Spatial steering with quadruple electrodes in 27 MHz capacitively coupled interstitial hyperthermia
Spatial steering with quadruple electrodes in 27 MHz capacitively coupled interstitial hyperthermia
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DOI：
10.1080/026567399285792
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发表时间：
1999-03-01
影响因子：
3.1
通讯作者：
Lagendijk, JJW
中科院分区：
文献类型：
--
作者：
Crezee, J;Kaatee, RSJP;Lagendijk, JJW
用途：27 MHz 多电极电流源 (MECS) 间质热疗系统使用由多个 10-20 毫米长的独立电极组成的探头来引导 3-D 功率沉积。集成到探头中的七点热电偶提供匹配的 3D 温度反馈数据。为了改善空间转向，增加了独立段的数量；评估了将四个独立电极集成到单个探头中的可行性和可靠性，特别关注效率和单独电极之间的干扰。方法：使用简单的分析模型计算二次耦合对表观电极阻抗的贡献以及交叉耦合对引线、热电偶和电极之间距离的依赖性。通过比较双电极和四电极以及尼龙导管中不同电极配置（段长 10 或 20 毫米）的四电极在肌肉等效介质中的功率输送，通过实验评估了二次耦合的效果。结果：经计算，热电偶和其他电极的交叉耦合与四电极的主耦合具有相同的幅度。幸运的是，这不会影响电极的操作，四重电极和双电极之间的性能没有差异，并且输出功率实际上与电极配置无关。结论：用于改进的 3D 功率控制的四重 MECS 电极是可行的。
Purpose: The 27 MHz Multi Electrode Current Source (MECS) interstitial hyperthermia system uses probes consisting of multiple independent electrodes, 10-20 mm long, to steer the 3-D power deposition. Seven point thermocouples integrated into the probes provide matching 3-D temperature feedback data. To improve spatial steering the number of independent segments was increased; the feasibility and reliability of four independent electrodes integrated into a single probe were evaluated, with special attention to efficiency and to interference between separate electrodes.Methods: The contribution of secondary coupling on the apparent electrode impedance and the dependence of cross coupling on the distance between leads, thermocouple and electrodes are computed using simple analytical models. The effect of this secondary coupling was assessed experimentally by comparing power delivery by dual and quadruple electrodes, and by quadruple electrodes in different electrode configurations (segment length 10 or 20 mm) in a nylon catheter in a muscle equivalent medium.Results: Cross coupling with the thermocouple and other electrodes was computed to be of the same magnitude as the primary coupling for a quadruple electrode. Fortunately, this does not affect operation of the electrode, there was no difference in performance between quadruple and dual electrodes, and the output power was effectively independent of the electrode configuration.Conclusion: Quadruple MECS electrodes for improved 3-D power control are feasible.