Bertarelli Foundation Chair in Neuroprosthetic Technology Laboratory for Soft Bioelectronic Interfaces Institute of Microengineering Institute of Bioengineering Center for Neuroprosthetics Ecole Polytechnique Fédérale de Lausanne (EPFL) Geneva 1202 Switzerland.
Department of Neurosurgery University Hospital of Lausanne (CHUV) and University of Lausanne (UNIL) Lausanne 1010 Switzerland.
Adv Sci (Weinh). 2021 Mar 8;8(9):2003761. doi: 10.1002/advs.202003761. eCollection 2021 May.
Intraoperative electrocorticography (ECoG) captures neural information from the surface of the cerebral cortex during surgeries such as resections for intractable epilepsy and tumors. Current clinical ECoG grids come in evenly spaced, millimeter-sized electrodes embedded in silicone rubber. Their mechanical rigidity and fixed electrode spatial resolution are common shortcomings reported by the surgical teams. Here, advances in soft neurotechnology are leveraged to manufacture conformable subdural, thin-film ECoG grids, and evaluate their suitability for translational research. Soft grids with 0.2 to 10 mm electrode pitch and diameter are embedded in 150 µm silicone membranes. The soft grids are compatible with surgical handling and can be folded to safely interface hidden cerebral surface such as the Sylvian fold in human cadaveric models. It is found that the thin-film conductor grids do not generate diagnostic-impeding imaging artefacts (<1 mm) nor adverse local heating within a standard 3T clinical magnetic resonance imaging scanner. Next, the ability of the soft grids to record subdural neural activity in minipigs acutely and two weeks postimplantation is validated. Taken together, these results suggest a promising future alternative to current stiff electrodes and may enable the future adoption of soft ECoG grids in translational research and ultimately in clinical settings.
术中皮层电图 (ECoG) 在手术中从大脑皮层表面捕获神经信息，例如难治性癫痫和肿瘤的切除。目前的临床 ECoG 网格采用均匀间隔、毫米大小的电极嵌入硅橡胶中。手术团队普遍报告说，其机械刚性和固定的电极空间分辨率是常见的缺点。在这里，利用软神经技术的进步来制造顺应性的硬脑膜下、薄膜 ECoG 网格，并评估其在转化研究中的适用性。具有 0.2 至 10 毫米电极间距和直径的软网格嵌入 150 微米厚的硅橡胶膜中。软网格与手术处理兼容，可折叠以安全地贴合隐藏的大脑表面，如人类尸体模型中的 Sylvian 褶皱。研究发现，薄膜导体网格不会产生妨碍诊断的成像伪影（<1 毫米），也不会在标准 3T 临床磁共振成像扫描仪内产生不良局部加热。接下来，验证了软网格在植入后急性和两周内在小型猪中记录硬脑膜下神经活动的能力。总之，这些结果表明，目前的硬电极有一个很有前途的替代方案，并且可能使软 ECoG 网格在转化研究中并最终在临床环境中得到采用。
