scholarly journals Analysis of the effect of external heating in the human tissue: A finite element approach

2020 ◽  
Vol 26 (4) ◽  
pp. 251-262
Author(s):  
Mridul Sannyal ◽  
Abul Mukid Mohammad Mukaddes ◽  
Md. Matiar Rahman ◽  
M. A. H. Mithu
Keyword(s):  
Finite Element ◽  
Human Tissue ◽  
Transfer Problem ◽  
Thermal Response ◽  
Blood Perfusion ◽  
Element Model ◽  
Bioheat Transfer ◽  
Tissue Temperature ◽  
Blood Temperature ◽  
External Heating

AbstractThermal therapy which involves either raising or lowering tissue temperature to treat malignant cells needs precise acknowledgment of thermal history inside the biological system to ensure effective treatment. For this purpose, this study presents a two-dimensional unsteady finite element model (FEM) of the bioheat transfer problem based on Pennes bio-heat equation to analyze the thermal response of tissue subject to external heating. Crank-Nikolson scheme was used for the unsteady solution. A finite element code was developed using C language to calculate results. The obtained numerical result was compared with the analytical and other numerical results available in the literature. A good agreement was found from the comparison. Temperature distribution inside the human body due to constant and sinusoidal spatial and surface heating were analyzed. Response to point heating was also investigated. Moreover, a sensitivity analysis was carried out to know the effect of various parameters, i.e. blood temperature, thermal conductivity, and blood perfusion rate on tissue temperature. The outcome of this study will be helpful for the researchers and physicians involved in the thermal treatment of human tissue.

Temperature Profiles in a Finite Element Thermal Model of the Prostate Region Under Hyperthermia Treatment

1990 ◽  
Vol 189 ◽  
Author(s):  
Indira Chatterjee ◽  
Roy E. Adams ◽  
Namdar Saniei
Keyword(s):  
Finite Element ◽  
Phased Array ◽  
Blood Perfusion ◽  
Element Model ◽  
Bioheat Transfer ◽  
Transient Temperature ◽  
Temperature Profiles ◽  
Hyperthermia Treatment ◽  
Finite Element Software ◽  
Transient Temperature Distribution

ABSTRACTThe detailed transient temperature distribution in an inhomogeneous model of a cross section through the prostate region of the human body undergoing hyperthermia treatment forcancer has been calculated. The finite element method has been used to solve the bioheattransfer equation. A commercially available finite element software package called ANSYS® has been adapted to the present problem.The model consists of 523 triangular elements and incorporates a tumor in the prostate.The hyperthermia device under test is an Annular Phased Array consisting of dipole antennas. The model is surrounded by a bolus of deionized water. The calculated electromagnetic energy distribution is input into the bioheat transfer equation and the resulting temperature distributions calculated.The increase in blood perfusion rates due to heating is incorporated into the model. Detailed transient temperature profiles in the finite element model are presented for various values of blood perfusion rates in the tumor and surrounding tissues. It is observed that the Annular Phased Array is effective in raising the temperature of the tumor to therapeutic values.

A Finite Element Model of Skin Subjected to a Flash Fire

1994 ◽  
Vol 116 (3) ◽  
pp. 250-255 ◽  
Author(s):  
D. A. Torvi ◽  
J. D. Dale
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Closed Form Solution ◽  
Blood Perfusion ◽  
Element Model ◽  
Form Solution ◽  
Bioheat Transfer ◽  
Multiple Layer ◽  
Degree Burn ◽  
Flash Fire

A variable property, multiple layer finite element model was developed to predict skin temperatures and times to second and third degree burns under simulated flash fire conditions. A sensitivity study of burn predictions to variations in thermal physical properties of skin was undertaken using this model. It was found that variations in these properties over the ranges used in multiple layer skin models had minimal effects on second degree burn predictions, but large effects on third degree burn predictions. It was also found that the blood perfusion source term in Pennes’ bioheat transfer equation could be neglected in predicting second and third degree burns due to flash fires. The predictions from this model were also compared with those from the closed form solution of this equation, which has been used in the literature for making burn predictions from accidents similar to flash fires.

Thermal Response Analysis and FE Modeling of Weapon

2012 ◽  
Vol 503-504 ◽  
pp. 11-14
Author(s):  
Yan Jun Zhao ◽  
Xin Jun Li ◽  
Yong Hai Wu ◽  
Cheng Xu
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Temperature Field ◽  
Research Work ◽  
Thermal Response ◽  
Element Model ◽  
Response Analysis ◽  
Fe Modeling ◽  
Effects Of Temperature ◽  
The Finite Element Model

Thermal is a important factor that affect weapon firing accuracy and security in the process of weapon fire, so thermal analysis of weapon has important meaning . Aim at researched Weapon, the finite element model of the gun body was built, the temperature field of the gun body was calculated by FEM. The effects of temperature of the gun body on firer and aiming mechanism were also studied. Current research work will be helpful the weapon design

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.

Implicit Heterogeneous 1D/2D Coupling for Aero-Thermo-Mechanical Simulation of Secondary Air Systems

2015 ◽  
Author(s):  
Vlad Ganine ◽  
Nick Hills ◽  
Matt Miller ◽  
Chris Barnes ◽  
Steve Curzons ◽  
...  
Keyword(s):  
Finite Element ◽  
Transfer Problem ◽  
Network Models ◽  
Physical Nature ◽  
Element Model ◽  
Computational Procedure ◽  
Coupled Analysis ◽  
Time Step ◽  
Flow Network ◽  
Secondary Air

The paper presents a computational procedure for heterogeneous coupled analysis of 1D flow network models of air engine secondary air systems and 2D/3D solid thermo-mechanical finite element models of engine components. We solve an unsteady heat transfer problem over solid domain coupled to a sequence of structural static and steady flow problems using a quasi-steady state approximation. Strong coupling is achieved at each time step by a fixed-point iteration, based on the successive solution of the fluid and the solid sub-problems. The procedure is applied to a 2D axisymmetric finite element model of an intermediate pressure turbine assembly coupled to a flow network model of whole engine secondary air system simulated through a square cycle. The simulation results are compared to reference stand-alone predictions showing important non-negligible coupled effects and component interactions of a multidisciplinary multi-physical nature resolved in an efficient and automatic fashion.

scholarly journals Bioheat transfer model of transcutaneous spinal cord stimulation-induced temperature changes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4921
Author(s):  
Luyao Chen ◽  
Ang Ke ◽  
Peng Zhang ◽  
Zhaolong Gao ◽  
Xuecheng Zou ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Temperature Rise ◽  
Spinal Cord Stimulation ◽  
Blood Perfusion ◽  
Bioheat Transfer ◽  
Transfer Model ◽  
Temperature Changes ◽  
Stimulation Parameters ◽  
Transcutaneous Spinal Cord Stimulation

Transcutaneous spinal cord stimulation (tSCS) has been extensively studied due to its promising application in motor function restoration. Many previous studies have explored both the essential mechanism of action and the methods for determining optimal stimulation parameters. In contrast, the bioheat transfer analysis of tSCS therapy has not been investigated to the same extent, despite widely existing, and being of great significance in assuring a stable and thermally safe treatment. In this paper, we concentrated on the thermal effects of tSCS using a finite element-based method. By coupling the electric field and bioheat field, systematic finite element simulations were performed on a human spinal cord model to survey the influence of anatomical structures, blood perfusion, and stimulation parameters on temperature changes for the first time. The results show that tSCS-induced temperature rise mainly occurs in the skin and fat layers and varies due to individual differences. The current density distribution along with the interactions of multiple biothermal effects synthetically determines the thermal status of the whole spinal cord model. Smaller stimulation electrodes have a higher risk of thermal damage when compared with larger electrodes. Increasing the stimulation intensity will result in more joule heat accumulation, hence an increase in the temperature. Among all configurations in this study that simulated the clinical tSCS protocols, the temperature rise could reach up to 9.4 °C on the skin surface depending on the stimulation parameters and tissue blood perfusion.

Simulation of Frictional Thermal Effect during Blade-to-Case Full Annular Rub

2015 ◽  
Vol 743 ◽  
pp. 79-84 ◽  
Author(s):  
L.L. Wang ◽  
Shun Ming Li ◽  
G.C. Tian ◽  
Ji Yong Li
Keyword(s):  
Finite Element ◽  
Thermal Effect ◽  
Thermal Structure ◽  
Equivalent Stress ◽  
Thermal Response ◽  
Element Model ◽  
Response Characteristic ◽  
The Finite Element Method ◽  
Friction Process ◽  
Transient Thermal

During blade-to-case full annular rub, the frictional thermal response characteristic of blade-to-case was analyzed by the finite element method. A thermal structure coupling finite element model of blade-to-case was established and the transient thermal and structural field was analyzed. The distributions of temperature field and equivalent stress field were obtained on the basis of a certain centrifugal force, friction coefficient and rotate speed of the blade. The numerical simulations have been conducted to show that the heat affected zone (HAZ) locates in a very thin layer of blade-to-case, and the thermal stress is very high in this layer. The thermal effect in the blade-to-case friction process is more obvious as the rotate speed of blade and centrifugal pressure are increased. In practice, it is suggested that the friction thermal effect in the process of rotor-stator rub-impact should not be ignored.

TWO-DIMENSIONAL FINITE ELEMENT MODEL OF TEMPERATURE DISTRIBUTION IN DERMAL TISSUES OF EXTENDED SPHERICAL ORGANS OF A HUMAN BODY

2013 ◽  
Vol 06 (01) ◽  
pp. 1250065 ◽  
Author(s):  
AKSHARA MAKRARIYA ◽  
NEERU ADLAKHA
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Blood Perfusion ◽  
Element Model ◽  
The Body ◽  
Two Dimensional ◽  
Human Breast ◽  
Physical Conditions ◽  
Dimensional Finite Element ◽  
Body Core

In the present study the thermal model of skin and subdermal tissues (SST) of human breast have been developed. The human breast is assumed to be spherical in shape with upper hemisphere projecting out from the trunk of the body and lower hemisphere is considered to be a part of the body core. The upper hemisphere represents the breast and its SST region is divided into three layers namely epidermis, dermis and subdermal tissues. The inner part of the breast represents the core/shell of the breast. The outer surface of the breast is assumed to be exposed to the environment from where the heat loss takes place by conduction, convection, radiation and evaporation. The heat transfer from core to the surface takes place by thermal conduction and blood perfusion. Also metabolic activity takes place at different rates in different SST layers of the breast. Boundary conditions have been framed on the basis of physical conditions. A finite element model has been developed for a two-dimensional steady state case.

Finite-element simulation of blood perfusion in muscle tissue during compression and sustained contraction

1997 ◽  
Vol 273 (3) ◽  
pp. H1587-H1594 ◽  
Author(s):  
W. J. Vankan ◽  
J. M. Huyghe ◽  
D. W. Slaaf ◽  
C. C. van Donkelaar ◽  
M. R. Drost ◽  
...  
Keyword(s):  
Finite Element ◽  
Blood Flow ◽  
Finite Element Model ◽  
Muscle Tissue ◽  
Three Dimensional ◽  
Blood Perfusion ◽  
Element Model ◽  
Loading Conditions ◽  
Sustained Contraction ◽  
Dimensional Finite Element

Mechanical interaction between tissue stress and blood perfusion in skeletal muscles plays an important role in blood flow impediment during sustained contraction. The exact mechanism of this interaction is not clear, and experimental investigation of this mechanism is difficult. We developed a finite-element model of the mechanical behavior of blood-perfused muscle tissue, which accounts for mechanical blood-tissue interaction in maximally vasodilated vasculature. Verification of the model was performed by comparing finite-element results of blood pressure and flow with experimental measurements in a muscle that is subject to well-controlled mechanical loading conditions. In addition, we performed simulations of blood perfusion during tetanic, isometric contraction and maximal vasodilation in a simplified, two-dimensional finite-element model of a rat calf muscle. A vascular waterfall in the venous compartment was identified as the main cause for blood flow impediment both in the experiment and in the finite-element simulations. The validated finite-element model offers possibilities for detailed analysis of blood perfusion in three-dimensional muscle models under complicated loading conditions.

Numerical Solution of Bioheat Transfer Problems with Transient Blood Temperature

2019 ◽  
Vol 16 (04) ◽  
pp. 1843001 ◽  
Author(s):  
Kuo-Chi Liu ◽  
Fong-Jou Tu
Keyword(s):  
Transient Process ◽  
Blood Perfusion ◽  
Feedback Mechanism ◽  
Bioheat Transfer ◽  
Bioheat Equation ◽  
Negative Feedback Mechanism ◽  
Blood Temperature ◽  
The Laplace Transform ◽  
Transfer Behavior ◽  
Transfer Problems

In the heat treatment process, blood perfusion starts up a negative feedback mechanism. The blood temperature undergoes a transient process before onset of equilibrium and then changes the situation of temperature distribution. In substance, the blood temperature undergoes a transient process for heat exchange between blood and tissue. For more fully exploring the heat transfer behavior of biological tissue, this paper analyzes the bioheat transfer problems with the nonconstant blood temperature based on the Pennes bioheat equation. A numerical scheme based on the Laplace transform is proposed for solving the present problems.

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