Barreto A B, Scargle S D, Adjouadi M
Department of Electrical and Computer Engineering, Florida International University, Miami 33174, USA.
J Rehabil Res Dev. 2000 Jan-Feb;37(1):53-63.
In line with the mission of the Assistive Technology Act of 1998 (ATA), this study proposes an integrated assistive real-time system which "affirms that technology is a valuable tool that can be used to improve the lives of people with disabilities." An assistive technology device is defined by the ATA as "any item, piece of equipment, or product system, whether acquired commercially, modified, or customized, that is used to increase, maintain, or improve the functional capabilities of individuals with disabilities." The purpose of this study is to design and develop an alternate input device that can be used even by individuals with severe motor disabilities. This real-time system design utilizes electromyographic (EMG) biosignals from cranial muscles and electroencephalographic (EEG) biosignals from the cerebrum's occipital lobe, which are transformed into controls for two-dimensional (2-D) cursor movement, the left-click (Enter) command, and an ON/OFF switch for the cursor-control functions. This HCI system classifies biosignals into "mouse" functions by applying amplitude thresholds and performing power spectral density (PSD) estimations on discrete windows of data. Spectral power summations are aggregated over several frequency bands between 8 and 500 Hz and then compared to produce the correct classification. The result is an affordable DSP-based system that, when combined with an on-screen keyboard, enables the user to fully operate a computer without using any extremities.
根据1998年《辅助技术法案》（ATA）的使命，本研究提出了一种集成辅助实时系统，该系统“确认技术是一种宝贵工具，可用于改善残疾人的生活”。ATA将辅助技术设备定义为“任何物品、设备或产品系统，无论是商业购买、改装还是定制的，用于增加、维持或改善残疾人的功能能力”。本研究的目的是设计和开发一种即使是严重运动残疾人士也能使用的替代输入设备。这种实时系统设计利用来自颅肌的肌电图（EMG）生物信号和来自大脑枕叶的脑电图（EEG）生物信号，将其转换为二维（2-D）光标移动、左键点击（Enter）命令以及光标控制功能的开/关切换的控制信号。该人机交互（HCI）系统通过应用幅度阈值并对离散数据窗口执行功率谱密度（PSD）估计，将生物信号分类为“鼠标”功能。在8至500Hz的几个频段上汇总频谱功率总和，然后进行比较以产生正确的分类。结果是一个基于经济实惠的数字信号处理器（DSP）的系统，当与屏幕键盘结合使用时，用户无需使用任何肢体就能完全操作计算机。
