Somatosensory Research Articles

Effect of Compressive Strain Rates on Viscoelasticity and Water Content in Intact Porcine Stomach Wall Tissues.

Laparoscopic staplers are used extensively to seal and transect tissue. These devices compress tissue between the stapler jaws to achieve a desired compressed tissue thickness in preparation for stapling. The extent and rate of compression are dependent on surgeon technique, tissue characteristics, and stapler type, all of which can impact stapling outcomes such as bleeding, staple line leaks, and tissue healing. Historically, surgeons have relied on their experience, training, and tactile feedback from the device to optimize stapling. In recent years, the transition to electromechanical and robotic staplers has greatly impacted the tactile feedback available to the surgeon. This raises new questions about the optimal rates of tissue compression and the resultant tissue forces. This study quantifies the transmural biomechanics of the porcine stomach wall. Multi-rate indentation tests were used to observe the effects of indentation rate on the viscoelastic behavior of the stomach tissue during indentation, stress relaxation, and unconstrained recovery. Results show that the stomach wall demonstrates higher stress relaxation (88% vs 80%) and greater strain recovery (52% vs 47%) when indented at high rates (37.5%/s) vs slow rates (7.5%/s). Additionally, water content analysis was used to study fluid flow away from indented regions. Unindented regions were found to have greater water content compared to indented regions (78% compared to 75%). This data generated in this study may be used to enable the development of constitutive models of stomach tissue, which in turn may inform the control algorithms that drive compressive surgical devices.

The relics of Jesus and Eucharistic miracles: scientific analysis of shared AB blood type.

Various relics ascribed to have been in physical contact with the historical Jesus of Nazareth have been evaluated for the presence of blood, including the Tunic of Argenteuil, the Sudarium of Oviedo, and most famously, the Shroud of Turin. Interestingly, the blood type on all three textiles was found to be AB by serological testing; a similar result was observed for various modern Eucharistic miracles, in which consecrated hosts are reported to change into human cardiac tissue and blood. As AB is a relatively rare blood type, these collective observations have been used in numerous contemporary media outlets to support the idea that all such objects share a common origin. Here, the scientific validity of mutual blood type expression is evaluated. As discussed, AB antigens are not unique to human red blood cells but are also expressed in bacteria, providing a practical connection between such varied objects. Moreover, this article clarifies that the communal presence of specific and unique polymorphic markers would be required to validate that bloodstains associated with such items truly originate from a single source.

Compact Carbon-Based Ultra-High-Power Electrodes: A Sodium Alginate-Induced Self-Shrinkage and Densification Approach.

The trade-off between compact energy storage and high-power performance presents a significant challenge in device development. While densifying carbon materials enhances volumetric energy density by optimizing the balance between porosity and packing density, it often disrupts electronic conductivity due to random physical contact between nanomodules, limiting the power performance. This work presents a sodium alginate (SA)-induced self-shrinkage densification strategy that overcomes this limitation by incorporating nanometer-sized "spacers," namely carbon quantum dots (CQDs), into graphene nanosheets and crosslinking them by carbonizing SA accompanying with the shrinkage. These CQDs and SA-derived carbon enhance specific surface area, electronic conductivity, and ion transport rate due to the CQDs' spacer function and the formation of welded junction between the reduced graphene oxide (rGO)/CQDs nanosheets. Subsequently, the rGO/CQDs/SA-derived carbon film exhibits an extraordinary volumetric power density of 12307.7W cm-3 in an aqueous electrolyte under a mass loading of 0.12mg cm-2. Notably, the assembled aqueous supercapacitors achieve a high volumetric power density of 349.5W cm-3 under a higher mass loading of 0.49mg cm-2. This paves the way for developing compact, highly conductive carbon-based electrodes without compromising high porosity, offering a significant advancement in ultra-high-power energy storage devices.

Dermal macrophages control tactile perception under physiological conditions via NGF signaling

We demonstrated previously that sorting nexin 25 (SNX25) in nerve-associated macrophages plays critical roles in pain sensation by regulating tissue NGF content under both physiological and neuropathic conditions. In the present study, we apply the SNX25–NGF paradigm to tactile perception by showing that Snx25+/- mice or macrophage-specific Snx25 conditional knock-out (mcKO) mice had weaker responses to tactile stimuli in normal conditions. Snx25 mcKO mice responded poorly to transcutaneous electrical stimuli at a frequency of 5 Hz (C fiber responses), but normally to stimuli at a frequency of 250 Hz (Aδ fiber responses) or of 2000 Hz (Aβ fiber responses). CX3CR1-positive dermal macrophages were frequently found near calcitonin gene–related peptide (CGRP)- positive nerves and, less frequently, tyrosine hydroxylase (TH)-positive nerves. We confirmed that the tissue content of NGF was lower in Snx25 mcKO mice than in wild-type mice, and in turn, dermal NGF injection restored tactile sensitivity in Snx25+/- mice and Snx25 mcKO mice to normal levels. These results indicate that CGRP-positive C-nociceptors (possibly also TH-positive C-LTMRs) associated dermal macrophages control tactile perception by producing NGF and secreting it into the dermis.

Preventive Behaviors Among Higher Education Students in Response to COVID-19: The Role of Risk Perception

In response to the COVID-19 pandemic, higher education institutions adopted a set of measures to ensure safe face-to-face teaching and to control potential outbreaks. However, the effectiveness of the implemented measures is dependent on the behavior of students, who are generally young, often displaced, living with other colleagues, and constantly seeking physical contact, which makes their behavior outside the institution also of particular relevance to controlling the pandemic. An online questionnaire was developed and applied to characterize the behaviors adopted by students inside and outside the higher education institution, as well as risk perception based on the health belief model (HBM) and unrealistic optimism, with the participation of 620 students from three Portuguese higher education institutions. The adoption of safe behaviors is related to a greater perception of the benefits and of the severity of COVID-19. Unrealistic optimism also has a negative impact on preventive behaviors. The behaviors least adopted by students concerning potential exposure to COVID-19 were disinfecting hands and equipment after use, as well as physical distancing from colleagues. With regard to behaviors adopted outside the institution, it was found that students did not avoid physical contact with colleagues and family members. These findings contribute to our understanding of student behavior during the COVID-19 pandemic, help institutions understand if the applied strategies were effective or not, and denote the need to reinforce or improve the implemented strategies.

Pro-Con Debate: Air or Saline for Loss-of-Resistance Technique of Interlaminar Epidural Access with Fluoroscopy-Guided Pain Medicine Procedures

In this Pro-Con commentary article, the Pro side advocates that using the loss of resistance (LOR) to air technique for interlaminar epidural access is safe as the risk of pneumocephalus is exceptionally low. They note that case reports detailing complications typically utilize at least 1 mL of air, frequently exceeding this amount. Even a 1-mL dosage surpasses the requirement, particularly when fluoroscopy is applied in the context of chronic pain management. The proponents also suggest a modified technique, where a syringe containing a drop of saline or contrast acts as a visual cue, minimizing air injection into the epidural space to a negligible quantity. Moreover, they emphasize that air facilitates the identification of any fluid as an indicator of unintended intrathecal access. The Con perspective argues against the utilization of air for epidural access and advocates for the use of LOR with saline instead. This stance is supported by evidence pointing to a greater occurrence of adverse events, such as postdural puncture headache (PDPH) and pneumocephalus, associated with LOR to air compared to LOR with saline. They also argue that saline’s physical properties enhance tactile feedback, potentially contributing to its increased safety. Both saline and air have been used for many years for epidural access via the interlaminar approach. Although both are generally accepted in practice, neither has been formally established as the standard of care. It would benefit the medical community to further delineate the pros and cons of each medium, enabling practitioners to make more informed decisions. This Pro-Con debate will provide 2 perspectives (Table) on the evidence and rationales for the use of air or saline for the LOR technique in interlaminar epidural access with fluoroscopy.

Designing a Tactile Document UI for 2D Refreshable Tactile Displays: Towards Accessible Document Layouts for Blind People

Understanding document layouts is vital for enhancing document exploration and information retrieval for sighted individuals. However, for blind and visually impaired people, it becomes challenging to have access to layout information using typical assistive technologies such as screen readers. In this paper, we examine the potential benefits of presenting documents on two-dimensional (2D) refreshable tactile displays. These displays enable the tactile perception of 2D data, offering the advantage of dynamic and interactive functionality. Despite their potential, the development of user interfaces (UIs) for such displays has not advanced significantly. Thus, we propose a design of an intelligent tactile user interface (TUI), incorporating touch and audio feedback to represent documents in a tactile format. Our exploratory study for evaluating this approach revealed satisfaction from participants with the experience of directly viewing documents in their true form, rather than relying on screen-reading interpretations. Additionally, participants offered recommendations for incorporating additional features and refining the approach in future iterations. To facilitate further research and development, we have made our dataset and models publicly available.

Effectiveness of a web-based foot-ankle exercise program for treating ulcer risk factors in diabetic neuropathy in a randomized controlled trial

The need for strategies to prevent complications from diabetic neuropathy (DPN) is well recognized. However, foot-ankle exercise programs show weak to moderate evidence, and barriers to their implementation persist, including broad and facilitated access to exercise programs, which guarantee for equity. In this paper, we report for the first time the effectiveness of a web-based foot-ankle exercise program aiming to improve DPN-related outcomes, gait biomechanics and functional outcomes. Sixty-two participants with DPN were randomly allocated into the control group (CG; n = 31), which received the usual care, or the intervention group (IG; n = 31), which received the usual care plus a 12-week foot-ankle exercise program using a web-based software (the SOPeD software). The primary outcomes, DPN symptoms and severity, were assessed using the Brazilian version of the Michigan Neuropathy Screening Instrument and the Decision Support System for Classification of Diabetic Polyneuropathy, respectively. Secondary outcomes included tactile sensitivity (monofilaments) and vibration perception (tuning fork), functional outcomes, such as foot pain and function (Foot Health Status Questionnaire), foot muscle strength and plantar pressure during gait (emed plate), and foot-ankle kinematics and kinetics during gait. Outcomes were assessed at baseline, 12 and 24 weeks by an assessor blinded to group allocation. DPN symptoms and severity remained unchanged after the web-based foot-ankle program. However, IG showed improvements compared to CG, with greater functional reach at 12 weeks, better foot function, reduced foot pain and greater plantarflexion degree during push-off at 24 weeks. Regarding plantar loading during gait, the forefoot pressure reduced in the IG at 12 weeks compared to baseline, but at 24 weeks, forefoot load increased in the IG compared to CG. The 12-week web-based foot-ankle exercise program was feasible, acceptable, demonstrating safety with minimal adverse events, such as delayed onset muscle soreness and foot muscle cramping. While DPN-related outcomes were unaffected by the 12-week SOPeD program, modest improvements in foot pain and function, functional reach, and changes in plantar pressure and plantarflexion degree during gait were noted, mostly at 24 weeks.Trial registration: ClinicalTrials.gov, NCT04011267. Registered on 8 July 2019.

The artistry and algorithms in fabric origami tessellations

This article describes artistic and algorithmic strategies in making fabric origami to create fabric art with tactile sensitivities and expressive shadow effects.

Innovative navigation: a smart cane solution with GPS, GSM, and real-time image capture

Our article presents the design, study, and implementation of a smart cane aimed at enhancing the autonomy and safety of individuals who are blind or visually impaired. The solution is built around an Arduino board, integrated with various sensors and modules, to provide real-time tactile and auditory feedback to the user. Utilizing a combination of basic and advanced technologies, this smart cane detects obstacles at varying distances, triggering sound and vibration alerts to assist the user in navigation. Beyond these essential functions, the cane offers advanced features such as real-time image capture and obstacle recognition through the ESP32-CAM module. Additionally, the system is equipped with a GSM module that facilitates emergency communication by sending SMS messages with the user’s GPS location, obtained via the Neo-6M GPS module. These technological enhancements improve user safety by streamlining obstacle detection and enabling remote assistance when needed. The primary objective is to create a comprehensive solution that not only detects and avoids obstacles but also provides visual information and supports communication with caregivers or emergency services. By doing so, the smart cane contributes to a higher degree of independence and an improved quality of life for blind and visually impaired individuals.

Tactile Sensitivity to Missing tones in Complex Vibrotactile Signals.

Haptic interactions with objects induce complex vibrotactile signals that are central to tactile perception. Despite the broad literature on vibrotactile perception, surprisingly little is known about the sensory processing of complex tactile signals made of multiple pure tones. To fill this gap, the study reported here investigated the impact of the constitutive pure tones of a complex vibrotactile signal on its perception. Participants completed a 3-AFC task, in which they were asked to identify an odd signal among two complex references. The odd signal was created by removing one pure tone from the reference, which varied in spectral composition, harmonicity, and inter-frequency intervals. Each reference signal was made of either two, three, or four pure tones. The results revealed that the removed pure tone's value as well as the inter-frequency interval play a significant role on participants' performance whereas changes in harmonicity and complexity have little impact. The smaller the ratio between the removed frequency and the lowest one of the reference signals, the better the participants' capacity to identify the signal with the missing tone. As this ratio correlates with that of pure tone's perceived intensity, participants' performance can be linked to either of them. Analysis of a subset of complex signals made of pure tones perceived with roughly equal intensity showed that the correlation still holds but slightly decreases. Overall, these results suggest that perception of complex vibrations might be mediated by tactile mechanisms related to both frequency selectivity and to pure tones perceived intensity.

Viewed touch influences tactile detection by altering decision criterion.

Our tactile perception is shaped not only by somatosensory input but also by visual information. Prior research on the effect of viewing touch on tactile processing has found higher tactile detection rates when paired with viewed touch versus a control visual stimulus. Therefore, some have proposed a vicarious tactile system that activates somatosensory areas when viewing touch, resulting in enhanced tactile perception. However, we propose an alternative explanation: Viewing touch makes the observer more liberal in their decision to report a tactile stimulus relative to not viewing touch, also resulting in higher tactile detection rates. To disambiguate between the two explanations, we examined the effect of viewed touch on tactile sensitivity and decision criterion using signal detection theory. In three experiments, participants engaged in a tactile detection task while viewing a hand being touched or approached by a finger, a red dot, or no stimulus. We found that viewing touch led to a consistent, liberal criterion shift but inconsistent enhancement in tactile sensitivity relative to not viewing touch. Moreover, observing a finger approach the hand was sufficient to bias the criterion. These findings suggest that viewing touch influences tactile performance by altering tactile decision mechanisms rather than the tactile perceptual signal.

Neurophysiological evidence of motor contribution to vicarious affective touch.

Understanding observed interpersonal touch, particularly the so-called affective touch targeting the CT fibers, is essential for social interactions. Research has documented that observing other people being touched activates the same cortical areas involved in direct tactile experiences. However, observing interpersonal touch also activates an inner simulation of the movements in the observer's motor system. Given the social and affective significance of CT-optimal touch, the present study tested the hypothesis that observing stroking touches targeting or not targeting the CT fibers system might distinctly influence motor resonance to vicarious touch. With this aim, we used single-pulse transcranial magnetic stimulation and motor-evoked potentials recording while participants observed video clips of interpersonal touch events at different stroking velocities. We found a modulation of motor system activity, particularly a decrease in corticospinal excitability, when observing CT-optimal touch as opposed to non-CT-optimal velocities, a mechanism that might aid in understanding the touchee's feelings during vicarious interpersonal touch. Moreover, participants with higher reliance on bodily cues to be emotionally aware showed greater motor suppression for CT-optimal compared to non-CT-optimal velocities. These results shed light on the complex interplay between motor and somatosensory systems in social touch perception and emphasize the importance of affective touch in human social interactions.

YOLOv5DA: An Improved YOLOv5 Model for Posture Detection of Grouped Pigs

Accurate posture detection is the foundation for analyzing animal behavior, which can promote animal welfare. With the development of computer vision, such technology has been widely used in analyzing animal behavior without physical contact. However, computer vision technology for pig posture detection often suffers from problems of missed or false detection due to complex scenarios. To solve the problem, this study proposed a novel object detection model YOLOv5DA, which was based on YOLOv5s and designed for pig posture detection from 2D camera video. Firstly, we established the annotated dataset (7220 images) including the training set (5776 images), validation set (722 images), and test set (722 images). Secondly, an object detection model YOLOv5DA based on YOLOv5s was proposed to recognize pig postures (standing, prone lying, and side lying), which incorporated Mosaic9 data augmentation, deformable convolution, and adaptive spatial feature fusion. The comparative and ablation experiments were conducted to verify the model’s effectiveness and reliability. Finally, we used YOLOv5DA to detect the posture distribution of pigs. The results revealed that the standing posture was more frequent in the morning and afternoon and the side-lying posture was most common at noon. This observation demonstrated that the posture of pigs is influenced by temperature variations. The study demonstrated that YOLOv5DA could accurately identify three postures of standing, prone lying, and side lying with an average precision (AP) of 99.4%, 99.1%, and 99.1%, respectively. Compared with YOLOv5s, YOLOv5DA could effectively handle occlusion while increasing the mean precision (mAP) by 1.7%. Overall, our work provided a highly accurate, effective, low-cost, and non-contact strategy of posture detection in grouped pigs, which can be used to monitor pig behavior and assist in the early prevention of disease.

Immersive Learning: A Systematic Literature Review on Transforming Engineering Education Through Virtual Reality

Integrating Virtual Reality (VR) with developing technology has become crucial in today’s schools to transform in-the-moment instruction. A change in perspective has occurred because of VR, enabling teachers to create immersive learning experiences in addition to conventional classes. This paper presents a systematic literature review with an in-depth analysis of the changing environment of immersive learning. It discusses advantages and challenges, noting results from previous researchers. VR facilitates more profound knowledge and memory of complex subjects by allowing students to collaborate with digital structures, explore virtual landscapes, and participate in simulated experiments. Developing VR gear, like thin headsets and tactile feedback mechanisms, has democratised immersive engineering learning by making it more approachable and natural for a broader range of students. This study sheds light on the revolutionary potential of immersive learning via VR integration with new technologies in real-time education by examining current trends, discussing obstacles, and an outlook on future directions using the new Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). This study used four databases: Scopus, IEEE, Springer, and Google Scholar. During the selection, 24 articles were added during the review, and 53 studies were selected. It clarifies best practices for adopting VR-enhanced learning environments through empirical analysis and case studies, and it also points out directions for future innovation and growth in the field of immersive pedagogy.

Whisker-Implanted Biomimetic Electronic Skin for Tactile Sensing and Blind Perception.

Rodent whiskers are a distinct class of tactile sensors that work in conjunction with the biological skin to discern airstreams and obstacles with remarkable sensitivity, facilitating navigation around proximate objects. In this study, a flexible artificial skin is developed comprising sensory active units, including electronic skin (e-skin) and an artificial whisker, inspired by the sensory capabilities of rodent skin and whiskers. As a novel strategy, unique congruent air pockets are introduced within the e-skin to enhance the sensitivity. Mechanical stimuli applied to the artificial whisker are efficiently transmitted to the active e-skin, which generates a sensitive tactile perception response. The developed artificial skin exhibits high sensitivity, a wide sensing range, high flexibility, superior stability, and tensile strength. The artificial whisker facilitates the sensitive detection of a broad range of applied mechanical forces. Therefore, the artificial skin can sense subtle and vigorous tactile stimuli including airstreams and field obstacles. The ability to sense, discriminate, and decipher the airstreams and obstacles imparts outstanding tactile sensing and blind perception characteristics to the artificial skin. This artificial skin is a promising platform for the development of sensitive e-skins suitable for a broad range of applications, such as human-machine interfaces, robotics, and wearable electronics.

Efficacy of anesthetics in an echinoderm based on multifaceted stress biomarkers

Animal care committees remain ambiguous on the need for anesthetics during experimental procedures on invertebrate taxa due to long-standing questioning of their sentience and pain perception. When used, anesthetizing procedures for invertebrates have commonly been adapted from those developed for vertebrates, under the largely unverified assumption that they afford the same benefits. The present study formally tested the efficacy of four common anesthetics of aquatic invertebrates (ethanol, MgCl2, clove oil, MS-222) using behavioural (reaction to physical contact and presence of a predator), physiological (respiration rate), cellular (coelomocytes), and hormonal (cortisol) biomarkers in the holothuroid Cucumaria frondosa (Echinodermata). While subjects recovered from exposures to all anesthetics tested, their responses differed markedly. Ethanol did not immobilize the individuals and concurrently increased their respiration rate, and cellular and hormonal stress markers. MgCl2 and clove oil reduced the behavioural and physiological responses, and decreased the cellular markers, but increased the cortisol levels. Only MS-222 fully immobilized the treated individuals and decreased their respiration rate, both during exposure and throughout ulterior interactions with a predator, while keeping coelomocyte counts and cortisol concentrations at baseline levels. MS-222 thus appears to induce the loss of sensation, representing a promising anesthetic and sedative in soft-bodied aquatic invertebrates.

Food rejection is associated with tactile sensitivity and tactile appreciation in three-year-old children.

Food rejections are common in young children and often include healthy foods, hereby impairing the quality of their diet. Previous studies indicate that food texture may play a role in children's food preferences and intake. Building on these findings, as part of an ongoing longitudinal project, the present study investigated whether food rejection is related to tactile sensitivity and tactile appreciation in three-year-old children. A total of 259 children and 289 parents participated in the study. Child food rejection was measured using an ad libitum taste test, in which children were asked to try four different types of vegetables. Next to this, parents reported on their child's food rejection tendencies by completing the Child Food Rejection Scale (CFRS), and indicating their child's liking of 14 vegetables and 11 fruits (Liking of foods). Tactile appreciation was measured using a behavioural Affective Appreciation of Textures (AAT) task, in which children were asked to feel five different objects with their hands and were asked to indicate the pleasantness of the sensation on a three-point smiley-scale. The subscale Touch of the parental questionnaire Sensory Profile (SP-t) was further used to measure tactile sensitivity. Results show that stronger food rejection measured using an ad-libitum taste test is related to a dislike of textures measured using the AAT task. Similarly, parent-reported food rejection measured using CFRS and Liking of foods is positively related to parent-reported tactile sensitivity measured using SP-t. Together, these findings suggest that some children do not only reject food because of its taste, but also because of their dislike of textures. To increase healthy food intake in picky children, it may thus prove helpful to improve children's appreciation of textures.

TouchMark: Partial Tactile Feedback Design for Upper Limb Rehabilitation in Virtual Reality.

The use of Virtual Reality (VR) technology, especially in medical rehabilitation, has expanded to include tactile cues along with visual stimuli. For patients with upper limb hemiplegia, tangible handles with haptic stimuli could improve their ability to perform daily activities. Traditional VR controllers are unsuitable for patient rehabilitation in VR, necessitating the design of specialized tangible handles with integrated tracking devices. Besides, matching tactile stimulation with corresponding virtual visuals could strengthen users' embodiment (i.e., owning and controlling virtual bodies) in VR, which is crucial for patients' training with virtual hands. Haptic stimuli have been shown to amplify the embodiment in VR, whereas the effect of partial tactile stimulation from tangible handles on embodiment remains to be clarified. This research, including three experiments, aims to investigate how partial tactile feedback of tangible handles impacts users' embodiment, and we proposed a design concept called TouchMark for partial tactile stimuli that could help users quickly connect the physical and virtual worlds. To evaluate users' tactile and comfort perceptions when grasping tangible handles in a non-VR setting, various handles with three partial tactile factors were manipulated in Study 1. In Study 2, we explored the effects of partial feedback using three forms of TouchMark on the embodiment of healthy users in VR, with various tangible handles, while Study 3 focused on similar investigations with patients. These handles were utilized to complete virtual food preparation tasks. The tactile and comfort perceptions of tangible handles and users' embodiment were evaluated in this research using questionnaires and interviews. The results indicate that TouchMark with haptic line and ring forms over no stimulation would significantly enhance users' embodiment, especially for patients. The low-cost and innovative TouchMark approach may assist users, particularly those with limited VR experience, in achieving the embodiment and enhancing their virtual interactive experience.

An Origami-Inspired Endoscopic Capsule With Tactile Perception for Early Tissue Anomaly Detection

An Origami-Inspired Endoscopic Capsule With Tactile Perception for Early Tissue Anomaly Detection