Nezamfar Hooman, Mohseni Salehi Seyed Sadegh, Higger Matt, Erdogmus Deniz
Cognitive Systems Laboratory, Electrical and Computer Engineering Department, Northeastern University, Boston, MA 02115, USA.
Brain Sci. 2018 Jul 7;8(7):130. doi: 10.3390/brainsci8070130.
Even with state-of-the-art techniques there are individuals whose paralysis prevents them from communicating with others. Brain⁻Computer-Interfaces (BCI) aim to utilize brain waves to construct a voice for those whose needs remain unmet. In this paper we compare the efficacy of a BCI input signal, code-VEP via Electroencephalography, against eye gaze tracking, among the most popular modalities used. These results, on healthy individuals without paralysis, suggest that while eye tracking works well for some, it does not work well or at all for others; the latter group includes individuals with corrected vision or those who squint their eyes unintentionally while focusing on a task. It is also evident that the performance of the interface is more sensitive to head/body movements when eye tracking is used as the input modality, compared to using c-VEP. Sensitivity to head/body movement could be better in eye tracking systems which are tracking the head or mounted on the face and are designed specifically as assistive devices. The sample interface developed for this assessment has the same reaction time when driven with c-VEP or with eye tracking; approximately 0.5⁻1 second is needed to make a selection among the four options simultaneously presented. Factors, such as system reaction time and robustness play a crucial role in participant preferences.
即使采用了最先进的技术，仍有一些瘫痪患者无法与他人交流。脑机接口（BCI）旨在利用脑电波为那些需求尚未得到满足的人构建一种声音。在本文中，我们将脑机接口的输入信号——通过脑电图获得的编码视觉诱发电位（code-VEP）与最常用的方式之一——眼动追踪的效果进行了比较。这些针对无瘫痪健康个体的结果表明，虽然眼动追踪对一些人效果良好，但对另一些人则效果不佳或完全不起作用；后一组包括视力矫正者或在专注于某项任务时会无意眯眼的人。同样明显的是，与使用c-VEP相比，当使用眼动追踪作为输入方式时，接口的性能对头部/身体运动更为敏感。在专门设计为辅助设备的、追踪头部或安装在面部的眼动追踪系统中，对头部/身体运动的敏感度可能会更好。为此次评估开发的示例接口在由c-VEP或眼动追踪驱动时具有相同的反应时间；在同时呈现的四个选项中做出选择大约需要0.5到1秒。系统反应时间和鲁棒性等因素在参与者的偏好中起着至关重要的作用。
