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.

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.

scholarly journals Temperature Monitoring and Perioperative Thermoregulation

2008 ◽  
Vol 109 (2) ◽  
pp. 318-338 ◽  
Author(s):  
Daniel I. Sessler ◽  
David S. Warner ◽  
Mark A. Warner
Keyword(s):  
Body Temperature ◽  
General Anesthesia ◽  
Core Temperature ◽  
Core Body Temperature ◽  
Neuraxial Anesthesia ◽  
General Anesthetics ◽  
The Core ◽  
Core Body ◽  
Dose Dependent ◽  
Body Heat

Most clinically available thermometers accurately report the temperature of whatever tissue is being measured. The difficulty is that no reliably core-temperature-measuring sites are completely noninvasive and easy to use-especially in patients not undergoing general anesthesia. Nonetheless, temperature can be reliably measured in most patients. Body temperature should be measured in patients undergoing general anesthesia exceeding 30 min in duration and in patients undergoing major operations during neuraxial anesthesia. Core body temperature is normally tightly regulated. All general anesthetics produce a profound dose-dependent reduction in the core temperature, triggering cold defenses, including arteriovenous shunt vasoconstriction and shivering. Anesthetic-induced impairment of normal thermoregulatory control, with the resulting core-to-peripheral redistribution of body heat, is the primary cause of hypothermia in most patients. Neuraxial anesthesia also impairs thermoregulatory control, although to a lesser extent than does general anesthesia. Prolonged epidural analgesia is associated with hyperthermia whose cause remains unknown.

Relationship between metabolic rate and core body temperature during sleep in human

2015 ◽  
Vol 16 ◽  
pp. S186-S187 ◽  
Author(s):  
I. Park ◽  
M. Kayaba ◽  
K. Iwayama ◽  
H. Ogata ◽  
Y. Sengoku ◽  
...  
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Core Body

Monitoring of the core body temperature of cows using implantable wireless thermometers

2019 ◽  
Vol 163 ◽  
pp. 104849 ◽  
Author(s):  
Wataru Iwasaki ◽  
Shuichi Ishida ◽  
Daisuke Kondo ◽  
Yuichi Ito ◽  
Jun Tateno ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
The Core ◽  
Core Body

scholarly journals Skipping Breakfast for 6 Days Delayed the Circadian Rhythm of the Body Temperature without Altering Clock Gene Expression in Human Leukocytes

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2797 ◽  
Author(s):  
Hitomi Ogata ◽  
Masaki Horie ◽  
Momoko Kayaba ◽  
Yoshiaki Tanaka ◽  
Akira Ando ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Clock Gene ◽  
Core Body Temperature ◽  
The Core ◽  
Clock Gene Expression ◽  
Meal Timing ◽  
Dim Light ◽  
Core Body ◽  
Skipping Breakfast

Breakfast is often described as “the most important meal of the day” and human studies have revealed that post-prandial responses are dependent on meal timing, but little is known of the effects of meal timing per se on human circadian rhythms. We evaluated the effects of skipping breakfast for 6 days on core body temperature, dim light melatonin onset, heart rate variability, and clock gene expression in 10 healthy young men, with a repeated-measures design. Subjects were provided an isocaloric diet three times daily (3M) or two times daily (2M, i.e., breakfast skipping condition) over 6 days. Compared with the 3M condition, the diurnal rhythm of the core body temperature in the 2M condition was delayed by 42.0 ± 16.2 min (p = 0.038). On the other hand, dim light melatonin onset, heart rate variability, and clock gene expression were not affected in the 2M condition. Skipping breakfast for 6 days caused a phase delay in the core body temperature in healthy young men, even though the sleep–wake cycle remained unchanged. Chronic effects of skipping breakfast on circadian rhythms remain to be studied.

scholarly journals The Use of Percutaneous Thermal Sensing Microchips for Body Temperature Measurements in Horses Prior to, during and after Treadmill Exercise

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2274
Author(s):  
Hyungsuk Kang ◽  
Rebeka R. Zsoldos ◽  
Solomon M. Woldeyohannes ◽  
John B. Gaughan ◽  
Albert Sole Guitart
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Central Venous ◽  
Exertional Heat Illness ◽  
The Core ◽  
Thermal Sensing ◽  
Positive Correlations ◽  
The Right ◽  
Nuchal Ligament ◽  
Core Body

Accurately measuring body temperature in horses will improve the management of horses suffering from or being at risk of developing postrace exertional heat illness. PTSM has the potential for measuring body temperature accurately, safely, rapidly, and noninvasively. This study was undertaken to investigate the relation between the core body temperature and PTSM temperatures prior to, during, and immediately after exercise. The microchips were implanted into the nuchal ligament, the right splenius, gluteal, and pectoral muscles, and these locations were then compared with the central venous temperature, which is considered to be the “gold standard” for assessing core body temperature. The changes in temperature of each implant in the horses were evaluated in each phase (prior to, during, and immediately postexercise) and combining all phases. There were strong positive correlations ranging from 0.82 to 0.94 (p < 0.001) of all the muscle sites with the central venous temperature when combining all the phases. Additionally, during the whole period, PTSM had narrow limits of agreement (LOA) with central venous temperature, which inferred that PTSM is essentially equivalent in measuring horse body temperature. Overall, the pectoral PTSM provided a valid estimation of the core body temperature.

scholarly journals Circulation and metabolic rates in a natural hibernator: an integrative physiological model

2010 ◽  
Vol 299 (6) ◽  
pp. R1478-R1488 ◽  
Author(s):  
Marshall Hampton ◽  
Bethany T. Nelson ◽  
Matthew T. Andrews
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Circulatory System ◽  
Physiological Model ◽  
Ground Squirrels ◽  
Metabolic Rates ◽  
Spermophilus Tridecemlineatus ◽  
Brown Adipose ◽  
Core Body

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels ( Spermophilus tridecemlineatus ). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system.

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.

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