Search Results (53)

This paper presents the development of “MateREAL Touch”, a tactile display system that reproduces the sensation of stroking various material textures. The system can store up to 30 samples of material, which are connected via a continuous piece of tape. When not touching, the material switches seamlessly, and the tape moves in sync with the user’s finger, dynamically replicating the feeling of stroking. Additionally, the device simulates transitions between contact and non-contact states by adjusting the grip mechanism based on virtual interactions. As fundamental performance assessments, the material’s switching time was measured. In addition, a discrimination task compared users’ ability to distinguish eight materials under static and dynamic touch conditions in both real and virtual environments. The results showed comparable discrimination accuracy, demonstrating the effectiveness of the system in reproducing real-world material textures in VR. These findings confirm the system’s ability to enable realistic texture perception in virtual environments. Full article

Background: When engaging with the environment, multisensory cues interact and are integrated to create a coherent representation of the world around us, a process that has been suggested to be affected by the lack of visual feedback in blind individuals. In addition, the presence of voluntary movement can be responsible for suppressing somatosensory information processed by the cortex, which might lead to a worse encoding of tactile information. Objectives: In this work, we aim to explore how cross-modal interaction can be affected by active movements and the role of vision in this process. Methods: To this end, we measured the precision of 18 blind individuals and 18 age-matched sighted controls in a velocity discrimination task. The participants were instructed to detect the faster stimulus between a sequence of two in both passive and active touch conditions. The sensory stimulation could be either just tactile or audio–tactile, where a non-informative sound co-occurred with the tactile stimulation. The measure of precision was obtained by computing the just noticeable difference (JND) of each participant. Results: The results show worse precision with the audio–tactile sensory stimulation in the active condition for the sighted group (p = 0.046) but not for the blind one (p = 0.513). For blind participants, only the movement itself had an effect. Conclusions: For sighted individuals, the presence of noise from active touch made them vulnerable to auditory interference. However, the blind group exhibited less sensory interaction, experiencing only the detrimental effect of movement. Our work should be considered when developing next-generation haptic devices. Full article

In this study, we developed a colloidal gold immunochromatographic strip (CGIS) method that used the matrix-matched calibration curves of contamination ratio models to quantitatively determine the total aflatoxin in five herbal medicines. This approach addresses issues related to false results and poor accuracy associated with conventional methods. The CGIS was analyzed using a Vertu touch reader, and the matrix-matched calibration was established based on the absorbance ratios of the T and C lines, as well as the logarithmic values of the total aflatoxin concentrations. The total aflatoxins could be accurately and digitally detected from 2.5 to 40 μg/kg, and the LOD of total aflatoxins was 1 μg/kg in the five herbal medicines. The recovery rates from the spiked samples ranged from 65.1% to 98.6%, and the RSD was less than 16.9%. A total of 229 samples were analyzed by both CGIS and HPLC-FLD, with agreement ranging from 78.4% to 132.6% (Arecae semen), 82.6% to 133.0% (Nelumbinis semen), 79.9% to 117.9% (Coicis semen), 78.1% to 119.0% (Platycladi semen), and 76.1% to 123.0% (Ziziphi spinosae semen). This process for the discrimination of the CGIS results was established to assess if samples met the requirement of aflatoxin limits, which could save approximately 75% in time and reduce the workload of retesting by a designated confirmatory reference method to less than 10%. This study demonstrated that the application of matrix-matched calibration curves based on contamination ratio models to CGIS can effectively enhance the rapid quantitative determination capability of total aflatoxins in herbal medicine matrices. Full article

Background/Objectives: Proprioception and sensory disorders have been reported in children with arthrogryposis multiplex congenita (AMC) and myelomeningocele (MMC), but valid and reliable assessment tools are limited in accurately identifying the sensory aspects of motor disorders. This study aimed to investigate the somatosensory status in the feet and legs. An additional purpose of this study was to explore pain, skin irritations, and health status. Methods: Nineteen children with AMC, twenty-three with MMC, and twenty-two typically developing (TD) children (7–18 years old) were tested using a somatosensory test battery in ankle kinesthesia and in identifying four different types of floors. Results: In the AMC and MMC groups, the threshold to perceive the somatosensory stimuli was not achieved by all participants. MMC participants perceived somatosensory stimuli less than TD participants in all tests, with a higher level of the lesion and more affected ambulation. The MMC group identified one floor significantly less often than the TD group. The AMC group performed better than the MMC group in two-point discrimination, vibration sensation, and some light-touch pressure tests. There were no differences among the TD, AMC, and MMC groups in ankle kinesthesia. Pain was reported by four (21%) subjects in the AMC group and five (22%) in the MMC group, and skin irritations were reported by three (13%) participants in the MMC group. There was no difference among the TD, AMC, and MMC groups in health status as reported using the EQ-5D-Y visual analog scale. Conclusions: Although differences in sensory aspects were the most evident between the groups, assessments of activity and participation levels in the rehabilitation of children with disabilities are also recommended. Full article

The aim of this cross-sectional study was to investigate the relationship between physical fitness, executive function, and academic performance in children and adolescents. A total of 131 students (49% female) aged 10–15 years from a public school in Rio de Janeiro were assessed in executive functions (hearts and flowers, Corsi’s block, and digit span tasks), academic performance (Portuguese, reading, math, and overall school grade), physical tests (touch test disc, agility, lower limb and upper limb explosive strength), and anthropometric measurements. Regression results showed that the composite of sports-related fitness measures was the best predictor of executive functions (β = 0.472; t = −6.075 p < 0.001). Decision tree classifier analysis showed that the combination of factors that discriminated better and worse executive function groups were better performance in hand–eye coordination (TTD), math, and upper limb strength (ULEST). Sports-related fitness is significantly correlated with executive function. Hand–eye motor coordination has been identified as the most important predictor of improved cognitive outcomes, surpassing even academic skills. These findings should be considered in the design of physical activity programs in school settings, which may have a positive impact on child development, reflected in the reduction of academic and socioeconomic disparities. Full article

Background and Objectives: Sensation of the breast skin and nipple-areolar complex (NAC) is commonly assumed to be diminished or completely absent following nipple-sparing mastectomy (NSM) with implant- or expander-based reconstruction. The purpose of this cohort study was to evaluate breast skin and NAC long-term touch pressure sensibility, from 1 month to 1 year, after NSM followed by reconstruction with an implant or expander, and patient quality of life (QoL), hypothesizing that sensibility may diminish with a small progressive return throughout the postoperative period. Materials and Methods: This was achieved by performing sensation tests using Semmes-Weinstein monofilaments (SWM) in nine predefined points of the breast and NAC, a two-point discrimination test (TPD) in the four quadrants of the breast, and QoL assessment using the BREAST-Q. We evaluated 42 patients in Pauls Stradiņš Clinical University Hospital, with a total of 66 breasts, who underwent NSM between 2021 and 2023, performing the breast sensation tests before surgery and postoperatively at 1/3/6 months and 1 year. The BREAST-Q was administered to assess patient satisfaction and well-being. Results: Our results reflect a decline in breast skin and NAC sensation in the 1-month evaluation after NSM (mean: 4.67) when compared to the assessment before surgery (mean: 2.57), with a small progressive return reflected in the 3 months (mean: 3.79), 6 months (mean: 3.68), and 1-year evaluations (mean: 3.14). The following were the mean scores obtained from the BREAST-Q: Psychosocial Well-being (mean: 66), Sexual Well-being (mean: 50), Satisfaction with Breasts Pre-OP (mean: 58), satisfaction with breast reconstruction (mean: 52), Satisfaction with Implants, Satisfaction with nipple reconstruction, Physical Well-being Chest, Adverse effects of radiation, and Satisfaction with Information. Conclusions: This study confirms that sensibility diminishes after this procedure, as observed when comparing the sensation evaluation results before the operation with the 1-month evaluation, reflecting a small progressive return in the following months. Full article

Bradymonabacteria, as the representative of the facultative prey-dependent predators, were re-classified from the preceding Deltaproteobacteria into the phylum Myxococcota and proposed as a novel class named Bradymonadia. However, it was ambiguous whether their predatory pattern and properties were similar to those of the other myxobacterial predators. Therefore, the physiologic features were compared to determine the similarities and differences during the process of group attack and kin discrimination. Comparative genomic analyses were performed to conclude the core genome encoded commonly by bradymonabacteria, Myxococcia, and Polyangia. In conclusion, we proposed that bradymonabacteria have a predation pattern similar to the that of the representative of opportunistic predators like Myxococcus xanthus but with some subtle differences. Their predation was predicted to be initiated by the needle-less T3SS*, and the S-motility mediated by T4P also participated in the process. Meanwhile, their group attacks relied on cell contact and cell destiny. Inter-species (strains) kin discriminations occurred without the existence of T6SS. However, no extracellular lethal substance was detected in the fermentation liquor culture of bradymonabacteria, and the death of prey cells could only be observed when touched by their cells. Moreover, the prey-selective predation was observed when the predator encountered certain prey from Bacillus (G⁺), Algoriphagus (G⁻), and Nocardioides (G⁺). Bradymonabacteria can be regarded as a potential consumer and decomposer, and preying on many sea-dwelling or human pathogenic bacteria allows this group a broad application prospect in marine culture and clinical disease control. Our study will provide more evidence for its exploitations and applications. Full article

Background and Objectives: This study focused on the impact of mental fatigue induced by motor imagery on upper limb function, an area with limited research compared to lower limb performance. It aimed to explore how diaphragmatic breathing exercises influence these effects. Materials and Methods: This study included 30 participants, and Group 1 participated in 12 sessions of diaphragmatic breathing exercises under the supervision of a physiotherapist; Group 2 did not receive any intervention. For all the participants, mental fatigue was induced with motor imagery before and after the intervention, and evaluations were performed before and after mental fatigue. Upper extremity functions were evaluated using isometric elbow flexion strength, hand grip strength, upper extremity reaction time and endurance, finger reaction time, the nine-hole peg test, shoulder position sense, light touch-pressure threshold, and two-point discrimination. Results: The study results showed that after mental fatigue, there was a decrease in isometric elbow flexion strength, nondominant hand grip strength, and nondominant upper extremity endurance, and an increase in nondominant tactile sensation (p < 0.05). No changes were found in two-point discrimination, nine-hole peg test time, and position sense on either side (p > 0.05). The effect of mental fatigue on isometric elbow flexion strength and nondominant grip strength showed significant improvement following diaphragmatic breathing exercises (p < 0.05). Conclusions: This study found that mental fatigue from motor imagery can impact elbow flexion, hand grip strength, upper extremity endurance, and tactile sensitivity. Breathing exercises may help improve strength parameters affected by mental fatigue. It is crucial to consider these effects on upper extremity functions in rehabilitation programs. Full article

Stroke recovery is multifaceted and complex. Machine learning approaches have potential to identify patterns of brain activity associated with clinical outcomes, providing new insights into recovery. We aim to use machine learning to characterise the contribution of and potential interaction between resting state functional connectivity networks in predicting touch discrimination outcomes in a well-phenotyped, but small, stroke cohort. We interrogated and compared a suite of automated machine learning approaches to identify patterns of brain activity associated with clinical outcomes. Using feature reduction, the identification of combined ‘golden features’, and five-fold cross-validation, two golden features patterns emerged. These golden features identified patterns of resting state connectivity involving interactive relationships: 1. The difference between right insula and right superior temporal lobe correlation and left cerebellum and vermis correlation; 2. The ratio between right inferior temporal lobe and left cerebellum correlation and left frontal inferior operculum and left supplementary motor area correlation. Our findings demonstrate evidence of the potential for automated machine learning to provide new insights into brain network patterns and their interactions associated with the prediction of quantitative touch discrimination outcomes, through the automated identification of robust associations and golden feature brain patterns, even in a small cohort of stroke survivors. Full article

Matching-to-sample tasks have been a useful method in visual cognitive studies on non-human animals. The use of touch panels in matching-to-sample tasks has contributed to cognitive studies on terrestrial animals; however, there has been a difficulty in using these devices underwater, which is one of the factors that has slowed the progress of visual studies on underwater animals. Cetaceans (e.g., dolphins and whales) are highly adapted to underwater environments, and further studies on their cognitive abilities are needed to advance our understanding of the interactions between environmental factors and the evolution of cognitive abilities. In this study, we aimed to develop a new experimental method in which a captive killer whale performed a matching-to-sample task using a monitor shown through an underwater window as if a touch panel were used. In order to confirm the usefulness of this method, one simple experiment on mirror image discrimination was conducted, and the pairs with mirror images were shown to be more difficult to identify than the pairs with other normal images. The advantages of using this method include (1) simplicity in the devices and stimuli used in the experiments, (2) appropriate and rigorous experimental control, (3) the possibility of increasing the number of individuals to be tested and interspecies comparisons, and (4) contributions to animal welfare. The use of this method solves some of the problems in previous visual cognitive studies on cetaceans, and it suggests the further possibility of future comparative cognitive studies. It is also expected to contribute to animal welfare in terms of cognitive enrichment, and it could help with the proposal of new exhibition methods in zoos and aquariums. Full article

In soybeans, off-target damage from the use of dicamba and 2,4-D herbicides for broadleaf weed control can significantly impact sensitive vegetation and crops. The early detection and assessment of such damage are critical for plant diagnostic labs and regulatory agencies to inform regulated usage policies. However, the existing technologies that calculate the average spectrum often struggle to detect and differentiate the damage caused by these herbicides, as they share a similar mode-of-action. In this study, a high-precision spatial and spectral imaging solution was tested for the early detection of dicamba and 2,4-D-induced damage in soybeans. A 2021 study was conducted using LeafSpec, a touch-based hyperspectral leaf scanner, to detect damage on soybean leaves. VIS-NIR (visible–near infrared) hyperspectral images were captured from 180 soybean plants exposed to nine different herbicide treatments at different intervals after spraying. Leaf damage was distinguished as early as 2 h after treatment (HAT) using pairwise partial least squares discriminant analysis (PLS-DA) models based on spectral data. Leaf color distribution, texture, and morphological features were analyzed to separate herbicide dosages. By fully exploiting the spatial and spectral information from high-resolution hyperspectral images, classification accuracy was improved from 57.4% to over 80% for all evaluation dates. This work demonstrates the potential and advantages of using spectral and spatial features of LeafSpec hyperspectral images for the early and accurate detection of herbicide damage in soybean plants. Full article

Hundreds of thousands of people living along the Yatsushiro Sea coast have been exposed to methylmercury from the contaminated water of the Chisso factory in Minamata. The most common neurological disorder caused by methylmercury is somatosensory disturbance, but very few studies have been conducted in the world to determine its pathophysiology and origin, including the Japanese cases, which have produced numerous intoxicated individuals. We have already shown in previous studies the body part where the disorder occurs and that its cause is not peripheral nerve damage but damage to the parietal lobes of the cerebrum. We reanalyzed the results of subjective symptoms, neurological findings, and quantitative sensory measurements in 197 residents (63.2 ± 10.7 years old) from contaminated areas exposed to methylmercury from seafood and 130 residents (63.7 ± 9.3 years old) from control areas, the same subjects as in previous studies, to determine the characteristics of somatosensory disturbance in detail. The most commonly affected sensory modalities were superficial peripheral touch and pain in the extremities, followed by two-point discrimination and deep senses, and in the most severe cases, full-body sensory dysfunction and impairment of all sensory submodalities. The severity of sensory submodalities correlated with each other but not with peripheral nerve conduction test indices, further confirming the correctness of our assertion about the responsible foci of sensory disturbance. The health effects of chronic methylmercury toxicosis can be elucidated by a detailed examination of sensory deficits. Full article

Dragon fruit is a tropical fruit with significant potential for consumers and producers. The quality assurance of this high-value product is crucial to satisfy consumer expectations. The quality of imported dragon fruit after storage may deteriorate due to inappropriate storage conditions. The firmness of dragon fruit is an essential parameter to estimate its conditions, and it is usually measured by destructive testing. The objective of the present study is to develop and test a non-destructive robotic sensor for assessing dragon fruit quality related to texture deterioration. Sixty white-fresh dragon fruits obtained from a store were divided in two sets of thirty fruits and stored 48 h at different conditions (cold and room storage) to produce deteriorated and consumer-acceptable fruits. First, the fruit samples were assessed non-destructive with the force sensor of a collaborative robot while they were touched. The robot tool is a pad capable of adapting and copying fruit shapes while controlling its hardness with the jamming transition of its internal granular fill. Second, the fruits were evaluated with destructive tests such as fruit firmness, flesh firmness, and soluble solid content. The procedure followed to produce deteriorated and acceptable fruits were confirmed. A discriminant analysis was carried out to segregate the fruit between the two categories according to the non-destructive variables extracted from the sensor. The variables obtained from the robotic first slope (S1) and the difference between the maximum value and the first overshoot (Os) were significant predictors for the separation in the two quality categories. Promising results were obtained with 77.50% of well classified fruit from the model data set, and 84.21% from the validation data set. The use of the robot could be an efficient tool in evaluating the quality of dragon fruit. This process may lead to substantial savings, particularly considering the elevated cost associated with the importation of tropical fruits into the European market. Full article

Tactile perception encompasses several submodalities that are realized with distinct sensory subsystems. The processing of those submodalities and their interactions remains understudied. We developed a paradigm consisting of three types of touch tuned in terms of their force and velocity for different submodalities: discriminative touch (haptics), affective touch (C-tactile touch), and knismesis (alerting tickle). Touch was delivered with a high-precision robotic rotary touch stimulation device. A total of 39 healthy individuals participated in the study. EEG cluster analysis revealed a decrease in alpha and beta range (mu-rhythm) as well as theta and delta increase most pronounced to the most salient and fastest type of stimulation. The participants confirmed that slower stimuli targeted to affective touch low-threshold receptors were the most pleasant ones, and less intense stimuli aimed at knismesis were indeed the most ticklish ones, but those sensations did not form an EEG cluster, probably implying their processing involves deeper brain structures that are less accessible with EEG. Full article

There is a growing demand for flexible pressure sensors in environmental monitoring and human–robot interaction robotics. A flexible and susceptible sensor can discriminate multidirectional pressure, thus effectively detecting signals of small environmental changes and providing solutions for personalized medicine. This paper proposes a multidimensional force detection sensor inspired by a wind chime structure with a three-dimensional force structure to detect and analyze normal and shear forces in real time. The force-sensing structure of the sensor consists of an upper and lower membrane on a polydimethylsiloxane substrate and four surrounding cylinders. A piezoelectric hemisphere is made of BTO/PVDF/PDMS composite material. The sensor columns in the wind chime structure surround the piezoelectric layer in the middle. When pressure is applied externally, the sensor columns are connected to the piezoelectric layer with a light touch. The piezoelectric hemisphere generates a voltage signal. Due to the particular structure of the sensor, it can accurately capture multidimensional forces and identify the direction of the external force by analyzing the position of the sensor and the output voltage amplitude. The development of such sensors shows excellent potential for self-powered wearable sensors, human–computer interaction, electronic skin, and soft robotics applications. Full article