Numerical Analysis Of Cavitation Bubbles Kinematics In Tumor Ultrasound Therapy

As a new ultrasonic therapy of minimally invasive malignant tumor,mainly through to the tumor blood vessels around the injection foam agent,using ultrasonic wave to make the cavitation bubbles in the blood causes the tumor vascular thrombosis,so as to cut off sources of nutrition,so that tumor would due to a lack of nutrition be died.So as to better improve the effect of tumor therapy,the ultrasonic parameters and foam agent and the mixture of blood parameters on the effect of ultrasonic cavitation bubbles in the liquid,has the very vital significance.According to the tumor ultrasound treatment,considering at the therapy environment about ultrasonic frequency,surface tension and viscous force affect on the bubbles,establishe the ultrasonic cavitation bubble model.Ultrasound role of bubbles by any time and make the bubbles inflated bubble walls were analyzed,and the force is deduced a single bubble in single frequency ultrasonic fields of cavitation bubble in liquid cavitation equation of motion.By analyzing the initial radius of bubble effect on the ultrasonic frequency and sound pressure threshold,select the ultrasonic frequency and sound pressure range.For cavitation bubbles movement equation can be solved by using the fourth-order runge-kutta method and numerical analysis,Tumor treatment of ultrasonic vibration system is discussed,ultrasonic frequency and ultrasonic amplitude microbubble agent mixed with blood the initial radius of the bubbles in the liquid,the surface tension coefficient,bubble polytropic exponent and the viscous coefficient of liquid and so on various treatment parameters on the influence of cavitation bubbles.The results show that under the single frequency ultrasound field,the effect of surface tension coefficient on ultrasonic cavitation is the largest,and the rest is the initial radius of bubble,ultrasonic amplitude,viscosity coefficient,ultrasonic frequency and polytropic exponent of bubbles.On the basis of single frequency at the same time established the multifrequency ultrasonic cavitation bubbles equation of motion,discuss the bubble cavitation influence of ultrasonic amplitude,phase difference and the initial radius of cavitation bubble with same frequency different frequency multifrequency frequency frequency,and discuss the bubble cavitation influence of ultrasonic frequency and the initial radius of cavitation bubble with the different frequency multifrequency frequency,Results show that in same frequency multifrequency frequency the condition of complex frequency,vibration amplitude of the ultrasonic cavitation bubbles more intense,cavitation bubbles generated pressure decreases with the increase of initial radius of bubble,the phase Angle difference between close to 0,the bubble cavitation of the smaller the pressure;Under the condition of different frequency multifrequency frequency,ultrasonic frequency make the pressure produced by the cavitation bubble more intense,Pressure by bubble cavitation bubble decreases with the increasing of the initial radius.This paper according to the study of single frequency and multifrequency frequency ultrasonic tumor therapy parameters on bubble cavitation effect,for ultrasonic tumor therapy system and micro bubble agent development and therapy parameters provide theoretical basis,in order to achieve better therapeutic purposes.