Towards development of a 3-state self-paced brain-computer interface.
Towards development of a 3-state self-paced brain-computer interface.
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DOI：
10.1155/2007/84386
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发表时间：
2007
影响因子：
--
通讯作者：
Birch GE
中科院分区：
文献类型：
--
作者：
Bashashati A;Ward RK;Birch GE
大多数现有的脑机接口（BCI）以所谓的同步范式检测特定的心理活动。与在特定系统定义的周期运行的同步系统不同，自定进度（异步）接口具有始终运行的优点。低频异步开关设计 (LF-ASD) 是一种 2 态自定进度 BCI，可检测正在进行的 EEG 中是否存在特定的手指运动。最近对 2 状态 LF-ASD 的评估显示，在固定假阳性率为 1% 的情况下，平均真阳性率为 41%。本文提出了两种能够处理空闲大脑状态的三态自定进度 BCI 设计。这两种提议的设计旨在检测正在进行的脑电图的右手和左手延伸。它们由两个连续的探测器组成。第一个检测是否存在右手或左手运动，第二个将检测到的运动分类为右手或左手运动。在对从四名健全人收集的脑电图数据进行离线分析时，3 状态脑机接口显示出与 2 状态系统相当的性能，并且如果用作 2 状态 BCI，即在检测右手或左手运动（无论运动类型如何）的存在时，性能会显着提高。在 3 状态自定进度 BCI 的背景下，其检测右手和左手延伸的平均真阳性率分别为 37.5% 和 42.8%（假阳性率为 1%），在 2 状态自定进度 BCI 的背景下，平均检测率为 58.1%（假阳性率为 1%）。
Most existing brain-computer interfaces (BCIs) detect specific mental activity in a so-called synchronous paradigm. Unlike synchronous systems which are operational at specific system-defined periods, self-paced (asynchronous) interfaces have the advantage of being operational at all times. The low-frequency asynchronous switch design (LF-ASD) is a 2-state self-paced BCI that detects the presence of a specific finger movement in the ongoing EEG. Recent evaluations of the 2-state LF-ASD show an average true positive rate of 41% at the fixed false positive rate of 1%. This paper proposes two designs for a 3-state self-paced BCI that is capable of handling idle brain state. The two proposed designs aim at detecting right- and left-hand extensions from the ongoing EEG. They are formed of two consecutive detectors. The first detects the presence of a right- or a left-hand movement and the second classifies the detected movement as a right or a left one. In an offline analysis of the EEG data collected from four able-bodied individuals, the 3-state brain-computer interface shows a comparable performance with a 2-state system and significant performance improvement if used as a 2-state BCI, that is, in detecting the presence of a right- or a left-hand movement (regardless of the type of movement). It has an average true positive rate of 37.5% and 42.8% (at false positives rate of 1%) in detecting right- and left-hand extensions, respectively, in the context of a 3-state self-paced BCI and average detection rate of 58.1% (at false positive rate of 1%) in the context of a 2-state self-paced BCI.