IEEE Trans Biomed Eng. 2020 Oct;67(10):2862-2869. doi: 10.1109/TBME.2020.2972465. Epub 2020 Feb 7.
Electrosurgical vessel sealing is a process commonly used to control bleeding during surgical procedures. Finite element (FE) modeling is often performed to obtain a better understanding of thermal spread during this process. The accuracy of the FE model depends on the implemented material properties. Thermal conductivity is one of the most important properties that affect temperature distribution. The goal of this study is to determine the tissue thermal conductivity as a function of thermal dose. Methods: We developed an iterative approach to correlating tissue thermal conductivity to more accurately calculated thermal dose, which cannot be experimentally measured. The resulting regression model was then implemented into an electrosurgical vessel sealing FE model to examine the accuracy of this FE model. Results: The results show that with the regression model, more reasonable temperature and thermal dose prediction can be achieved at the center of the sealed vessel tissue. The resulting electrical current and impedance from the FE model match with the experimental results. Conclusion: The developed approach can be used to determine the correlation between thermal dose and thermal conductivity. Describing the thermal conductivity as a function of thermal dose allows modeling of irreversible changes in tissue properties. Significance: By having a more accurate temperature estimation at the center of the sealed vessel, more insight is provided into how the tissue reacts during the vessel sealing process.
电外科血管密封是一种在手术过程中控制出血的常用方法。有限元（FE）建模通常用于更好地理解该过程中的热扩散。FE 模型的准确性取决于所实施的材料特性。导热系数是影响温度分布的最重要特性之一。本研究的目的是确定组织导热系数作为热剂量的函数。
我们开发了一种迭代方法，将组织导热系数与更准确计算的热剂量相关联，而热剂量无法通过实验测量。然后将得到的回归模型实施到电外科血管密封的 FE 模型中，以检查该 FE 模型的准确性。
结果表明，通过回归模型，可以在密封血管组织的中心实现更合理的温度和热剂量预测。FE 模型产生的电流和阻抗与实验结果匹配。
所开发的方法可用于确定热剂量与导热系数之间的相关性。将导热系数描述为热剂量的函数可以对组织性质的不可逆变化进行建模。
通过更准确地估计密封血管中心的温度，可以更深入地了解组织在血管密封过程中的反应。
