Elucidating viscoelastic effects on focused ultrasound thermal therapy with acoustic-solid-thermal coupling analysis  

通过声固热耦合分析揭示黏弹性对聚焦超声热疗的影响

作　　者：Zhibo Du Haolong Chen Weican Li Zhuo Zhuang Zhanli Liu 杜智博;陈豪龙;李维灿;庄茁;柳占立

机构地区：[1]School of Aerospace Engineering,Tsinghua University,Beijing 100084,China [2]School of Civil Engineering,Hefei University of Technology,Hefei 230009,China

出　　处：《Acta Mechanica Sinica》2025年第2期41-51,共11页力学学报(英文版)

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.11972205,11921002,11972210,and 12302096);the National Key Research Development Program of China(Grant No.2020-JCJQ-ZD-254).

摘　　要：Focused ultrasound(FUS)therapy generates sufficient heat for medical interventions like tumor ablation by concentrating energy at the focal point.The complex viscoelastic properties of biological tissues pose challenges in balancing focusing precision and penetration depth,impacting the safety of surrounding tissues and treatment efficacy.This study develops an acoustic-solid-thermal coupling computational model to elucidate the dynamic mechanical response and energy dissipation mechanisms of soft tissue during FUS thermal therapy using a hyper-viscoelastic constitutive model.Results indicate that the high compressibility and low shear resistance of biological tissues result in a unique shear dissipation mechanism.Energy dissipation efficiency per area is indirectly influenced by load frequency via its effect on the dynamic shear modulus and is directly proportional to load amplitude.Focusing precision,represented by the focal zone width,is inversely controlled by frequency via wavelength.A mathematical model for evaluating temperature rise efficiency is proposed,and an optimal frequency for efficient FUS thermal therapy in brain-like soft materials is identified.This research elucidates the link between viscoelastic tissue behavior and FUS treatment outcomes,offering insights for optimizing FUS applications in various medical fields.聚焦超声(Focused ultrasound,FUS)治疗通过将能量集中在焦点,为肿瘤消融等医疗干预产生足够的热量.生物组织复杂的黏弹性特性对平衡聚焦精度和穿透深度提出了挑战,影响了周围组织的安全性和治疗效果.本研究开发了一个声固热耦合计算模型,使用黏超弹性本构模型来阐明FUS热疗过程中软组织的动态力学响应和能量耗散机制.结果表明,生物组织的抗压不抗剪特性形成了独特的剪切耗散机制.单位面积的能量耗散率通过动态剪切模量间接受到载荷频率的影响,并与载荷振幅成正比.聚焦精度由聚焦区宽度表示,通过波长由频率反向控制.提出了一个评估温升效率的数学模型,并确定了类脑软材料中有效FUS热疗的最佳频率.这项研究阐明了黏弹性组织行为与FUS治疗结果之间的联系,为优化FUS在各个医学领域的应用提供了见解.

关 键 词：Focused ultrasound(FUS) Thermal therapy Acoustic-solid-thermal coupling Hyper-viscoelastic constitutive model Mechanical parameters 

分 类 号：R318.01[医药卫生—生物医学工程]