Electric and thermal field effects in tissue around radiofrequency electrodes
Electric and thermal field effects in tissue around radiofrequency electrodes
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DOI：
10.1111/j.1526-4637.2005.00076.x
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发表时间：
2005-11-01
期刊：
影响因子：
3.1
通讯作者：
Cosman, ER
中科院分区：
文献类型：
--
作者：
Cosman, ER;Cosman, ER
目的：研究了用于疼痛治疗的射频（RF）电极周围组织中电场和热场的空间分布和时间依赖性。进行磁场的有限元计算，并将结果与离体组织数据进行比较。现场预测连续和脉冲RF application.Design：一个特殊的RF套管电极是由宏观和微观热电偶传感器来测量平均和快速，瞬态温度效应。使用市售射频损伤发生器的信号输出，在肝脏和蛋清模型中记录温度和阻抗。这些数据进行了比较，使用电场方程和bio-heat equation.Results的有限元计算的结果：在RF电极的平均温度和蒸发温度进行测量。在脉冲RF突发期间观察到快速温度尖峰。这些数据比较以及与理论计算使用已知的电和热组织parameters.Conclusion：连续RF损伤导致热破坏的神经元。脉冲射频损伤（PRFL）产生热脉冲，其温度范围与破坏性热损伤相关。PRFL还产生非常高的电场，其可能能够破坏神经元膜和功能。基本上同意的测量数据，给信心，他们的预测RF电极周围的领域的元素计算。
Objective: A study is carried out of the spatial distribution and time dependence of electric and thermal fields in the tissue around a radiofrequency (RF) electrode used in pain therapy. Finite-element calculation of the fields is performed, and results are compared with ex vivo tissue data. Field predictions are made for continuous and for pulsed RF applications.Design: A special RF cannula electrode is constructed with both macro and micro thermocouple sensors to measure both average and rapid, transitory temperature effects. Temperatures and impedances are recorded in liver and egg-white models using signal outputs from a commercially available RF lesion generator. These data are compared with the results of finite-element calculations using electric field equations and the bio-heat equation.Results: Average and pulsatory temperatures at the RF electrode are measured. Rapid temperature spikes during pulsed RF bursts are observed. These data compared well with theoretical calculations using known electrical and thermal tissue parameters.Conclusion: Continuous RF lesioning causes heat destruction of neurons. Pulsed RF lesioning (PRFL) produces heat bursts with temperatures in the range associated with destructive heat lesions. PRFL also produces very high electric fields that may be capable of disrupting neuronal membranes and function. Finite-element calculations agree substantially with the measured data, giving confidence to their predictions of fields around the RF electrode.