scholarly journals Thermal Detection of Embedded Tumors Using Infrared Imaging

2006 ◽  
Vol 129 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Manu Mital ◽  
E. P. Scott
Keyword(s):  
Genetic Algorithm ◽  
Temperature Distribution ◽  
Heat Source ◽  
Heat Generation ◽  
Infrared Imaging ◽  
Estimation Method ◽  
Generation Rate ◽  
Tissue Temperature ◽  
Heat Generation Rate ◽  
Bioheat Equation

Breast cancer is the most common cancer among women. Thermography, also known as thermal or infrared imaging, is a procedure to determine if an abnormality is present in the breast tissue temperature distribution. This abnormality in temperature distribution might indicate the presence of an embedded tumor. Although thermography is currently used to indicate the presence of an abnormality, there are no standard procedures to interpret these and determine the location of an embedded tumor. This research is a first step towards this direction. It explores the relationship between the characteristics (location and power) of an embedded heat source and the resulting temperature distribution on the surface. Experiments were conducted using a resistance heater that was embedded in agar in order to simulate the heat produced by a tumor in the biological tissue. The resulting temperature distribution on the surface was imaged using an infrared camera. In order to estimate the location and heat generation rate of the source from these temperature distributions, a genetic algorithm was used as the estimation method. The genetic algorithm utilizes a finite difference scheme for the direct solution of the Pennes bioheat equation. It was determined that a genetic algorithm based approach is well suited for the estimation problem since both the depth and the heat generation rate of the heat source were accurately predicted.

scholarly journals Thermal Detection of Embedded Tumors Using Infrared Imaging

2004 ◽  
Author(s):  
Manu Mital ◽  
E. P. Scott
Keyword(s):  
Breast Cancer ◽  
United States ◽  
Genetic Algorithm ◽  
Temperature Distribution ◽  
Infrared Imaging ◽  
Estimation Method ◽  
The United States ◽  
Tissue Temperature ◽  
Bioheat Equation ◽  
Temperature Distributions

Breast cancer is the most common cancer among women. Statistics released by American Cancer Society (1999) show that every 1 in every 8 women in the United States is likely to get breast cancer during her lifetime. Thermography, also known as thermal or infrared imaging, is a procedure to determine if an abnormality is present in the breast tissue temperature distribution, which may indicate the presence of an embedded tumor. In the year 1982, United States Food and Drug Administration (FDA) approved thermography as an adjunct method of detecting breast cancer, which could be combined with other established techniques like mammography. Although thermography is currently used to indicate the presence of an abnormality, there are no standard protocols to interpret the abnormal thermal images and determine the size and location of an embedded tumor. This research explores the relationship between the physical characteristics of an embedded tumor and the resulting temperature distributions on the skin surface. Experiments were conducted using a resistance heater that was embedded in agar in order to simulate the heat produced by a tumor in the biological tissue. The resulting temperature distribution on the surface was imaged using an infrared camera. In order to estimate the location and heat generation rate of the source from these temperature distributions, a genetic algorithm was used as the estimation method. The genetic algorithm utilizes a finite difference scheme for the direct solution of Pennes bioheat equation. It was determined that a genetic algorithm based approach is well suited for the estimation problem and that thermography can prove to be a valuable tool in locating tumors if combined with such an algorithm.

A Comparative Analysis of the Tumor Pathology and the Metabolic Heat Generation of Growing Malignant Tumors

2020 ◽  
Author(s):  
Alyssa Owens ◽  
Manasi Godbole ◽  
Donnette Dabydeen ◽  
Lori Medeiros ◽  
Pradyumna Phatak ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Heat Generation ◽  
Infrared Imaging ◽  
Malignant Tumors ◽  
Blood Perfusion ◽  
The United States ◽  
Generation Rate ◽  
Heat Generation Rate ◽  
Clinical Patient ◽  
Tumor Pathology

Abstract Cancer is one of the most debilitating diseases in the world, affecting over 9.6 million people worldwide every year. Breast cancer remains the second largest cause of death in women. Despite major advances in treatment, over 40,920 women died of breast cancer in 2018 in the United States alone. Early detection of abnormal masses can be crucial for diagnosis and dramatically increase survival. Current screening techniques have varying accuracy and perform poorly when used on heterogeneously and extremely dense breast tissue. Infrared imaging has the potential to detect growing tumors within the breast based on thermal signatures on the breast surface by imaging temperature gradients induced by blood perfusion and tumor metabolic activity. Using clinical patient images, previous methods to estimate tumor properties involve an iterative algorithm to estimate the tumor position and diameter. The details from the MRI are used in estimating the volumetric heat generation rate. This is compared with the published values and the reasons for differences are investigated. The tumor pathology is used in estimating the expected growth rate and compared with the predicted values. The correlation between the tumor characteristics and heat generation rate is fundamental information that is needed in accurately predicting the tumor size and location.

A Multi-Dimensional Coupled Electro-Thermal Model of a LFP Battery

2012 ◽  
Vol 569 ◽  
pp. 386-390
Author(s):  
Hong Zhang Cen ◽  
Xue Zhe Wei ◽  
Hai Feng Dai ◽  
Li Song
Keyword(s):  
Temperature Distribution ◽  
Heat Generation ◽  
Thermal Model ◽  
Porous Electrode ◽  
Generation Rate ◽  
Heat Generation Rate ◽  
Battery Model ◽  
Model Based ◽  
D Model

In this article a multi-dimensional coupled electro-thermal model of a LFP battery is proposed. The model includes a 1-d model based on porous-electrode theory and a 3-d battery model solving the temperature distribution of the battery. These models are coupled through heat generation rate during discharging process. Moreover, an experiment is designed to check the inside temperature information of the battery.

scholarly journals A Simplified Calculation Method of Heat Source Model for Induction Heating

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2938 ◽  
Author(s):  
Hongbao Dong ◽  
Yao Zhao ◽  
Hua Yuan ◽  
Xiaocai Hu ◽  
Zhen Yang
Keyword(s):  
Heat Flux ◽  
Temperature Field ◽  
Heat Source ◽  
Heat Generation ◽  
Induction Heating ◽  
Generation Rate ◽  
Heat Generation Rate ◽  
Line Heating ◽  
Computation Efficiency ◽  
Computation Process

Line heating is used in forming the complex curve plates of ships, and this process is becoming integrated into automated tools. Induction heating equipment has become commonly used in automatic line heating. When applying automated equipment, it is necessary to calculate the relationship between the heating parameters and the temperature field. Numerical methods are primarily used to accomplish the calculations for induction heating. This computation process requires repeated iterations to obtain a stable heat generation rate. Once the heat generation rate changes significantly, a recalculation takes place. Due to the relative position of the coil and plate changes during heating, the grid needs to be frequently re-divided during computation, which dramatically increases the total computation time. In this paper, through an analysis of the computation process for induction heating, the root node that restricts the computation efficiency in the conventional electromagnetic-thermal computation process was found. A method that uses a Gaussian function to represent the heat flux was proposed to replace the electromagnetic computation. The heat flux is the input for calculating the temperature field, thus avoiding the calculation of the electromagnetic analysis during induction heating. Besides, an equivalence relationship for multi-coil was proposed in this paper. By comparing the results of the experiment and the numerical method, the proposed heat source model’s effectiveness was verified.

scholarly journals A Profile of the Heat Generation Inside a Cigarette During Puffing

2005 ◽  
Vol 21 (5) ◽  
pp. 294-302
Author(s):  
A Nagao ◽  
Y Yamada ◽  
K Miura ◽  
M Horio
Keyword(s):  
Temperature Distribution ◽  
Heat Generation ◽  
Solid Phase ◽  
Initial Period ◽  
Generation Rate ◽  
Transient Temperature ◽  
Heat Generation Rate ◽  
Maximum Heat ◽  
Phase Temperature ◽  
Cigarette Paper

AbstractThe transient temperature distribution inside a burning cigarette during a 2-second constant-draw single puff was measured to determine the heat generation rate at various positions. The calculation of the heat generation was applied only to a vertically positioned cigarette. The solid-phase temperature was measured by an infrared thermometer with an optical fiber probe, and the gas-phase temperature was measured by a thermocouple. Heat generation rates at various positions inside the burning cigarette were obtained from the temperature distribution profile based on the heat balance equations. Heat generation was found to be concentrated within a region 2 to 3 mm behind the paper char line. The maximum heat generation rate was observed during the initial period of puffing and the heat generation rate decreased significantly in the interval during the middle unsteady period. Steady heat generation was observed in the latter period. The puffing volume as well as the properties of cigarette paper affected the heat generation rate during the unsteady period. The amount of the heat generated during the unsteady period was more than half of the total regardless of the cigarette paper basis weight and the puffing volume.

Theoretical Simulation of Temperature Elevations in a Joint Wear Simulator During Rotations

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Alireza Chamani ◽  
Hitesh P. Mehta ◽  
Martin K. McDermott ◽  
Manel Djeffal ◽  
Gaurav Nayyar ◽  
...  
Keyword(s):  
Finite Element ◽  
Heat Source ◽  
Heat Generation ◽  
Rotation Frequency ◽  
Generation Rate ◽  
Frictional Heat ◽  
Direct Result ◽  
Temperature Elevation ◽  
Heat Generation Rate ◽  
Baseline Model

The objective of this study is to develop a theoretical model to simulate temperature fields in a joint simulator for various bearing conditions using finite element analyses. The frictional heat generation rate at the interface between a moving pin and a stationary base is modeled as a boundary heat source. Both the heat source and the pin are rotating on the base. We are able to conduct a theoretical study to show the feasibility of using the COMSOL software package to simulate heat transfer in a domain with moving components and a moving boundary source term. The finite element model for temperature changes agrees in general trends with experimental data. Heat conduction occurs primarily in the highly conductive base component, and high temperature elevation is confined to the vicinity of the interface in the pin. Thirty rotations of a polyethylene pin on a cobalt-chrome base for 60 s generate more than 2.26 °C in the temperature elevation from its initial temperature of 25 °C at the interface in a baseline model with a rotation frequency of 0.5 Hz. A higher heat generation rate is the direct result of a faster rotation frequency associated with intensity of exercise, and it results in doubling the temperature elevations when the frequency is increased by100%. Temperature elevations of more than 7.5 °C occur at the interface when the friction force is tripled from that in the baseline model. The theoretical modeling approach developed in this study can be used in the future to test different materials, different material compositions, and different heat generation rates at the interface under various body and environmental conditions.

A novel heat generation acquisition method of cylindrical battery based on core and surface temperature measurements

2021 ◽  
pp. 1-17
Author(s):  
Xiaoli Yu ◽  
Qichao Wu ◽  
Rui Huang ◽  
Xiaoping Chen
Keyword(s):  
Surface Temperature ◽  
Heat Generation ◽  
Discharge Rate ◽  
Total Heat ◽  
Temperature Measurements ◽  
Generation Rate ◽  
Air Cooling ◽  
Heat Generation Rate ◽  
Environmental Chamber ◽  
Average Heat

Abstract Heat generation measurements of the lithium-ion battery are crucial for the design of the battery thermal management system. Most previous work uses the accelerating rate calorimeter (ARC) to test heat generation of batteries. However, utilizing ARC can only obtain heat generation of the battery operating under the adiabatic condition, deviating from common operation scenarios with heat dissipation. Besides, using ARC is difficult to measure heat generation of the high-rate operating battery because the battery temperature easily exceeds the maximum safety limit. To address these problems, we propose a novel method to obtain heat generation of cylindrical battery based on core and surface temperature measurements and select the 21700 cylindrical battery as the research object. Based on the method, total heat generation at 1C discharge rate under the natural convection air cooling condition in the environmental chamber is about 3.2 kJ, and the average heat generation rate is about 0.9 W. While these two results measured by ARC are about 2.2 kJ and 0.6 W. This gap also reflects that different battery temperature histories have significant impacts on heat generation. In addition, using our approach, total heat generation at 2C discharge rate measured in the environmental chamber is about 5.0 kJ, with the average heat generation rate being about 2.8 W. Heat generation results obtained by our method are approximate to the actual battery operation and have advantages in future applications.

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