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脑电波输出成现实

关键字： 便携设备  Mind Speller 

来自欧洲研究机构IMEC旗下Holst Center的研究人员，以及鲁汶天主教大学神经与生理心理学实验室，合作展示了一套命名为“Mind Speller”的思想转文字(thought-to-text)装置，希望能为肢障者提供协助。

 

全世界有不少研究机构也在开发类似的装置，利用电子脑电图(EEG)与积极生物性回馈，让个人只要透过思想就能控制鼠标或是让计算机动作。整套Mind Speller系统的形状像是一顶帽子，IMEC表示它很容易穿戴也可携，能让瘫痪的病人或是有说话、语言障碍的患者进行沟通。

 

图：整套Mind Speller系统的形状像是一顶帽子

 

Mind Speller会撷取EEG轨迹，并将脑波转译为文字与句子；具体来说，该装置能侦测并转译人脑EEG讯号中被称为“P300”的事件相关电位，并从一个显示器上以交替式排列的字母表中选出字母。P300电位通常是在大脑的决策过程之中，用来做为认知功能指针；但目前能判读P300的装置通常又大又昂贵，也不方便使用。

 

新研发的Mind Speller则是一种便携设备，其主机只有火柴盒大小，连结到使用者头上戴着的、一顶内部特定位置配备电极的帽子，以撷取相关的EEG讯号。该火柴盒内的电子组件都是由Holst Center所开发，包括一款专门能处理EEG讯号的8信道芯片、一颗负责将EEG讯号数字化的商用微处理器，以及将EEG讯号无线传送至旁边PC的2.4GHz无线芯片。

 

Mind Speller所撷取到的信息，会透过一种讯号处理算法转译到PC上；该算法是由鲁汶天主教大学神经与生理心理学实验室教授Marc Van Hulle所开发。他表示，该装置是一种能轻松适应不同使用者的通用型设备，对有需要的身心障碍者来说，也是一种更具成本效益的通讯解决方案。

 

此外Van Hulle也指出，由于Mind Speller的原理与现有那些需要靠动作来驱动的装置完全不同，是透过侦测P300 EEG电位来判读人们的思想，因此能帮助更多行动不便的病患。而因为IMEC让装置可用干式电极来运作，也降低了使用上的困难度。

 

(参考原文： IMEC team shows wireless 'thought-to-text' cap，by Peter Clarke) 
下面是原文

NEWS FEATURE - IMEC team shows wireless 'thought-to-text' cap


addthis_pub = 'techinsights'; addthis_logo = 'http://www.techinsights.com/images/Img_TechInsightsLogo1.jpg'; addthis_logo_background = 'EFEFFF'; addthis_logo_color = '666699'; addthis_brand = 'Techinsights'; addthis_options = 'favorites, email, twitter, slashdot, digg, delicious, myspace, facebook, google, newsvine, linkedin, more'; By Peter Clarke   (03/23/10, 06:19:00 H EDT) LONDON — A team of researchers from IMEC, the Holst Center and the lab of neuro- and psychophysiology at the Katholieke Universiteit Leuven has presented Mind Speller, a thought-to-text device intended to help people with motor disabilities.

A number of research institutes are working on similar devices which make use of electro-encephalogram (EEG) brainwaves and positive biological feedback so that individuals can use thought processes alone to control a cursor or a computer action.

The Mind Speller comes in the form of a cap, which IMEC claimed is easy-to-wear and portable. The textual and verbal communications prototype device was presented at Medtech Conference in Stuttgart, Germany, and it is claimed that it could enable people suffering from paralysis or speech or language disorders to communicate.

The Mind Speller captures EEG traces and interprets the brain waves to spell words and phrases. Specifically it detects and interprets what are known as P300 event-related potentials in the EEG-signals of a person that is selecting characters from a display presenting alternate rows and columns of characters. P300 potentials are often used as metrics of cognitive function in decision making processes. However, currently available P300 devices are large, expensive and uncomfortable in use.

The Mind Speller, on the other hand, uses a portable device, the size of a matchbox, connected to a cap that contains electrodes located at specific positions on the head to capture the relevant EEG-signals. The electronics in the matchbox are developed by IMEC and the Holst Center. It contains IMEC's and Holst Center's proprietary eight-channel EEG-chip to process the EEG signals, a commercially available microcontroller that digitizes the EEG signals and a 2.4-GHz radio that transmits the EEG signals wirelessly to a nearby PC. The data is interpreted on the PC by signal processing algorithms developed by the team of Professor Marc Van Hulle at the lab of neuro- and psychophysiology of the Katholieke Universiteit Leuven.

"The Mind Speller is a generic device that can be easily adjusted to different users. Therefore, it could be a cost-efficient communication solution for people with temporal impairments for whom the existing solutions are too expensive. Moreover, the Mind Speller may help those patients that are not helped with the existing devices driven by motor activity, as the Mind Speller is based on a different principle, using P300 EEG potentials to read people's thoughts," said Professor Van Hulle.

IMEC is adapting the electronics to allow it to work with dry electrodes, thus making the system less difficult to use.