Finite element analysis of the needle type applicator made of shape memory alloy

In this paper, we propose a new heating method in which we use shape memory alloy (SMA) in a needle type applicator for brain tumor hyperthermia. In order to expand the heating area of a needle type applicator and to control the heating pattern for various sizes of tumors, some kinds of SMA needle type applicators were developed. To apply the proposed heating method safely to clinical hyperthermia, it is necessary to make appropriate thermal distribution to the region of the brain tumor. However, it is not easy to predict the three dimensional temperature distribution during the human brain tumor hyperthermia. Therefore, we estimated the temperature distribution inside the agar phantom by the finite element method (FEM). Here, first, the computer simulation results of temperature distributions under the different heating times are discussed. Second, a comparison of the heating properties obtained by using the needle type electrodes made of different shaped SMA is discussed. From these results, it is confirmed that the proposed heating method can expand the heating area and control the heating pattern for the various sizes of brain tumors.