PLoS Biology:德国科学家利用人机接口帮助瘫痪患者进行沟通

摘要 : 2017年1月31日，国际著名学术杂志《PLoS Biology》上在线发表了德国图宾根大学Ujwal Chaudhary研究员和Niels Birbaumer研究员的一篇研究论文，研究报道了通过人机接口帮助完全瘫痪患者与外界进行了沟通交流

2017年1月31日，国际著名学术杂志《PLOS BioLogy》上在线发表了德国图宾根大学Ujwal Chaudhary研究员和Niels Birbaumer研究员的一篇研究论文，研究报道了通过人机接口帮助完全瘫痪患者与外界进行了沟通交流，研究成果对改善闭锁综合征患者的生活质量有极大影响。

完全瘫痪患者在医学上被称为闭锁综合征，多因脑桥基底部血栓所致。顾名思义，患者会被“锁定在自己的身体”里，但患者的大脑半球和脑干被盖部网状激活系统并未受损，因此意识可以保持清醒，对语言的理解也没有问题。不过，因为双侧皮质脑干束与皮质脊髓束均被阻断，患者运动性传出功能丧失，会表现为不能言语，失去身体控制能力。其中一部分患者仍可以利用眼睛运动来进行沟通，但另一些则失去了包括控制眼球移动在内的所有运动能力。

此前科学家已经知道，脑细胞活动会改变血液中的氧气水平，从而改变血液的颜色。此次，研究团队开发了一种“脑—机”界面，用于阅读完全瘫痪患者的想法。他们利用近红外光谱分析技术探测实验对象大脑血液颜色，尝试解读完全瘫痪患者的思维。这些实验对象处于“完全闭锁”状态，即连眼球都无法运动。

在实验中，他们尝试询问患者例如“你丈夫的姓名是否为某某”这类的问题，以训练计算机解读大脑信号。结果显示，解读的准确率达到了75%，这就意味着可以通过反复询问问题，最终确定患者的答案，以实现简单沟通的功能。

研究人员表示，这种形式可用作实际的日常交流手段，如探查患者的疼痛程度等，帮助完全瘫痪患者与外界产生交流，与周围世界进行第一步的互动。

原文链接：

Brain–Computer InterfAce–Based Communication in the Completely Locked-In State

原文摘要：

Despite partial success, communication has remained impossible for persons suffering from complete motor paralysis but intact cognitive and emotional processing, a state called complete locked-in state (CLIS). Based on a motor learning theoretical context and on the failure of neuroelectric brain–computer interface (BCI) communication attempts in CLIS, we here report BCI communication using functional near-infrared spectroscopy (fNIRS) and an implicit attentional processing procedure. Four patients suffering from advanced amyotrophic lateral sclerosis (ALS)—two of them in permanent CLIS and two entering the CLIS without reliable means of communication—learned to answer personal questions with known answers and open questions all requiring a “yes” or “no” thought using frontocentral oxygenation changes measured with fNIRS. Three patients completed more than 46 sessions spread over several weeks, and one patient (patient W) completed 20 sessions. Online fNIRS classification of personal questions with known answers and open questions using linear support vector machine (SVM) resulted in an above-chance-level correct response rate over 70%. Electroencephalographic oscillations and electrooculographic signals did not exceed the chance-level threshold for correct communication despite occasional differences between the physiological signals representing a “yes” or “no” response. However, electroencephalogram (EEG) changes in the theta-frequency band correlated with inferior communication performance, probably because of decreased vigilance and attention. If replicated with ALS patients in CLIS, these positive results could indicate the first step towards abolition of complete locked-in states, at least for ALS.

doi:10.1371/journal.pbio.1002593

作者：Ujwal Chaudhary

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