Improved focalization of electrical microstimulation using microelectrode arrays: a modeling study.
Improved focalization of electrical microstimulation using microelectrode arrays: a modeling study.
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DOI：
10.1371/journal.pone.0004828
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Yvert B
中科院分区：
文献类型：
--
作者：
Joucla S;Yvert B
中枢神经系统(CNS)的细胞外电刺激(EES)已经被经验地使用了几十年，有基本的和临床的目标。目前，微电极阵列为中枢神经系统微刺激提供了新的可能性。然而，尽管中枢神经系统的局部激活对于实现有效的刺激策略是至关重要的，但对EES的精确空间范围仍然知之甚少。目前这项工作的目的有两个。首先，我们验证了一个有限元模型，可以准确地计算由MEAS提供的EES在整个细胞外介质中产生的电位场。该模型使用Robin边界条件，考虑了电极/介质界面的表面电导。利用这个模型，我们确定了电位场是如何受到刺激和地电极阻抗以及神经组织的电导率的影响的。我们确认，为了控制势场的幅度，电流控制刺激比电压控制刺激更可取。其次，我们评估了不同电极配置下的电位场和阈值-距离曲线的聚焦性。我们提出了一种新的结构来改善聚焦，使用地面包围阵列的所有电极。我们发现，这个表面的阻抗越低，刺激的焦点就越多。总之，这项研究为设计精确的细胞外刺激计算模型提出了新的边界条件，并提出了一种新的电极配置，该配置可以很容易地集成到未来的MEA设备中，无论是在体外还是在体内，以更好地控制中枢神经系统微刺激的空间。
Extracellular electrical stimulation (EES) of the central nervous system (CNS) has been used empirically for decades, with both fundamental and clinical goals. Currently, microelectrode arrays (MEAs) offer new possibilities for CNS microstimulation. However, although focal CNS activation is of critical importance to achieve efficient stimulation strategies, the precise spatial extent of EES remains poorly understood. The aim of the present work is twofold. First, we validate a finite element model to compute accurately the electrical potential field generated throughout the extracellular medium by an EES delivered with MEAs. This model uses Robin boundary conditions that take into account the surface conductance of electrode/medium interfaces. Using this model, we determine how the potential field is influenced by the stimulation and ground electrode impedances, and by the electrical conductivity of the neural tissue. We confirm that current-controlled stimulations should be preferred to voltage-controlled stimulations in order to control the amplitude of the potential field. Second, we evaluate the focality of the potential field and threshold-distance curves for different electrode configurations. We propose a new configuration to improve the focality, using a ground surface surrounding all the electrodes of the array. We show that the lower the impedance of this surface, the more focal the stimulation. In conclusion, this study proposes new boundary conditions for the design of precise computational models of extracellular stimulation, and a new electrode configuration that can be easily incorporated into future MEA devices, either in vitro or in vivo, for a better spatial control of CNS microstimulation.
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影响因子：
3
作者：
Grumet, AE;Wyatt, JL;Rizzo, JF
通讯作者：
Rizzo, JF
DOI：
10.1007/s00249-002-0213-7
发表时间：
2002-06-01
影响因子：
2
作者：
Fromherz, P
通讯作者：
Fromherz, P
影响因子：
3.2
作者：
CHURCH, P;LEDUC, A;DEROME, JR
通讯作者：
DEROME, JR
影响因子：
4.6
作者：
Buitenweg, JR;Rutten, WLC;Marani, E
通讯作者：
Marani, E
影响因子：
64.8
作者：
Mainen, ZF;Sejnowski, TJ
通讯作者：
Sejnowski, TJ