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

描述(申请人提供)：该项目的长期目标是恢复因脊髓损伤而瘫痪在颈部以下的人的手臂和手的功能。新植入的神经假体设备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的运动。安装在轮椅上的机械臂还可以为严重瘫痪的人提供伸展和抓取能力。然而，这些技术目前的一个限制是，用户必须能够向设备传达他们希望他们的手臂和手如何移动。在颈部以下瘫痪的人中，任何辅助设备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、触摸舌头的键盘或下巴操作的操纵杆，可能会很笨拙，可能会干扰交谈、饮食和正常的社交活动。直接从大脑获得所需的肢体运动将允许这些人仅仅通过考虑这样做来移动他们的手臂和手，同时还允许他们保持面部和嘴巴的正常使用。两种主要类型的植入式脑记录技术正在开发和商业化，供慢性人类使用：1)植入大脑几毫米处的皮质内小型微电极，可以检测许多单个神经元的放电活动；2)更大的皮质外电极，检测大脑以外位置更大组神经元的平均电活动。这两种类型的记录技术都显示出作为一种手段来生成用于控制辅助设备的移动命令的前景。大脑皮质内微电极已经用于猴子和人类身上，直接控制计算机光标和机械臂的二维和三维运动。皮质外大脑记录也被用于人类来控制计算机光标和机器人的二维运动。目前的研究将使用猴子模型，在该模型中，每只动物都会接受两种类型的大脑记录技术，其配置类似于可能在未来五年内对瘫痪的人类进行商业使用的配置。然后将开发方法，将来自每种类型的大脑记录技术的信号转换为使用当前上肢神经假体系统所需的特定运动指令(即，将手放在空间中的什么位置，手的张开/闭合程度，前臂的旋前/旋后角，以及手腕的屈伸角度)。将测量由每种类型的脑记录技术产生的运动命令的速度、准确性和稳定性。通过开发使用这两种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，这项研究将推动这两种脑记录技术进入实际应用，同时为潜在用户提供他们所需的性能信息，以权衡这些好处与固有风险，并确定这些植入的脑记录系统中的任何一种对他们来说都是正确的。与公共卫生相关：植入的设备现在可以用来激活瘫痪患者的肌肉，恢复手臂和手的运动。这个项目的目标是使这些瘫痪的人能够控制自己的手臂和手的运动，只要想到这样做就行了。这项研究开发了使用两种不同类型的传感器从大脑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，以确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.