Influence of Exercise Condition on Tissue Blood Temperature Using Whole Body Model

2013 ◽  
Author(s):  
Swarup A. Zachariah ◽  
Anup K. Paul ◽  
Rupak K. Banerjee ◽  
Liang Zhu
Keyword(s):  
Human Body ◽  
Core Body Temperature ◽  
Thermal Response ◽  
The Body ◽  
Tissue Temperature ◽  
Whole Body ◽  
Transfer Model ◽  
Blood Temperature ◽  
Exercise Condition ◽  
Core Body

Predicting thermal responses of the human body accurately during different exercise conditions is of increasing importance. Computing changes in the core body temperature (T c) during exercise require detailed modeling of both the body tissue temperature and the time-dependent blood temperature. Predicting changes in T c is challenging because the model needs to respond effectively to the changes in perfusion or sweating. Our study was to demonstrate the ability of a recently developed whole body heat transfer model. It simulates the tissue-blood interaction to predict the thermal response of the human body under different exercise intensities. The cases simulated were of a human being walking on a treadmill at 0.9, 1.2 and 1.8 m/s for 30 minutes. It was shown that T c was effectively regulated within 0.17 °C of the steady state value of 37.23 °C for the three cases by means of adjusting the cardiac output; varying between 15 to 25 liters per minute.

scholarly journals Safe Duration Of A Person Soaking Inside A Hot Tub: Theoretical Prediction of Temperature Elevations in Human Bodies Using A Whole Body Heat Transfer Model

2020 ◽  
Author(s):  
Myo Min Zaw ◽  
Manpreet Singh ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Heat Transfer ◽  
Human Body ◽  
Energy Balance Equation ◽  
The Body ◽  
Whole Body ◽  
Equation Modeling ◽  
Transient Temperature ◽  
Transfer Model ◽  
Bioheat Equation ◽  
Arterial Blood

In this study, we first develop a whole body model based on measurements of a human body, with realistic boundary conditions incorporated before and after a person jumps into a hot tub. For the transient heat transfer simulation, the initial condition is the established steady state temperature field of the human body with appropriate clothing layer to ensure the thermal equilibrium of the body with its surroundings. Once the person is inside a hot tub, the Pennes bioheat equation is used to simulate the transient temperature elevations of the body, and the rising of the arterial blood temperature is solved by an energy balance equation modeling thermal exchange between body tissue and the blood in the body. The safe duration of soaking in hot tubs is then determined as affected by the hot tub water temperatures.

Comparison Between Experimental and Heart Rate-Derived Core Body Temperatures Using a Three-Dimensional Whole Body Model

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Rupak K. Banerjee ◽  
Robins T. Kalathil ◽  
Swarup A. Zachariah ◽  
Anup K. Paul ◽  
Amit Bhattacharya ◽  
...  
Keyword(s):  
Heart Rate ◽  
Real Time ◽  
Core Body Temperature ◽  
Three Dimensional ◽  
Thermal Response ◽  
Whole Body ◽  
Body Model ◽  
Thermoregulatory Model ◽  
Core Body ◽  
Whole Body Model

Abstract Determination of core body temperature (Tc), a measure of metabolic rate, in firefighters is needed to avoid heat-stress related injury in real time. The measurement of Tc is neither routine nor trivial. This research is significant as thermal model to determine Tc is still fraught with uncertainties and reliable experimental data for validation are rare. The objective of this study is to develop a human thermoregulatory model that uses the heart rate measurements to obtain Tc for firefighters using a 3D whole body model. The hypothesis is that the heart rate-derived computed Tc correlates with the measured Tc during firefighting activities. The transient thermal response of the human body was calculated by simultaneously solving the Pennes' bioheat and energy balance equations. The difference between experimental and numerical values of Tc was less than 2.6%. More importantly, a ± 10% alteration in heart rate was observed to have appreciable influence on Tc, resulting in a ± 1.2 °C change. A 10% increase in the heart rate causes a significant relative % increase (52%) in Tc, considering its allowable/safe limit of 39.5 °C. Routine acquisition of the heart rate data during firefighting scenario can be used to derive Tc of firefighters in real time using the proposed 3D whole body model.

Theoretical Predictions of Body Tissue and Blood Temperature During Cold Water Immersion Using a Whole Body Model

2013 ◽  
Author(s):  
Anup K. Paul ◽  
Swarup A. Zachariah ◽  
Liang Zhu ◽  
Rupak K. Banerjee
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Cold Water ◽  
Water Immersion ◽  
The Body ◽  
Stress Conditions ◽  
Body Tissue ◽  
Whole Body ◽  
Transfer Model ◽  
Blood Temperature

Understanding the thermal response of the human body under various environmental and thermal stress conditions is of growing importance. Calculation of the core body temperature and the survivability of the body during immersion in cold water require detailed modeling of both the body tissue and the time-dependent blood temperature. Predicting body temperature changes under cold stress conditions is considered challenging since factors like thickness of the skin and blood perfusion within the skin layer become influential. Hence, the aim of this research was to demonstrate the capability of a recently developed whole body heat transfer model that simulates the tissue-blood interaction to predict the cooling of the body during immersion in cold water. It was shown that computed drop in core temperature agrees within 0.57 °C of the results calculated using a detailed network model. The predicted survival time in 0 °C water was less than an hour whereas in 18.5 °C water, the body attained a relatively stable core temperature of 34 °C in 2.5 hours.

The effects of oil contamination and cleaning on sea otters (Enhydra lutris). II. Metabolism, thermoregulation, and behavior

1988 ◽  
Vol 66 (12) ◽  
pp. 2782-2790 ◽  
Author(s):  
R. W. Davis ◽  
T. M. Williams ◽  
J. A. Thomas ◽  
R. A. Kastelein ◽  
L. H. Cornell
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Thermal Conductance ◽  
The Body ◽  
Whole Body ◽  
Base Line ◽  
Enhydra Lutris ◽  
Sea Otters ◽  
Core Body

The purpose of this study was to develop a method to clean and rehabilitate sea otters (Enhydra lutris) that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters captured in Alaska and brought to the Sea World Research Institute in San Diego. Measurements of average metabolic rate, core body temperature, behavior, and squalene (the major lipid of sebum) concentration on the fur were made under three conditions: (i) before oiling (base line), (ii) 1–3 days after 20% of the body surface area was covered with fresh crude oil, and (iii) after cleaning. Under base-line conditions in water at 13 °C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9 °C, and whole body thermal conductance was 10.7 W/(m2∙ °C). Otters spent 35% of their time grooming, 45% resting, 10% swimming, and 10% feeding. The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39 °C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using Dawn detergent, we were able to clean the oiled fur during 40 min of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3–6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1–2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning.

Effects of simulated weightlessness on thermal sweating of human body: An experimental study

2018 ◽  
Vol 28 (1) ◽  
pp. 88-99 ◽  
Author(s):  
Hui Zhu ◽  
Hanqing Wang ◽  
Chuck Yu ◽  
Zhiqiang Liu
Keyword(s):  
Human Body ◽  
Thermal Response ◽  
Bed Rest ◽  
The Body ◽  
Whole Body ◽  
Simulated Weightlessness ◽  
Human Thermal Comfort ◽  
Terrestrial Condition ◽  
Thermal Sweating ◽  
Male Subjects

Thermal sweating is the thermoregulatory activity of the human body in hot and warm environments, which is critical to the human thermal comfort and health. The sweating of a human body in a real weightlessness environment has seldom been researched, and simulated weightlessness has usually been conducted under comfortable environments. In order to study the sweating of the human body under weightlessness, a 7-day −6° head down bed rest experiment was carried out on six male subjects lying on their backs to simulate the physiological changes that occur under a weightless environment. The skin microcurrents of the subjects were recorded to evaluate sweating under a range of environments. The results showed that sweating was more significant in the torso and head areas than on the arms and lower body. The whole body sweat rates of subjects were lower than those before the simulated weightlessness experiment. However, the threshold air temperature for the onset of sweating under simulated weightlessness was higher than that before the simulation. This was possibly due to the raising of thermoregulatory set-point temperature of the body. Findings have shown that the sweating behaviour and thermal response of a male human body in a weightless environment could be different to those in the terrestrial condition.

scholarly journals Uncertainty Analysis of the Core Body Temperature Under Thermal and Physical Stress Using a Three-Dimensional Whole Body Model

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Robins T. Kalathil ◽  
Gavin A. D'Souza ◽  
Amit Bhattacharya ◽  
Rupak K. Banerjee
Keyword(s):  
Thermal Conductivity ◽  
Heat Stress ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Thermal Response ◽  
Whole Body ◽  
Tissue Properties ◽  
The Core ◽  
Core Body

Heat stress experienced by firefighters is a common consequence of extreme firefighting activity. In order to avoid the adverse health conditions due to uncompensable heat stress, the prediction and monitoring of the thermal response of firefighters is critical. Tissue properties, among other parameters, are known to vary between individuals and influence the prediction of thermal response. Further, measurement of tissue properties of each firefighter is not practical. Therefore, in this study, we developed a whole body computational model to evaluate the effect of variability (uncertainty) in tissue parameters on the thermal response of a firefighter during firefighting. Modifications were made to an existing human whole body computational model, developed in our lab, for conducting transient thermal analysis for a firefighting scenario. In conjunction with nominal (baseline) tissue parameters obtained from literature, and physiologic conditions from a firefighting drill, the Pennes' bioheat and energy balance equations were solved to obtain the core body temperature of a firefighter. Subsequently, the uncertainty in core body temperature due to variability in the tissue parameters (input parameters), metabolic rate, specific heat, density, and thermal conductivity was computed using the sensitivity coefficient method. On comparing the individual effect of tissue parameters on the uncertainty in core body temperature, the metabolic rate had the highest contribution (within ±0.20 °C) followed by specific heat (within ±0.10 °C), density (within ±0.07 °C), and finally thermal conductivity (within ±0.01 °C). A maximum overall uncertainty of ±0.23 °C in the core body temperature was observed due to the combined uncertainty in the tissue parameters. Thus, the model results can be used to effectively predict a realistic range of thermal response of the firefighters during firefighting or similar activities.

scholarly journals Pathophysiology of Fever and Application of Infrared Thermography (IRT) in the Detection of Sick Domestic Animals: Recent Advances

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2316
Author(s):  
Daniel Mota-Rojas ◽  
Dehua Wang ◽  
Cristiane Gonçalves Titto ◽  
Jocelyn Gómez-Prado ◽  
Verónica Carvajal-de la Fuente ◽  
...  
Keyword(s):  
Body Temperature ◽  
Infrared Thermography ◽  
Core Body Temperature ◽  
The Body ◽  
Farm Animals ◽  
Economic Losses ◽  
Febrile Response ◽  
Temperature Range ◽  
Stable Temperature ◽  
Core Body

Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.

scholarly journals Comparison of Tympanic and Tail Temperatures in Angus and Brahman Steers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dikmen S ◽  
Davila KMS ◽  
Rodriquez E ◽  
Scheffler TL ◽  
Oltenacu PA ◽  
...  
Keyword(s):  
Body Temperature ◽  
Repeated Measures ◽  
Core Body Temperature ◽  
The Body ◽  
Tympanic Temperature ◽  
Repeated Measure ◽  
Important Indicator ◽  
Significant Difference ◽  
Brahman Steers ◽  
Core Body

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.

scholarly journals BIOLOGICAL AGE AS A METHOD FOR ESTIMATING HEALTH LEVEL UNDER ENVIRONMENTAL RISKS (LITERATURE REVIEW)

2019 ◽  
Vol 98 (7) ◽  
pp. 761-765 ◽  
Author(s):  
N. I. Prokhorov ◽  
V. I. Dontsov ◽  
Vyacheslav N. Krutko ◽  
T. M. Khodykina
Keyword(s):  
Human Body ◽  
Quantitative Assessment ◽  
Modern Human ◽  
The Body ◽  
Biological Age ◽  
Whole Body ◽  
New Methods ◽  
Biomarkers Of Aging ◽  
Age Related ◽  
Definition Of

The widespread formation of unfavorable environmental, the swiftness of modern life with large information and psycho-emotional loads and extremely natural and climatic cataclysms, as well as harmful addictions and wrong way of life of modern human, lead to the development of stress and disruption of the mechanisms of adaptation of the human body and its accelerated wear. This stimulates the development of research on the creation of new methods of integrated assessment of health and quantitative assessment of the aging processes of the body systems and the whole body, as well as the possibilities of new methods of risk assessment of climatic and environmentally related pathological and age-related diseases. The aim of the work was to consider the methodology of quantitative assessment of individual health and the rate of aging of the human body on the basis of the system index of Biological age (BA); description of its essence and structure, requirements for tests - biomarkers of aging used as the index of BA, definition of possibilities and scope of application of the BA method in modern practice of Biomedicine. The use of modern methods of scientific analysis - a systematic approach to the analysis of the processes of human aging and determine its quantitative side - the value of BA, allows a reasonable approach to the choice of the number of BM, to take into account their information content and precision, and the cost of diagnostics and availability for different users, to take into account the specific objectives of the researcher. The use of the index-partial BA allows individual approaching the choice of biomarkers and create personalized panels for the definition of BA programs for the prevention of aging in personalized preventive medicine. The complexity of the content and calculation of indices of BA requires automation and the use of methods of modern computer science and computer calculations and programs. For this purpose, we have created special computer software for diagnosing aging by calculating the BA indices with the possibility of choosing BM and automatic calculation of indicators and conclusions.

scholarly journals A Case Report on Osborn Waves of Hypothermia Induced LV Systolic Dysfunction

2021 ◽  
Vol 70 (2) ◽  
Author(s):  
Rajnandini Singha ◽  
Amazing Grace Siangshai ◽  
Jashlyn Lijo
Keyword(s):  
Body Temperature ◽  
Sinus Bradycardia ◽  
Core Body Temperature ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
The Body ◽  
Qrs Complex ◽  
Pr Interval ◽  
Gradual Expansion ◽  
Core Body

Hypothermia, described as a core body temperature of < 95%, is associated with ECG alteration abnormalities. Sinus bradycardia occurs when the body temperature drops below 90°F, and is correlated with gradual prolongation of the PR interval, QRS complex, QT interval. It can progress to ventricular and atrial fibrillation at a temperature reaching 89°F, which can lead to left ventricular dysfunction. Hypothermia is connected to the osborn waves, which at the end of the QRS complex consist of additional deflection. The inferior and lateral precordial leads are seen by Osborn waves, also known as J waves, Camel hump waves and hypothermic waves. As the body temperature decreases, it becomes more pronounced and a gradual expansion of the QRS complex raises the likelihood of ventricular fibrillation causing ventricle dysfunction.

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