State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, People's Republic of China.
Biomed Phys Eng Express. 2020 Mar 13;6(3):035010. doi: 10.1088/2057-1976/ab4a1c.
Transcranial magnetic stimulation (TMS) as a safe, noninvasive brain regulation technology has been gradually applied to clinical treatment. Traditional TMS devices do not adjust output based on real-time brain activity information when regulating the cerebral cortex, but the current activity information from the brain, especially the EEG phase, may affect the stimulation effect. It is necessary to calculate the synchronous EEG phase during TMS.
In this study, a set of closed-loop TMS device a fast EEG phase prediction algorithm based on the AR model was designed to meet the demand. EEG data for twenty-seven healthy college students were collected to verify the accuracy of the algorithm.
The calculation results showed that the prediction accuracy of the AR model algorithm is better than that of the conventional algorithm when the model order is lower, and the prediction accuracy will increase with improvements in the signal quality.
When the experimental environment is good, the EEG data with a high SNR can be recorded, and when the order of the AR model is properly set, the prediction algorithm can make correct judgments most of the time and the stimulation pulse can be output when the EEG phase reaches a set value.
经颅磁刺激(TMS)作为一种安全、非侵入性的大脑调节技术,已逐渐应用于临床治疗。传统的 TMS 设备在调节大脑皮层时,不会根据实时脑活动信息来调整输出,但当前的脑活动信息,特别是 EEG 相位,可能会影响刺激效果。因此,有必要计算 TMS 期间的同步 EEG 相位。
本研究设计了一套基于 AR 模型的闭环 TMS 设备快速 EEG 相位预测算法,以满足需求。收集了 27 名健康大学生的 EEG 数据来验证算法的准确性。
计算结果表明,在模型阶数较低时,AR 模型算法的预测精度优于传统算法,并且随着信号质量的提高,预测精度会增加。
当实验环境良好,能够记录到具有高 SNR 的 EEG 数据,并且适当设置 AR 模型的阶数时,预测算法大部分时间都能做出正确的判断,并在 EEG 相位达到设定值时输出刺激脉冲。