Intra vs. extracortical command signals to restore six dimensional hand movements

描述（由申请人提供）：该项目的长期目标是为因脊髓损伤而颈部以下瘫痪的人恢复手臂和手部功能。新的植入式神经修复装置现在可以通过电激活周围神经来恢复瘫痪患者的手臂和手部运动。安装在轮椅上的机械臂还可以为严重瘫痪的人提供伸手和抓握的能力。然而，目前这些技术的一个限制是，用户必须能够向设备传达他们希望自己的手臂和手如何移动。对于颈部以下瘫痪的人，任何辅助装置的控制选项都仅限于使用颈部以上的保留功能。许多命令选项，如语音命令、舌头触摸键盘或下巴操作的操纵杆，可能会让人感到尴尬，并且会干扰说话、吃饭和正常的社交互动。直接从大脑获取所需的肢体运动将允许这些人仅仅通过思考就可以移动他们的手臂和手，同时还允许他们保持正常的面部和嘴巴的使用。两种主要类型的植入脑记录技术正在开发和商业化，以供人类长期使用：1)小的皮质内微电极，植入大脑几毫米，可以检测许多单个神经元的放电活动；2)大的皮质外电极，从大脑外的位置检测更大的神经元群的平均电活动。这两种类型的记录技术都显示出了为控制辅助设备生成运动命令的希望。皮质内微电极已被用于猴子和人类，以直接控制计算机光标和机械臂的二维和三维运动。大脑皮层外的记录也被用于人类控制电脑光标和机器人的二维运动。目前的研究将使用一个猴子模型，在这个模型中，每只动物都接受两种类型的大脑记录技术，其配置类似于未来五年内可能用于瘫痪人类的商业配置。然后将开发各种方法，将来自每种脑记录技术的信号转化为使用当前上肢神经假体系统所需的特定运动指令（即，手在空间中的位置，手打开/关闭的程度，前臂的旋前/旋后角度以及手腕的屈曲/伸角）。每一种大脑记录技术产生的运动指令的速度、准确性和稳定性将被测量。通过开发使用这两种大脑记录技术来生成控制上肢神经假体所需的运动命令的方法，本研究将使这两种大脑记录技术向前推进到实际应用中，同时为潜在用户提供他们需要的性能信息，以权衡这些好处与固有风险，并决定这两种植入大脑记录系统中的任何一种是否适合他们。公共卫生相关性：现在有植入式装置可以激活瘫痪者的肌肉，以恢复手臂和手部的运动。这个项目的目标是让这些瘫痪的人仅仅通过思考就能控制他们自己的手臂和手的运动。这项研究开发了使用两种不同类型的传感器从大脑中检测一个人想要的运动的方法，然后为潜在用户提供他们需要的信息，以决定哪种类型的传感器适合他们。

DESCRIPTION (provided by applicant): The long-term goal of this project is to restore arm and hand function to people paralyzed below the neck due to a spinal cord injury. New implanted neuroprosthetic devices can now restore arm and hand movements to paralyzed individuals by electrically activating the peripheral nerves. Wheelchair-mounted robotic arms can also provide reach and grasp capabilities to the severely paralyzed. However, one current limitation of these technologies is that the user must be able to convey to the device how they want their arm and hand to move. In people paralyzed below the neck, control options for any assistive device are limited to using retained function from the neck up. Many command options, such as voice commands, tongue-touch keypads, or chin- operated joysticks, can be awkward and can interfere with talking, eating, and normal social interaction. Accessing desired limb movements directly from the brain would allow these people to move their arm and hand just by thinking about doing so while also allowing them to retain normal use of their face and mouth. Two main types of implanted brain recording technologies are being developed and commercialized for chronic human use: 1) small intracortical microelectrodes that are implanted a few millimeters into the brain and can detect the firing activity of many individual neurons, and 2) larger extracortical electrodes that detect the average electrical activity of larger groups of neurons from locations outside the brain. Both types of recording technologies have shown promise as a means to generate movement commands for controlling assistive devices. Intracortical microelectrodes have been used in monkeys and humans to directly control two- and three-dimensional movements of computer cursors and robotic arms. Extracortical brain recordings have also been used in humans to control the two-dimensional movements of computer cursors and robots. The present study will use a monkey model in which each animal receives both types of brain recording technologies in configurations similar to those likely to be commercially available to paralyzed humans within the next five years. Methods will then be developed to translate signals from each type of brain recording technology into the specific movement instructions needed to use the current upper-limb neuroprosthesis systems (i.e. where to place the hand in space, how much to open/close the hand, pronation/supination angle of the forearm, and wrist flexion/extension angle). The speed, accuracy, and stability of the movement commands generated with each type of brain recording technology will be measured. By developing methods for using both brain recording technologies to generate the movement commands needed to control an upper limb neuroprosthesis, this study will move both brain recording technologies forward into practical applications while providing potential users with the performance information they need to weigh these benefits against the inherent risks and decide if either of these implanted brain recording systems is right for them. PUBLIC HEALTH RELEVANCE: Implanted devices are now available that can activate muscles of paralyzed individuals to restore arm and hand movements. The goal of this project is to enable these paralyzed individuals to control the movements of their own arm and hand just by thinking about doing so. This study develops methods for detecting a person's desired movement from the brain using two different types of sensors and then provides potential users with the information they need to decide which type of sensor is right for them.