Sadegh-Zadeh Seyed-Ali, Fakhri Elham, Bahrami Mahboobe, Bagheri Elnaz, Khamsehashari Razieh, Noroozian Maryam, Hajiyavand Amir M
Department of Computing, School of Digital, Technologies and Arts, Staffordshire University, Stoke-on-Trent ST4 2DE, UK.
Behavioral Sciences Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan 8174533871, Iran.
Diagnostics (Basel). 2023 Jan 28;13(3):477. doi: 10.3390/diagnostics13030477.
Electroencephalography (EEG) signal analysis is a rapid, low-cost, and practical method for diagnosing the early stages of dementia, including mild cognitive impairment (MCI) and Alzheimer's disease (AD). The extraction of appropriate biomarkers to assess a subject's cognitive impairment has attracted a lot of attention in recent years. The aberrant progression of AD leads to cortical detachment. Due to the interaction of several brain areas, these disconnections may show up as abnormalities in functional connectivity and complicated behaviors.
This work suggests a novel method for differentiating between AD, MCI, and HC in two-class and three-class classifications based on EEG signals. To solve the class imbalance, we employ EEG data augmentation techniques, such as repeating minority classes using variational autoencoders (VAEs), as well as traditional noise-addition methods and hybrid approaches. The power spectrum density (PSD) and temporal data employed in this study's feature extraction from EEG signals were combined, and a support vector machine (SVM) classifier was used to distinguish between three categories of problems.
Insufficient data and unbalanced datasets are two common problems in AD datasets. This study has shown that it is possible to generate comparable data using noise addition and VAE, train the model using these data, and, to some extent, overcome the aforementioned issues with an increase in classification accuracy of 2 to 7%.
In this work, using EEG data, we were able to successfully detect three classes: AD, MCI, and HC. In comparison to the pre-augmentation stage, the accuracy gained in the classification of the three classes increased by 3% when the VAE model added additional data. As a result, it is clear how useful EEG data augmentation methods are for classes with smaller sample numbers.
脑电图(EEG)信号分析是一种快速、低成本且实用的方法,用于诊断痴呆症的早期阶段,包括轻度认知障碍(MCI)和阿尔茨海默病(AD)。近年来,提取合适的生物标志物以评估受试者的认知障碍受到了广泛关注。AD的异常进展会导致皮质脱离。由于多个脑区的相互作用,这些连接中断可能表现为功能连接异常和复杂行为。
这项工作提出了一种基于EEG信号在两类和三类分类中区分AD、MCI和健康对照(HC)的新方法。为了解决类别不平衡问题,我们采用了EEG数据增强技术,例如使用变分自编码器(VAE)重复少数类,以及传统的加噪方法和混合方法。本研究从EEG信号中提取特征时使用的功率谱密度(PSD)和时间数据相结合,并使用支持向量机(SVM)分类器区分三类问题。
数据不足和数据集不平衡是AD数据集中的两个常见问题。本研究表明,使用加噪和VAE可以生成可比数据,使用这些数据训练模型,并在一定程度上克服上述问题,分类准确率提高2%至7%。
在这项工作中,我们利用EEG数据成功检测出了AD、MCI和HC三类。与增强前阶段相比,当VAE模型添加额外数据时,三类分类的准确率提高了3%。因此,很明显EEG数据增强方法对于样本数量较少的类别非常有用。