Zhao Xueli, Kinouchi Y, Yasuno E, Gao D, Iritani T, Morimoto T, Takeuchi M
Laboratory of Biomedical Engineering, Institut de recherches cliniques de Montreal, 110 Avenue des Pins O, Montreal, QC, H2W 1R7, Canada.
IEEE Trans Biomed Eng. 2004 Feb;51(2):362-70. doi: 10.1109/TBME.2003.820403.
This paper outlines a new method for measuring multilayer tissue conductivity and structure by using divided electrodes, in which current electrodes are divided into several parts. Our purpose is to estimate the multilayer tissue structure and the conductivity distribution in a cross section of the local tissue by using bioresistance data measured noninvasively. The effect of the new method is assessed by computer simulations using a typical two-dimensional (2-D) model. In this paper, the conductivity distribution in the model is analyzed based on a finite difference method (FDM) and a steepest descent method (SDM). Simulation results show that the conductivity values of skin, fat, and muscle layers can be estimated with an error of less than 0.1%. When random noise at various levels is added to the measured resistance values, estimates of the conductivity values for skin, fat, and muscle layers are still reasonably precise: their root mean square errors are about 1.06%, 1.39%, and 1.61% for 10% noise. In a 2-D model, increasing the number of divided electrodes permits simultaneous estimates of tissue structure and conductivity distribution. Optimal configuration for divided electrodes is examined in terms of dividing pattern.
本文概述了一种通过使用分割电极测量多层组织电导率和结构的新方法，其中电流电极被分成几个部分。我们的目的是通过使用非侵入性测量的生物电阻数据来估计局部组织横截面中的多层组织结构和电导率分布。使用典型的二维（2-D）模型通过计算机模拟评估该新方法的效果。本文基于有限差分法（FDM）和最速下降法（SDM）分析模型中的电导率分布。模拟结果表明，皮肤、脂肪和肌肉层的电导率值能够以小于0.1%的误差进行估计。当在测量的电阻值中添加不同水平的随机噪声时，皮肤、脂肪和肌肉层电导率值的估计仍然相当精确：对于10%的噪声，它们的均方根误差分别约为1.06%、1.39%和1.61%。在二维模型中，增加分割电极的数量可以同时估计组织结构和电导率分布。从分割模式的角度研究了分割电极的最佳配置。
