Skin Displacement Research Articles

The spatial profile of skin indentation shapes tactile perception across stimulus frequencies

Multiple human sensory systems exhibit sensitivity to spatial and temporal variations of physical stimuli. Vision has evolved to offer high spatial acuity with limited temporal sensitivity, while audition has developed complementary characteristics. Neural coding in touch has been believed to transition from a spatial to a temporal domain in relation to surface scale, such that coarse features (e.g., a braille cell or corduroy texture) are coded as spatially distributed signals, while fine textures (e.g., fine-grit sandpaper) are encoded by temporal variation. However, the interplay between the two domains is not well understood. We studied tactile encoding with a custom-designed pin array apparatus capable of deforming the fingerpad at 5 to 80 Hz in each of 14 individual locations spaced 2.5 mm apart. Spatial variation of skin indentation was controlled by moving each of the pins at the same frequency and amplitude, but with phase delays distributed across the array. Results indicate that such stimuli enable rendering of shape features at actuation frequencies up to 20 Hz. Even at frequencies > 20 Hz, however, spatial variation of skin indentation continues to play a vital role. In particular, perceived roughness is affected by spatial variation within the fingerpad even at 80 Hz. We provide evidence that perceived roughness is encoded via a summary measure of skin displacement. Relative displacements in neighboring pins of less than 10 µm generate skin stretch, which regulates the roughness percept.

Perceived Intensities of Normal and Shear Skin Stimuli Using a Wearable Haptic Bracelet

Our aim is to provide effective interaction with virtual objects, despite the lack of co-location of virtual and real-world contacts, while taking advantage of relatively large skin area and ease of mounting on the forearm. We performed two human participant studies to determine the effects of haptic feedback in the normal and shear directions during virtual manipulation using haptic devices worn near the wrist. In the first study, participants performed significantly better while discriminating stiffness values of virtual objects when the feedback consisted of normal displacements compared to shear displacements. Participants also commented that they could detect normal cues much easier than shear, which motivated us to perform a second study to find the point of subjective equality (PSE) between normal and shear stimuli. Our results show that shear stimuli require a larger actuator displacement but less force than normal stimuli to achieve perceptual equality for our haptic bracelets. We found that normal and shear stimuli cannot be equalized through skin displacement nor the interaction forces across all users. Rather, a calibration method is needed to find the point of equality for each user where normal and shear stimuli create the same intensity on the user's skin.

Aging of the Neck Decoded: New Insights for Minimally Invasive Treatments.

Many signs of aging manifest in the neck region, including platysmal bands, excess skin, horizontal neck lines and decreasing contour of the neck. While the clinical signs of an aged neck are well-known, data determining the underlying aging process are limited. To decode aging of the neck. This prospective study investigated elasticity and firmness of skin, muscle activity and skin displacement upon muscular contraction in the neck in 77 young-, middle- and old-age individuals. Objective outcome measures, including 3-dimensional imaging, cutometry and surface electromyography, were utilized for all assessments. Mean firmness of skin decreased significantly from young to old individuals (0.37 ± 0.13mm, 0.30 ± 0.12mm and 0.26 ± 0.12mm in young, middle and old subjects, respectively; p < 0.001). Gross elasticity decreased significantly from 75.1 ± 13.0% in young subjects, to 64.53 ± 15.7% in middle-aged subjects and 55.79 ± 13.0% in old subjects (p < 0.001). The mean y-axis skin displacement increased from 2.48 ± 4.33mm in young subjects, to 3.11 ± 4.49mm in middle-aged subjects and 3.61 ± 5.38mm in old subjects (p = 0.006). The mean signal-to-noise ratio decreased significantly from 16.74 ± 5.77µV in young subjects, to 14.41 ± 4.86µV in middle-aged subjects and to 12.23 ± 5.99µV in old subjects (p < 0.001). This study provides insights into the interplay between skin elasticity, muscular activity and the reflected movement of the skin of the neck. Appreciation of these age-related changes lays the fundament for aesthetic treatments in this delicate region. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Feasibility of Specular Reflection Imaging for Extraction of Neck Vessel Pressure Waveforms.

Cardiovascular disease (CVD) is a leading cause of death worldwide and was responsible for 31% of all deaths in 2015. Changes in fluid pressures within the vessels of the circulatory system reflect the mechanical function of the heart. The jugular venous (JV) pulse waveform is an important clinical sign for assessing cardiac function. However, technology able to aid evaluation and interpretation are currently lacking. The goal of the current study was to develop a remote monitoring tool that aid clinicians in robust measurements of JV pulse waveforms. To address this need, we have developed a novel imaging modality, Specular Reflection Vascular Imaging (SRVI). The technology uses specular reflection for visualization of skin displacements caused by pressure pulsations in blood vessels. SRVI has been tested on 10 healthy volunteers. 10-seconds videos of the neck illuminated with a diffuse light source were captured at 250 fps. SRVI was able to identify and discriminate skin displacements caused by carotid artery and jugular vein pulsations to extract both carotid artery and jugular vein waveforms, making them easier to be visualized and interpreted. The method provided a 6-fold improvement in signal strength over a comparator remote PPG dataset. The current pilot study is a proof-of-concept demonstration of the potential of Specular Reflection Vascular Imaging for extraction of JV pulse waveforms.

Template Matching and Matrix Profile for Signal Quality Assessment of Carotid and Femoral Laser Doppler Vibrometer Signals.

Background: Laser-Doppler Vibrometry (LDV) is a laser-based technique that allows measuring the motion of moving targets with high spatial and temporal resolution. To demonstrate its use for the measurement of carotid-femoral pulse wave velocity, a prototype system was employed in a clinical feasibility study. Data were acquired for analysis without prior quality control. Real-time application, however, will require a real-time assessment of signal quality. In this study, we (1) use template matching and matrix profile for assessing the quality of these previously acquired signals; (2) analyze the nature and achievable quality of acquired signals at the carotid and femoral measuring site; (3) explore models for automated classification of signal quality.Methods: Laser-Doppler Vibrometry data were acquired in 100 subjects (50M/50F) and consisted of 4–5 sequences of 20-s recordings of skin displacement, differentiated two times to yield acceleration. Each recording consisted of data from 12 laser beams, yielding 410 carotid-femoral and 407 carotid-carotid recordings. Data quality was visually assessed on a 1–5 scale, and a subset of best quality data was used to construct an acceleration template for both measuring sites. The time-varying cross-correlation of the acceleration signals with the template was computed. A quality metric constructed on several features of this template matching was derived. Next, the matrix-profile technique was applied to identify recurring features in the measured time series and derived a similar quality metric. The statistical distribution of the metrics, and their correlates with basic clinical data were assessed. Finally, logistic-regression-based classifiers were developed and their ability to automatically classify LDV-signal quality was assessed.Results: Automated quality metrics correlated well with visual scores. Signal quality was negatively correlated with BMI for femoral recordings but not for carotid recordings. Logistic regression models based on both methods yielded an accuracy of minimally 80% for our carotid and femoral recording data, reaching 87% for the femoral data.Conclusion: Both template matching and matrix profile were found suitable methods for automated grading of LDV signal quality and were able to generate a quality metric that was on par with the signal quality assessment of the expert. The classifiers, developed with both quality metrics, showed their potential for future real-time implementation.

Vibrations of a Cylindrical Sandwich Shell with a Honeycomb Core Made Using FDM technology

Presented is a model of the dynamic deformation of a three-layer cylindrical shell with a honeycomb core, manufactured by fused deposition modeling (FDM), and skins reinforced with oriented carbon nano-tubes (CNT). A ULTEM 9085 thermoplastic-based honeycomb core is considered. To analyze the stress-strain state of the honeycomb core, a finite element homogenization procedure was used. As a result of this procedure, the dynamic response of the honeycomb core is modeled by a homogeneous orthotropic material, whose mechanical properties correspond to those of the core. The proposed model is based on the high-order theory, extended for the analysis of sandwich structures. The skin displacement projections are expanded along the transverse coordinate up to quadratic terms. The honeycomb core displacement projections are expanded along the transverse coordinate up to cubic terms. To ensure the integrity of the structure, shell displacement continuity conditions at the junction of the layers are used. The investigation of linear vibrations of the shell is carried out using the Rayleigh-Ritz method. For its application, the potential and kinetic energies of the structure are derived. Considered are the natural frequencies and modes of vibrations of a one-side clamped cylindrical sandwich shell. The dependence of the forms and frequencies of vibrations on the honeycomb core thickness and the direction of reinforcement of the shell skins have been investigated. It was found that the eigenforms of a sandwich shell are characterized by a smaller number of waves in the circumferential direction, as well as a much earlier appearance of axisymmetric forms. This means that when analyzing the resonant vibrations of a sandwich shell, it is necessary to take into account axisymmetric shapes. Changing the direction of reinforcement of the skins with CNTs makes it possible to significantly influence the frequencies of the natural vibrations of the shell, which are characterized by a nonzero number of waves in the circumferential direction. It was found that this parameter does not affect the frequencies of the axisymmetric shapes of the shell under consideration.

A novel tool for assessing the correlation of internal/external markers during SGRT guided stereotactic ablative radiotherapy treatments.

An in-house developed tool was implemented and validated to investigate the skin surface, hepatic dome, and target displacement for stereotactic ablative radiotherapy (SABR) of thoracic/abdominal lesions using a Surface Guided Radiation Therapy (SGRT) system combined with 4D- images. Fourteen consecutive patients with tumors near the hepatic dome undergoing SABR treatments were analyzed. For each patient, a planning 4D-CT and five 4D-CBCT images were acquired. The C-RAD technology was also used to register/monitor the position of the skin reference point (SRP) as an external marker representative of patient breathing. The 4D images were imported in the developed tool, and the absolute maximum height (Pmax,dome) of the hepatic dome on the ten respiratory phases was semi-automatically detected. Similarly, the contour of the skin surface was extracted in correspondence with the SRP position. The tool has been validated using an ad hoc modified moving phantom with pre-selected amplitudes and numbers of cycles. The Pearson correlation coefficients and Bland-Altman plots were calculated. There was a strong correlation between the skin motion amplitude based on 4D-CBCT and the C-RAD in all the patients (0.90±0.08). Similarly, the mean±SD of Pearson correlation coefficients of skin and Pmax,dome movements registered by 4D-CT and 4D-CBCT were 0.90±0.05 and 0.94±0.05, respectively. The mean±SD of Pearson correlation coefficients comparing the skin and Pmax,dome displacements within each imaging modality were 0.88±0.05 and 0.90±0.05 for 4D-CT and 4D-CBCT, respectively. The SRP displacement during the set-up imaging and the treatment delivery were similar in all the investigated patients. Similar results were obtained for the ad hoc modified phantom in the preliminary validation phase. The strong correlation between the tumor/ hepatic dome and skin displacements confirms that the SGRT approach can be considered appropriate for intra- and inter-fraction motion management in SABR therapy.

On Lightmyography: A New Muscle Machine Interfacing Method for Decoding Human Intention and Motion.

Recognising and classifying human hand gestures is important for effective communication between humans and machines in applications such as human-robot interaction, human to robot skill transfer, and control of prosthetic devices. Although there are already many interfaces that enable decoding of the intention and action of humans, they are either bulky or they rely on techniques that need careful positioning of the sensors, causing inconvenience when the system needs to be used in real-life scenarios and environments. Moreover, electromyography (EMG), which is the most commonly used technique, captures EMG signals that have a nonlinear relationship with the human intention and motion. In this work, we present lightmyography (LMG) a new muscle machine interfacing method for decoding human intention and motion. Lightmyography utilizes light propagation through elastic media and the change of light luminosity to detect silicone deformation. Lightmyography is similar to forcemyography in the sense that they both record muscular contractions through skin displacements. In order to experimentally validate the efficiency of the proposed method, we designed an interface consisting of five LMG sensors to perform gesture classification experiments. Using this device, we were able to accurately detect a series of different hand postures and gestures. We also compared LMG data with processed EMG data.

Three-Dimensional Motion Capture of a Smile in Repaired Unilateral Cleft Lip: What's Our Vector, Victor?

Following surgical repair, patients with unilateral cleft lip (UCL) exhibit dynamic asymmetry during facial expressions compared to healthy individuals. Previous studies using Euclidean distances to describe this asymmetry fail to take the direction of the movement into account. The aim of this study is to compare differences in participants with UCL and controls using analysis of motion vectors during facial expressions. In this cross-sectional study, twenty-six pediatric participants were recruited: 13 participants with repaired left UCL and 13 participants with no craniofacial diagnosis. Participants were recorded performing a maximal smile by a 4D stereophotogrammetric system. Phases of the smile were divided into closed lip and open lip smiles. Ten regions of interest were analyzed: subnasal area, upper lip, lower lip, oral commissure, and ala on both sides. The motion vectors were calculated and vector magnitude and direction for each region was compared. Between cleft and control groups, the differences in vector direction were greater than the magnitude differences. Significant differences in vector direction were identified at both oral commissures in the closed lip smile; and at the oral commissure, subnasal, upper lip, and lower lip regions during open lip smile. Vector analysis demonstrated significant movement asymmetry during facial animation in participants following UCL repair, not previously identified when analyzing magnitude of skin displacement.

Dynamic evaluation of facial muscles: 3D skin displacement vector analysis using a facial painting model.

BackgroundBotulinum toxin A can be used to eliminate dynamic wrinkles by relaxing the muscles involved in facial expressions. Therefore, it is essential to know the location, origin, insertion, function, and changes of the facial expression muscles according to their contraction.MethodsAfter drawing the muscles on the face of a model, pictures were taken at rest. The model was then asked to make facial expressions that cause facial wrinkles. All images were taken with the Vectra H1 camera system (Canfield Scientific, Inc., Fairfield, New Jersey). Each expression image was aligned to its respective static image to compute the differences in skin position, so as to calculate the skin displacement vectors. The values for local changes in skin displacement were calculated by applying the automated algorithms of the Vectra Software Mirror Suite and visualized using the color and size of the arrow.ResultsFace painting and 3D skin vector displacement analyses enabled visualization of all the facial muscles involved in facial expressions working dynamically, allowing us to visualize the effect of each muscle in the creation of hyperkinetic wrinkles. Face painting and 3D skin vector displacement analyses can be combined to determine the location of the wrinkles, extent of the muscle, part of the muscle that contracts, presence of asymmetry, direction in which the muscle contracts, and correlation between the antagonists and synergistic muscles.ConclusionThe botulinum toxin A injection educational model using body painting and 3D skin vector displacement analyses can provide a deeper understanding of actual moving muscle anatomy.Level of Evidence4.

Mask-Type Sensor for Pulse Wave and Respiration Measurements and Eye Blink Detection.

This paper reports on a mask-type sensor for simultaneous pulse wave and respiration measurements and eye blink detection that uses only one sensing element. In the proposed sensor, a flexible air bag-shaped chamber whose inner pressure change can be measured by a microelectromechanical system-based piezoresistive cantilever was used as the sensing element. The air bag-shaped chamber is fabricated by wrapping a sponge pad with plastic film and polyimide tape. The polyimide tape has a hole to which the substrate with the piezoresistive cantilever adheres. By attaching the sensor device to a mask where it contacts the nose of the subject, the sensor can detect the pulses and eye blinks of the subject by detecting the vibration and displacement of the nose skin caused by these physiological parameters. Moreover, the respiration of the subject causes pressure changes in the space between the mask and the face of the subject as well as slight vibrations of the mask. Therefore, information about the respiration of the subject can be extracted from the sensor signal using either the low-frequency component (<1 Hz) or the high-frequency component (>100 Hz). This paper describes the sensor fabrication and provides demonstrations of the pulse wave and respiration measurements as well as eye blink detection using the fabricated sensor.

The effectiveness of massage for treating acne lesions: a case study

Background: Acne vulgaris is a chronic disease affecting almost 100% of the population. The treatment of this condition is not limited to the disease itself, but also involves eliminating the resultant scars. The most common treatments for acne and the associated scars are pharmacotherapy, cosmetic and physical therapy, and aesthetic medicine therapies. An alternative method for treating this condition may be massage, which, as a mechanical stimulus, may be effective at increasing scar mobility and reducing the pain experienced during movement. Aim of the study: The aim of this case study was to examine the effectiveness of massage for treating the scars resulting from keloid acne. Material and methods: Massage treatments were performed on a young man (32 years old) who, as a result of acne, had scars on the chest and back areas. Massage was performed twice a week for 3 weeks (6 treatments), and each session lasted 40 minutes. Before the therapy, the VAS scale was used to assess the perceived pain, and palpation was used to assess the consistency (hardness) of the post-acne lesions. Skin displacement was measured with the use of an innovative device allowing for determination of the angle of displacement of the superficial skin layer within the scar. A questionnaire was also used to assess well-being and quality of life. The measurements were repeated after each session and immediately after the end of the massage cycle. Results: After a series of massages, the experienced pain, as assessed by the VAS scale, was reduced from level 5 before therapy to level 1 after therapy. Skin mobility was also increased by the massage treatments, and the patient’s well-being and quality of life improved after each session. Conclusions: The presented case shows that massage can be used in the treatment of post-acne lesions. This therapy can support the conventional treatment process by contributing to a reduction in pain, increasing the limited mobility and displacement of the scarred skin, and improving overall well-being and quality of life.

Temporal coherency of mechanical stimuli modulates tactile form perception

The human hand can detect both form and texture information of a contact surface. The detection of skin displacement (sustained stimulus) and changes in skin displacement (transient stimulus) are thought to be mediated in different tactile channels; however, tactile form perception may use both types of information. Here, we studied whether both the temporal frequency and the temporal coherency information of tactile stimuli encoded in sensory neurons could be used to recognize the form of contact surfaces. We used the fishbone tactile illusion (FTI), a known tactile phenomenon, as a probe for tactile form perception in humans. This illusion typically occurs with a surface geometry that has a smooth bar and coarse textures in its adjacent areas. When stroking the central bar back and forth with a fingertip, a human observer perceives a hollow surface geometry even though the bar is physically flat. We used a passive high-density pin matrix to extract only the vertical information of the contact surface, suppressing tangential displacement from surface rubbing. Participants in the psychological experiment reported indented surface geometry by tracing over the FTI textures with pin matrices of the different spatial densities (1.0 and 2.0 mm pin intervals). Human participants reported that the relative magnitude of perceived surface indentation steeply decreased when pins in the adjacent areas vibrated in synchrony. To address possible mechanisms for tactile form perception in the FTI, we developed a computational model of sensory neurons to estimate temporal patterns of action potentials from tactile receptive fields. Our computational data suggest that (1) the temporal asynchrony of sensory neuron responses is correlated with the relative magnitude of perceived surface indentation and (2) the spatiotemporal change of displacements in tactile stimuli are correlated with the asynchrony of simulated sensory neuron responses for the fishbone surface patterns. Based on these results, we propose that both the frequency and the asynchrony of temporal activity in sensory neurons could produce tactile form perception.

The unique role of parietal cortex in action observation: Functional organization for communicative and manipulative actions

Action observation is supported by a network of regions in occipito-temporal, parietal, and premotor cortex in primates. Recent research suggests that the parietal node has regions dedicated to different action classes including manipulation, interpersonal interactions, skin displacement, locomotion, and climbing. The goals of the current study consist of: 1) extending this work with new classes of actions that are communicative and specific to humans, 2) investigating how parietal cortex differs from the occipito-temporal and premotor cortex in representing action classes. Human subjects underwent fMRI scanning while observing three action classes: indirect communication, direct communication, and manipulation, plus two types of control stimuli, static controls which were static frames from the video clips, and dynamic controls consisting of temporally-scrambled optic flow information. Using univariate analysis, MVPA, and representational similarity analysis, our study presents several novel findings. First, we provide further evidence for the anatomical segregation in parietal cortex of different action classes: We have found a new site that is specific for representing human-specific indirect communicative actions in cytoarchitectonic parietal area PFt. Second, we found that the discriminability between action classes was higher in parietal cortex than the other two levels suggesting the coding of action identity information at this level. Finally, our results advocate the use of the control stimuli not just for univariate analysis of complex action videos but also when using multivariate techniques.

The Difference in Facial Movement Between the Medial and the Lateral Midface: A 3-Dimensional Skin Surface Vector Analysis.

Our understanding of the functional anatomy of the face is constantly improving. To date, it is unclear whether the anatomic location of the line of ligaments has any functional importance during normal facial movements such as smiling. The authors sought to identify differences in facial movements between the medial and lateral midface by means of skin vector displacement analyses derived from 3-dimensional (3D) imaging and to further ascertain whether the line of ligaments has both a structural and functional significance in these movements. The study sample consisted of 21 healthy volunteers (9 females and 12 males) of Caucasian ethnic background with a mean age of 30.6 (8.3) years and mean BMI of 22.57 (2.5) kg/m2. 3D images of the volunteers' faces in repose and during smiling (Duchenne type) were taken. 3D imaging-based skin vector displacement analyses were conducted. The mean horizontal skin displacement was 0.08 (2.0) mm in the medial midface (lateral movement) and was -0.08 (1.96) mm in the lateral midface (medial movement) (P = 0.711). The mean vertical skin displacement (cranial movement of skin toward the forehead/temple) was 6.68 (2.4) mm in the medial midface, whereas it was 5.20 (2.07) mm in the lateral midface (P = 0.003). The results of this study provide objective evidence for an antagonistic skin movement between the medial and lateral midface. The functional boundary identified by 3D imaging corresponds to the anatomic location of the line of ligaments.

Ultra-Conformable Ionic Skin with Multi-Modal Sensing, Broad-Spectrum Antimicrobial and Regenerative Capabilities for Smart and Expedited Wound Care.

While rapid wound healing is essential yet challenging, there is also an unmet need for functional restoration of sensation. Inspired by natural skin, an ultra‐conformable, adhesive multi‐functional ionic skin (MiS) with multi‐modal sensing capability is devised for smart and expedited wound care. The base of MiS is a unique skin‐like, conductive and self‐adaptive adhesive polyacrylamide/starch double‐network hydrogel (PSH) and self‐powered, flexible, triboelectric sensor(s) is integrated on top of PSH for multi‐tactile sensing. MiS could enhance wound contraction, collagen deposition, angiogenesis, and epidermis formation in a full‐thickness skin defect wound model in vivo, while significantly inhibiting the biofilm formation of a wide range of microorganisms. MiS also exhibits multi‐modal sensing capability for smart and instant therapeutics and diagnostics, including skin displacement or joint motion, temperature, pressure and tissue exudate changes of wound bed, and locally releasing drugs in a pH‐responsive manner. More importantly, MiS could restore the skin‐mimicking tactile sensing function of both touch location and intensity, and thus could be used as a human‐machine interface for accurate external robotic control. MiS demonstrates a new comprehensive paradigm of combining wound diagnosis and healing, broad‐spectrum anti‐microbial capability and restoration of multi‐tactile sensing for the reparation of severe wound.

Skin Burn by Termal Mattress - A Therapeutic Approach

Background: Burns are caused by a direct or indirect action of heat on an organism, compromising the functional integrity of the skin. Hypothermia is a common intercurrence in animals during the transoperative period; thermal mattresses are used to maintain the animal’s body temperature, but inappropriate use can cause the patient’s skin to burn. In humans, burns are quite common; however, in veterinary medicine, they are infrequent. The aim of this study was to describe a case of accidental burn in a canine caused by a thermal mattress, emphasizing wound treatment and analgesia used.Case: A 12-year-old male canine without defined breed weighing 15 kg underwent an emergency exploratory laparotomy due to rupture of a spleen mass and presented with intercurrence hypothermia during the anesthesia procedure, which was controlled using a thermal mattress. Ten days after the surgical procedure, he developed a skin lesion with erythema, suffusion, and necrosis, evolving skin displacement along the entire back with a lot of pain which was possibly caused by the use of a thermal mattress in the transoperative procedure. The intuited analgesic treatment involved the use of numerous and different drugs, including Methadone (0.3 mg/kg, QID, SC), Dipyrone (25 mg/kg, TID, IV), and Ketamine (0.5 mg/kg, TID, SC) (during hospitalization), as well as Tramadol (4 mg/kg, TID, PO) and Dipyrone (25 mg/kg, TID, PO) after medical release as support therapy. For the wound treatment, calcium alginate was initially used daily and subsequently changed for daily application of dermisana oil. The patient followed up weekly for approximately two months for wound monitoring as well as adjustments to the drug therapy. The would almost completely healed, but the patient showed a significant worsening in the general clinical condition correlated with the neoplasm that he had, and the owner and clinical staff of the veterinary hospital opted for euthanasia.Discussion: Hypothermia should be avoided as much as possible during anesthesia, as the body’s temperature is very important in homeostasis, in addition to being able to change the pharmacokinetics and pharmacodynamics of some drugs. The use of a thermal mattress to avoid hypothermia during the intraoperative period is a common and useful tool in veterinary routine, but should be used with caution and constant monitoring of the animal under general anesthesia to avoid skin burns which are not immediately noted. When diagnosed, the treatment should aim for wound healing and provide analgesia. Different pharmacological approaches can be used for this purpose, including topical therapies with different products that provide wound healing and regard to analgesia can be used for association of non-steroidal anti-inflammatory drugs such as meloxicam, opioids like morphine and tramadol, and N-Methyl-D-aspartate (NMDA) blockers like ketamine for analgesia. Burn treatment is difficult but can have a favorable prognosis. In the present report, the conservative wound management using sodium alginate and dermisana oil almost completely cured the wound, and the canine responded positively to the analgesic protocol instituted with the association of different drugs. It is still important to highlight the attendance and commitment of the owner in the proposed treatment, as euthanasia, in this case, was due to the comorbidity presented by the patient.

Perception of Tactile Directionality via Artificial Fingerpad Deformation and Convolutional Neural Networks.

Humans can perceive tactile directionality with angular perception thresholds of 14-40° via fingerpad skin displacement. Using deformable, artificial tactile sensors, the ability to perceive tactile directionality was developed for a robotic system to aid in object manipulation tasks. Two convolutional neural networks (CNNs) were trained on tactile images created from fingerpad deformation measurements during perturbations to a handheld object. A primary CNN regression model provided a point estimate of tactile directionality over a range of grip forces, perturbation angles, and perturbation speeds. A secondary CNN model provided a variance estimate that was used to determine uncertainty about the point estimate. A 5-fold cross-validation was performed to evaluate model performance. The primary CNN produced tactile directionality point estimates with an error rate of 4.3% for a 20° angular resolution and was benchmarked against an open-source force estimation network. The model was implemented in real-time for interactions with an external agent and the environment with different object shapes and widths. The perception of tactile directionality could be used to enhance the situational awareness of human operators of telerobotic systems and to develop decision-making algorithms for context-appropriate responses by semi-autonomous robots.

MMP-2 and TIMP-2 expression, quantitative analysis and biomechanical changes in scar hypertrophy after autologous free transplantation of rabbit oral mucosa and scrotal skin.

This study aimed to investigate the long-term scar hypertrophy in the rabbit transplanted oral mucosa and scrotal skin with changed matrix environment, as well as the scar location expression, quantitative analysis of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) and biomechanical changes in the transplanted tissues. The split-thickness skin grafts were collected from the oral mucosas and scrotal skins of 30 male rabbits, and prepared into reelpipes for autologous transplantation into the rabbit back muscular tissues. Samples were collected to carry out elastic tensile mechanical detection and histological observation. The maximum longitudinal tensile displacement of scrotal skin before 8 weeks of transplantation was greater than that after 8 weeks of transplantation (P < 0.05). The expression intensities of MMP-2 and TIMP-2 in the oral mucosa and in scrotal skin at 2 W time point were higher than those at To time point (P < 0.05). The expression quantities of TIMP-2 in oral mucosa and scrotal skin during 8–24 W were higher than those of MMP-2 (P < 0.05). At 8 W time point, the TIMP-2/MMP-2 ratio in scrotal skin was higher than that in oral mucosa (P < 0.05). MMP-2 and TIMP-2 expression in normal oral mucosa and scrotal skin is weak, but their expression is remarkably up-regulated after 2 weeks of transplantation, revealing that scar formation was related to the high expression of MMP-2 and TIMP-2. At the 8th–24th weeks, the AOD values of TIMP-2 in oral mucosa and scrotal skin are apparently higher than those of MMP-2; moreover, the TIMP-2/MMP-2 ratio in scrotal skin at the 8th week was higher than that in oral mucosa, which can well explain the earlier scar formation in scrotal skin than in oral mucosa, and it also suggests that the different expression levels between TIMP-2 and MMP-2 may account for the important cause of scar formation.

Measurement System for Finger Skin Displacement on a Textured Surface Using Index Matching

Understanding the relationship between the displacement of the skin when tracing a textured object and the resulting subjective sensations is essential in designing tactile displays. Previous studies observed skin displacement using flat glass plates or uneven surfaces that do not optically interfere with finger surface observations. In contrast, no direct method for observing skin surface displacement on a texture exists. We propose a system that enables observation of the interaction between a textured surface and the skin of the finger using an index-matching technique. In the proposed system, a texture plate is immersed in oil having the same refractive index as the plate, and measurements are made when the interface is nearly optically transparent. Further, printed markers are attached to the skin of the finger, and their movements analyzed using an image-processing algorithm. The system enables spatial measurement of the skin shear and the vibration of the contact area. Evaluation experiments conducted on a 1D textured surface having a pitch of 0.6 mm verify the feasibility of the proposed system. Optical misalignment simulation results indicate that the system is slightly less accurate than type-I mechanoreceptors but can measure skin deformation on a texture and also observe it spatially and temporally.