基于深度学习的头皮脑电信息解码研究进展

头皮脑电(EEG)拥有毫秒级时间分辨力,可实时获取大脑意念认知、思维决策的神经电生理信息。EEG已广泛用于脑成像研究,并成为21世纪神经科学与工程研究开发的重要工具之一。但受颅内组织容积导电效应的影响,使其信噪比与空间分辨率较差,信息解码严重受阻。随着本世纪深度学习(DL)的快速兴起与深入发展,研究者开始尝试将深度学习与脑科学研究相结合,探究深度学习应用于脑电数据处理的新方法,并已取得瞩目的阶段性成果,但采用现有方法进行EEG信息解码仍面临诸多急需解决的难题。结合近些年深度学习在EEG数据处理领域的研究和应用,综合论述目前主流DNN模型结构在EEG信息解码领域的研究现状及进展成果,分析归纳其潜力优势与瓶颈难题及未来趋势,以促进深度学习解码脑电信息的研究更深入有效发展。     

卷积神经网络在阿尔茨海默病诊断中的应用研究

随着深度学习技术在疾病诊断方面的广泛应用,尤其是卷积神经网络(CNN)在计算机视觉、图像处理方面的突出表现,越来越多的研究提出使用该算法实现阿尔茨海默病(AD)、轻度认知障碍(MCI)以及正常认知(CN)之间的诊断。本文系统地回顾了几种经典的卷积神经网络模型在该疾病不同阶段脑影像分析诊断方面的应用进展,进一步探讨了其存在的问题及研究方向,以期为该领域的研究提供一定的参考和借鉴。     

基于时空特征学习卷积神经网络的运动想象脑电解码方法

基于运动想象脑电(EEG)的脑-机接口系统能够为用户提供更为自然、灵活的控制方式,已广泛应用到人机交互领域。然而,由于目前运动想象脑电的信噪比及空间分辨率较低,导致信号解码正确率较低。针对这一问题,本文提出一种基于时空特征学习卷积神经网络(TSCNN)的运动想象脑电解码方法。首先,针对经过带通滤波预处理的脑电信号,依次设计时间和空间维度上的卷积层,构造出运动想象脑电的时空特征;然后,利用2层二维卷积结构对脑电的时空特征进行抽象学习;最后,通过全连接层和Softmax层对TSCNN学习的抽象特征进行解码。利用公开数据集对该方法进行实验测试,结果表明,所提方法的平均解码精度达到80.09%,分别比经典的解码方法共空间模式(CSP)+支持向量机(SVM)和滤波器组CSP(FBCSP)+SVM提高了13.75%和10.99%,显著提升了运动想象脑电解码的可靠性。     

人工神经网络在脑电分析中的应用

人工神经网络是脑电分析研究中适用的新工具和技术。本结合神经网络在脑电分析中的应用，着重归纳出其中的几项比较关键，即神经网络输入数据的形式、神经网络训练样本的选取、神经网络的学习方式和神经网络用于认知问题研究等。     

脑电波分析在精神病诊断中的应用

在生存竞争日益激烈的今天,精神疾病越来越受到人们的关注。而对它的诊断却一直未能达到完全客观准确。本文讨论了脑电技术中包括EEG、EP和BEAM在内的几种主要技术,在精神病诊断中的研究情况和应用现状。并对脑电在精神病诊断方面的应用前景做了展望。     

人工神经网络在脑电分析中的应用

人工神经网络是脑电分析研究中适用的新工具和技术。本文结合神经网络在脑电分析中的应用，着重归纳出其中的几项比较关键问题，即神经网络输入数据的形式、神经网络训练样本的选取、神经网络的学习方式和神经网络用于认知问题研究等。     

Design of BCI application system based on Java3D

目的 为在理想环境下研究脑机交互(brain computer interface,BCI)系统,并为系统的实际应用开发做铺垫,本文基于Java3D设计了脑机交互应用系统.方法 EEG信号经分析处理后转换成的实时控制命令,通过TCP/IP协议传给Java3D应用系统,实时控制虚拟小车运动.该应用系统的设计分三步:首先搭建虚拟场景,包括对场景模型的建立以及对场景的布局设计;其次设计虚拟小车的运动,实现小车前进和旋转的连续运动;最后对场景中的模型配置进行碰撞检测,用基于运动想象的EEG分析结果实时控制小车运动,检验本系统的功能.结果 EEG信号可以实时控制虚拟小车进行连续运动,且碰撞检测功能正常.结论 研究结果初步证明该应用系统的可行性,为BCI应用系统的设计提供了新颖思路并奠定了良好基础.     

基于时频分析的EEG信号分析处理方法研究进展

由于脑电信号(EEG)是典型的非平稳时变信号,因此时频分析方法比较适用于分析和处理EEG信号。本文在简要介绍时频分析的发展及主要方法的基础上,综述了时频分析方法在EEG信号分析处理中的应用及研究进展,并对现存的问题作了探讨。     

基于时频分析的EEG信号分析处理方法研究进展

由于脑电信号(EEG)是典型的非平稳时变信号，因此时频分析方法比较适用于分析和处理EEG信号。本在简要介绍时频分析的发展及主要方法的基础上，综述了时频分析方法在EEG信号分析处理中的应用及研究进展，并对现存的问题作了探讨。     

基于Java3D的脑机交互应用系统设计

目的 为在理想环境下研究脑机交互（brain computer interface,BCI）系统,并为系统的实际应用开发做铺垫,本文基于Java3D设计了脑机交互应用系统.方法 EEG信号经分析处理后转换成的实时控制命令,通过TCP/IP协议传给Java3D应用系统,实时控制虚拟小车运动.该应用系统的设计分三步：首先搭建虚拟场景,包括对场景模型的建立以及对场景的布局设计;其次设计虚拟小车的运动,实现小车前进和旋转的连续运动;最后对场景中的模型配置进行碰撞检测,用基于运动想象的EEG分析结果实时控制小车运动,检验本系统的功能.结果 EEG信号可以实时控制虚拟小车进行连续运动,且碰撞检测功能正常.结论 研究结果初步证明该应用系统的可行性,为BCI应用系统的设计提供了新颖思路并奠定了良好基础.     

运动想象脑电多视角深度森林解码算法

针对运动想象脑电信号特征提取操作繁琐及解码精度低等问题,提出一种基于多视角深度森林的运动想象脑电解码算法。首先,通过子频带滤波及时间窗口划分对原始信号进行细粒度分析,生成空时频能量特征。然后,对上述空时频能量特征分别进行稀疏选择和时序扫描得到重要的浅层能量特征及多示例先验类别特征。继而,将上述两类特征进行融合构建运动想象脑电多视角特征集。最后,利用级联森林的逐层特征变换挖掘深层次的抽象特征进行脑电解码。根据脑机接口竞赛数据和自行采集的数据进行算法测试,并与单视角特征模型、传统共空间模式方法以及深度神经网络算法进行对比。在2个脑机接口竞赛数据集和1个真实数据集上分别取得了91.4%、75.2%和70.7%的最高平均分类准确率,结果表明该文所提多视角深度森林算法具有更优的分类识别准确率。     

Medical image translation using an edge-guided generative adversarial network with global-to-local feature fusion

In this paper, we propose a framework based deep learning for medical image translation using paired and unpaired training data. Initially, a deep neural network with an encoder-decoder structure is proposed for imageto-image translation using paired training data. A multi-scale context aggregation approach is then used to extract various features from different levels of encoding, which are used during the corresponding network decoding stage. At this point, we further propose an edge-guided ge...     

神经元群体解码方法及其在脑-机接口中的应用

基于脑神经元放电信号的脑-机接口(brain-computer interface,BCI)系统近年来有了越来越深入的研究,它使BCI在皮层运动控制等方面更加精确、迅速.从神经工程角度,此类BCI的实现不仅依赖于多电极神经记录硬件技术的发展,还依赖于其软件技术的核心神经元群体解码方法.本文综述了目前神经元群体解码方法中已成功运用于BCI研究的四类主要算法:群矢量算法、最佳线性估计、卡尔曼滤波法、贝叶斯方法.     

深度学习在脑胶质瘤影像学的研究进展

深度学习是基于多层神经网络计算模型发现数据内复杂特征的一种深度网络,较多应用于医学图像的分割与分类中,在各类脑胶质瘤的研究中也有许多成果。本文就深度学习在脑胶质瘤的准确分割定位、组织遗传学特征预测及预后评估等方面展开综述,总结深度学习在脑胶质瘤影像图像分割与分类的研究进展,从而为胶质瘤患者的精准诊断、个体化治疗提供新思路。     

基于深度学习的跨模态医学图像转换

运用深度学习的方法基于脑部CT扫描图像合成相应的MRI。将28例患者进行颅脑CT和MRI扫描得到的CT和MRI的断层图像进行刚性配准,随机选取20例患者的图像输入U-Net卷积神经网络进行训练,利用训练好的网络对未参与训练的8例患者的CT图像进行预测,得到合成的MRI。研究结果显示:通过对合成的MRI进行定量分析,利用基于L2损失函数构建的U-Net网络合成MRI效果良好,平均绝对平均误差（MAE）为47.81,平均结构相似性指数（SSIM）为0.91。本研究表明可以利用深度学习方法对CT图像进行转换,获得合成MRI,现阶段可以达到扩充MRI医学图像数据库的目的,随着合成图像精度的提高,可以用于帮助诊断等临床应用。     

Automatic seizure detection using three-dimensional CNN based on multi-channel EEG

Background

Automated seizure detection from clinical EEG data can reduce the diagnosis time and facilitate targeting treatment for epileptic patients. However, current detection approaches mainly rely on limited features manually designed by domain experts, which are inflexible for the detection of a variety of patterns in a large amount of patients’ EEG data. Moreover, conventional machine learning algorithms for seizure detection cannot accommodate multi-channel Electroencephalogram (EEG) data effectively, which contains both temporal and spatial information. Recently, deep learning technology has been widely applied to perform image processing tasks, which could learns useful features from data and process multi-channel data automatically. To provide an effective system for automatic seizure detection, we proposed a new three-dimensional (3D) convolutional neural network (CNN) structure, whose inputs are multi-channel EEG signals.

Methods

EEG data of 13 patients were collected from one center hospital, which has already been inspected by experts. To represent EEG data in CNN, firstly time series of each channel of EEG data was converted into the two-dimensional image. Then all channel images were combined into 3D images according to the mutual correlation intensity between different electrodes. Finally, a CNN was constructed using 3D kernels to predict different stages of EEG data, including inter-ictal, pre-ictal, and ictal stages. The system performance was evaluated and compared with the traditional feature-based classifier and the two-dimensional (2D) deep learning method.

Results

It demonstrated that multi-channel EEG data could provide more information for increasing the specificity and sensitivity in cpmparison result between the single and multi-channel. And the 3D CNN based on multi-channel outperformed the 2D CNN and traditional signal processing methods with an accuracy of more than 90%, an sensitivity of 88.90% and an specificity of 93.78%.

Conclusions

This is the first effort to apply 3D CNN in detecting seizures from EEG. It provides a new way of learning patterns simultaneously from multi-channel EEG signals, and demonstrates that deep neural networks in combination with 3D kernels can establish an effective system for seizure detection.

     

Automated EEG signal analysis for identification of epilepsy seizures and brain tumour

Abstract

Electroencephalography (EEG) is a clinical test which records neuro-electrical activities generated by brain structures. EEG test results used to monitor brain diseases such as epilepsy seizure, brain tumours, toxic encephalopathies infections and cerebrovascular disorders. Due to the extreme variation in the EEG morphologies, manual analysis of the EEG signal is laborious, time consuming and requires skilled interpreters, who by the nature of the task are prone to subjective judegment and error. Further, manual analysis of the EEG results often fails to detect and uncover subtle features. This paper proposes an automated EEG analysis method by combining digital signal processing and neural network techniques, which will remove error and subjectivity associated with manual analysis and identifies the existence of epilepsy seizure and brain tumour diseases. The system uses multi-wavelet transform for feature extraction in which an input EEG signal is decomposed in a sub-signal. Irregularities and unpredictable fluctuations present in the decomposed signal are measured using approximate entropy. A feed-forward neural network is used to classify the EEG signal as a normal, epilepsy or brain tumour signal. The proposed technique is implemented and tested on data of 500 EEG signals for each disease. Results are promising, with classification accuracy of 98% for normal, 93% for epilepsy and 87% for brain tumour. Along with classification, the paper also highlights the EEG abnormalities associated with brain tumour and epilepsy seizure.     

Deep learning approach to detect seizure using reconstructed phase space images

Epilepsy is a chronic neurological disorder that affects the function of the brain in people of all ages. It manifests in the electroencephalogram (EEG) signal which records the electrical activity of the brain. Various image processing, signal processing, and machine-learning based techniques are employed to analyze epilepsy, using spatial and temporal features. The nervous system that generates the EEG signal is considered nonlinear and the EEG signals exhibit chaotic behavior. In order to capture these nonlinear dynamics, we use reconstructed phase space (RPS) representation of the signal. Earlier studies have primarily addressed seizure detection as a binary classification (normal vs. ictal) problem and rarely as a ternary class (normal vs. interictal vs. ictal) problem. We employ transfer learning on a pre-trained deep neural network model and retrain it using RPS images of the EEG signal. The classification accuracy of the model for the binary classes is (98.5±1.5)% and (95±2)% for the ternary classes. The performance of the convolution neural network (CNN) model is better than the other existing statistical approach for all performance indicators such as accuracy, sensitivity, and specificity. The result of the proposed approach shows the prospect of employing RPS images with CNN for predicting epileptic seizures.