基于脑-机接口技术的虚拟现实康复训练平台

对神经损伤的瘫痪病人进行功能恢复训练时应强调患者的主动参与。开发了一套基于脑-机接口技术的虚拟现实康复训练平台。该平台采用患者在想象运动时的脑电信号作为虚拟人运动的控制信号,从而把想象运动与运动功能恢复训练结合在一起。由于虚拟现实系统的实时性与沉浸感能给受试者提供较好的训练反馈信息,因此,使用本平台有望改善患者的训练效果。详细介绍了快速在线脑-机接口算法以及虚拟现实的实时交互技术,并提供了三名受试者的实测结果。初步实验证明了该平台设计的可行性。     

一种运动想象脑机接口训练系统的设计

目的 为提高运动想象的脑机接口训练速度和效率,本文设计了一种训练系统.系统功能主要包括参数设置、EEG采集、特征提取、分类及其结果反馈、分类器模型建立.方法 在训练系统设计中,首先使用VC＋＋编写的脑电信号采集软件获取脑电信号,而后通过TCP/IP实现与MATLAB之间的数据传输,在MATLAB中实现特征提取与分类识别,并将识别结果实时反馈给受试者,使受试者能够及时调整自身状态,并选择合适的反馈方式,从而在较短时间内生成有效的分类器模型.结果 该系统具有接口方便、功能强大、界面友好的特点,通过建立的在线系统对训练系统进行了初步检验.结论 该系统可使使用者进行方便有效的训练,进而缩短训练时间并提高脑机接口系统的识别正确率,为脑机接口应用系统的实现奠定了基础.     

基于脑电信号的神经反馈系统研究

神经反馈技术是一种可供选择的行为学治疗手段,是将脑电(EEG)信号转换成容易被人们理解的声音、动画等形式,受试者通过训练,选择性地增强或抑制某一频段的EEG信号,可以达到调节脑功能的目的。本文基于脑-机接口技术,从实时EEG信号中提取特征参数并产生反馈信息,针对放松训练和注意力训练设计了两个反馈界面,搭建了一套完整的神经反馈系统。通过系统仿真和初步实验,验证了本套神经反馈系统的准确性和可行性。     

脊髓小脑共济失调的运动想象脑电信号分析

通过基于运动想象脑电信号的脑机接口系统, 研究对比了5名脊髓小脑共济失调患者和5名健康受试者,在运动想象状态与思想放松状态下的脑电信号功率谱、地形图、差值地形图等指标。研究发现,同健康受试者相比,脊髓小脑共济失调患者的事件相关去同步相关区域有所扩大,而且相关域的面积与共济失调功能分级近似呈线性关系。因此可以利用运动想象脑电信号,判断受试者是否存在脊髓小脑共济失调病症以及症状轻重程度。另外,健康受试者利用脑-机接口系统对光标运动控制的平均成功率为8425%,脊髓小脑共济失调患者为6575%。实验表明,同健康受试者相比,脊髓小脑共济失调患者的实验成功率明显降低,但仍可以使用脑机接口系统实现外部控制。     

基于MI-BCI的上肢在线运动康复原型系统

目的为实现单侧肢体运动想象与实际运动康复的身体部位及运动模式的一致化,进一步改善康复效果,本文设计了一种基于MI-BCI的上肢在线运动功能康复原型系统。方法该系统主要包括以g.MOBIlab脑电仪为核心的运动想象脑电信号(motor imagery electroencephalogram,MI-EEG)实时采集模块、在线处理模块及机械手臂控制模块等几部分。利用MATLAB和C语言混合编程及多线程技术完成对MI-EEG的实时采集、眼电伪迹去除、特征提取与分类,基于ARM9的S3C2440A微处理器设计机械手臂控制系统,控制模块与PC机间采用基于请求响应模式的通信协议,用手臂伸/屈MI-EEG的分类结果实现对机械手臂伸/屈同运动模式的实时控制。结果对5名受试者进行实际测试,对手臂伸/屈MI-EEG的平均识别率为76.75%,验证了系统的实用性。结论本系统具有良好的自适应性和实时性,为研制出更加自然、可临床应用的上肢运动康复系统奠定了基础。     

一种基于两种不同范式的混合型脑-机接口系统

混合模式脑机接口是脑-机接口研究的一个新方向,它为进一步提高脑-机接口系统性能提供了可能。现有的混合模式脑-机接口所采用的范式通常需要借助较强的视觉刺激,容易引起受试者疲劳等问题。本研究提出将运动想象和运动起始时刻视觉诱发电位两种无需强烈视觉刺激的范式以串行的方式相结合,通过运动起始时刻视觉诱发电位控制字符的输入,通过运动想象控制界面的开关和允许输入下一字符,实现了一种可用于字符输入的混合模式脑-机接口系统。为了验证系统的可行性,共完成了5例实验。实验中受试者首先进行两种范式的训练,然后进行开关系统界面和输入字符的测试。实验结果显示,经过一定训练的受试可以较好地完成系统的操作,运动想象单步操作平均时间最短为3.9 s,字符输入的正确率最高可达93.3%。除了不容易令受试者产生疲劳外,本系统相比单一感觉模式的脑-机接口也具有可完成任务种类多、控制方式灵活等优势。     

基于EMD-多尺度熵和ELM 的运动想象脑电特征提取和模式识别

运动想象脑电特征是进行动作模式识别进而实现生物反馈技术的重要依据。在对侧躯体运动想象脑电识别方法的基础上,研究单侧躯体不同运动想象模式下的脑电特征提取问题,提出基于EMD-多尺度熵(MSE)的脑电信号瞬态特征提取及定量描述的方法,设计基于极限学习机(ELM)的动作模式识别模型。通过对10名正常受试者在左侧手臂屈、伸动作模式下的运动想象脑电的分析,提取其特征并进行动作识别,结果证实其识别率可以达到90%以上。实验表明：所提出基于EMD-MSE的运动想象EEG特征提取方法,能够定量刻画不同运动模式下脑电信号的多尺度局部瞬态特征;进一步运用基于ELM学习算法的前馈神经网络,可以实现对不同运动模式下脑电EMD-SME特征的有效分类。     

基于功能性近红外光谱识别右脚三种想象动作研究

基于功能性近红外光谱(fNIRS)的脑机接口(BCI)是一种新型的人机交互手段。为探究单个肢体不同运动想象动作fNIRS信号的可分性,研究采集了15名受试者(业余足球爱好者)在想象右脚三种动作(传球、停球和射门)期间的fNIRS信号,提取了不同想象动作期间HbO信号的相关系数作为特征,构造了基于支持向量机的三分类模型。试验结果发现:右脚三种想象动作的分类准确率为78.89%±6.161%;两类运动想象动作的分类,即传球与停球、传球与射门和停球与射门的分类准确率分别为85.17%±4.768%、82.33%±6.011%、89.33%±6.713%。研究结果表明单个肢体不同运动想象的fNIRS具有可分性,这可望为fNIRS-BCI增加新的控制命令,也可为单侧中风患者康复训练和控制外设提供一种新的选择。此外,研究也表明相关系数可以作为分类不同想象动作的一种有效特征。     

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.     

基于Java3D的虚拟飞机脑机交互应用系统设计

目的本文基于Java3D设计了虚拟飞机脑机交互（braincomputerinterface,BCI）应用系统．研究BCI对虚拟飞机的控制效果。方法通过TCP／IP协议将BCI中对脑电信号（electroencephalogram．EEG）分析处理的结果传给Java3D应用系统,进而将结果转换成对应的控制命令,实现实时控制虚拟飞机的飞行,可以直观反映并检验BCI的控制效果。应用系统的设计分为两个步骤：一是搭建三维虚拟场景,其中包括建立场景模型和设计场景的布局;二是虚拟飞机飞行控制的设计,以实现飞机前进和旋转的飞行控制。结果本应用系统能够实时正确通过TCP／IP接收EEG信号的分析结果,实时控制虚拟飞机的连续飞行运动。结论初步验证了Java3D应用系统的可行性,为BCI应用系统的设计提供了新的方法和发展方向。     

Mirror neural training induced by virtual reality in brain-computer interfaces may provide a promising approach for the autism therapy

Previous studies have suggested that the dysfunction of the human mirror neuron system (hMNS) plays an important role in the autism spectrum disorder (ASD). In this work, we propose a novel training program from our interdisciplinary research to improve mirror neuron functions of autistic individuals by using a BCI system with virtual reality technology. It is a promising approach for the autism to learn and develop social communications in a VR environment. A test method for this hypothesis is also provided.     

Brain–computer interface: Changes in performance using virtual reality techniques

The ability to control electroencephalographic (EEG) signals when different mental tasks are carried out would provide a method of communication for people with serious motor function problems. This system is known as a brain–computer interface (BCI). Due to the difficulty of controlling one's own EEG signals, a suitable training protocol is required to motivate subjects, as it is necessary to provide some type of visual feedback allowing subjects to see their progress. Conventional systems of feedback are based on simple visual presentations, such as a horizontal bar extension. However, virtual reality is a powerful tool with graphical possibilities to improve BCI-feedback presentation. The objective of the study is to explore the advantages of the use of feedback based on virtual reality techniques compared to conventional systems of feedback. Sixteen untrained subjects, divided into two groups, participated in the experiment. A group of subjects was trained using a BCI system, which uses conventional feedback (bar extension), and another group was trained using a BCI system, which submits subjects to a more familiar environment, such as controlling a car to avoid obstacles. The obtained results suggest that EEG behaviour can be modified via feedback presentation. Significant differences in classification error rates between both interfaces were obtained during the feedback period, confirming that an interface based on virtual reality techniques can improve the feedback control, specifically for untrained subjects.     

Beyond Distraction: Virtual Reality Graded Exposure Therapy as Treatment for Pain‐Related Fear and Disability in Chronic Pain

The current review describes a novel virtual reality (VR) paradigm intended to optimize graded exposure treatment for pain‐related fear and associated disability in chronic musculoskeletal pain, focusing on chronic low back pain. By combining an established treatment protocol with the innovative Kinect system by Microsoft, virtual reality graded exposure therapy (VRGET) addresses several central limitations of traditional exposure and VR approaches to pain/disability treatment. In addition to mitigating costs associated with traditional exposure protocols, the VRGET platform facilitates patient treatment engagement, provides real‐time assessment of valuable outcome variables such as affective response and kinematic adaptation, and promotes generalizability of treatment gains across clinical and home environments. The current review provides an overview of current and future clinical directions for this new technology.     

Virtual reality for relearning daily living skills

The explosive increase in the power of computers has enabled the creation of fast, interactive 3D environments, sometimes called virtual reality (VR). This technology, often associated with arcade games, is increasingly being used for more serious applications. This paper describes research showing transfer of skills from a virtual environment to the real world. We then describe our VR authoring tool and an application to help cognitively impaired individuals relearn important daily living skills. Additionally we describe the development of a prototype networked system to enable a doctor to monitor remotely the rehabilitation of a group of patients.     

The use of virtual reality in assessment and treatment of anxiety and related disorders

In recent years the development of new virtual environments has been qualitatively high and fast at the same time, but the dissemination of virtual reality (VR) in clinical practice is still scarce. The aim of this review is to give an insight into the state of the art of the use of VR as an assessment tool and treatment intervention in anxiety and related disorders as posttraumatic stress disorder and obsessive–compulsive disorders. Besides an overview into the efficacy of VR, a summary will be given on assumed working mechanisms in virtual reality exposure therapy and how this aligns with current theoretical models. Further, it will be discussed how VR is accepted by patients and research into the reluctance of therapist to use this technology during treatment with focus on the therapeutic alliance and how it may be influenced by the use of VR. Finally, we discuss clinical and future issues as, for example, dissemination into clinical practice and what VR has to offer therapists in future. This not only in adult population but as well in younger patients, as young adolescents VR has a great potential as it connects easily with its playful elements to this population and might be a low threshold step to offer treatment or preventive interventions.     

Case study: using a virtual reality computer game to teach fire safety skills to children diagnosed with fetal alcohol syndrome

OBJECTIVE: To assess the effectiveness of a computer-based virtual reality (VR) game in teaching five children diagnosed with fetal alcohol syndrome (FAS) fire safety skills and to generalize these skills to a real world simulation. METHOD: Children participated in a study by using a multiple baseline, multiple probe design. Before the game, no child could correctly describe what actions to take during a home fire. A computerized game allowed them to learn the recommended safety steps in a virtual world. Skill learning and real-world generalization were tested immediately after the intervention and at 1-week post-test. RESULTS: All children reached 100% accuracy on the computer intervention, defined as successfully completing each of the safety steps. At the 1-week follow-up, all the children were able to perform the steps correctly in a real world simulation. CONCLUSIONS: The results suggest that this method of intervention warrants further study as an educational delivery system for children with FAS.