中文摘要：

不可逆电穿孔肿瘤消融的有效性与安全性已经过多年的临床应用而得到验证，新近发展起来的高频不可逆电穿孔肿瘤消融新方法兼具传统不可逆电穿孔的优势和缓解肌肉收缩的长处，然而目前对其作用机理还未深入研究。为此，从阻抗谱分析角度分析了高频不可逆电穿孔与传统不可逆电穿孔组织消融的差异性，研究了相同剂量下高频不可逆电穿孔与传统不可逆电穿孔消融新西兰大白兔肝脏组织引起的组织阻抗谱变化，并通过等效电路的拟合提取了阻抗谱变化中的信息。研究结果表明：脉冲处理后组织阻抗谱显著变化，阻抗模在中低频段显著减小，阻抗角在中高频段从负值向零值方向变化；通过等效电路拟合发现，处理后显著变化的是细胞外液等效电阻，由于细胞膜穿孔而增加了新的与细胞外液等效电阻并联的电流通路；脉冲剂量相同条件下，传统不可逆电穿孔脉冲作用引起的细胞外液等效电阻变化最大，高频不可逆电穿孔作用下，脉冲宽度越宽，细胞外液等效电阻变化就越显著。因此，组织阻抗谱变化及由它得到的等效电路元器件值变化，可以有效地反映电穿孔程度，有望成为临床应用中检测不可逆电穿孔治疗效果的有效方式。

英文摘要：

The effectiveness and safety of irreversible electroporation （IRE） in tumor therapy has been proved by clinical applications for many years. The high-frequency irreversible electroporation （H-FIRE） proposed recently has both the advantages of the conventional IRE and the benefit of inhibiting the muscle contraction during the treatment. However, the mechanism of tumor ablation is unknown yet. We tried to analyze the difference between IRE and H-FIRE in tissue ablation based on impedance spectrum. The variation of the impedance spectrum of the New Zealand White Rabbit liver was studied when treated by both conventional IRE and H-FIRE, and then the circuit model was used to fit the impedance curve and extract the information from the change of the impedance spectrum. The results showed that the impedance spectrum of the tissue changed significantly when treated by pulses and the impedance mode variated significantly in the low-middle frequency while the impedance phase changed significantly in the middle-high frequency with the direction from negative values to zero. After fitting the impedance data to the circuit model, the information showed that the change of the extracellular resistance decreased significantly because the new pathway for current was in parallel with the extra- cellular resistance. The change of the extracellular resistance induced by conventional IRE was larger than that induced by H-FIRE when they had the same pulse dose, and among the H-FIRE, the change would go with the increase of pulse duration. The variations of the impedance and the elements in the circuit model can reflect the degree of IRE accurately and is expected to be an effective approach to detect the outcome of IRE in clinical.