Microbubble synergistic dynamic experiment system based on double frequency superimposed ultrasonic pulse in viscoelastic medium and microbubble synergistic dynamic experiment method based on double frequency superimposed ultrasonic pulse in viscoelastic medium

Abstract

The invention discloses a microbubble synergistic dynamic experiment system based on a double frequency superimposed ultrasonic pulse in a viscoelastic medium and a microbubble synergistic dynamic experiment method based on the double frequency superimposed ultrasonic pulse in the viscoelastic medium. The experiment method comprises the following steps 1) according to an actual waveform of a focal region sound field measured by a hydrophone, setting KZK equation parameters and establishing a microbubble nonlinear excitation waveform; 2) constructing a HIFU synergistic model according to viscoelasticity of a biological tissue and vibration characteristics of the microbubble in compressible fluid; 3) establishing a microbubble synergistic dynamic method based on double frequency superimposition; 4) in combination with simulation results of steps above, determining a HIFU waveform phase, sound pressure and frequency parameters to perform a thermal ablation or tissue damage experiment. According to the system and the method provided by the invention, the dynamic characteristics of the microbubble in the biological tissue are used fully to design the sound wave waveform and the phase parameter, maximum vibration of the microbubble is triggered at a focal region, a cavitation effect is enhanced, and safety and efficiency of HIFU thermal ablation and tissue damage are improved.

Description

technical field [0001] The invention belongs to the field of ultrasonic technology, and in particular relates to a microbubble synergistic dynamics experiment system and method in a viscoelastic medium. Background technique [0002] High Intensity Focused Ultrasound (HIFU) has become a hot spot in the field of therapeutic ultrasound due to its non-invasive and strong focusing characteristics. At present, there are two mechanisms of action of high-intensity focused ultrasound: thermal ablation mechanism and tissue damage mechanism. The traditional HIFU thermal ablation mode mainly uses the thermal effect of ultrasound. The high-intensity ultrasound energy focused from the outside to the target area ablates the tissue locally, causing coagulation necrosis of the target tissue due to the instantaneous high temperature; the tissue damage (Histotripsy) mode mainly uses The cavitation mechanical effect of HIFU shatters the target tissue into micron-sized fragments. [0003] The ...

AI Technical Summary

Problems solved by technology

[0005] The existing methods of thermal ablation and tissue damage still have the following defects: Biological tissue is a kind of compressible fluid with viscoelasticity, and there are theoretical deficiencies in the development of HIFU process guided by the microbubble model in RPNNP incompressible fluid. There is no viscoelastic model in compressible fluid for simulation to guide the HIFU process, and the previous excitation waveform did not consider the nonlinear effect, resulting in inaccurate setting of thermal ablation and tissue damage parameters, and the cavitation activity in the focal area in single-frequency mode is not intense enough , so that the cavitation threshold is too high, the required peak sound pressure is too high, and the volume of the single focus is only a few mm 3

Images