A Conformable Two-Dimensional Resistance Temperature Detector for Measuring Average Skin Temperature

Various medical procedures are accomplished by manipulating skin temperature in a nonuniform pattern. Skin temperature monitoring is essential to assess conformance to protocol specifications and to prevent thermal injury. Existing solutions for skin temperature monitoring include single point sensors, such as thermocouples, and two-dimensional methods of sensing surface temperature, such as infrared thermography, and wearable technology. Single point sensors cannot detect the average temperature and consequently their measurements cannot be representative of average surface temperature in a nonuniform temperature field. Infrared thermography requires optical access, and wearable sensors may require complex manufacturing processes and impede the heat exchange with a source by introducing a layer of insulation. Our solution is a two-dimensional resistance temperature detector (2D RTD) created by knitting copper magnet wire into custom shapes. The 2D RTDs were calibrated, compared to one-dimensional sensors and wearable sensors, and analyzed for hysteresis, repeatability, and surface area conformation. Resistance and temperature were correlated with an R2 of 0.99. The 2D RTD proved to be a superior device for measuring average skin temperature exposed to a nonuniform temperature boundary in the absence of optical access such as when a full body thermal control garment is worn.

Effect of underwear on microclimate heat transfer in clothing based on computational fluid dynamics simulation

In order to study the influence of underwear on microclimate heat transfer among different age groups, this study measured the temperature of the microclimate layer corresponding to the main parts of the human body or the key parts that affect average skin temperature. A computational fluid dynamics numerical model was then used to simulate the influence of underwear on heat transfer between the human body and the microenvironment and to explore the physical phenomenon. The results obtained show that underwear has a great influence on the average temperature of the microclimatic air layer, especially the air layer at the upper arm, forearm, and thigh. The findings of this study provide fundamental knowledge to improve the thermal comfort of underwear.

Numerical two-dimensional thermal analysis of the human skin using the multigrid method

Heat can be used as an adjuvant treatment of many diseases and also as a powerful tool to help diagnose cancers, with the advantage to be a noninvasive exam. Some tumors may be best diagnosed by evaluating body temperature distribution, for instance, it is observed that local temperatures of the skin over a tumor are higher than the average skin temperature. Certainly, it is expected from medical diagnostics to be, early, fast and very precise. Especially if the health problem is a tumor, it is necessary to know the shape and the size of the cancer. Thermal images can provide further information about the tumor, generally, the thermal diagnostic is made comparing images of the region with a bioheat model. In this context, the present study shows interesting results about the multigrid method applied to solve the Pennes bioheat equation in two dimensions, using a non-stationary and steady state cases for the skin heath and with melanoma. The multigrid method presented itself as an extremely efficient and fast tool to solve the bioheat equation with refined grids that provide good spatial precision.

Liposomal Vitamin D3 as an Anti-aging Agent for the Skin

Vitamin D3 is an effective skin protective substance to prevent photoaging. Liposomes were used as a carrier to deliver vitamin D3 to improve the stability and to enhance the treatment effect of vitamin D3. The stability of vitamin D3 liposomes, average cumulative penetration, and retention of vitamin D3 in the skin were then evaluated and compared with free vitamin D3. Finally, the treatment effect of vitamin D3 liposomes in a rat photoaging model was appraised and Haematoxylin-Eosin (H&E) staining was used to assess the histology changes of the skin after vitamin D3 liposome treatment. The results indicated that liposomes could significantly improve the stability of vitamin D3. The average skin retention of vitamin D3 liposomes was 1.65 times that of the vitamin D3 solution. Vitamin D3 liposomes could repair the surface morphology of skin in the photoaging model and promote the production of new collagen fibers. Vitamin D3 liposomes as a potential skin care agent could significantly improve skin appearance and repair damage in the histology of photoaging.

Pectus excavatum repair using bridge fixation system

Background The stability of the pectus bar is an important determinant of the success of pectus excavatum repair surgery. In practice, several different types of fixation method are in use for stabilizing pectus bars. The aim of this study was to compare the performance of the bridge fixation system with previous fixation systems for stabilizing pectus bars. Methods We performed a retrospective review of 1760 pectus excavatum repair cases conducted in the Thoracic Department of Choray Hospital and its satellite hospitals, between 2007 and 2017. We compared the results of 560 patients who had the bridge fixation system with the previous 1200 patients who had other fixation techniques. Results The bridge fixation system with 2 bars in 560 patients gave better results in terms of bar stabilization, operative time, and postoperative complications, compared to the previous 1200 patients who had other stabilization techniques. The average skin-to-skin surgery time using the bridge fixation system was 55 min. Of the 560 cases, only one patient showed trivial one bar dislocation, and one had a postoperative complication (pneumothorax). Conclusions We found the bridge fixation system to be superior not only in terms of stabilizing the bars but also for minimizing the time of surgery and postoperative complications, compared to other fixation systems. The bridge fixation system with 2 bars showed excellent results. Use of 3 bars is not necessary. One bar was used in the other fixation techniques and the results were found to be inferior compared to those using 2 bars.

INVESTIGATION OF THE THERMAL STATE OF ATHLETES IN NATURAL HOT CLIMATE

The article presents results of a study of the thermal stability in athletes during specific activities in hot climate. This happened on a training camp at the sports center, located in the district Sredneakhtubinsky of the Volgograd region with the registration of climate indices. The study was conducted in July at an effective temperature +44,6° - +45,4°C. The study involved 6 athletes, representatives of athletics, sports category on the following candidate for master of sports. During the endurance, training (cross) in athletes showed a significant increase in the rectal temperature (RT), average skin temperature (AST), average body temperature (ABT) against the background of the gain in the heart rate. During the training as "repeated cuts", the increase in indices of the thermal state in athletes also persisted, but their values were significantly lower than on the cross. The comparison of the dynamics of indices of the thermal state with the level of sports skills of each athlete showed the following features: the smallest gain in the rectal temperature, average skin temperature and average body temperature observed in cross-country race was observed in sportsman, whose level of training coach the evaluated as a minimal in the group. The highest gain in indices of the thermal state at the cross happened in the athlete with an average fitness level. Optimal gain in such indices as RT, AST and ABT was observed in the most prepared athlete. There was revealed a high level of adaptationness of athletes to the exposure to high temperatures. This is confirmed by the data of the evaluation of dynamics of subjective evaluation of warmth sense modality in athletes during the study period.

Efficiency of special cooling liquid on thermal state of athletes at high temperatures

The article presents results of evaluating efficiency of special cooling liquid influence on heat state of athletes at high temperatures. The study covered 7 male athletes of cyclic sports, with sport rank at least 1 adult, average age 19.29±1.80 years. All the athletes underwent double examination including: anamnesis and complaints records, doctor’s examination, subjective evaluation of heat sensations, weight measurements, thermometry (tympanic, sublingual, rectal and skin (in 5 points)), ergospirometric stress testing. Changes in the athletes’ heat state were evaluated via dynamics of weighted average skin temperature and rectal temperature. Moreover, subjective evaluation of heat sensations was considered. Efficiency of the cooling liquid was assessed via dynamics of exercises performance time, maximal oxygen consumption and anaerobic metabolism threshold. The cooling liquid use appeared to be expedientin sport teams of summer sports for specific exertion after individual tests for adverse allergic reactions.

Are combi parks just as useful as regular parks for fatteners for part-time group housing of rabbit does?

<p>Group housing of lactating rabbit does is desirable from a welfare standpoint, but agonistic behaviour can cause severe skin injuries, which are undesired for animal welfare. Park layout, creating hiding places and escape possibilities, may help redirect attention away from fighting, which could in turn help prevent skin damage. An experiment was performed to test whether more damaging behaviour would occur in a combi park (with nest box panels) after mixing, compared to a regular park for fatteners, as nest box panels would obstruct does when escaping aggressive interactions. In addition, the position of the PVC pipe underneath the platform differed between parks (longitudinal or transversal), resulting in different escape routes. Twenty-two parks were used, in which 5 does per park were grouped at 23 d of lactation until weaning at 36 d of lactation. Skin injuries were scored at 4 d after grouping and on the day before weaning. The presence of nest box panels in a combi park and the position of the PVC pipe underneath the platform did not affect the level of skin damage. Moderate to severe injuries were observed, mostly at the hind quarters, ears and head. Five to 6% of the does were severely injured (wounds). There was a positive relationship between the average skin injury per park at 4 d after grouping and at weaning. On average, average injury score per park increased from grouping to weaning, but there are differences between individual parks. From this experiment it can be concluded that group housing of lactating rabbit does involves animals getting injured. In fact, 5 to 6% of the does were severely injured (wounds). Social dynamics of group housed does are insufficiently understood and might be important to reduce damaging behaviour in group housing.</p>

Impact of trajectory profiles on user stress in close human-robot interaction

The impact of different trajectory embodiments in terms of velocity profiles on users’ mental stress in close human-robot interaction is investigated. A cooperative assembly scenario is chosen using a standard industrial robot. Conditions are implemented in a repeated measures within-subjects design comparing linear with trapezoidal trajectories. Heart rate variability and galvanic skin conductance are chosen as objective stress markers and evaluated using the average standard deviation of the beat-to-beat intervals (SDNN) and the average skin resistance. Additionally, evaluations of user experience and acceptance are conducted based on evaluated subjective measures. The results of the user study reveal a significant increase of average heart rate variability and average skin resistance in the trapezoidal condition indicating a reduced mental stress level independent of demographical and dispositional factors.

A preliminary study for the assessment of hypertension using static and dynamic IR thermograms

Structural changes in blood vessels occur due to prolonged hypertension. Early detection of blood pressure (mm Hg) is essential for disease prevention. The aim of this work is to propose a computer-aided diagnostic (CADx) model for the diagnosis of hypertension using variables derived from non-contact static and dynamic thermal imaging in comparison with the pulse wave velocity (PWV)-derived parameters. Static and dynamic infrared (IR) thermograms of selected skin areas of the body from known hypertensive (n=14) and age- and sex-matched normal subjects were captured. The average skin surface temperature [SST (°C)] of selected skin areas of the body was calculated from a static IR thermogram. After denoising the dynamic IR thermogram using wavelets, the statistical variables power, mean, standard deviation (SD), variance, skewness and kurtosis were calculated. The variables derived from both static and dynamic thermograms were used to develop the CADx model. The performance of the CAD model was also tested by feature selection using principal component analysis (PCA). An accuracy of 75% (sensitivity=78.6%, specificity=71.4%) could be achieved with the average SST (°C) of the static IR thermogram alone. The statistical variables derived from the dynamic IR thermogram alone gave an accuracy of 82% (and 85% after feature selection by PCA), whereas the accuracy using standard methods like variables derived from PWV was only 71.4% (with and without feature selection). The highest accuracy of 89% could be achieved by combining variables like average SST (°C) measured from static and dynamic IR thermograms and PWV-derived variables.