Search Results (22)

Background and Objectives: Multiple sclerosis (MS) is characterized by progressive disability and a spectrum of motor and cognitive impairments. Exergames and virtual reality (VR) are proposed as motivating exercise tools, potentially useful for improving adherence and expanding access to rehabilitation. The objectives are to explore the feasibility and safety of a supervised rehabilitation program based on a high-intensity exercise program with immersive virtual reality (IVR) in people with MS and to describe its effects on physical, cognitive, and functional domains, as well as on the serum biomarker neurofilament light chain (sNfL). Materials and Methods: Pre–post exploratory study in five volunteers from a local MS Association [Vigo, Spain]. Intervention: 8 weeks, two sessions/week, 10 min/session of an IVR boxing-based exergame combined with usual rehabilitation, supervised by a physiotherapist. The variables studied were safety (Simulator Sickness Questionnaire [SSQ]), usability (System Usability Scale [SUS]), disability (Expanded Disability Status Scale [EDSS]), gait (25-Foot Walk Test [25FWT]), manual dexterity (9 Hole Peg Test [9HPT]), cognition (Symbol Digit Modalities Test [SDMT]), and axonal damage biomarker (sNfL). Results: The intervention could be feasible and safe (100% adherence, no adverse events (without SSQ symptoms), 95% usability [SUS]). There were positive changes in all variables studied (mean ± SD): EDSS −0.5 ± 0.9; 25FWT −4.9 ± 9.8 s; right 9HPT −3.3 ± 0.9 s; sNfL −4.4 ± 4.5 pg/mL, except for left 9HPT +0.5 ± 5.0 s and cognition (SDMT −2.4 ± 1.3 points). Conclusions: A brief, supervised exercise program combing an IVR exergame with standard rehabilitation was feasible and safe in people with MS. Although the results seem promising with the proposed design, the clinical and biological changes are merely exploratory, and it is not possible to infer their efficacy. Our findings open the door to future controlled studies including perceived high-intensity exercise programs and larger sample sizes to explore efficacy and estimate clinically relevant effect sizes. Full article

Background: Bone vibrator (BV) stimulation applied to skin sites on the body elicits hearing by soft tissue conduction (STC). However, BV stimulation to sites far from the ear requires the delivery of higher-intensity stimulus vibrations to achieve threshold, which can then induce hearing by air conduction (AC) contamination. This problem limits the study of STC thresholds at sites more distant from the ear. Objective: To overcome this problem, we evaluated the possibility of delivering STC vibratory stimuli to body sites in a water bath, based on the different acoustic impedances between air and water, which produces a 30 dB reduction in transmission from water to air. Methods: A standard clinical BV delivered vibration stimuli (tonal and speech stimuli) applied directly to two body sites: finger and foot. BV and body sites were immersed in a water bath. One control involved both stimulation site and BV both in water, but not in contact. In an additional control, the BV was in the bath, while the stimulation site was out of the bath. Results: STC hearing of both pure tones and speech could be elicited at stimulus intensities below those induced by control stimulation (body site and BV both in water, but not in contact; BV in bath, stimulation site out of bath). STC thresholds at the finger site were lower than those at the foot. Conclusions: The current results suggest that water-immersion method enables study of STC hearing in response to higher-intensity vibrational stimuli, and at body sites more distant from the ear, without contamination by AC hearing. Full article

Obstacle negotiation during locomotion depends on the integration of exteroceptive information about the environment, proprioceptive signals from the body, and exproprioceptive visual feedback about the limbs. This study examined how removing visual limb information and introducing VR-specific sensory uncertainty affect overground obstacle-crossing behavior. Participants walked under three conditions: natural environment with full vision, natural environment with lower-limb occlusion, and immersive VR without a lower-limb representation. Removing limb vision in the real world selectively increased toe clearance while leaving baseline gait unchanged, demonstrating the role of exproprioceptive feedback in fine-tuning foot trajectory. VR amplified these adaptations, yielding slower speeds, wider bases of support, and even greater clearance margins, reflecting compounded uncertainty from altered exteroceptive cues. Yet obstacle location effects were consistent across environments, suggesting preserved underlying control and the potential for a scaling relationship between VR and real-world performance. Findings highlight key design considerations for VR-based gait assessment and rehabilitation. Full article

Natural and unconstrained locomotion remains a fundamental challenge in creating truly immersive virtual reality (VR) experiences. This paper presents the design and control of a novel robotic omnidirectional treadmill (ODT) based on the bilateral symmetry of two cooperative five-bar planar mechanisms designed to replicate realistic walking mechanics. The central contribution is a human in the loop control strategy designed to achieve stable walking in place. This framework employs a specific control strategy that actively repositions the footplates along a dynamically defined ‘Line of Movement’ (LoM), compensating for the user’s motion to ensure the midpoint between the feet remains stabilized and symmetrical at the platform’s geometric center. A comprehensive dynamic model of both the ODT and a coupled humanoid robot was developed to validate the system. Numerical simulations demonstrate robust performance across various gaits, including turning and catwalks, maintaining the user’s locomotion center with a maximum resultant drift error of 11.65 cm, a peak value that occurred momentarily during a turning motion and remained well within the ODT’s safe operational boundaries, with peak errors along any single axis remaining below 9 cm. The system operated with notable efficiency, requiring RMS torques below 22 Nm for the primary actuators. This work establishes a viable dynamic and control architecture for foot-tracking ODTs, paving the way for future enhancements such as haptic terrain feedback and elevation simulation. Full article

What key characteristics of forest sites and trails contribute to enjoyable and healthy immersive nature experiences for visitors? Previous research has helped identify the conceptual structure and criteria important in facilitating successful experiences, but there remains a knowledge gap in translating this information into operational guidelines. To address this gap, the present work used a descriptive inventory approach combining field research with a variety of secondary data to develop a protocol for assessing four site level criteria (beauty, integrity, tranquility, accessibility) and six trail level criteria (ease of travel, attractiveness of layout, natural features, built features, explorable nature, interpretation and stewardship). Through an iterative process, the protocol was refined and applied to selected sites (n = 56) and trails (n = 157) in two study areas in metropolitan Chicago, Illinois, and the rural Northwoods of Wisconsin. Qualitative and quantitative information describes preferred conditions across criteria, while quantitative ratings highlight commonalities and differences between urban and rural sites and trails. Although the principal focus was on foot trails, sub-analyses show how the criteria can apply to bike and paddle trails. With regional adaptations, the protocol has utility for the planning and design of new and management of existing trails for the growing practice of forest therapy and related forms of nature-based recreation. Full article

Driven by “Dual Carbon” goals, advancing the green development of oil and gas resources is imperative. The Shaximiao Formation tight gas reservoirs in the Sichuan Basin suffer from wellbore instability, impairing drilling efficiency and elevating energy use and emissions. This study integrates mineralogy, mechanics, drilling fluid optimization, and geostress modeling to address instability mechanisms and support low-carbon drilling. XRD shows that clay content decreases with depth (11–48%), while quartz and plagioclase dominate (45–80%). Synthetic-based drilling fluids fully inhibit clay swelling (0% expansion), outperforming calcium-based (2.4–3.1%) and water-based systems (5.4%). Synthetic and calcium-based fluids also reduce waste treatment difficulty and carbon intensity. Rolling recovery reaches 98.12% for synthetic-based vs. 78.18% for water-based. Strength tests reveal a 36.9% reduction after 14-day immersion in synthetic-based fluid, whereas water-based systems with nano-plugging agents show self-recovery, cutting energy use per foot by ~15%. Geostress modeling indicates a maximum horizontal stress of 90.08 MPa (NE114° ± 13°) and minimum of 67.2 MPa (NE24° ± 13°). Collapse pressure (48–60 MPa) varies azimuthally, requiring higher density (58–60 MPa) along the min. horizontal stress direction. A low-carbon mitigation strategy is proposed: prioritize synthetic or calcium-based drilling fluids, and optimize well trajectory using geostress models. This reduces fluid loss risk by >20%, limits methane emissions, shortens drilling cycles, and enhances efficiency while lowering carbon footprint. These insights support green and efficient natural gas development through intelligent drilling and eco-material applications. Full article

Simulating the experience of flight is a key objective of virtual reality (VR) technology. To enhance the sense of flying and immersion, we developed Drone Rider, a VR system that simulates free-flight atop a drone. In this study, we investigated whether delivering vibratory stimuli to the user’s feet could improve these sensations. While high-frequency drone propeller vibrations typically induce sensory numbness, alternative vibration patterns were explored. In Experiment 1, participants rated 13 different vibration patterns derived from various mechanical sounds, such as those from chainsaws, motorcycles, and washing machines. The motorcycle-based vibrations were most effective in enhancing both the sense of flight and immersion. In Experiment 2, we synthesized new vibration patterns by superimposing the highest-rated vibrations from Experiment 1, but no combination outperformed the original motorcycle vibration. These findings suggest that vibrations with multiple components below 100 Hz may reduce sensory adaptation and enhance the sense of flight and immersion in VR. This work provides valuable insights for developers aiming to optimize haptic feedback in VR flight simulators. Full article

Virtual reality (VR) exercise has been used as a strategy to promote physical health in older adults. Studies have revealed that the effects of exercise interventions vary across age groups. This study aimed to investigate the effects of a 12-week semi-immersion VR-based multicomponent exercise program on the functional fitness of young-old (65–73 years) and middle-old (74–85 years) adults. This study recruited two age groups (young-old adults, n = 49; middle-old adults, n = 37) and randomly assigned them to the experimental (EG) and control (CG) groups. EG participants performed a 75–90-min semi-immersion VR exercise routine twice weekly for 12 weeks, whereas CG participants maintained their original lifestyles without any alterations. The Senior Fitness Test was used to measure functional fitness by assessing upper- and lower-limb flexibility and muscle strength, cardiorespiratory fitness, and balance. EG participants exhibited greater improvements than their CG counterparts in certain functional fitness tests, specifically the Back Scratch, Arm Curl, 2-Minute Step, and 8-Foot Up-and-Go Tests. On comparing the age groups, a difference was exclusively noted in the effects of the Chair Sit-and-Reach Test. In the EG, the intervention significantly improved lower-body flexibility in young-old adults but elicited no such improvement in middle-old adults. Semi-immersion VR exercise improved the functional fitness of young-old and middle-old adults in the EG, with superior results in the former. Elucidating the impact of age-specific exercise interventions on functional capacity will help practitioners design age-specific exercise training content that enhances functional fitness in older adults of different ages. Full article

Rooftop solar modules are usually held in place by racks or frames that are mechanically attached to a roof structure and/or by heavyweight, ballasted footing mounts. These mounts ensure that the panel system remains in position against wind load. However, mechanical connectors create penetrations into the water-resistant layer of the roof, whereas ballasted footing mounts cause a significant additional load on the load-bearing structure of roof. For these reasons, adhesive connection seems to be a beneficial solution. Acrylic adhesive tapes, marked as VHB^TM, may provide sufficient strength, and they have no need for mechanical fasteners or ballast. Acrylic adhesive tapes also provide a comfortable, fast, and efficient bonding process with no curing compared to liquid adhesives. On the other hand, resistance to water at load-bearing joints has not been sufficiently studied yet and could be critical for connections exposed to the outdoor environment. The present study aims at the determination of water resistance and durability of the VHB^TM tapes from the GPH series, which are typically used to bond a variety of substrates including many metals. The mechanical properties and failure modes are compared for the specimens before and after a 21-day immersion in water. A significant reduction in strength was observed, depending on the substrate material. The study of chemical changes in the acrylic tape and in its leachate through infrared spectroscopy (FT-IR), X-ray fluorescence, and X-ray diffraction analyses clarified the reduction in mechanical properties. The selected VHB^TM tape demonstrated strong resistance to the effects of water. However, the overall strength of the joint after immersion was significantly impacted by the decrease in adhesion to a specific substrate. Full article

Pathological conditions in diabetic feet cause surface temperature variations, which can be captured quantitatively using infrared thermography. Thermal images captured during recovery of diabetic feet after active cooling may reveal richer information than those from passive thermography, but diseased foot regions may exhibit very small temperature differences compared with the surrounding area, complicating plantar foot segmentation in such cold-stressed active thermography. In this study, we investigate new plantar foot segmentation methods for thermal images obtained via cold-stressed active thermography without the complementary information from color or depth channels. To better deal with the temporal variations in thermal image contrast when planar feet are recovering from cold immersion, we propose an image pre-processing method using a two-stage adaptive gamma transform to alleviate the impact of such contrast variations. To improve upon existing deep neural networks for segmenting planar feet from cold-stressed infrared thermograms, a new deep neural network, the Plantar Foot Segmentation Network (PFSNet), is proposed to better extract foot contours. It combines the fundamental U-shaped network structure, a multi-scale feature extraction module, and a convolutional block attention module with a feature fusion network. The PFSNet, in combination with the two-stage adaptive gamma transform, outperforms multiple existing deep neural networks in plantar foot segmentation for single-channel infrared images from cold-stressed infrared thermography, achieving an accuracy of 97.3% and 95.4% as measured by Intersection over Union (IOU) and Dice Similarity Coefficient (DSC) respectively. Full article

Determining how to apply hydrogen as a therapeutic/preventive antioxidant for oxidative-stress-related diseases practically in daily life has not been studied. The effects of bathtubs and buckets filled with hydrogen water (41 °C, >10 min bathing) were investigated on six subjects, without a medical prescription, suffering from skin roughness on the foot, hand, finger, or elbow. They were also treated with an electrolyzer composed of a lattice-shaped, microscopically flat, platinum-plated three-layer electrode, except for one subject who was treated with a micro-porous emittance terminal hydrogen-jetting apparatus, resulting in improvements in both cases. For another subject with similar skin roughness on both hands, immersing the right hand in an electrolytically generated hydrogen water bucket showed more marked improvement than immersing the left hand in a bucket with normal water. The nano-bubbles (average, mode, and median sizes of 157 nm, 136 nm, and 94 nm, respectively) increased 3.79 fold to 2.20 × 10⁸/mL after 30 min electrolysis with 2 L of tap water and were boiling (98 °C, 2 min)-resistant, with heat stability in nano-bubbles as small as 69–101 nm, as evaluated by laser-beam-based Brownian movement trailing Nano-Sight analysis. The marked increase in nano-bubbles caused by electrolysis correlated with an increase in dissolved hydrogen (<15 μg/L to 527 μg/L) but not a decrease in dissolved oxygen (9.45 mg/L to 6.94 mg/L). Thus, the present study proposed the novelty of hydrogen regarding its contribution to health from the perspective that hydrogen-nano-bubble-rich water in a foot bucket, which was additively used together with a conventional bathtub and can be frequently used in daily life, improved diverse types of skin roughness. Full article

While developing traffic-based cognitive enhancement technology (CET), such as bike accident prevention systems, it can be challenging to test and evaluate them properly. After all, the real-world scenario could endanger the subjects’ health and safety. Therefore, a simulator is needed, preferably one that is realistic yet low cost. This paper introduces a way to use the video game Grand Theft Auto V (GTA V) and its sophisticated traffic system as a base to create such a simulator, allowing for the safe and realistic testing of dangerous traffic situations involving cyclists, cars, and trucks. The open world of GTA V, which can be explored on foot and via various vehicles, serves as an immersive stand-in for the real world. Custom modification scripts of the game give the researchers control over the experiment scenario and the output data to be evaluated. An off-the-shelf bicycle equipped with three sensors serves as a realistic input device for the subject’s movement direction and speed. The simulator was used to test two early-stage CET concepts enabling cyclists to sense dangerous traffic situations, such as trucks approaching from behind the cyclist. Thus, this paper also presents the user evaluation of the cycling simulator and the CET used by the subjects to sense dangerous traffic situations. With the knowledge of the first iteration of the user-centered design (UCD) process, this paper concludes by naming improvements for the cycling simulator and discussing further research directions for CET that enable users to sense dangerous situations better. Full article

Individuals with mild cognitive impairment (MCI) usually report navigation and spatial memory impairments. Spatial navigation is an embodied process that requires the active involvement of both physical (e.g., motor commands and proprioception) and cognitive (e.g., decision-making and mental rotation) information. Immersive virtual reality (IVR) is a valuable tool that employs this information as real-world navigation does. Given the crucial impact of spatial navigation on daily life, research should focus on ways to enhance it. Though they are still in their development, contemporary IVR methods for spatial navigation training in MCI seem promising. In this usability study, eight patients with MCI syndrome tested an IVR spatial navigation training demo and interacted with the CAVE using active stereo glasses, a foot-motion pad, and a joypad. During the demo, users were asked to report their impressions on the IVR training using the thinking-aloud procedure. Moreover, questionnaires regarding usability, presence and cybersickness were administered at the end of the experience. Our results show that the first version of this system is usable by the patients even if most of them did not have experience with PC/IVR. The system provided a moderate sense of spatial presence and limited negative effects. Issues found during the thinking-aloud procedure concerned the visual aspects, which affected the interaction user-system. Participants reported that they needed more practice with the foot-motion pad even though the overall experience was positively evaluated. Identifying these critical features was essential to develop an improved version of the current system. Full article

Background: Cold-induced vasodilation (CIVD) is a phenomenon that refers to a paradoxical increase in finger temperature that sometimes occurs during cold exposure. The aim of this study was to compare CIVD responses between women and men, during exposure to different environmental conditions. Methods: Seven men and seven women participated in a matched controlled study consisting of a familiarization protocol followed by three experimental sessions (cool (10.8 °C WBGT), thermoneutral (17.2 °C WBGT), and hot (27.2 °C WBGT)). In each session, participants were asked to immerse their left hand and foot in warm water (35 ± 1 °C) for five minutes. Thereafter, the left hand and foot were immersed in cold water (8 ± 1 °C) for 40 min. After that, the left hand and foot were removed from the water and participants remained seated for five minutes. Results: For a matched thermal stress, women experienced an elevated cardiovascular strain (heart rate and in some cases mean arterial pressure) and higher frequency of CIVD reactions (men: 31 vs. women: 60) in comparison to their male counterparts. Conclusions: The present study demonstrated that women experienced elevated cardiovascular strain and higher frequency of CIVD reactions, particularly in the toes, compared to their male counterparts during cold-water immersion. Full article

Suture anchors are extensively used in rotator cuff tear surgery. With the advancement of three-dimensional printing technology, biodegradable metal has been developed for orthopedic applications. This study adopted three-dimensional-printed biodegradable Fe suture anchors with double-helical threads and commercialized non-vented screw-type Ti suture anchors with a tapered tip in the experimental and control groups, respectively. The in vitro study showed that the Fe and Ti suture anchors exhibited a similar ultimate failure load in 20-pound-per-cubic-foot polyurethane foam blocks and rabbit bone. In static immersion tests, the corrosion rate of Fe suture anchors was 0.049 ± 0.002 mm/year. The in vivo study was performed on New Zealand white rabbits and SAs were employed to reattach the ruptured supraspinatus tendon. The in vivo ultimate failure load of the Fe suture anchors was superior to that of the Ti suture anchors at 6 weeks. Micro-computed tomography showed that the bone volume fraction and bone surface density in the Fe suture anchors group 2 and 6 weeks after surgery were superior, and the histology confirmed that the increased bone volume around the anchor was attributable to mineralized osteocytes. The three-dimensional-printed Fe suture anchors outperformed the currently used Ti suture anchors. Full article