Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 54 11 2023 01 21 Numerical Study of Microbubble Dynamics Subjected to Ultrasound and Its Effect on Thermal Ablation of Biological Tissue Numerical Study of Microbubble Dynamics Subjected to Ultrasound and Its Effect on Thermal Ablation of Biological Tissue 2561 2582 5044 10.22060/mej.2023.21626.7480 FA Ghassem Heidarinejad Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran Afsaneh Mojra Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran 0000-0001-8790-7016 Hossein Azizi Sormoli Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran Journal Article 2022 07 25 High-intensity focused ultrasound is a non-invasive method and provides many therapeutic applications for physicians. One of the ways to increase the efficiency of High-intensity focused ultrasound is using a Levovist contrast agent, which consists of microbubbles. In the present study, we calculate the pressure field due to the High-intensity focused ultrasound using the Helmholtz equation for linear ultrasonic wave propagation. Using the Keller-Miksis equation, we calculate the thermal effects caused by microbubble injection after determining the acoustic pressure. The Pennes bioheat transfer equation is used for studying the tissue temperature distribution. The simulation results show that in the presence of a microbubble under the influence of a High-intensity focused ultrasound pressure field, increasing the applied frequency and power increases the value of heat sources caused by the microbubble oscillation. An increase in the temperature of biological tissue can be observed after the injection of microbubbles. Within the pressure range of 2.54 MPa, the tissue temperature at the focal point, for the case where the microbubble with the initial radius of 50 μm is injected, increases by 8.28 ℃. Meanwhile, if a microbubble with an initial radius of 50 micrometers is injected, there is a further increase in the tissue temperature by 57.72%. In the absence of microbubbles, the corresponding temperature rise is only 5.42 ℃ for the same operating conditions. Finally, the Arrhenius model shows that the microbubbles with different initial radii increase the ablated tissue volume by about 38%. High-intensity focused ultrasound is a non-invasive method and provides many therapeutic applications for physicians. One of the ways to increase the efficiency of High-intensity focused ultrasound is using a Levovist contrast agent, which consists of microbubbles. In the present study, we calculate the pressure field due to the High-intensity focused ultrasound using the Helmholtz equation for linear ultrasonic wave propagation. Using the Keller-Miksis equation, we calculate the thermal effects caused by microbubble injection after determining the acoustic pressure. The Pennes bioheat transfer equation is used for studying the tissue temperature distribution. The simulation results show that in the presence of a microbubble under the influence of a High-intensity focused ultrasound pressure field, increasing the applied frequency and power increases the value of heat sources caused by the microbubble oscillation. An increase in the temperature of biological tissue can be observed after the injection of microbubbles. Within the pressure range of 2.54 MPa, the tissue temperature at the focal point, for the case where the microbubble with the initial radius of 50 μm is injected, increases by 8.28 ℃. Meanwhile, if a microbubble with an initial radius of 50 micrometers is injected, there is a further increase in the tissue temperature by 57.72%. In the absence of microbubbles, the corresponding temperature rise is only 5.42 ℃ for the same operating conditions. Finally, the Arrhenius model shows that the microbubbles with different initial radii increase the ablated tissue volume by about 38%. https://mej.aut.ac.ir/article_5044_996740de914ced0902e686373e319391.pdf