50 Years of Computer Simulation of the Human Thermoregulatory System

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Daniel W. Hensley ◽  
Andrew E. Mark ◽  
Jayvee R. Abella ◽  
George M. Netscher ◽  
Eugene H. Wissler ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Skin Blood Flow ◽  
Blood Perfusion ◽  
High Rate ◽  
Glabrous Skin ◽  
Entire Body ◽  
Dynamic Regulation ◽  
Therapeutic Procedures ◽  
Hands And Feet

This paper presents an updated and augmented version of the Wissler human thermoregulation model that has been developed continuously over the past 50 years. The existing Fortran code is translated into C with extensive embedded commentary. A graphical user interface (GUI) has been developed in Python to facilitate convenient user designation of input and output variables and formatting of data presentation. Use of the code with the GUI is described and demonstrated. New physiological elements were added to the model to represent the hands and feet, including the unique vascular structures adapted for heat transfer associated with glabrous skin. The heat transfer function and efficacy of glabrous skin is unique within the entire body based on the capacity for a very high rate of blood perfusion and the novel capability for dynamic regulation of blood flow. The model was applied to quantify the absolute and relative contributions of glabrous skin flow to thermoregulation for varying levels of blood perfusion. The model also was used to demonstrate how the unique features of glabrous skin blood flow may be recruited to implement thermal therapeutic procedures. We have developed proprietary methods to manipulate the control of glabrous skin blood flow in conjunction with therapeutic devices and simulated the effect of these methods with the model.

scholarly journals Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Laura H. Namisnak ◽  
Sepideh Khoshnevis ◽  
Kenneth R. Diller
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Maximum Level ◽  
Thermal Stimulation ◽  
Glabrous Skin ◽  
Whole Body ◽  
Outcome Variable ◽  
Laser Doppler Flow ◽  
Body Cooling ◽  
Whole Body Cooling

Abstract The objective of this study was to test the feasibility of selective thermal stimulation (STS) as a method to upregulate glabrous skin blood flow. STS is accomplished by mild surface heating along the spinal cord. Four healthy subjects were tested in this study. Each participated in a control experiment and an intervention experiment (STS). Both experiments included establishing a maximum level of vasodilation, considered unique to a subject on a test day, and then cooling to a maximum level of vasoconstriction. Perfusion was measured by a laser Doppler flow probe on the index fingertip. The percent of perfusion in the range of minimum to maximum was the primary outcome variable. The data were fit to a linear mixed effects model to determine if STS had a significant influence on perfusion during whole body cooling. STS had a statistically significant effect on perfusion and increased glabrous skin blood flow by 16.3% (P < 0.001, CI (13.1%, 19.5%)) as skin temperature was decreased. This study supports the theory that STS improves the heat exchanger efficiency of palmar and plantar surfaces by increasing the blood flow.

EFFECTS OF MUSCLE METABORECEPTOR STIMULATION ON SKIN BLOOD FLOW IN GLABROUS AND NON-GLABROUS SKIN DURING MILD HEATING IN HUMANS

2002 ◽  
Vol 34 (5) ◽  
pp. S224
Author(s):  
N Kondo ◽  
S Yanagimoto ◽  
M Inoue ◽  
M Shibasaki ◽  
S Koga ◽  
...  
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Glabrous Skin

Levamisole-Adulterated Cocaine Leading to Fatal Vasculitis: A Case Report

2017 ◽  
Vol 37 (4) ◽  
pp. 49-57 ◽  
Author(s):  
Belinda B. Hammond ◽  
Jordan Craven
Keyword(s):  
Blood Flow ◽  
Case Report ◽  
Severe Neutropenia ◽  
Peripheral Blood Flow ◽  
Entire Body ◽  
Tissue Necrosis ◽  
Cutaneous Lesions ◽  
Cocaine Use ◽  
Hands And Feet ◽  
Parasitic Worms

Cocaine is often “cut” with various additives to increase the profitability of the drug. One of the most common additives on today’s market is levamisole, an anthelmintic medication used to destroy and expel parasitic worms in animals. The use of levamisole-contaminated cocaine can result in agranulocytosis and vasculitis (inflammation and constriction of small blood vessels). The resulting clotting and decrease in peripheral blood flow lead to cutaneous lesions, particularly on the ears, face, hands, and feet, and in severe cases can cause generalized tissue necrosis throughout the entire body. Treatment is generally supportive, and symptoms typically abate with complete cessation of cocaine use. However, symptoms may recur with subsequent cocaine use and, as this case illustrates, severe neutropenia and extensive vasculitis may lead to overwhelming sepsis and death.

The interrealtionship between locally applied heat, ageing and skin blood flow on heat transfer into and from the skin

2011 ◽  
Vol 35 (5) ◽  
pp. 262-274 ◽  
Author(s):  
Jerrold Petrofsky ◽  
Faris Alshahmmari ◽  
Jong Eun Yim ◽  
Adel Hamdan ◽  
Haneul Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Skin Blood Flow

scholarly journals The Recovery Benefit on Skin Blood Flow Using Vibrating Foam Rollers for Postexercise Muscle Fatigue in Runners

2020 ◽  
Vol 17 (23) ◽  
pp. 9118
Author(s):  
Yi-Horng Lai ◽  
Ai-Yi Wang ◽  
Chia-Chi Yang ◽  
Lan-Yuen Guo
Keyword(s):  
Blood Flow ◽  
Muscle Fatigue ◽  
Skin Blood Flow ◽  
Gastrocnemius Muscle ◽  
Blood Perfusion ◽  
Endothelial Activation ◽  
Flow Oscillation ◽  
Flow Perfusion ◽  
Before And After ◽  
Blood Flow Oscillation

Purpose: To determine the effect of vibrating rollers on skin blood flow after running for recovery from muscle fatigue. Method: 23 healthy runners, aged between 20 to 45 years, participated in a crossover trial. Muscle fatigue was induced by running, and recovery using a vibrating roller was determined before and after the intervention. Each subject was measured at three time points (prerun, postrun, and postroller) to compare skin blood flow perfusion and blood flow oscillation at the midpoint of the dominant gastrocnemius muscle. The results show that blood perfusion is greater when a vibrating roller is used than a foam roller, but there is no statistical difference. The analysis of blood flow oscillation shows that vibrating rollers induce 30% greater endothelial activation than a foam roller. Vibrating rollers significantly stimulate the characteristic frequency for myogenic activation (p < 0.05); however, the effect size is conservative.

A New Simplified Bioheat Equation for the Effect of Blood Flow on Local Average Tissue Temperature

1985 ◽  
Vol 107 (2) ◽  
pp. 131-139 ◽  
Author(s):  
S. Weinbaum ◽  
L. M. Jiji
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Blood Perfusion ◽  
Basic Mechanism ◽  
Simple Expression ◽  
Tissue Temperature ◽  
Bioheat Equation ◽  
Countercurrent Exchange

A new simplified three-dimensional bioheat equation is derived to describe the effect of blood flow on blood-tissue heat transfer. In two recent theoretical and experimental studies [1, 2] the authors have demonstrated that the so-called isotropic blood perfusion term in the existing bioheat equation is negligible because of the microvascular organization, and that the primary mechanism for blood-tissue energy exchange is incomplete countercurrent exchange in the thermally significant microvessels. The new theory to describe this basic mechanism shows that the vascularization of tissue causes it to behave as an anisotropic heat transfer medium. A remarkably simple expression is derived for the tensor conductivity of the tissue as a function of the local vascular geometry and flow velocity in the thermally significant countercurrent vessels. It is also shown that directed as opposed to isotropic blood perfusion between the countercurrent vessels can have a significant influence on heat transfer in regions where the countercurrent vessels are under 70-μm diameter. The new bioheat equation also describes this mechanism.

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