【摘要】 目的 在传统的消融手术中，医生通过观察患者的二维影像对肿瘤大小、位置、形态进行粗略估算从而进行手术方案规划。这种方式严重依赖医生的主观经验和专业技能，极易造成消融范围过大或不彻底，增加了术后并发症的风险。因此，科学的术前规划和精准的消融电极及电场作用区域定位具有非常重要的意义。本文提出一种胰腺肿瘤最优空间覆盖模型算法，以为胰腺肿瘤不可逆电穿孔消融提供最佳电场作用区域。方法 基于单根双极高压脉冲电极产生的电场消融区域为椭球体，在椭球长轴方向与电极导入路径即胰管方向相同、球心在胰管上及长短轴轴长满足一定比例关系的约束条件下，首先利用积极集算法求解球心，再借助Rodrigues旋转求解正定矩阵，得到的椭球即为电场作用区域，然后对长短轴轴长比值进行迭代寻优，最后将肿瘤在椭球中的占比作为评价指标以寻找最小消融椭球即最优电场作用区域。本文在公开数据集MSD上进行广泛实验寻找每个病例肿瘤的最小消融椭球及其占比。结果 最小消融椭球与肿瘤的几何形状及其距胰管的位置密切相关，对于大多数病例，肿瘤在最小消融椭球中的占比在20%～50%之间，最高能达到59.5%。结论 本文提出的算法可为胰腺肿瘤不可逆电穿孔消融的最优电场消融区域提供可行的理论依据，辅助临床医生高效决策。更多还原

【Abstract】 Objective In traditional ablation surgery, doctors roughly estimate the size, location, and shape of the tumor by observing the patient’s two-dimensional images, in order to plan the surgical plan. This method heavily relies on the subjective experience and professional skills of doctors, which can easily lead to excessive or incomplete ablation, increasing the risk of postoperative complications. Therefore, scientific preoperative planning and precise localization of ablation electrodes and electric field action areas are of great significance. This article proposes an optimal space coverage model algorithm for pancreatic tumors, which provides the optimal electric field action area for irreversible electroporation ablation of pancreatic tumors. Methods Based on the fact that the electric field ablation area generated by a single bipolar high-voltage pulse electrode is an ellipsoid, under the constraint that the direction of the long axis of the ellipsoid is the same as the direction of the electrode introduction path, the center of the ellipsoid is on the pancreatic duct and the length of the long and short axis meets a certain proportion, the Active-Set algorithm is used to solve the center of the ellipsoid, and then Rodrigues rotation is used to solve the positive definite matrix. The ellipsoid obtained is the electric field action area. After that, the ratio of long axis to short axis is iteratively optimized. Finally, the proportion of tumor in the ellipsoid is used as an evaluation index to find the minimum ablation ellipsoid, that is, the optimal electric field action area. Extensive experiments are carried out on MSD dataset to find the smallest ablation ellipsoid and proportion of tumors of each case. Results The minimal ablation ellipsoid is closely related to the geometric shape of the tumor and its location from the pancreatic duct. For most cases, the proportion of tumors in the minimal ablation ellipsoid is between 20% and 50%,and the maximum is 59.5%. Conclusions The algorithm proposed in this paper can provide a feasible theoretical basis for the optimal electric field ablation area of irreversible electroporation ablation of pancreatic tumors, and assist clinicians in making efficient decisions.更多还原