3638 集束超音波医療における温度上昇の数値解析(G05-4 流体機械・医療機器,G05 流体工学)  [in Japanese] 3638 Simulation of Temperature Rise during High Intensity Focused Ultrasound Therapy  [in Japanese]

Focused ultrasound treatment is widely applied in the clinical treatment, for example the tumor ablation with High Intensity Focused Ultrasound (HIFU). HIFU shows considerable nonlinearity due to its high pressure amplitude, and it is attenuated, reflected and refracted in the medium. Previously, researchers have simulated the ultrasound field using linear and nonlinear approximation equations. However, the predictions using these equations have restrictions such that the higher order nonlinearity or the reflection and refraction cannot be reproduced. So we apply axsymmetric Navier-Stokes equation to the governing equation to solve the ultrasound propagation without such restrictions. We calculated the profile of temperature rise in a liver with the model of an array transducer and an absorption effect. It is concluded that the temperature rise is focused at focal point by modeling array transducer and the ratio of the parameters inside the absorption coefficient affects the temperature rise and distribution.