ABSTRACT
Breast thermography is a non-invasive tool for early detection of breast cancer. It was subject for many years to some controversial issues regarding its efficiency. Advances in infrared camera technology and progress in image processing systems had brought thermal breast imaging back as a valid tool for mammography. Numerical modelling of heat transfer within a woman breast is being an attractive tool that may reveal the conditions under which tumours can be detected in a thermogram. The aim of this work is to use the transmission line matrix (TLM) to model a regular three-dimensional breast with embedded tumour and analyse sensitivity parameters.
Subject(s)
Breast Neoplasms/pathology , Breast/anatomy & histology , Breast/pathology , Imaging, Three-Dimensional/methods , Models, Biological , Thermography/methods , Algorithms , Computational Biology , Female , Hemorheology , Humans , Perfusion Imaging , TemperatureABSTRACT
A numerical model based on the transmission line matrix method is presented for the quantitative prediction of skin burn resulting from exposure of a specific region of human skin surface to a high temperature heat source. Transient temperatures were numerically estimated by Pennes' bioheat equation, and the damage function denoting the extent of burn was calculated using the Arrhenius assumptions for protein damage rate. A two-dimensional transmission line matrix model was used to predict the effects of exposure time and structure thicknesses on the transient temperature distribution and damage extent. Compared with other numerical sources the transmission line matrix results revealed good agreement, suggesting that this method may be an effective tool for the thermal diagnostic of burns.
Subject(s)
Burns/physiopathology , Models, Biological , Skin Temperature , Skin/injuries , Body Temperature Regulation , Burns/pathology , Humans , Skin/pathology , Skin/physiopathology , Thermal Conductivity , ThermodynamicsABSTRACT
Microwave heating technology is becoming a successful technique used for sintering ceramic materials. However, various aspects of sintering experiments, such as the use of process stimulus and the preparation of sample arrangements, depend mainly on human expertise. The Transmission Line Matrix (TLM) method is first used to solve the combined electromagnetic and thermal equations modeling microwave heating of dielectric materials. It is then used to simulate microwave sintering of a low-loss ceramic material in a multimode microwave cavity. To enhance the microwave sintering process, Silicon Carbid (SiC) was first used as a susceptor and in a picket fence arrangement. As multiple samples may be processed in a microwave oven, the TLM was used to model such a process, and the introduction of SiC as a stimulus was also examined. Results show the importance of the stimulus thickness and configuration on the uniformity and density of the electromagnetic field distribution and, therefore, on the power dissipation within the ceramic load.
