背景:脑机接口可以通过将与尝试的语音相关的皮层活动转换为计算机屏幕上的文本来实现瘫痪者的交流。与脑机接口的通信受到广泛的培训要求和有限的准确性的限制。
方法:一名患有肌萎缩性侧索硬化症(ALS)并伴有严重构音障碍的45岁男子在发病5年后接受了4个微电极阵列在其左腹侧中央前回的手术植入;这些阵列记录了256个皮质内电极的神经活动。我们报告了解码他的皮质神经活动的结果,因为他试图在提示和非结构化的会话环境中讲话。解码后的单词显示在屏幕上,然后使用设计成听起来像他的ALS前语音的文本到语音软件发声。
结果:在使用的第一天(手术后25天),神经假体在50个单词的词汇量下达到99.6%的准确率.当参与者试图说话时,神经假体的校准需要30分钟的皮质记录,随后进行后续处理。第二天,经过1.4个小时的系统培训,使用125,000个单词的词汇量,神经假体的准确率达到90.2%.随着进一步的培训数据,神经假体在手术植入后8.4个月内保持了97.5%的准确率,参与者使用它以每分钟约32个单词的速度进行自定进度对话,累计超过248个小时。
结论:在患有ALS和严重构音障碍的人中,经过简短的训练,皮质内语音神经假体达到了适合恢复对话交流的性能水平。(由负责卫生事务的助理国防部长办公室和其他人资助;BrainGate2ClinicalTrials.gov编号,NCT00912041。).
BACKGROUND: Brain-computer interfaces can enable communication for people with paralysis by transforming cortical activity associated with attempted speech into text on a computer screen. Communication with brain-computer interfaces has been restricted by extensive training requirements and limited accuracy.
METHODS: A 45-year-old man with amyotrophic lateral sclerosis (ALS) with tetraparesis and severe dysarthria underwent surgical implantation of four microelectrode arrays into his left ventral precentral gyrus 5 years after the onset of the illness; these arrays recorded neural activity from 256 intracortical electrodes. We report the results of decoding his cortical neural activity as he attempted to speak in both prompted and unstructured conversational contexts. Decoded words were displayed on a screen and then vocalized with the use of text-to-speech software designed to sound like his pre-ALS voice.
RESULTS: On the first day of use (25 days after surgery), the neuroprosthesis achieved 99.6% accuracy with a 50-word vocabulary. Calibration of the neuroprosthesis required 30 minutes of cortical recordings while the participant attempted to speak, followed by subsequent processing. On the second day, after 1.4 additional hours of system training, the neuroprosthesis achieved 90.2% accuracy using a 125,000-word vocabulary. With further training data, the neuroprosthesis sustained 97.5% accuracy over a period of 8.4 months after surgical implantation, and the participant used it to communicate in self-paced conversations at a rate of approximately 32 words per minute for more than 248 cumulative hours.
CONCLUSIONS: In a person with ALS and severe dysarthria, an intracortical speech neuroprosthesis reached a level of performance suitable to restore conversational communication after brief training. (Funded by the Office of the Assistant Secretary of Defense for Health Affairs and others; BrainGate2 ClinicalTrials.gov number, NCT00912041.).