Department of Electronics & Information, Seoul National University of Science and Technology, 172 Gongneung-dong, Nowon-gu, Seoul 139-743, South Korea.
Biosens Bioelectron. 2011 Jan 15;26(5):2347-53. doi: 10.1016/j.bios.2010.10.009. Epub 2010 Oct 14.
Impedance spectroscopy was applied to determine glucose concentration in the interstitial fluid for its potential use in diabetic monitoring. For this purpose, the changes in the measured dielectric properties due to the presence of glucose in water and saline solutions were examined between 40 Hz and 110 MHz. Electrode polarization (EP) was a dominant factor which shaped the spectrum at low frequencies. A theoretical model of EP using a constant phase-angle-element produced excellent matches to the measured data. By fitting the measured data to the model, the relative permittivity (ɛ(h)) and conductivity (σ(l)) were obtained. For deionized water, the relative permittivity dropped from 80.1 to 73.2 and conductivity ranged between 0.142 and 0.212 mS/m when the glucose concentration was increased from 0 to 32 g/dl. For the same variation of glucose level in 0.15 M NaCl, ɛ(h) was reduced from 79.8 to 71.5 and σ(l) decreased from 1.384 to 0.522 S/m. Glucose level produced a definite change in dielectric properties. However, the changes within the physiological range of glucose (less than a few hundred mg/dl) were small and appeared to be within the measurement error.
阻抗谱法被应用于检测间质液中的葡萄糖浓度，以期用于糖尿病监测。为此，研究了在 40Hz 至 110MHz 频率范围内，水和盐溶液中存在葡萄糖时测量介电性能的变化。电极极化（EP）是低频谱下形成频谱的主要因素。使用恒相角元件的 EP 理论模型与实测数据吻合得非常好。通过将实测数据拟合到模型中，可以得到相对介电常数（ɛ(h)）和电导率（σ(l)）。对于去离子水，当葡萄糖浓度从 0 增加到 32g/dl 时，相对介电常数从 80.1 降至 73.2，电导率在 0.142 至 0.212mS/m 之间变化。对于 0.15M NaCl 中葡萄糖浓度相同的变化，相对介电常数从 79.8 降至 71.5，电导率从 1.384 降至 0.522S/m。葡萄糖水平确实会引起介电性能的变化。然而，在生理范围内（小于几百毫克/分升）的葡萄糖变化较小，似乎在测量误差范围内。
