Laboratory of Brain-Computer Interfaces, Institute for Knowledge Discovery, Graz University of Technology Graz, Austria.
Front Neurosci. 2010 Apr 21;4:30. doi: 10.3389/fnpro.2010.00003. eCollection 2010.
Nowadays, everybody knows what a hybrid car is. A hybrid car normally has two engines to enhance energy efficiency and reduce CO2 output. Similarly, a hybrid brain-computer interface (BCI) is composed of two BCIs, or at least one BCI and another system. A hybrid BCI, like any BCI, must fulfill the following four criteria: (i) the device must rely on signals recorded directly from the brain; (ii) there must be at least one recordable brain signal that the user can intentionally modulate to effect goal-directed behaviour; (iii) real time processing; and (iv) the user must obtain feedback. This paper introduces hybrid BCIs that have already been published or are in development. We also introduce concepts for future work. We describe BCIs that classify two EEG patterns: one is the event-related (de)synchronisation (ERD, ERS) of sensorimotor rhythms, and the other is the steady-state visual evoked potential (SSVEP). Hybrid BCIs can either process their inputs simultaneously, or operate two systems sequentially, where the first system can act as a "brain switch". For example, we describe a hybrid BCI that simultaneously combines ERD and SSVEP BCIs. We also describe a sequential hybrid BCI, in which subjects could use a brain switch to control an SSVEP-based hand orthosis. Subjects who used this hybrid BCI exhibited about half the false positives encountered while using the SSVEP BCI alone. A brain switch can also rely on hemodynamic changes measured through near-infrared spectroscopy (NIRS). Hybrid BCIs can also use one brain signal and a different type of input. This additional input can be an electrophysiological signal such as the heart rate, or a signal from an external device such as an eye tracking system.
如今，大家都知道混合动力汽车是什么。混合动力汽车通常有两个引擎，以提高能源效率并减少二氧化碳排放。同样，混合脑机接口（BCI）由两个 BCI 组成，或者至少一个 BCI 和另一个系统。与任何 BCI 一样，混合 BCI 必须满足以下四个标准：（i）设备必须依赖于直接从大脑记录的信号；（ii）必须有至少一个可记录的大脑信号，用户可以有意调节以影响目标导向的行为；（iii）实时处理；（iv）用户必须获得反馈。本文介绍了已经发表或正在开发的混合 BCI。我们还介绍了未来工作的概念。我们描述了分类两种 EEG 模式的 BCI：一种是感觉运动节律的事件相关（去）同步（ERD、ERS），另一种是稳态视觉诱发电位（SSVEP）。混合 BCI 可以同时处理其输入，或者顺序运行两个系统，其中第一个系统可以充当“大脑开关”。例如，我们描述了一种同时结合 ERD 和 SSVEP BCI 的混合 BCI。我们还描述了一种顺序混合 BCI，其中受试者可以使用大脑开关来控制基于 SSVEP 的手部矫形器。使用这种混合 BCI 的受试者表现出的假阳性率约为单独使用 SSVEP BCI 时的一半。大脑开关还可以依赖于通过近红外光谱（NIRS）测量的血液动力学变化。混合 BCI 也可以使用一种大脑信号和另一种类型的输入。此附加输入可以是诸如心率的电生理信号，或者是来自外部设备（例如眼动跟踪系统）的信号。
