Numerical study of the effect of vascular bed on heat transfer during high intensity focused ultrasound (HIFU) ablation of the liver tumor

Ultrasound-Guided High-Intensity Focused Ultrasound for Devascularization of Uterine Fibroid: A Feasibility Study

“…Therefore, uterine fibroids comorbid with adenomyosis should be diagnosed in pre-treatment patient selection and treated to achieve the NPV setting. Additionally, the sonication can be impacted by vessel diameter and velocity (Mohammadpour and Firoozabadi 2019), and Doppler flow measurements can aid in predicting adenomyosis and UAE failure (McLucas et al 2002). Thus, the parameters of blood flow velocity such as peak systolic velocity, resistive index and pulsatility index could be analyzed in the following study.…”

Numerical study of high‐intensity focused ultrasound (HIFU) in fat reduction

“…To obtain the acoustic pressure, the nonlinear propagation equation (Westervelt) of the ultrasonic waves is used. The following full‐wave Westervelt equation, which is based on the effects of diffraction, absorption, and nonlinear propagation, is used 19–25 : $$$$\begin{equation}{\nabla }^2p - \frac{1}{{{c}^2}}\frac{{{\partial }^2p}}{{\partial {t}^2}} + \frac{\delta }{{{c}^2}}\frac{\partial }{{\partial t}}({\nabla }^2p) = \frac{\beta }{{{\rho }_0{c}^4}}\frac{{{\partial }^2}}{{\partial {t}^2}}\left( {{p}^2} \right)\ \end{equation}$$$$ $$$$\begin{equation}\delta = \frac{1}{{{\rho }_0}}\left( {\frac{4}{3}\mu + {\mu }_B + \frac{{\left( {\gamma - 1} \right)k}}{{{c}_p}}} \right)\end{equation}$$$$where p , c , ρ , and δ are the acoustic pressure, speed of the sound propagation in the medium, density, and the diffusivity of sound (Equation 2), respectively, and β $$( {1 + \frac{B}{{2A}}} )$$ is a nonlinearity coefficient. In Equation (2), μ , μ B , γ , k , and c p are the dynamic viscosity coefficient, the bulk viscosity coefficient, the heat capacity ratio, the thermal conductivity, and the specific heat capacity, respectively.…”

“…To obtain the acoustic pressure, the nonlinear propagation equation (Westervelt) of the ultrasonic waves is used. The following full-wave Westervelt equation, which is based on the effects of diffraction, absorption, and nonlinear propagation, is used [19][20][21][22][23][24][25] :…”

Fluid–Structure Interaction and Non-Fourier Effects in Coupled Electro-Thermo-Mechanical Models for Cardiac Ablation

“…where → u (= u x , u y , u z ) is the velocity vector, ρ b is the density of blood, P is the blood pressure, µ is the dynamic viscosity of blood (= 2.1 × 10 −3 Pa•s), ε is the porosity and K is the permeability of porous cardiac tissue (= 7.7 × 10 −11 m 2 ). Other models for the fluid part of the fluid-structure interaction (FSI) problem can be easily incorporated in the proposed framework, including those based on non-Newtonian flows (e.g., [30][31][32][33][34]).…”