肺肿瘤冷冻消融中的温度场和应力场仿真研究OA

Objective To investigate the patterns of temperature and stress variation during cryoablation and their effects on the clinical ablation zone based on different tumor blood supply conditions.Methods First,a lung tumor cryoablation model consisting of a lung tumor,lung tissue and a cryoprobe was constructed using Comsol Multiphysics finite element software.The effective energy part of the probe was set as the cold source,the cryoprobe temperature was set,and the temperature variation during cryoablation was analyzed.Second,the temperature field was coupled with the stress field to explore stress variations at sample points at different distances from the tumor source center.Finally,ablation under different tumor blood supply conditions was evaluated.Results The distance between the edge of the damaged lung tissue region and the ice ball edge exceeded 1 cm,indicating complete tumor ablation.As the distance from the tumor center increased from 1 mm to 10 mm,the temperature difference at the sample points decreased from 220 ℃ to 120 ℃.As the distance from the tumor source center rose from 1 mm to 10 mm,the stress value at the sample points declined from 1.86×10⁷ N/m² to 1.64×10⁷ N/m².Under identical ablation conditions,hypovascular tumors had lower minimum temperatures and greater maximum stress values compared with hypervascular tumors.The maximum displacement change in tissue during the ablation cycle was less than 0.2 mm.Conclusion In the central region near the cryoprobe,a large temperature gradient exists in the phase-change zone of the lung tissue,generating great stress and irreversible damage to the tumor tissue.Meanwhile,hypovascular tumors are prone to greater damage under the same conditions when compared with hypervascular tumors,though no significant thermal contraction occurs during the entire cryoablation process,showing that the deformation induced by cryoablation can be considered negligible in clinical practice.[Chinese Medical Equipment Journal,2026,47(5):29-36]