Guo Jing, Yuan Jie, Chan Mansun
Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong.
IEEE Trans Biomed Circuits Syst. 2012 Dec;6(6):605-13. doi: 10.1109/TBCAS.2012.2189569.
Microelectrodes are widely used in the physiological recording of cell field potentials. As microelectrode signals are generally in the μV range, characteristics of the cell-electrode interface are important to the recording accuracy. Although the impedance of the microelectrode-solution interface has been well studied and modeled in the past, no effective model has been experimentally verified to estimate the noise of the cell-electrode interface. Also in existing interface models, spectral information is largely disregarded. In this work, we developed a model for estimating the noise of the cell-electrode interface from interface impedances. This model improves over existing noise models by including the cell membrane capacitor and frequency dependent impedances. With low-noise experiment setups, this model is verified by microelectrode array (MEA) experiments with mouse muscle myoblast cells. Experiments show that the noise estimated from this model has <;10% error, which is much less than estimations from existing models. With this model, noise of the cell-electrode interface can be estimated by simply measuring interface impedances. This model also provides insights for micro- electrode design to achieve good recording signal-to-noise ratio.
微电极广泛应用于细胞场电位的生理记录。由于微电极信号通常在微伏范围内，细胞-电极界面的特性对记录精度至关重要。尽管过去对微电极-溶液界面的阻抗进行了深入研究并建立了模型，但尚未有经过实验验证的有效模型来估计细胞-电极界面的噪声。而且在现有的界面模型中，光谱信息在很大程度上被忽略了。在这项工作中，我们开发了一种从界面阻抗估计细胞-电极界面噪声的模型。该模型通过纳入细胞膜电容和频率相关阻抗，对现有噪声模型进行了改进。利用低噪声实验装置，通过对小鼠肌肉成肌细胞进行微电极阵列（MEA）实验验证了该模型。实验表明，该模型估计的噪声误差<10%，远低于现有模型的估计值。利用该模型，只需测量界面阻抗就能估计细胞-电极界面的噪声。该模型还为实现良好记录信噪比的微电极设计提供了思路。
