物理化学学报 >> 2020, Vol. 36 >> Issue (12): 2003014.doi: 10.3866/PKU.WHXB202003014

所属专题: 神经界面

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面向脑机接口的犹他神经电极技术

谢凡, 奚野, 徐庆达, 刘景全()   

  • 收稿日期:2020-03-05 录用日期:2020-05-11 发布日期:2020-05-14
  • 通讯作者: 刘景全 E-mail:jqliu@sjtu.edu.cn
  • 作者简介:刘景全,出生于1971年。本科毕业于吉林工业大学(现吉林大学)。现为上海交通大学教授,博士生导师,主要研究方向:生物医学微机电系统、极端环境微传感器与微执行器、微能源技术
  • 基金资助:
    国家重点研发计划(2017YFB1002501);国家自然科学基金(61728402);上海市科委项目(17JC1402800);上海市优秀学术/技术带头人计划(18XD1401900)

Utah Neural Electrode Technology for Brain-Computer Interface

Fan Xie, Ye Xi, Qingda Xu, Jingquan Liu()   

  • Received:2020-03-05 Accepted:2020-05-11 Published:2020-05-14
  • Contact: Jingquan Liu E-mail:jqliu@sjtu.edu.cn
  • Supported by:
    the National Key R & D Program of China(2017YFB1002501);the National Natural Science Foundation of China(61728402);the Research Program of Shanghai Science and Technology Committee, China(17JC1402800);the Program of Shanghai Academic/Technology Research Leader, China(18XD1401900)

摘要:

脑机接口(Brain-computer interface,BCI),是指在人或动物脑与计算机或其它电子设备之间建立的连接通路,实现了脑与外部设备的直接交互,在认识脑、保护脑和模拟脑方面有着重要的作用,尤其是将来可用于治疗患有神经系统疾病的患者,使他们受损的运动和感知等功能得以恢复。神经电极作为脑机接口的核心部分,是与神经元相互作用的电生理器件,可以用来记录或干预神经活动状态,由美国犹他大学提出的犹他电极阵列(Utah Electrode Array,UEA)是神经电极的一个典型代表。犹他独特的三维针状结构使每个电极具有高时空分辨率的同时相互之间有良好的绝缘,植入后电极尖端只作用于周围一小群神经元,甚至可以记录单个神经元的放电活动。本文主要介绍了UEA的结构、制造工艺流程和功能特点,重点论述其在高密度阵列、无线传输、光电极阵列等方面的研究进展,同时分析了可用于提高电极可靠性的表面修饰方法,并举例说明了UEA的临床应用,最后对未来的发展趋势进行了展望。

关键词: 神经电极, 植入式, 犹他电极阵列, 表面修饰, 生物相容性

Abstract:

A human brain is composed of a large number of interconnected neurons forming a neural network. To study the functional mechanism of the neural network, it is necessary to record the activity of individual neurons over a large area simultaneously. Brain-computer interface (BCI) refers to the connection established between the human/animal brain and computers/other electronic devices, which enables direct interaction between the brain and external devices. It plays an important role in understanding, protecting, and simulating the brain, especially in helping patients with neurological disorders to restore their impaired motor and sensory functions. Neural electrodes are electrophysiological devices that form the core of BCI, which convert neuronal electrical signals (carried by ions) into general electrical signals (carried by electrons). They can record or interfere with the state of neural activity. The Utah Electrode Array (UEA) designed by the University of Utah is a mainstream neural electrode fabricated by bulk micromachining. Its unique three-dimensional needle-like structure enables each electrode to obtain high spatiotemporal resolution and good insulation between each other. After implantation, the tip of each electrode affects only a small group of neurons around it even allowing to record the action potential of a single neuron. The availability of a large number of electrodes, high quality of signals, and long service life has made UEA the first choice for collecting neuronal signals. Moreover, UEA is the only implantable neural electrode that can record signals in the human cerebral cortex. This article mainly serves as an introduction to the construction, manufacturing process, and functioning of UEA, with a focus on the research progress in fabricating high-density electrode arrays, wireless neural interfaces, and optrode arrays using silicon, glass, and metal as that material of construction. We also discuss the surface modification techniques that can be used to reduce the electrode impedance, minimize the rejection by brain tissue, and improve the corrosion resistance of the electrode. In addition, we summarize the clinical applications where patients can control external devices and get sensory feedback by implanting UEA. Furthermore, we discuss the challenges faced by existing electrodes such as the difficulty in increasing electrode density, poor response of integrated wireless neural interface, and the problems of biocompatibility. To achieve stability and durability of the electrode, advancements in both material science and manufacturing technology are required. We hope that this review can broaden the scope of ideas for the development of UEA. The realization of a fully implantable neural microsystem can contribute to an improved understanding of the functional mechanisms of the neural network and treatment of neurological diseases.

Key words: Neural electrode, Implantable, Utah electrode array, Surface modification, Biocompatibility

MSC2000: 

  • O646