A Vascular Model for Heat Transfer in an Isolated Pig Kidney During Water Bath Heating

2003 ◽  
Vol 125 (5) ◽  
pp. 936-943 ◽  
Author(s):  
Cuiye Chen ◽  
Lisa X. Xu
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Water Bath ◽  
Bioheat Transfer ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Hyperthermia Treatment ◽  
Pig Kidney ◽  
Vascular Model ◽  
Water Bath Heating

Isolated pig kidney has been widely used as a perfused organ phantom in the studies of hyperthermia treatments, as blood perfusion plays an essential role in thermoregulation of living tissues. In this research, a vascular model was built to describe heat transfer in the kidney phantom during water bath heating. The model accounts for conjugate heat transfer between the paired artery and vein, and their surrounding tissue in the renal medulla. Tissue temperature distribution in the cortex was predicted using the Pennes bioheat transfer equation. An analytical solution was obtained and validated experimentally for predicting the steady state temperature distribution in the pig kidney when its surface kept at a uniform constant temperature. Results showed that local perfusion rate significantly affected tissue temperature distributions. Since blood flow is the driving force of tissue temperature oscillations during hyperthermia, the newly developed vascular model provides a useful tool for hyperthermia treatment optimization using the kidney phantom model.

scholarly journals An Inverse Problem of Temperature Optimization in Hyperthermia by Controlling the Overall Heat Transfer Coefficient

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Seyed Ali Aghayan ◽  
Dariush Sardari ◽  
Seyed Rabii Mahdi Mahdavi ◽  
Mohammad Hasan Zahmatkesh
Keyword(s):  
Heat Transfer ◽  
Inverse Problem ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cooling System ◽  
Adjoint Equation ◽  
Bioheat Transfer ◽  
Tissue Temperature ◽  
Hyperthermia Treatment ◽  
Overall Heat Transfer Coefficient

A novel scheme to obtain the optimum tissue heating condition during hyperthermia treatment is proposed. To do this, the effect of the controllable overall heat transfer coefficient of the cooling system is investigated. An inverse problem by a conjugated gradient with adjoint equation is used in our model. We apply the finite difference time domain method to numerically solve the tissue temperature distribution using Pennes bioheat transfer equation. In order to provide a quantitative measurement of errors, convergence history of the method and root mean square of errors are also calculated. The effects of heat convection coefficient of water and thermal conductivity of casing layer on the control parameter are also discussed separately.

Theoretical and Experimental Studies of Local Tissue Temperature Oscillation Under Hyperthermic Conditions Using Preserved Pig Kidney

2000 ◽  
Author(s):  
Cuiye Chen ◽  
Lisa X. Xu
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Temperature Oscillation ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Transient Temperature ◽  
Thermal Bath ◽  
Target Tissue ◽  
Local Tissue ◽  
Pig Kidney

Abstract It has been long recognized that local tissue temperature may osculate due to vascular thermo-regulation under hyperthermic conditions. To effectively heat the target tissue while sparing its surroundings, it is necessary to understand and then to control the temperature oscillation. A model based on the pig kidney vasculature was developed to study the transient temperature variations in the kidney when subjected to heating in a thermal bath. In the medullary region, a vascular model previously developed in (Chen and Xu, 2000) was used to account for the conjugate heat transfer between the paired artery and vein, and their surrounding tissue. Considering that numerous small vessels exist in the cortex region, the Pennes bio-heat transfer equation was used for modeling in this region. A code was written to numerically compute the 3-D transient temperature distribution in the kidney subjected to heating. To examine the validity of the model, experiments were performed to measure the temperatures and perfusion rates using thermistor microprobes in the cortex of the preserved pig kidney. This model will be utilized for future studies to investigate the relationships among the local blood perfusion rate, the heating rate, and the tissue temperature oscillation.

Temperature Response in Living Skin Tissue Subject to Convective Heat Flux

2018 ◽  
Vol 387 ◽  
pp. 1-9
Author(s):  
Sanatan Das ◽  
Tilak Kumer Pal ◽  
Rabindra Nath Jana ◽  
Oluwole Daniel Makinde
Keyword(s):  
Heat Transfer ◽  
Biot Number ◽  
Temperature Response ◽  
Bioheat Transfer ◽  
Heat Transfer Analysis ◽  
Skin Tissue ◽  
Tissue Temperature ◽  
Convective Heating ◽  
Transform Method ◽  
Living Tissues

This paper examines the heat transfer in living skin tissue that is subjected to a convective heating. The tissue temperature evolution over time is classically described by the one-dimensional Pennes' bioheat transfer equation which is solved by applying Laplace transform method. The heat transfer analysis on skin tissue (dermis and epidermis) has only been studied defining the Biot number. The result shows that the temperature in skin tissue is less subject to the convected heating skin compared to constant skin temperature. The study also shows that the Biot number has a significant impact on the temperature distribution in the layer of living tissues. This study finds its application in thermal treatment.

Analysis of Dual Phase Lag Heat Conduction in Gold Nanoparticle Based Hyperthermia Treatment

2008 ◽  
Author(s):  
C. Liu ◽  
B. Q. Li ◽  
C. Mi
Keyword(s):  
Heat Conduction ◽  
Gold Nanoparticle ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Transient Temperature ◽  
Short Time Scale ◽  
Phase Lag ◽  
Dual Phase ◽  
Hyperthermia Treatment ◽  
Lag Model

This paper addresses the fast-transient heat conduction phenomena of a gold nanoparticle embedded in cancerous tissue in hyperthermia treatment. Dual phase lag model in spherical coordinates was employed and a semi-analytical solution of 1-D non-homogenous dual phase lag equation was presented. Results show that transient temperature depends dramatically on the lagging characteristic time of the surrounding tissue. Temperature predicted by dual phase lag model greatly exceeds that predicted by a classical diffusion model, with either a constant source or a pulsed source. This phenomenon is mainly attributed by the phase lag of heat flux of tissue. The overheating in short time scale and the consequent biological effect needs to be paid more attention in the related study.

The Effects of Large Blood Vessels on Three-Dimensional Tissue Temperature Distributions During Electromagnetic Induced Nano-Hyperthermia: Numerical Simulation

2008 ◽  
Author(s):  
Zhong-Shan Deng ◽  
Jing Liu
Keyword(s):  
Blood Vessels ◽  
Tumor Cells ◽  
Three Dimensional ◽  
The Body ◽  
Thermal Therapy ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Temperature Profiles ◽  
Hyperthermia Treatment ◽  
Tumor Hyperthermia

As is well known, the blood flowing through large blood vessels acts as a heat sink and plays an important role in affecting temperature profiles of heated tissues [1]. In hyperthermia, heating is usually limited to the tumor and a small margin of the surrounding tissue. Since the temperatures in the rest of the body remain normal, the blood that supplies the tumor will be relatively cold. Consequently, the blood flow inside a large vessel will represent a sink which cools the nearby heated tissues and then limits heating lesion during tumor hyperthermia. Under this adverse condition, a part of vital tumor cells may remain in the thermally lethal area and lead to recurrence of tumors after hyperthermia treatment. More specifically, tumor cell survival in the vicinity of large blood vessels is often correlated with tumor recurrence after thermal therapy. Therefore, it is difficult to implement an effective hyperthermia treatment when a tumor is contiguous to a large blood vessel or such vessel transits the tumor. How to totally destroy tumor cells in the vicinity of large blood vessels has been a major challenge in hyperthermia [2].

scholarly journals Numerical Analysis of Breast Cancer Cell with Gold Nanoparticles Necrosis by Laser Hyperthermia

2020 ◽  
Vol 10 (2) ◽  
pp. 138-144
Author(s):  
Shna A. Karim ◽  
Yousif M. Hassan
Keyword(s):  
Breast Cancer ◽  
Heat Transfer ◽  
Gold Nanoparticles ◽  
Cancer Cells ◽  
Biological Tissues ◽  
Surrounding Tissue ◽  
Threshold Temperature ◽  
Cancer Tissue ◽  
Hyperthermia Treatment ◽  
Laser Hyperthermia

Laser hyperthermia treatment of cancer tissue is widely used in cancer treatment to destroy cancer cells. This study focus on the mechanisms of heat transfer in biological tissues to minimize damage to the tissues resulting from extra heat applied. The important feature of this method is heating of specific region to raise its temperature to a threshold temperature and destroying cancer cells without to destroy surrounding tissue. In this study, we have used the combinations of laser light and gold nanoparticles to investigate the influence of nanoparticles on the spatial distribution of temperature in the tumor and healthy tissues. Accurate simulations and solving Penne’s bio-heat transfer equation were used to solve and model the thermal tumor breast cancer in the presence of gold. Nanoparticles of some particular sizes and concentrations were selected. We would like here to stress that our attempt was a theoretical and computer model with some real and hypothesized parameters and homogeneous target. The results of this study help the doctors in the study for results of hyperthermia treatment before using it on the vivo by known the properties of the laser used and the properties of the breast tumor trying to reduce the damage of the treatment.

Thermal-Electric Finite Element Analysis and Experimental Validation of Bipolar Electrosurgical Cautery

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Robert E. Dodde ◽  
Scott F. Miller ◽  
James D. Geiger ◽  
Albert J. Shih
Keyword(s):  
Heat Transfer ◽  
Electrical Conductivity ◽  
Finite Element ◽  
Temperature Distribution ◽  
Tissue Temperature ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Temperature Dependent Thermal Conductivity ◽  
Insight Into ◽  
Good Agreement

Cautery is a process to coagulate tissues and seal blood vessels using heat. In this study, finite element modeling (FEM) was performed to analyze temperature distribution in biological tissue subject to a bipolar electrosurgical technique. FEM can provide detailed insight into the tissue heat transfer to reduce the collateral thermal damage and improve the safety of cautery surgical procedures. A coupled thermal-electric FEM module was applied with temperature-dependent electrical and thermal properties for the tissue. Tissue temperature was measured using microthermistors at different locations during the electrosurgical experiments and compared to FEM results with good agreement. The temperature- and compression-dependent electrical conductivity has a significant effect on temperature profiles. In comparison, the temperature-dependent thermal conductivity does not impact heat transfer as much as the temperature-dependent electrical conductivity. Detailed results of temperature distribution were obtained from the model. The FEM results show that the temperature distribution can be changed with different electrode geometries. A flat electrode was modeled that focuses the current density at the midline of the instrument profile resulting in higher peak temperature than that of the grooved electrode (105 versus 96°C).

scholarly journals Numerical Analysis of Human Cancer Therapy Using Microwave Ablation

2019 ◽  
Vol 10 (1) ◽  
pp. 211 ◽  
Author(s):  
Marwa Selmi ◽  
Abdul Aziz Bin Dukhyil ◽  
Hafedh Belmabrouk
Keyword(s):  
Temperature Distribution ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Microwave Power ◽  
Microwave Ablation ◽  
Human Cancer ◽  
Surrounding Tissue ◽  
Hyperthermia Treatment ◽  
Distribution Profile ◽  
Wave Effects

Microwave ablation is one type of hyperthermia treatment of cancer that involves heating tumor cells. This technique uses electromagnetic wave effects to kill cancer cells. A micro-coaxial antenna is introduced into the biological tissue. The radiation emitted by the antenna is absorbed by the tissue and leads to the heating of cancer cells. The diffuse increase in temperature should reach a certain value to achieve the treatment of cancer cells but it should be less than a certain other value to avoid damaging normal cells. This is why hyperthermia treatment should be carefully monitored. A numerical simulation is useful and may provide valuable information. The bio-heat equation and Maxwell’s equations are solved using the finite element method. Electro-thermal effects, temperature distribution profile, specific absorption rate (SAR), and fraction of necrotic tissue within cancer cells are analyzed. The results show that SAR and temperature distribution are strongly affected by input microwave power. High microwave power causes a high SAR value and raises the temperature above 50 °C, which may destroy healthy cells. It is revealed that with a power of 10 W, the tumor cells will be killed without damaging the surrounding tissue.

Efficiency function: improvement of classical bioheat approach

1994 ◽  
Vol 77 (4) ◽  
pp. 1617-1622 ◽  
Author(s):  
H. Brinck ◽  
J. Werner
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
The Body ◽  
Tissue Temperature ◽  
Whole Body ◽  
Function Concept ◽  
Perfusion Rate ◽  
Efficiency Function ◽  
Vascular Model ◽  
The Difference

In view of the complex vascular architecture and the intricate physical heat transfer processes in the human body, convective heat transfer via the blood is generally described by simple substitutional processes (“non-vascular models”). The classical “bioheat” approach of Pennes (J. Appl. Physiol. 1: 93–122, 1948), defining the heat flow to or from the tissue as being proportional to the product of perfusion rate and the difference of arterial and tissue temperature, has been seriously questioned after having been used for > 40 yr in many applications. In our laboratory, we have at our disposal a complex three-dimensional vascular model for the special case of tissue in a human extremity. This was used to test the performance of simple nonvascular models. It turned out that the Pennes approach may deliver acceptable results if the body is in the thermoneutral zone or if heat stress acts uniformly on the whole body. However, when cold stress or local hyperthermia is present, unreliable results must be expected. As the vascular model is not generally practicable because of its extreme complexity, we offer the efficiency function concept as a simple way of correcting the classical bioheat approach by factor multiplication. Efficiency function is determined as a function of perfusion rate and tissue depth in a way that compensates for the deficiencies of the Pennes bioheat term. The results are reasonable compared with those of the vascular model and experimental results.

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