Restoring High Dimensional Hand Function to Persons with Chronic High Tetraplegia

目前的提议旨在开发一种由皮质信号直接控制的物理神经假体系统， 高位颈椎致慢性四肢瘫痪退伍军人手功能恢复 脊髓损伤(SCI)。这一独特的方法结合了皮质内脑机接口(IBCI)， 通过经皮功能性电刺激(FES)捕捉用户随意的运动 用于激活瘫痪肌肉的系统。虽然已经有研究努力使用脑机接口来控制运动 对于简单的计算机光标和机器人设备，本提案将调查恢复 高维多抓，控制自己瘫痪的手。一旦实现，该系统将使 患有高度颈椎SCI的退伍军人在皮质上掌握的手抓握模式比现在的FES所认识到的更多 神经假体系统，从而使它们能够执行更大范围的日常抓取任务。 灵巧的手功能是能够执行必要的物体操作的关键组件 成功地完成了各种各样的日常接触和掌握任务。例如，手抓握 捡起小的扁平物体所需的时间与与较大的圆柱形物体相互作用所需的时间不同，后者 不同于指向任务所需的手柄(例如，按下按钮)。当前的临床相关性 神经假体系统实现一个或最多两个预先编程的手部抓取模式 在两者之间切换，尽管通常不是无缝的。一种手抓式神经假体，允许用户使用更多种类 通过允许独立的拇指和食指控制，以及可能的更大的 一组可切换的预编程抓取模式，很可能证明在功能上优于电流 临床可用的系统。目前可用的系统在功能范围上受到部分限制，原因是 缺乏有效的信号来指挥增加抓握灵活性所需的多个维度。 通过皮质内脑机接口记录与手功能直接相关的脑信号 (IBCI)可以允许更丰富的信号源，以指挥更高维度的手功能。这项建议 因此，我将研究使用iBCI作为实现高维FES手的命令源 神经假体，通过调查1)从大脑皮质指挥多种握手类型的可能性 活动，以及2)从皮质活动中控制个人拇指和食指运动的可能性， 从而允许用户在创建他们自己的手柄时具有更大的灵活性。 拟议的工作将吸引退伍军人和其他参加BrainGate2试点临床试验的参与者。AS 作为BrainGate2试点临床试验的一部分，这些参与者将已经接受了两个皮质内注射 植入运动皮质区域的微电极，控制手臂和手的运动，以及b)经皮 由植入手臂和手部不同肌肉的细丝电极组成的FES系统 通过电刺激恢复伸手和抓握功能。因此，这项提议将允许直接 测试瘫痪退伍军人的控制概念。如果成功，建议的工作将1)导致 脑控高度灵巧的手神经假体用于瘫痪退伍军人，2)提供量化洞察力 关于iBCI在指挥退伍军人复杂神经假手功能方面的长期潜力 考虑神经损伤或疾病后皮质内植入以恢复功能抓握。

The current proposal aims to develop a physical neuroprosthesis system, directly controlled by cortical signals, to restore high-dimension hand functionality to Veterans with chronic tetraplegia resulting from high cervical spinal cord injury (SCI). This unique approach combines an intracortical brain-computer-interface (iBCI) that captures a user’s volitionally intended movements, with a percutaneous functional electrical stimulation (FES) system for activation of paralyzed muscles. While there exist research efforts to use BCIs to control the motion of simple computer cursors and robotic devices, the present proposal will investigate the possibility of restoring high-dimensional multi-grasp control of one’s own paralyzed hand. When realized, this system will enable Veterans with high cervical SCI to cortically command more hand grasp patterns than is realized by current FES neuroprosthetic systems, thereby allowing them to carry out a larger range of everyday grasping tasks. Dexterous hand function is a critical component to being able to perform the object manipulations necessary for successfully completing a wide variety of everyday reaching-and-grasping tasks. For example, the hand grasp required to pick up small flat objects differs from that required to interact with larger cylindrical objects, which differs from the hand grasp required for pointing tasks (e.g. pushing a button). Current clinically relevant neuroprosthetic systems implement one or at most two preprogrammed hand grasp patterns that the user can switch between, though usually not seamlessly. A hand grasp neuroprosthesis that allows users a larger variety of hand grasp patterns by allowing for independent thumb and index finger control, as well as possibly a larger set of switchable preprogrammed grasp patterns, will likely prove functionally advantageous over current clinically available systems. Currently available systems are partly limited in the scope of functionality due to the lack of available signals for commanding the multiple dimensions necessary for increased grasp flexibility. Recording of brain signals directly related to hand function, through an intracortical brain-computer-interface (iBCI) may allow for a richer source of signals for commanding higher dimensions of hand function. This proposal will thus investigate using iBCIs as a command source for implementing a high-dimensional FES hand neuroprostheses, by investigating 1) the possibility of commanding multiple hand grasp types from cortical activity, and 2) the possibility of commanding individual thumb and index movements from cortical activity, thereby allowing the user greater flexibility in creating their own hand grasps. The proposed work will engage Veterans and other participants enrolled in the BrainGate2 Pilot Clinical Trial. As part of the BrainGate2 Pilot Clinical Trial, these participants will already have received a) two intracortical microelectrodes implanted into motor cortical areas controlling arm and hand movements, and b) a percutaneous FES system consisting of small fine-wire electrodes implanted into various muscles of the arm and hand to restore reaching and grasping function through electrical stimulation. Thus this proposal will allow for direct testing of control concepts in Veterans with paralysis. When successful, the proposed work will 1) result in a brain-controlled highly dexterous hand neuroprosthesis for paralyzed Veterans, and 2) offer quantitative insight about the long term potential of iBCIs for commanding complex neuroprosthetic hand function for Veterans considering an intracortical implant for functional grasp restoration after neurological injury or disease.