Characterization of Nonlinearity and Dispersion in Tissue Impedance During High-Frequency Electroporation
Characterization of Nonlinearity and Dispersion in Tissue Impedance During High-Frequency Electroporation
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DOI：
10.1109/tbme.2017.2787038
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发表时间：
2018-10-01
影响因子：
4.6
通讯作者：
Davalos, Rafael, V
中科院分区：
文献类型：
--
作者：
Bhonsle, Suyashree;Lorenzo, Melvin F.;Davalos, Rafael, V
目的：使用高压高频双极脉冲（hfbp）是一种新兴的基于电穿孔的治疗实体肿瘤的方法。在这项研究中，我们量化了HFBP治疗期间的非线性和弥散程度。方法：利用平板电极捕捉猪肝组织在不同脉冲幅值下宽度为1和2 / s的hfbp脉冲输送过程中的阻抗。接下来，我们将阻抗数据拟合到频率相关的并联RC网络中，以确定不同外加电场下组织的电导率和介电常数作为频率的函数。最后，我们提出了一个简单的模型来近似组织中的场分布，使用电导率函数在一个频率上可以最小化由于使用非色散模型近似而产生的误差。结果：绘制了不同电场作用下组织的电导率/介电常数随频率的函数图。结果表明，随着外加电场强度的增大，色散程度减小。结论：这是第一个量化HFBP治疗过程中组织弥散和非线性的研究。该数据已被用于预测场分布的肝组织利用两个针电极的数值模型。意义：本研究中开发的监测治疗过程中组织电学特性的数据和技术可用于生成未来高频电穿孔治疗的治疗计划模型，并提供有关治疗效果的见解。
Objective: The use of high-voltage, high-frequency bipolar pulses (HFBPs) is an emerging electroporation-based therapy for the treatment of solid tumors. In this study, we quantify the extent of nonlinearity and dispersion during the HFBP treatment. Methods: We utilize flat-plate electrodes to capture the impedance of the porcine liver tissue during the delivery of a burst of HFBPs of widths 1 and 2 /is at different pulse amplitudes. Next, we fit the impedance data to a frequency-dependent parallel RC network to determine the conductivity and permittivity of the tissue as a function of frequency, for different applied electric fields. Finally, we present a simple model to approximate the field distribution in the tissue using the conductivity function at a frequency that could minimize the errors due to approximation with a nondispersive model. Results: The conductivity/permittivity of the tissue was plotted as a function of frequency for different electric fields. It was found that the extent of dispersion reduces with higher applied electric field magnitudes. Conclusion: This is the first study to quantify dispersion and nonlinearity in the tissue during the HFBP treatment. The data have been used to predict the field distribution in a numerical model of the liver tissue utilizing two needle electrodes. Significance: The data and technique developed in this study to monitor the electrical properties of tissue during treatment can be used to generate treatment planning models for future high-frequency electroporation therapies as well as provide insights regarding treatment effect.