Model-based analysis of cortical recording with silicon microelectrodes
Model-based analysis of cortical recording with silicon microelectrodes
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DOI：
10.1016/j.clinph.2005.05.018
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发表时间：
2005-09-01
影响因子：
4.7
通讯作者：
McIntyre, CC
中科院分区：
文献类型：
--
作者：
Moffitt, MA;McIntyre, CC
目的：本研究的目的是利用计算建模来更好地了解影响脑机接口中硅微电极神经记录的因素。方法：将V层锥体细胞的非线性电缆模型与微电极的有限元电场模型耦合。该模型系统能够分析细胞外神经记录作为电极接触大小，神经元位置，水肿和慢性封装的功能。结果：该模型预测的峰值波形和振幅与实验记录一致。小（< 1000 μ m(2)）和大（10 μ m(2)）电极触点具有相似的记录灵敏度，但当神经元靠近电极（50 μ m）时，小触点表现出更高的信号幅度（类似于50%）。模型结果支持这样的观点，即急性水肿导致信号减少（类似于24%），而某些包封条件可导致信号增加（类似于17%），这一机制可能有助于慢性记录实验中观察到的信号增加。结论：最佳电极设计与应用有关。小触点和大触点尺寸具有截然不同的记录特性，可在设计过程中加以利用。此外，电极柄周围局部电不均匀性（包封、水肿、涂层）的存在会严重影响神经记录，需要进一步的理论和实验研究。意义：使用皮层指令信号的思想控制装置对神经功能障碍患者具有令人兴奋的治疗潜力。研究结果为完善和优化脑机接口微电极设计奠定了基础。(c) 2005年国际临床神经生理学联合会。爱思唯尔爱尔兰有限公司出版。版权所有。
Objective: The purpose of this study was to use computational modeling to better understand factors that impact neural recordings with silicon microelectrodes used in brain-machine interfaces.Methods: A non-linear cable model of a layer V pyramidal cell was coupled with a finite-element electric field model with explicit representation of the microelectrode. The model system enabled analysis of extracellular neural recordings as a function of the electrode contact size, neuron position, edema, and chronic encapsulation.Results: The model predicted spike waveforms and amplitudes that were consistent with experimental recordings. Small (< 1000 mu m(2)) and large (10 mu m(2)) electrode contacts had similar volumes of recording sensitivity, but small contacts exhibited higher signal amplitudes (similar to 50%) when neurons were in close proximity (50 mu m) to the electrode. The model results support the notion that acute edema causes a signal decrease (similar to 24%), and certain encapsulation conditions can result in a signal increase (similar to 17%), a mechanism that may contribute to signal increases observed experimentally in chronic recordings.Conclusions: Optimal electrode design is application-dependent. Small and large contact sizes have contrasting recording properties that can be exploited in the design process. In addition, the presence of local electrical inhomogeneities (encapsulation, edema, coatings) around the electrode shank can substantially influence neural recordings and requires further theoretical and experimental investigation.Significance: Thought-controlled devices using cortical command signals have exciting therapeutic potential for persons with neurological deficit. The results of this study provide the foundation for refining and optimizing microelectrode design for human brain-machine interfaces. (c) 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.