Electrical Impedance of Stainless Steel Needle Electrodes
Electrical Impedance of Stainless Steel Needle Electrodes
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DOI：
10.1007/s10439-010-9989-2
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发表时间：
2010-07-01
影响因子：
3.8
通讯作者：
Martinsen, Orjan G.
中科院分区：
文献类型：
--
作者：
Kalvoy, Havard;Tronstad, Christian;Martinsen, Orjan G.
我们目前的实验结果的变异性和稳定性的电阻抗性能的医用级不锈钢针电极在体外。测量单极阻抗谱（1 Hz至1 MHz），并获得五种针类型的扫描电子显微镜图像，有效电极面积为0.28至0.7 mm（2）。使用盐水罐（0.9%NaCl）作为组织模型。在电解处理前后用1 μ A的阳极和阴极DC电流进行测量。当有效电极面积低于1 mm（2）时，预期在低频（LF）下电极极化阻抗（EPI）会产生较大影响。对于更高的频率（HF），EPI降低，并且周围组织的阻抗更明显。测试的假设是，在LF下的EPI将取决于接触面积、合金成分、表面结构和活性电极的处理，而在HF下则取决于电极面积几何形状和盐水的比电阻率。我们的研究结果表明，针类型之间的电性能有很大的差异。电解处理后EPI下降。盐水暴露5-48小时后，EPI增加，无论是处理过的还是未处理过的针头。阴极处理比阳极处理或不处理得到更低的阻抗和漂移。
We present experimental findings regarding variability and stability of the electrical impedance properties of medical grade stainless steel needle electrodes in vitro. Monopolar impedance spectra (1 Hz to 1 MHz) were measured and scanning electron microscope images were obtained for five needle types with active electrode area from 0.28 to 0.7 mm(2). A saline tank (0.9% NaCl) was used as tissue model. Measurements were done before and after electrolytic treatment with anodic and cathodic DC currents of 1 mu A. With active electrode areas below 1 mm(2), high influence from electrode polarization impedance (EPI) was expected at low frequencies (LF). For higher frequencies (HF) the EPI decreases and the impedance of the surrounding tissue is more pronounced. The hypothesis tested was that the EPI at LF would depend upon contact area, alloy composition, surface structure, and treatment of the active electrode, and at HF upon the electrode area geometry, and the specific resistivity of saline. Our results show large differences in electrical properties between needle types. After electrolytic treatment the EPI decreased. After 5-48 h of saline exposure the EPI increased, both for treated and untreated needles. Cathodic treatment gave lower impedance and drift than anodic or no treatment.