ABSTRACT Microwave ablation is used to treat lung tumors by releasing microwave magnetic field to produce high temperature of more than 60 ℃ in the tumor tissues, thus causing tissue coagulation, dehydration and necrosis to achieve the purpose of treatment. However, the lack of appropriate power and time parameters for microwave ablation in clinical treatment of lung tumors leads to poor ablation or excessive ablation. In this paper, a two-dimensional simulation model of microwave antenna and ideal lung was established to realize the simulation of microwave ablation process. Meanwhile, microwave ablation experiments were carried out in ex-vivo porcine lung under different power and time. The temperature distribution was obtained by thermocouples and compared with the simulation calculation. Set 60℃ as boundary of the ablation area and the ablation time was 360 s. The length of the ablation area parallel to the antenna direction is longitudinal, and the length perpendicular to the antenna direction is transverse. From the simulation results, with the increase of ablation power (20 W to 60 W), the transverse diameter of ablation area increased from 32.5 mm to 55.6 mm, and the longitudinal diameter increased from 47.8 mm to 69.1 mm. From the results of ex-vivo experiments, with the increase of ablation power (30 W to 50 W), the transverse diameter of ablation area increased from 29.5 mm to 48.9 mm, the longitudinal diameter increased from 41.1 mm to 66.3 mm, and the maximum slot temperature increased from 75.6 ℃ to 106.7 ℃. The results of numerical simulation are slightly larger than those of ex-vivo experiments under the same parameters. When the average diameter of lung tumors is less than 40 mm, 30 W and 40 W ablation power can be selected. The ablation time is limited to 360 s. 50 W ablation power can be used to ablate the lesion quickly in a shorter time to achieve the same purpose. Although there are differences between ex-vivo and in vivo, the validity of the lung model and the influence of ablation parameters in the simulation are verified in this paper. The ablation area under different parameters was obtained, which served as a reference data for clinical practice. A basic study was made to consider the complex lung model and the changes of parameters with temperature in the future.

中文翻译：

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离体猪肺微波消融的实验与数值研究

摘要 微波消融治疗肺肿瘤是通过释放微波磁场，在肿瘤组织中产生60℃以上的高温，使组织凝固、脱水、坏死，从而达到治疗目的。然而，在肺部肿瘤的临床治疗中，微波消融缺乏合适的功率和时间参数，导致消融不良或过度消融。本文建立了微波天线与理想肺的二维仿真模型，实现了微波消融过程的仿真。同时，在不同功率和时间下对离体猪肺进行微波消融实验。通过热电偶获得温度分布并与模拟计算进行比较。以60℃为消融区边界，消融时间为360 s。与天线方向平行的消融区长度为纵向，与天线方向垂直的长度为横向。从仿真结果来看，随着消融功率的增加（20 W~60 W），消融区域的横向直径从32.5 mm增加到55.6 mm，纵向直径从47.8 mm增加到69.1 mm。从离体实验结果看，随着消融功率的增加（30 W～50 W），消融区横向直径从29.5 mm增加到48.9 mm，纵向直径从41.1 mm增加到66.3 mm，最高槽温从75.6℃提高到106.7℃。数值模拟的结果略大于相同参数下离体实验的结果。当肺肿瘤平均直径小于40mm时，可选择30W和40W消融功率。消融时间限制为 360 秒。50W的消融功率可以在更短的时间内快速消融病灶，达到同样的目的。尽管离体和体内存在差异，但本文验证了肺模型的有效性以及模拟中消融参数的影响。获得不同参数下的消融面积，作为临床实践的参考数据。进行了基础研究，以考虑未来复杂的肺模型和参数随温度的变化。可选择 30 W 和 40 W 消融功率。消融时间限制为 360 秒。50W的消融功率可以在更短的时间内快速消融病灶，达到同样的目的。尽管离体和体内存在差异，但本文验证了肺模型的有效性以及模拟中消融参数的影响。获得不同参数下的消融面积，作为临床实践的参考数据。进行了基础研究，以考虑未来复杂的肺模型和参数随温度的变化。可选择 30 W 和 40 W 消融功率。消融时间限制为 360 秒。50W的消融功率可以在更短的时间内快速消融病灶，达到同样的目的。尽管离体和体内存在差异，但本文验证了肺模型的有效性以及模拟中消融参数的影响。获得不同参数下的消融面积，作为临床实践的参考数据。进行了基础研究，以考虑未来复杂的肺模型和参数随温度的变化。本文验证了肺模型的有效性以及仿真中消融参数的影响。获得不同参数下的消融面积，作为临床实践的参考数据。进行了基础研究，以考虑未来复杂的肺模型和参数随温度的变化。本文验证了肺模型的有效性以及仿真中消融参数的影响。获得不同参数下的消融面积，作为临床实践的参考数据。进行了基础研究，以考虑未来复杂的肺模型和参数随温度的变化。