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Low Frequency FDTD Algorithm and its Application to Inductive Hyperthermia

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The paper attempts to show the application of low frequency FDTD algorithm to the investigation of ACD and SAR distribution in female breast phantom and their dependence on frequency. Special attention has been given to the values of ACD and SAR in the skin layer because both of them play an important role in hyperthermia treatment when skin overheating occurs. Streszczenie. W artykule przedstawiono zastosowanie algorytmu niskoczęstotliwościowego FDTD do analizy gęstości prądów wirowych i SAR w modelu gruczołu piersiowego. Szczególną uwagę położono na wartość wspomnianych wielkości w warstwie skóry ze względu na efekt jej przegrzania, jaki ma miejsce podczas leczenia hipertermicznego (Zastosowanie niskoczęstotliwościowego algorytmu FDTD w hipertermii indukcyjnej.). Keywords: please : hyperthermia, FDTD, eddy currents, SAR. Słowa kluczowe: hipertermia, FDTD, gęstość prądów wirowych, SAR. Introduction The power of healing by heat generation has been known for a long time. It is known as an innovative form of cancer therapy among classical methods like chemotherapy, surgery and irradiation. In general, hyperthermia is based on the principle that temperatures higher than 420C may lead to apoptosis. Apart from clinical problems, theoretical and engineering tasks have to be solved. One of them is the proper design of hyperthermia applicators in order get the required temperature distribution inside a cancer [1] or to avoid the skin overheating during treatment in inductive hyperthermia. The main challenge during the development of such devices, is the detailed understanding of the field distribution inside the body, since measurement inside livin[...]

A Numerical Evaluation of Electric Field and SAR Distribution Around a Titanium Implant in the Trunk of a Child

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The paper presents a numerical evaluation of electric field and SAR distribution in the trunk of a 6-year-old boy. The analysis was done for two cases - a boy’s trunk with and without an implant. The electric field and SAR distribution were compared with regard to reference levels recommended by EU. The summary of results indicates that a conductive object in between tissues does not cause notable local enhancement both in the electric field and SAR distribution. Streszczenie. W artykule przedstawiono numeryczną analizę rozkładu pola elektrycznego i współczynnika SAR w tułowiu sześcioletniego chłopca. Analizę wykonano dla dwóch przypadków: model tułowia z implantem i bez niego. Uzyskane rozkłady pola elektrycznego i SARu odniesione zostały do norm rekomendowanych przez UE. Zaprezentowana analiza wykazała, że obecność implantu nie powoduje znaczących zmian w rozkładzie pola elektrycznego i SARu. (Numeryczna analiza rozkładu pola elektrycznego i SAR w tułowiu dziecka z tytanowym implantem). Słowa kluczowe: metalowy implant, pole elektryczne, SAR, normy ochronne. Keywords: metallic implant, electric field, SAR, safety standards. Introduction The environment is constantly exposed to electromagnetic field (EMF). The influence of EMF on living organisms is of various ways and results in different effects. One of its effects is the therapeutic one [1]. However, it should be consciously controlled by indicating, for example, safety zones [2]. It results from the fact that the reaction of organism on EMF depends on many factors, such as the quantity of absorbed energy, time of exposure, and EMF frequency. The frequency dependence divides the EMF effects into two main parts: physiological effects caused by eddy currents (low frequency) and thermal effects caused by dielectric losses (high frequency). The latter ones are demonstrated by SAR coefficient (Specific Absorption Rate). In order to evaluate SAR distribution in a human body a [...]

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