilities of students who study with the RADEC learning model and classes that use direct learning in class V science learning at SDN 13 Singkawang; 2) To describe the implementation of the RADEC learning model through the experimental method on the critical thinking abilities of class V students at SDN 13 Singkawang in science learning; 3) To describe students' responses to the RADEC learning model through experimental methods on students' critical thinking abilities. This research is a quantitative experimental research. This research method is a quasi experimental design, with a post-test only control group design. The population of this study was all fifth grade students, totaling 50 students. Samples were taken using probability sampling techniques with saturated sampling. Data collection techniques use test and non-test techniques. The test instrument is a critical thinking ability question sheet in the form of an essay. Meanwhile, non-tests are in the form of model implementation observation sheets and student response questionnaire sheets. The data analysis technique used was a two-sample t test. The results of the research, 1) show that tcount = 3.844 ttable = 2.010, which means that there is a significant difference in the results of students' critical thinking ability tests between students who applied the RADEC model through the experimental method and students who used the direct learning model. 2) The results of the model implementation analysis show a percentage of 90.5%, very good criteria and 3) the results of the analysis of student response questionnaires show a percentage of 75% good criteria, which means that learning using the RADEC learning model through the experimental method in science learning has an effect on critical thinking skills. students' science, so that students respond well to learning activities. So it can be concluded that the RADEC learning model during the learning process makes an impression, attracts students' attention, and provides a new learning atmosphere

IOT Based Remote Patient Monitoring System

Abstract: A remote monitoring technique that can accurately track human physiological indicators has applications in virtual reality, sports science, medicine, rehabilitation, and surveillance. The majority of systems now in use for tracking bodily parameters in humans need wiring that limits natural movement. In order to get over this restriction, a wearable wireless sensor network that monitors physiological human body characteristics has been built using an accelerometer, a pulse oximeter, a heart-rate sensor, a temperature sensor, and a galvanic skin response sensor. The individual is being tracked wirelessly using his own location. It would be simple to modify this system to watch athletes and young children. Unlike a tethered monitoring equipment, the wireless feature allows the human body to move freely, making the system genuinely portable, quick, and dependable. The portable and the designed sensor node's small size makes it simple to attach to the body.

Analysis of Hydrodynamic Loads by a Vertical Hollow Cylindrical Structure in A Two-Layer Fluid of Finite Depth

This paper aims to study the effect of surge radiation by a vertically hollow cylinder floating in a two-layer fluid of finite depth. Since most of the important characteristics of the oscillating water column are preserved by the hollow cylindrical structure, so the proposed device can be considered as an oscillating water column (OWC) which is one of the important wave energy device. In this two-layer fluid system, the upper layer is bounded above by a free surface and the lower layer is bounded below by a solid impermeable bottom, and the submerged hollow cylindrical structure allows it to oscillate in a surge mode of motion in the upper layer. On the assumption that wave amplitudes are small in comparison to wavelengths, hence the linear water wave theory is applied to formulate boundary value problems by dividing whole domain into 2 sub-domains. The formulated boundary value problems for surge radiated potentials in each sub-domain; we execute to obtain solutions in each sub-domain by using variable separation and matched eigenfunction expansion methods. With the help of obtained surge radiated potentials, we derive the radiation forces by the device in terms of added mass and damping coefficients. A set of influences of different parameters of the device on the added mass and damping coefficients are demonstrated in both surface and internal wave modes of motion. Hydrodynamic coefficients oscillate highly near a particular frequency, which leads to the resonance phenomena. In addition to that, the 3D plots of the free surface elevation in surface and internal wave modes are presented. A density ratio γ = 0.97 has a higher oscillation than a density ratio γ = 0.93, 0.95. High oscillations occur around a particular frequency ω = 3.83 due to the resonance phenomenon in which the waves incoming match with the natural motion of the object. HIGHLIGHTS A floating hollow vertical cylindrical structure is considered in a two-layer fluid system having finite depth The separation of variables and matched eigenfunction expansion methods are utilized to obtain the solutions to the boundary-value problems The diffracted velocity potentials under the surge mode of motion are evaluated in the identified regions The added mass, damping coefficients, free surface and interface elevations in surface and internal wave modes are evaluated with different set of parameters of the device A number of results are presented regarding the effect of parameters of the device on the added mass, damping coefficients, free surface and interface elevations It is observed that the density ratio of the two-layer fluid has significant effect on the added mass, damping coefficient and the elevations GRAPHICAL ABSTRACT

Implications of tactile enrichment on the behaviour and whisker movements of four species of carnivorans

Caniformia include a range of aquatic, semi-aquatic and terrestrial species, which reveal diversity in their whisker arrangements and shape. Whisker movements play a crucial role in the perception of tactile information, allowing whiskered mammals to distinguish between shapes, sizes, and textures. Despite the significance of whisker movements in sensory perception, few studies have focussed on measuring whisker movements during tactile sensing. Whisker enrichment tasks have the potential to expand behavioural repertoires of animals in captivity and reduce stereotypical behaviours. However, despite whiskers being essential in guiding foraging and exploration in many mammalian species, tactile whisker enrichment tasks are rare. Here, we utilised a novel tactile enrichment device to investigate the whisker movements in four Caniform species in captivity, including two pinnipeds- South African fur seals (Arctocephalus pussilus) and harbour seals (Phoca vitulina), a mustelid – Eurasian otter (Lutra lutra), and a canid – red fox (Vulpes vulpes) during a texture discrimination task. This study is the first to explore the impact of tactile enrichment on the behavioural repertoire of caniforms in captivity and provides the first insight of whisker movements in South African fur seals. The introduction of the tactile enrichment device did not increase the behavioural repertoire, nor did it lead to an increase in stereotypical behaviours or aggression in any of the species. However, it did successfully encourage natural whisker movements in the pinnipeds and otter. The whisker amplitude measure was especially high in the South African fur seals. We suggest that such a complex, discrimination-based enrichment task might only be feasible for more trainable caniforms, such as pinnipeds, rather than more neophobic species, such as the red fox, which did not interact with the enrichment device throughout the study. Therefore, while our enrichment device increased natural whisker movements, an even simpler foraging task might encourage tactile sensing without the requirement for training, making tactile whisker enrichment available to a wider group of species.

775 A Unique Semirigid Silicone Neck Collar for Management of Hypertrophic Scars

Abstract Introduction In the realm of burn injuries, the use of rigid hard neck collars, or soft collars, is indispensable for optimizing neck positioning and scar management. However, when injuries encompass the head and neck, a critical challenge arises only one rigid orthosis can typically be worn one at a time. We are introducing a novel solution: a semirigid neck collar crafted from flexible silicone. This collar combines the benefits of semirigid support with the freedom of natural neck and allows jaw movement and may be worn with a rigid facemask. Furthermore, it can be customized to effectively manage hypertrophic scarring, making it a promising advancement in burn injury care. Methods Our semirigid neck collar is crafted with High Consistency Rubber (HCR) silicone. The HCR can be fabricated as a solid sheet or perforated. This HCR applies a gentle, consistent minimum pressure of 20mmHg as displayed by the Kikuhime pressure monitoring device while remaining pliable enough to accommodate natural neck movements and TMJ mobility. The material is mixed, pigment tinted, and rolled to achieve the desired thickness. Following this, the HCR silicone is heated and molded based on a 3D scan of the patient's neck and fit to the patient. A successful trial was conducted in a patient with severe facial and neck burns, resulting in improved neck ROM and hypertrophic scar progression. The resulting scar displayed improvement on the Vancouver Scar Scale yielded as reported on the Likert scale and the patient reporting increased compliance of the semirigid collar. Results In the trial involving a patient with severe neck and facial burns: 1. Improved Neck ROM, Eating, and Mandibular Movement: While using the semirigid silicone neck collar, the patient experienced improvements in neck ROM, eating comfort, and mandibular movement. The average Likert scale rating for these improvements was five out of five. 2. Decreased Scarring upon Vancouver Scar Scale displaying the difference between the initial and final VSS scores, indicating how much the scar improved. 3. Patient Preference: A preference for the semirigid silicone neck collar, upon rating it a perfect five on the Likert scale. The patient was able to wear it in combination with a hard TFO facial orthotic. Conclusions The semirigid silicone neck collar represents a move forward in the field of neck orthosis design, particularly concerning scar management. Its innovative blend of design elements, including flexibility, adaptability, and customizable features, holds great promise for individuals dealing with burn-related neck scarring. Applicability of Research to Practice This semirigid appliance offers increased comfort compared to traditional rigid collars and an option in the management of neck positioning and scar hypertrophy. Its flexible nature, including color-tinting, and cost-effective modification options make it a valuable tool for improving scar management outcomes neck for patients with neck and combined facial/neck scarring.

A six degrees-of-freedom cable-driven robotic platform for head-neck movement.

This paper introduces a novel cable-driven robotic platform that enables six degrees-of-freedom (DoF) natural head-neck movements. Poor postural control of the head-neck can be a debilitating symptom of neurological disorders such as amyotrophic lateral sclerosis and cerebral palsy. Current treatments using static neck collars are inadequate, and there is a need to develop new devices to empower movements and facilitate physical rehabilitation of the head-neck. State-of-the-art neck exoskeletons using lower DoF mechanisms with rigid linkages are limited by their hard motion constraints imposed on head-neck movements. By contrast, the cable-driven robot presented in this paper does not constrain motion and enables wide-range, 6-DoF control of the head-neck. We present the mechatronic design, validation, and control implementations of this robot, as well as a human experiment to demonstrate a potential use case of this versatile robot for rehabilitation. Participants were engaged in a target reaching task while the robot applied both assistive and resistive moments on the head during the task. Our results show that neck muscle activation increased by 19% when moving the head against resistance and decreased by 28-43% when assisted by the robot. Overall, these results provide a scientific justification for further research in enabling movement and identifying personalized rehabilitation for motor training. Beyond rehabilitation, other applications such as applying force perturbations on the head to study sensory integration and applying traction to achieve pain relief may benefit from the innovation of this robotic platform which is capable of applying controlled 6-DoF forces/moments on the head.

Development of Heart Simulator and Analysis of Valve Dysfunction in Tricuspid Regurgitation

Tricuspid regurgitation (TR) resulting from valve abnormalities necessitates precise diagnostic tools and interventions. We employed a simulated heart movement device to examine the performance of heart valve functions and analyzed internal pressure changes to provide a quantitative guide for TR treatment. We developed a simulator capable of replicating the flow profile, mimicking natural heart movements, with sensors installed for measuring internal pressure changes. We conducted an ex vivo experiment on a porcine heart to assess tricuspid valve functionality. An endoscope was installed, with a sensor and endoscopic images to detect abnormalities. TR became evident when the heart rate spectrum exceeded an average of 85.2 bpm (standard deviation, 1.3 bpm) and showed an amplitude higher than an average of 12.3 mmHg (standard deviation, 3.2 mmHg). This critical threshold consistently indicated TR onset. The application of the Pivot-TR attenuated this specific spectral area. We confirmed TR disappearance by reducing the intensity of the Tricuspid Regurgitation Generator or employing the Pivot-TR. The Pivot-TR’s ability to attenuate specific spectral areas associated with TR onset and its effectiveness in restoring normal heart functionality has implications for managing and treating TR, particularly that resulting from age-related structural changes in the heart.

Exploring aspects of Neanderthal mobility in the Mani Peninsula: Evidence from Lithic Raw Material procurement and management at Kalamakia Cave, Greece

The Kalamakia cave located on the western Mani Peninsula, southern Greece is a Middle Palaeolithic site dated between ∼100,000 and >39,000 years BP. The aim of this paper is to provide insights into the Neanderthal groups’ mobility by addressing the lithic raw material procurement and management, with reference to the Kalamakia cave assemblage. The methodology included field survey and laboratory analyses, encompassing macroscopic, petrographic, and geochemical ones, for the location and identification of the sources of used lithic raw materials. Local, semi-local and allochthonous lithic raw materials were used by the Neanderthals at the Kalamakia cave to manufacture tools. The presence of various lithic raw materials used at the cave suggests diverse mobility strategies. The semi-local black/grey chert, followed by the allochthonous andesite was mostly used. Andesite transported across an east–west axis presents a long-term stability, both in terms of percentages and the different artefact types transported in both Unit III and IV of the cave. The significant quantities of andesite in the cave’s assemblage suggest non-random mobility, possibly linked to the exploitation of different ecological environments available in the region. The north-western part of the peninsula saw additional exploitation by groups moving along the coastal north–south corridor. However, cherts transported along this axis occurred occasionally, and their quantities were notably smaller in comparison to andesite. The strategic location of the cave close to the intersection of two natural movement routes, may have played a key role in the circulation of Palaeolithic inhabitants, facilitating movements along east–west and north–south axes.