电极和组织参数对动脉粥样硬化斑块射频消融影响的仿真研究

Simulation Study on the Impact of Electrode and Tissue Parameters on Radiofrequency Ablation of Atherosclerotic Plaque

摘要: 本文通过建立的射频消融电–热–力耦合仿真模型，分析了不同电极和组织参数下的温度和热应力分布，并借助Arrhenius模型定量描述了热损伤效果。最后对仿真模型中关键组织参数进行主效应和方差分析，得出对消融温度和消融体积有显著影响的敏感性参数。结果表明：1) 为实现有效消融并避免过热损伤，应增加电极间距并适度提高电压，使得高温不容易集中在纤维层。2) 调整电极位置至纤维层较厚区域可避免热应力过度集中，减小斑块硬化引起的破裂风险。3) 斑块电导率σ₂和血管电导率σ₁以及斑块热导率k₂对消融区域内温度的影响显著，其中σ₂和k₂分别与消融体积呈负相关和正相关，在仿真建模中可将上述参数设置为温度依赖的函数降低仿真误差。这些结论将为未来建立针对个体化差异的，组织参数不确定的仿真平台提供科学依据。

Abstract: This paper analyzes the temperature and thermal stress distribution under different electrodes and tissue parameters by the established simulation model of radiofrequency ablation coupled with electricity-heat-force, and quantitatively describes the thermal damage effect with the help of Arrhenius model. Finally, the main effect and ANOVA analyses of the key tissue parameters in the simulation model were performed to derive the sensitivity parameters that had a significant effect on the ablation temperature and ablation volume. The results showed that 1) To achieve effective ablation and avoid overheating damage, the electrode spacing should be increased and the voltage should be moderately increased so that the high temperature is not easily concentrated in the fiber layer. 2) Adjusting the electrode position to the thicker region of the fiber layer can avoid excessive concentration of thermal stress and reduce the risk of rupture caused by plaque hardening. 3) The plaque conductivity σ₂ and vessel conductivity σ₁, as well as the plaque thermal conductivity k₂, have a significant effect on the temperature in the ablation area, where σ₂ and k₂ are negatively and positively correlated with the ablation volume, respectively, and the above parameters can be set as a temperature-dependent function to reduce the simulation error in the simulation modeling. These conclusions will provide a scientific basis for the future establishment of a simulation platform for individualized differences with uncertain tissue parameters.