IEEE J Biomed Health Inform. 2019 Sep;23(5):1928-1939. doi: 10.1109/JBHI.2018.2870963. Epub 2018 Sep 18.
Recognizing the factors that cause stress is a crucial step toward early detection of stressors. In this regard, several studies make an effort to recognize individuals' stress using an Electroencephalogram (EEG). However, current EEG-based stress recognition frameworks have several drawbacks. First, they are mostly designed to recognize individuals' stress only in a controlled laboratory environment. Second, they do not take into account the changes in the EEG signals of different subjects under the same stressors. Third, most of the current stress recognition algorithms occur in an offline setting. To address these issues, this study proposes an EEG-based stress recognition framework that takes into account each subject's brainwave patterns to train the stress recognition classifier and continuously update its classifier based on new input signals in near real-time. The proposed framework first removes EEG signal artifacts, then extracts a broad range of EEG signal features, and finally applies different online multitask learning (OMTL) algorithms to recognize individuals' stress in near real time. The proposed framework was applied on the EEG collected in two environments-first on the EEG collected in a controlled lab environment using a wired-EEG and second on the EEG collected at in the field using a wearable EEG device. The OMTL-VonNeuman method resulted in the best prediction accuracy on both datasets (71.14% on the first dataset and 77.61% on second) among all tested algorithms. The proposed stress recognition framework continuously updates its classifier and therefore contributes to stress recognition for new stressful situations that are beyond the range of predefined stressful conditions in near real time both in a controlled lab environment and at real job sites.
认识导致压力的因素是早期发现压力源的关键步骤。在这方面,有几项研究努力使用脑电图 (EEG) 来识别个体的压力。然而,现有的基于 EEG 的压力识别框架存在几个缺点。首先,它们大多旨在仅在受控的实验室环境中识别个体的压力。其次,它们没有考虑到在相同压力源下不同受试者的 EEG 信号变化。第三,大多数现有的压力识别算法都是在离线环境中进行的。为了解决这些问题,本研究提出了一种基于 EEG 的压力识别框架,该框架考虑了每个受试者的脑电波模式,以训练压力识别分类器,并根据新的输入信号在近实时连续更新其分类器。该框架首先去除 EEG 信号伪影,然后提取广泛的 EEG 信号特征,最后应用不同的在线多任务学习 (OMTL) 算法来实时识别个体的压力。该框架应用于两种环境中的 EEG 数据进行评估:首先是在受控实验室环境中使用有线 EEG 收集的 EEG,其次是在现场使用可穿戴 EEG 设备收集的 EEG。在所有测试的算法中,OMTL-VonNeuman 方法在两个数据集上都取得了最佳的预测准确性(第一个数据集上为 71.14%,第二个数据集上为 77.61%)。该提出的压力识别框架不断更新其分类器,因此有助于实时实时识别新的压力情况,这些情况超出了预定义压力条件的范围,无论是在受控实验室环境还是在实际工作场所。