Al Harrach Mariam, Mousavi Hajar, Dieuset Gabriel, Ismailova Esma, Wendling Fabrice
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3428-3431. doi: 10.1109/EMBC44109.2020.9176032.
High Frequency Oscillations (HFOs, 200-600 Hz) are recognized as a biomarker of epileptogenic brain areas. This work aims at designing novel microelectrodes in order to optimize the recording and further detection of HFOs in brain (intracerebral electroencephalography, iEEG). The quality of the recorded iEEG signals is highly dependent on the electrode contact impedance, which is determined by the characteristics of the recording electrode (geometry, position, material). These properties are essential for the observability of HFOs. In this study, a previously published hippocampal neural network model is used for the simulation of interictal HFOs. An additional microelectrode model layer is implemented in order to simulate the impact of using different types and characteristics of microelectrodes on the recorded HFOs. Results indicate that a small layer PEDOT/PSS and PEDOT/CNT on microelectrodes can effectively decrease their impedance resulting in the increase of HFOs observability. This model-based study can lead to the actual design of new electrodes that will ultimately contribute to improved diagnosis prior to invasive therapies.
高频振荡（HFOs，200 - 600赫兹）被认为是致痫脑区的生物标志物。这项工作旨在设计新型微电极，以优化大脑中高频振荡的记录及进一步检测（颅内脑电图，iEEG）。所记录的iEEG信号质量高度依赖于电极接触阻抗，而电极接触阻抗由记录电极的特性（几何形状、位置、材料）决定。这些特性对于高频振荡的可观测性至关重要。在本研究中，一个先前发表的海马神经网络模型被用于模拟发作间期高频振荡。为了模拟使用不同类型和特性的微电极对所记录的高频振荡的影响，额外添加了一个微电极模型层。结果表明，微电极上的一层薄的聚3,4-乙撑二氧噻吩/聚苯乙烯磺酸盐（PEDOT/PSS）和聚3,4-乙撑二氧噻吩/碳纳米管（PEDOT/CNT）可以有效降低其阻抗，从而提高高频振荡的可观测性。这项基于模型的研究能够导向新型电极的实际设计，最终有助于在侵入性治疗之前改善诊断。
