IEEE Trans Neural Syst Rehabil Eng. 2022;30:2042-2051. doi: 10.1109/TNSRE.2022.3192543. Epub 2022 Jul 26.
The research on non-invasive BCI is nowadays hitting the bottleneck due to the humble quality of scalp EEG signals. Whereas invasive solutions that offer higher signal quality in contrast are suffocated in their spreading because of the potential surgical complication and health risks caused by electrode implantation. Therefore, it puts forward a necessity to explore a scheme that could both collect high-quality EEG signals and guarantee high-level operation safety.This study proposed a Minimally Invasive Local-skull Electrophysiological Modification method to improve scalp EEG signals qualities at specific brain regions. Six eight-month-old SD rats were used for in vivo verification experiment. A hole with a diameter of about 500 micrometers was drilled in the skull above the visual cortex of rats. Significant changes in rsEEG and SSVEP signals before and after modification were observed. After modification, the skull impedance of rats decreases by about 84 %, the average maximum bandwidth of rsEEG increase by 57 %, and the broadband SNR of SSVEP is increased by 5.13 dB. The time of piezoelectric drilling operation is strictly controlled under 30 seconds for each rat to prevent possible brain damage from overheating. Compared with traditional invasive procedures such as ECoG, Minimally Invasive Local-skull Electrophysiological Modification operation time is shorter and no electrode implantation is needed while it remarkably boosts the scalp EEG signal quality. This technical solution has the potential to replace the use of ECoG in certain application scenarios and further invigorate studies in the field of scalp EEG in the future.
目前，由于头皮 EEG 信号质量较差，非侵入性 BCI 的研究已经达到瓶颈。相比之下，虽然侵入性解决方案可以提供更高质量的信号，但由于电极植入带来的潜在手术并发症和健康风险，它们的应用受到了限制。因此，需要探索一种既能采集高质量 EEG 信号又能保证高水平操作安全性的方案。
本研究提出了一种微创局部颅骨电生理修饰方法，以改善特定脑区的头皮 EEG 信号质量。使用六只八个月大的 SD 大鼠进行体内验证实验。在大鼠视皮层上方的颅骨上钻一个直径约 500 微米的孔。观察到修饰前后 rsEEG 和 SSVEP 信号的显著变化。修饰后，大鼠颅骨阻抗降低约 84%，rsEEG 的平均最大带宽增加 57%，SSVEP 的宽带 SNR 增加 5.13dB。为了防止过热对大脑造成可能的损伤，每个大鼠的压电钻孔操作时间严格控制在 30 秒以内。与传统的侵入性程序（如 ECoG）相比，微创局部颅骨电生理修饰操作时间更短，不需要电极植入，同时显著提高了头皮 EEG 信号质量。该技术解决方案有可能替代 ECoG 在某些应用场景中的使用，并进一步激发未来头皮 EEG 领域的研究。
