Temperature Distribution Of Body Research Articles

Safety Assessment of Electromagnetic Environmental Exposure for GPS Antenna of Electric Vehicle

The present GPS (global positioning system) is widely used in electric vehicle navigation; it is usually installed in the middle-to-rear position on the car’s roof, near the rear windshield. Since the GPS antenna operating frequency is 1.575 GHz, the health risk of the passengers in the car in this high-frequency electromagnetic exposure is a matter of concern. In this paper, we construct models for a GPS antenna, an electric vehicle, and a human body. Through the multiphysics field coupling calculation in COMSOL Multiphysics, a finite element simulation software, in both frequency domain and transient analysis, we obtain the electric field strength distribution, specific absorption rate, and temperature distribution of the human body at three positions inside the electric vehicle after being exposed to the GPS antenna radiation for 30 minutes. The peak human-induced electric field is 18.4 V/m, and the peak specific absorption rate is 0.193 W/kg. The 30 minute average maximum human-induced electric field is 1.6906 V/m, which is 3.1% of the ICNIRP limit, the 30 minute average whole-body SAR is 0.0036 W/kg, which is 4.5% of the ICNIRP limit, and the 30 minute average human core temperature rise is 0.06°C, which is 6% of the ICNIRP limit. In addition, we simulate the impact of three different vehicle shell materials on the level of electromagnetic exposure to the human body, which can provide reference for electromagnetic shielding design in automobiles. The results indicate that the induced electric field strength, specific absorption rate (SAR), and temperature rise in various parts of the human body did not exceed the standard limits in the latest version of ICNIRP. This suggests that the electromagnetic exposure from the GPS antenna in a typical automotive environment does not pose a threat to human health.

An open-source porous media modelling approach to investigate thermohydraulic features of compact printed circuit heat exchangers

An experimental air-foil printed circuit heat exchanger (PCHE) with CO2 as a working fluid is numerically modelled and developed within the OpenFOAM environment as a freely available package for more general PCHE designs. The conjugate heat transfer solver (chtMultiRegionFoam) is adapted to include both the hot and cold fluid streams of the PCHE, along with the solid recuperator body, within three uniquely specified overlapping mesh regions. The fluid stream momentum equation is adapted to incorporate porosity, with the additional streamwise air-foil drag (friction factor) accounted for by the Darcy–Forcheimer porous media model. A simple linear ad-hoc model for the transverse friction factor is evaluated to determine the dispersion of the momentum across the flow. Heat transfer between the fluid streams and the solid body is driven by a volumetric thermal resistance with a cell volume-weighted interpolation method (volume-to-volume coupling), with experimentally determined Nusselt number correlations applied. Temperature-dependent parameters based on isobaric NIST data for CO2 are tabulated as a user library and integrated within the coding package. The model predictions of the solid body temperature distributions are assessed and validated against experimental data with eight equidistant fibre optical measurements across the PCHE core and compared against finite-element-based MATLAB numerical results. Thermal stresses are evaluated and qualitatively evaluated against experimental data, demonstrating the capability of the model to highlight potential design features for improvement.

Analysis of the Influence of Temperature Gradient on the Measurement Accuracy of Axial Force in Balance

As a measuring element in wind tunnel test, it is important to ensure the measurement accuracy of strain balance.However, in the continuous wind tunnel, due to the long running time of the wind tunnel and the continuous transformation of Mach number, the temperature distribution of the balance body will be uneven, resulting in temperature gradient.This temperature gradient has an obvious influence on the measurement accuracy of the axial force of the balance.In order to explore the influence of temperature gradient on the axial force and strain output of the balance in the continuous wind tunnel, three temperature loading conditions were summarized according to the actual working conditions, and the thermal-solid coupling analysis of the 80A balance was carried out by ANSYS Workbench.The results show that the higher the temperature of the base point of the temperature gradient is, the faster the temperature input is, the more uneven the temperature distribution of the balance is, and the larger the temperature gradient is, the larger the axial force and strain output is. Considering the heat conduction of the back support rod, the temperature distribution of the balance body is relatively uniform, the temperature gradient is small, and the output of axial force and strain is small.

Research on the Heating Effect of a Convection Radiator Based on a Human Thermophysiological Model

Forced convection is the most effective way to improve the thermal efficiency of a radiator under low-temperature conditions. This technical method differs significantly from the heating effects of general radiation and natural convection. Few studies have applied the objective evaluation method based on quantitative calculation to evaluate the effectiveness of indoor heating or optimize the technical parameters (air flow rate, air supply method, etc.) of heating systems. This article couples human metabolic factors with heating environmental factors and uses a 57-node human thermal physiological model to evaluate the effectiveness of forced convection radiator heating from the perspective of the local thermal comfort of the human body and demonstrates the feasibility of this scheme by comparing it with floor radiation heating. The research shows that the air supply speed of a radiator affects human thermal comfort. Continuing to increase the wind speed, at a speed of 3 m/s, the surface temperature of the human body reaches a high value and will then decrease, leading to a decrease in thermal comfort. Research on indoor air distribution shows that the use of bottom-side air supply provides better thermal comfort compared to top air supply. The local skin temperature distribution of the human body indicates that when the indoor average temperature is higher than 20 °C, the overall thermal comfort of convective radiator heating and floor radiant heating is comparable. The article provides a way of objectively calculating and directly quantifying the effect of heating equipment on human thermal physiological parameters.

Noninvasive measurement of body temperature distribution during radiofrequency hyperthermia for cancer treatment

Noninvasive measurement of body temperature distribution during radiofrequency hyperthermia for cancer treatment

Development of Methods and Computational Algorithms Parallelepiped in the Presence of Temperature and Heat Exchange

The article describes computational algorithms for estimating the law of distribution of body temperature in the form of a rectangular parallelepiped. The case is studied when a conditioned temperature is maintained on one of the boundaries of a rectangular parallelepiped, and heat exchange with the environment occurs on the opposite side. In addition, there are cases when other faces of the parallelepiped are thermally insulated or are under the influence of the environment. A polynomial is chosen as the approximating function. In accordance with the proposed layout, a function is formed that considers temperature, heat exchange with the environment, and insulation of the faces of a rectangular parallelepiped. The temperatures at the nodal points are determined by minimizing the function. Further, the temperature distribution law is determined according to the proposed approximating polynomial. The estimation of temperature distribution law is calculated for different amounts of partitioning into elements of a rectangular parallelepiped.

A variational approach for estimating the distribution of body temperature in the form of a rectangular parallelepiped under the influence of temperature, heat exchange and heat isolation of some facets

The article describes the use of a variational method involving the finite element method to estimate the law of temperature distribution in a body in the form of a rectangular parallelepiped. The case is considered when a certain temperature is maintained on one of the faces of a rectangular parallelepiped, and heat exchange with the environment occurs on the opposite side. In accordance with the proposed approach, an approximating function in the form of a polynomial of the third degree is proposed. To determine the law of temperature distribution in a solid in the form of a rectangular parallelepiped, a functional is compiled, which consists of terms that take into account temperature, heat exchange with the environment, isolation of the faces of a rectangular parallelepiped, as well as natural boundary conditions. Minimizing this functional, the temperature values at these nodes are determined by the nodal points of a rectangular parallelepiped. Further, substituting these values into the approximating function, we obtain the temperature distribution law. At the same time, variants are investigated when the remaining faces of a rectangular parallelepiped are thermally insulated or vice versa. The temperature distribution law is estimated for different amounts of partitioning of the sides of a rectangular parallelepiped. In addition, a comparison of the temperature distribution law for a rectangular parallelepiped and a rod close in size, other things being equal, was made. Their minor differences are shown.

The Immediate Effect of Exercising in a Virtual Reality Treadmill (C-Mill) on Skin Temperature of a Man with Lower Limb Amputation

Background. In amputees, exercising can impact the distribution of body temperature. The aim of this case report is to verify the acute effect of exercising in C-Mill on the temperature distribution in the lower limbs of a man with unilateral transfemoral amputation. Materials and Methods. The thigh and legs of a man with left distal transfemoral amputation were evaluated by thermography (infrared sensor FLIR T650sc) before and after a single 30-minute exercise session performed in a virtual reality treadmill device (C-Mill). Results. The thermographic evaluation showed a difference in temperature between the thighs both before and after the intervention. However, there was a decrease in asymmetry, which went from 4.0°C to 3.1°C in the anterior view and from 5.3°C to 2.9°C in the posterior view, after the intervention. Conclusion. Thermography allowed us to assess the difference in temperature in the lower limbs. Even though the temperature discrepancy has decreased after the single exercise session using the C-Mill, this difference persisted.

Використання НВЧ-радіометрії у побудові медичних приладів для неінвазивної діагностики

Temperature is often used among the information required to diagnose the state of a person’s internal organs, as pathological processes occurring in the human body are usually accompanied by thermal deviations not only on the surface but also inside the body. Modern medicine needs to improve non-invasive methods of measuring temperature deep in the human body for the purpose of early diagnosis and monitoring of various pathological processes. Medical radiothermography, in particular, allows non-invasive determination of the integral deep temperatures of internal organs. The development of modern radiometric equipment involves solving such complex problems as ensuring high sensitivity of devices, matching the antenna to the biological object, ensuring the required penetration depth, and measuring absolute temperature with an error of at least 0.1°C. Given the importance of this problem, this paper demonstrates the approaches to the development of modern radiothermographs that the authors used in the process of creating a device for diagnosing breast temperature abnormalities. The study considers the principles and schemes of construction of radiothermographic devices, requirements to the equipment as a whole, as well as to its main components. The authors conclude that it is optimal to use a modulation-compensation scheme of a radiometer for medical radiothermometry based on the measurement of two parameters: the integrated temperature and the integrated coefficient of reflection of electromagnetic waves from a biological object. A schematic diagram of a prototype radiothermograph, as well as its composition and design, is presented. The approaches to the creation of modern radiothermographs presented in this work should be useful for developers of medical equipment for surgery, otorhinolaryngology, orthopedics, pediatrics, gynecology, etc., where measuring the distribution of patient body temperatures is of diagnostic value.

Evaluation of thermal stability of ultra-precision water-lubricated spindle

Minimizing spindle thermal deformation is of key importance for reaching high machining accuracy. In this study, the thermal stability of a spindle with water-lubricated hydrostatic bearings was investigated via simulation with experimental data for defining boundary conditions for the simulations. The simulation study was divided into two separate tasks. In the first stage, the temperature distribution in the water flowing through spindle bearings was determined using commercial FEM flow simulation software. The experimentally obtained temperatures of lubricant and spindle surfaces were used as boundary conditions for a finite volume problem that introduced the temperature distribution of the spindle body and water flowing around the spindle. Then, a thermal analysis of the spindle was performed using the temperature field obtained in the first stage to investigate thermal deformation of the spindle. Temperatures at specific parts of the spindle derived from the temperature distribution were used as boundary conditions for analysis in the second stage. The results were used to investigate the influence of spindle thermal deformation on the positioning accuracy of the end surface of the spindle rotor. The pattern of gap variations in journal and thrust bearings due to the thermal deformation of bearing surfaces was established. The thermal stability of a spindle under the influence of an external temperature field was evaluated using the bearing load capacity and stiffness as indicators. The bearing load capacity and stiffness were defined based on the pressure distribution on the bearing surfaces with consideration of the non-uniformity of the bearing gap due to thermal deformation. A separate study was conducted to investigate the effect of changing viscosity of increasing the temperature of lubricating fluid on bearing performance. Furthermore, the resulting displacement of the spindle rotor end, which directly affects machining error, is also discussed.

Design of a wearable multi-point temperature monitoring system – practical application in waist temperature monitoring

PurposeHuman skin temperature data can provide reference advice for diagnosing many diseases, but current wearable skin temperature monitoring systems have few points and may miss temperature information in critical areas. This paper aims to develop a wearable system that can be used for local temperature monitoring and restore better the actual state of local human temperature by exploring ways to extend more temperature measurement points. This will provide better assistance in developing medical targeting and intelligent clothing.Design/methodology/approachThe temperature measurement system contains modules for temperature monitoring, digital-to-analog conversion and regulated power supply, enabling fast reading of 12 channels of monitoring data. The microprocessor unit is the STM32F407. The instructions and control modes are written in C. The waist area was chosen as the monitoring area because it is susceptible to temperature, and many diseases are associated with skin temperature. Twelve points, including temperature-related acupuncture points and heat-sensitive points, were selected for testing and the data results agreed well with the infrared imaging results.FindingsThe waist is selected as the monitoring object, and an easy-to-wear waist temperature monitoring belt is designed to verify the application value of the system. The development of the system provides reference suggestions for the exploration of multi-point temperature monitoring systems and the integration capabilities of temperature measurement modules in wearable multifunctional systems.Practical implicationsIn addition to waist temperature monitoring, the wearable temperature measurement system developed in this study can also be applied to other body parts. In addition, the system can be efficiently and effectively combined with various garments, making it a useful tool for researching human skin temperature.Originality/valueThe wearable temperature monitoring system designed in this paper extends the number of temperature test points to 12. The number of test points covers as many localized body areas as possible to indeed reproduce the temperature distribution of the human body. In addition, the selection of test points combines medically relevant body points with physiologically relevant heat-sensitive areas, which makes the temperature measurement data more valuable.

An Overview of Patients of Appendicitis and Surgical Site Infection Postappendectomy at Bethesda Hospital Yogyakarta Period 2019-2020

Appendicitis is inflammation of the appendix and is the case most often encountered by surgeons. This study aims to study the description of appendicitis and surgical site infection post appendectomy patients based on age, gender, type of appendicitis, chief complaint, temperature, leukocytes, preoperative antibiotics, type of appendectomy, duration of surgery, and surgical wound infection. The design of this study was descriptive observation using retrospective data from the medical records of appendicitis patients treated at Bethesda Hospital, Yogyakarta City in 2019-2020 with the whole sampling method. The highest distribution of age is the young adult age group at 43.58%. Appendicitis patients were more male (58.46%). The highest distribution of types of appendicitis was appendicitis simplex (39.48%). The chief complaint of right lower abdominal pain was found in all patients (100%). The highest distribution of body temperature was under 38ºC (94.36%) and the highest distribution of leukocyte count was under 16.000/mm3 (67.18%). Preoperative antibiotics were given to 89.74% of patients. The most common type of appendectomy performed was open appendectomy (60.51%) with the highest distribution of operation duration being 60–90 minutes (57.95%). The incidence of surgical wound infection was found in 4 people (2.05%). In conclusion, the results of this study are in accordance with the theory that has been included in the background.

Design of a multi-channel high precision wearable temperature collection system based on negative temperature coefficient thermistor

<p>Body temperature is often used to screen infectious diseases and monitor treatment. Through the method of measuring the resistance of constant voltage temperature measuring circuit, a wearable multi-point body temperature monitoring system is researched and designed to determine skin surface temperature. The STM32F103C8T6 chip is used as the core processor, and the negative temperature coefficient thermistor (NTC) as the temperature sensing component. ADS1256 chip is a temperature signal conditioner, Bluetooth module is a wireless transmission unit, and LABVIEW is used to design the host computer interface. The constant voltage bridge circuit composed of thermistor and resistor voltage divider to carry out the acquisition of 8 channels of temperature data, and the 24bits ultra-high-precision analog-to-digital conversion module is configured with differential inputs to amplify, filter and convert analog signals; the converted data is processed and calculated in the single-chip microcomputer; finally, the data is transmitted to the host computer via Bluetooth. The thermistor is linearly compensated using the fourth-order formulation of the Stein-hart formula. Reduce the impact of environmental interference and uneven body temperature distribution from software and hardware. The error during the temperature measurement of temperature sensor is analyzed. The experimental results showed that the resolution of measurement system reached 0. 01 , and the temperature measurement accuracy was up to ± 0. 02 . This design scheme has high stability and accuracy; and the circuit is simple in structure, small in size, and low power consumption which can be used in occasions requiring precise body temperature measurement.</p>

Impact of changing nozzle profiles on thermal and structural loads acting on nozzle wall

A nozzle of rockets is a window for the combustion chamber to the ambient air. It is subjected to several thermal and mechanical loads acting on the internal wall. So, the nozzle structural behavior has a significant impact on the mission achievement. The aim of this paper is studying a variety of nozzle profiles shape and its influences on structural behavior. Computational fluid dynamics software was applied to investigate the temperature and pressure on the internal wall of the nozzle while observing if there is any change at nozzle ballistic performance or not. Four different convergent profiles had been investigated to study its effect on structural stresses acting on nozzle wall. The results showed body temperature distribution, static pressure and thermal-structural stresses at nozzle wall. Changing the internal profile of the nozzle convergent caused significant change in pressure and temperature loads acting on nozzle wall structure. Conical shape convergent profile produced less stresses at throat section by 19.8% compared to original profile.

Experimental Study on Manned/Unmanned Thermal Environment in Radar Electronic Shelter Based on Different Air Supply Conditions

Studies on the thermal environment of the electronic radar shelter have been mainly focused on the simulation of the unmanned thermal environment, and there have been few studies on experiments in the thermal environment. Additionally, a comparative study of the experimental results from manned and unmanned shelters has been missing. In this paper, we experimented in thermal environments of manned/unmanned shelter under different air supply conditions. The experiment was divided into cooled, ventilated, and heated trials analyzing three aspects: (1) The average temperature distributions of walls, air inlet points, air outlet points, and surfaces were measured over time under different conditions in an unmanned shelter. The temperature distribution curve was fitted into the function. (2) Based on different working conditions, the temperature distribution experiments were carried out in three different areas for subjects wearing short or long clothing respectively. (3) The wind speed was measured at each measuring point in the air supply pipeline under different working conditions. The wind speed distribution was detected on the setting surfaces. The experimental results show that: (1) The air does not gradually tend to steady state with the time, and under different conditions, the air temperature obviously differs. (2) The clothing selection, air supply conditions, and locations of measuring points have significant influences on human body temperature distribution and left–right difference. (3) The mixing of the thermal plume caused by the vertical temperature difference of the human body and the jet generated by the mechanical air supply will reduce the wind speed of the airflow in the cabin, the adsorption of the jet to the bulkhead, and the stability of the airflow. The experimental data can provide the initial and boundary conditions for the simulation of the shelter. The results can provide a reference for the study of fluid control methods, the setting of thermal boundary conditions, and the simulation of the influence of thermal plumes on the airflow distribution. The experimental study in this paper has filled in the blanks regarding experimental study in electronic radar shelters. It has important research value and practical significance.

Thermogram classification using deep siamese network for neonatal disease detection with limited data

ABSTRACT Monitoring the body temperatures and evaluating the thermal asymmetry of newborns give an idea about neonatal diseases. Infrared thermography is a non-invasive, non-harmful, and non-contact modality that allows the monitoring of the body temperature distribution. Early diagnosis using a limited data set is extremely vital due to the high mortality rate in newborns and some difficulties in neonatal imaging. Thermography stands out as a useful tool in detecting neonatal diseases compared to other techniques. However, creating a thermogram database consisting of thousands of images from each class required by traditional artificial intelligence methods, is impossible due to the sensitivity of newborns. One of the meta-learning models that has recently gained success in applying limited data learning, especially one-shot, in various fields is Siamese neural networks. In this work, we perform a multi-class classification to provide pre-diagnosis to experts in disease detection using Siamese neural networks. By using two different optimisation techniques and data augmentation, critical diseases with only a few sample data are classified using the method tested in two- and three-class evaluation approaches. The results based on the disease type achieve 99.4% accuracy in infection diseases and 96.4% oesophageal atresia, 97.4% in intestinal atresia, and 94.02% in necrotising enterocolitis.

Body Temperature Frequency Distributions: A Tool for Assessing Thermal Performance in Endotherms?

There is increasing recognition that rather than being fully homeothermic, most endotherms display some degree of flexibility in body temperature. However, the degree to which this occurs varies widely from the relatively strict homeothermy in species, such as humans to the dramatic seasonal hibernation seen in Holarctic ground squirrels, to many points in between. To date, attempts to analyse this variability within the framework generated by the study of thermal performance curves have been lacking. We tested if frequency distribution histograms of continuous body temperature measurements could provide a useful analogue to a thermal performance curve in endotherms. We provide examples from mammals displaying a range of thermoregulatory phenotypes, break down continuous core body temperature traces into various components (active and rest phase modes, spreads and skew) and compare these components to hypothetical performance curves. We did not find analogous patterns to ectotherm thermal performance curves, in either full datasets or by breaking body temperature values into more biologically relevant components. Most species had either bimodal or right-skewed (or both) distributions for both active and rest phase body temperatures, indicating a greater capacity for mammals to tolerate body temperatures elevated above the optimal temperatures than commonly assumed. We suggest that while core body temperature distributions may prove useful in generating optimal body temperatures for thermal performance studies and in various ecological applications, they may not be a good means of assessing the shape and breath of thermal performance in endotherms. We also urge researchers to move beyond only using mean body temperatures and to embrace the full variability in both active and resting temperatures in endotherms.

Relationship Between First 24-h Mean Body Temperature and Clinical Outcomes of Post-cardiac Surgery Patients.

Background: This study was aimed to investigate the relationship between first 24-h mean body temperature and clinical outcomes of post cardiac surgery patients admitted to intensive care unit (ICU) in a large public clinical database.Methods: This is a retrospectively observational research of MIMIC III dataset, a total of 6,122 patients included. Patients were divided into 3 groups according to the distribution of body temperature. Multivariate cox analysis and logistic regression analysis were used to investigate the association between abnormal temperature, and clinical outcomes.Results: Hypothermia (<36°C) significantly associated with increasing in-hospital mortality (HR 1.665, 95%CI 1.218–2.276; p = 0.001), 1-year mortality (HR 1.537, 95% CI 1.205–1.961; p = 0.001), 28-day mortality (HR 1.518, 95% CI 1.14–2.021; p = 0.004), and 90-day mortality (HR 1.491, 95% CI 1.144–1.943; p = 0.003). No statistical differences were observed between short-term or long-term mortality and hyperthermia (>38°C). Hyperthermia was related to the extended length of ICU stay (p < 0.001), and hospital stay (p < 0.001).Conclusion: Hypothermia within 24h after ICU admission was associated with the increased mortality of post cardiac surgery patients. Enhanced monitoring of body temperature within 24h after cardiac surgery should be taken into account for improving clinical outcomes.

Establishment of a prognostic model for patients with sepsis based on SOFA: a retrospective cohort study.

ObjectiveTo construct a nomogram based on the Sequential Organ Failure Assessment (SOFA) that is more accurate in predicting 30-, 60-, and 90-day mortality risk in patients with sepsis.MethodsData from patients with sepsis were retrospectively collected from the Medical Information Mart for Intensive Care (MIMIC) database. Included patients were randomly divided into training and validation cohorts. Variables were selected using a backward stepwise selection method with Cox regression, then used to construct a prognostic nomogram. The nomogram was compared with the SOFA model using the concordance index (C-index), area under the time-dependent receiver operating characteristics curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), calibration plotting, and decision-curve analysis (DCA).ResultsA total of 5240 patients were included in the study. Patient’s age, SOFA score, metastatic cancer, SpO2, lactate, body temperature, albumin, and red blood cell distribution width were included in the nomogram. The C-index, AUC, NRI, IDI, and DCA of the nomogram showed that it performs better than the SOFA alone.ConclusionA nomogram was established that performed better than the SOFA in predicting 30-, 60-, and 90-day mortality risk in patients with sepsis.

Kızılötesi Termal Görüntülemenin Yapay Zeka Tabanlı Biyomedikal Uygulamaları

Infrared thermal imaging is a non-invasive, harmless radiation-free non-contact modality that allows monitoring of body temperature distribution and change. Providing physiological information about peripheral blood flow, autonomic nervous system, vasoconstriction / vasodilation, inflammation, sweating or other processes has expanded its use in the medical field. Developments in the field of artificial intelligence have also found response in medical applications, and machine learning methods have become used for many tasks such as decision making, disease monitoring, and surgical planning. Using artificial intelligence methods to interpret thermal data can be an effective solution to provide doctors with a second opinion in a diagnosis, treatment planning or surgical evaluation scenario. The purpose of this research; To evaluate the functioning of artificial intelligence methods in medical applications such as classification and decision making of thermal imaging by examining the literature sources and to provide information about the literature.