Electrical impedance measurements of biological tissue have many potential applications and tetrapolar impedance measurement (TPIM) with four electrodes is traditionally used which eliminates high skin contact impedance. A linear array of four electrodes for TPIM on the horizontal plane of a cylindrical volume conductor of diameter D, where the length of the array is πD/2 with potential electrodes near the centre of the array, will give a high sensitivity near the surface which reduces rapidly with depth. A recently proposed six-electrode variation of TPIM uses an additional pair of potential electrodes on the opposite side of the volume conductor in the same horizontal plane around the circumference, with the expectation that the sensitivity of the deeper regions will thereby be enhanced. The present work carries out a finite element simulation (using COMSOL) and an experimental phantom study (saline phantom) to quantitatively evaluate the improvement obtained by this new method. The new configuration doubled the sensitivity at the central region, which was reasonably uniform over a wider zone, gradually increasing towards the potential electrodes on both sides. This would be useful for a range of biological studies of deep body organs such as lungs, stomach, and bladder. where the respective external body shapes may be approximated by an oval cylinder and where electrical impedance techniques have shown promise.

中文翻译：

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一种用于探测人体深部器官的新型六电极电阻抗技术。

生物组织的电阻抗测量具有许多潜在的应用，传统上使用具有四个电极的四极阻抗测量（TPIM）可以消除高皮肤接触阻抗。在直径为D的圆柱形体积导体的水平面上，用于TPIM的四个电极的线性阵列，其中阵列的长度为πD/ 2，电位电极位于阵列的中心附近，将在表面附近产生高灵敏度随着深度迅速减小。TPIM的最近提出的六电极变体在围绕圆周的同一水平面中的体积导体的相对侧上使用了一对额外的电位电极，期望可以由此提高较深区域的灵敏度。本工作进行了有限元模拟（使用COMSOL）和实验体模研究（盐水体模），以定量评估通过这种新方法获得的改进。新的配置使中心区域的灵敏度翻了一番，在较宽的区域内该灵敏度是相当均匀的，并朝着两侧的电位电极逐渐增加。这对于深部器官（如肺，胃和膀胱）的一系列生物学研究将很有用。其中各个外部形状可以用椭圆圆柱体近似，并且电阻抗技术已显示出希望。它在较宽的区域内相当均匀，并逐渐向两侧的电位电极增加。这将有助于对深部器官（例如肺，胃和膀胱）进行一系列生物学研究。其中各个外部形状可以用椭圆圆柱体近似，并且电阻抗技术已显示出希望。它在较宽的区域内相当均匀，并逐渐向两侧的电位电极增加。这对于深部器官（如肺，胃和膀胱）的一系列生物学研究将很有用。其中各个外部形状可以用椭圆圆柱体近似，并且电阻抗技术已显示出希望。