Institute for Innovative Learning, Mahidol University, Nakhon Pathom, Thailand.
Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Sci Rep. 2024 Apr 29;14(1):9859. doi: 10.1038/s41598-024-60796-y.
Numerous models for sleep stage scoring utilizing single-channel raw EEG signal have typically employed CNN and BiLSTM architectures. While these models, incorporating temporal information for sequence classification, demonstrate superior overall performance, they often exhibit low per-class performance for N1-stage, necessitating an adjustment of loss function. However, the efficacy of such adjustment is constrained by the training process. In this study, a pioneering training approach called separating training is introduced, alongside a novel model, to enhance performance. The developed model comprises 15 CNN models with varying loss function weights for feature extraction and 1 BiLSTM for sequence classification. Due to its architecture, this model cannot be trained using an end-to-end approach, necessitating separate training for each component using the Sleep-EDF dataset. Achieving an overall accuracy of 87.02%, MF1 of 82.09%, Kappa of 0.8221, and per-class F1-socres (W 90.34%, N1 54.23%, N2 89.53%, N3 88.96%, and REM 87.40%), our model demonstrates promising performance. Comparison with sleep technicians reveals a Kappa of 0.7015, indicating alignment with reference sleep stags. Additionally, cross-dataset validation and adaptation through training with the SHHS dataset yield an overall accuracy of 84.40%, MF1 of 74.96% and Kappa of 0.7785 when tested with the Sleep-EDF-13 dataset. These findings underscore the generalization potential in model architecture design facilitated by our novel training approach.
利用单通道原始 EEG 信号进行睡眠阶段评分的模型有很多,通常采用 CNN 和 BiLSTM 架构。虽然这些模型在序列分类中结合了时间信息,表现出较高的整体性能,但对于 N1 阶段的性能往往较低,需要调整损失函数。然而,这种调整的效果受到训练过程的限制。在这项研究中,引入了一种名为分离训练的开创性训练方法,以及一种新的模型,以提高性能。所开发的模型由 15 个具有不同损失函数权重的 CNN 模型组成,用于特征提取,以及 1 个 BiLSTM 用于序列分类。由于其架构,该模型不能使用端到端的方法进行训练,需要使用 Sleep-EDF 数据集对每个组件进行单独训练。该模型实现了 87.02%的整体准确率、82.09%的 MF1、0.8221 的 Kappa 和每个类别的 F1 分数(W 为 90.34%、N1 为 54.23%、N2 为 89.53%、N3 为 88.96%和 REM 为 87.40%),表现出有前景的性能。与睡眠技术人员的比较显示 Kappa 值为 0.7015,表明与参考睡眠阶段一致。此外,通过使用 SHHS 数据集进行训练的跨数据集验证和自适应,当使用 Sleep-EDF-13 数据集进行测试时,模型的整体准确率为 84.40%、MF1 为 74.96%、Kappa 值为 0.7785。这些发现强调了我们新的训练方法在模型架构设计中的推广潜力。