Restoring High Dimensional Hand Function to Persons with Chronic High Tetraplegia

目前的提议旨在开发一种物理神经假体系统，直接由皮层信号控制， 恢复高维度的手功能，退伍军人与慢性四肢瘫痪造成的高颈部 脊髓损伤（SCI）。这种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）捕获用户的自愿预期运动 用于激活瘫痪肌肉的系统。虽然存在使用BCI来控制运动的研究努力， 简单的计算机光标和机器人设备，目前的建议将调查恢复的可能性， 对自己瘫痪手的高维多抓取控制。一旦实现，该系统将使 与当前FES相比，患有高位颈脊髓损伤的退伍军人在皮质上掌握更多的手抓握模式 神经假体系统，从而使他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对象操作的关键组成部分， 成功地完成各种各样的日常接触和抓取任务。例如，手抓 拾取小的扁平物体所需的力不同于与较大的圆柱形物体相互作用所需的力， 与指向任务（例如按下按钮）所需的手抓握不同。当前临床相关 神经假体系统实现一个或至多两个预先编程的手抓握模式 切换，虽然通常不是无缝的。一种手抓神经假体，允许用户进行更大范围的 通过允许独立的拇指和食指控制，以及可能更大的 一组可切换的预编程抓取模式，可能会证明在功能上优于当前的 临床上可用的系统。目前可用的系统在功能范围上部分受限， 缺乏用于控制增加抓取灵活性所需的多个维度的可用信号。 通过皮层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来命令更高维度的手功能。这项建议 因此，我们将研究如何使用iBCI作为实现高维FES手的命令源 神经假体，通过调查1）从皮层指挥多种手抓握类型的可能性， 活动，和2）指挥个人拇指和食指运动的可能性，从皮层活动， 从而允许使用者在创建他们自己的手抓握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BrainGate 2试点临床试验的参与者。作为 作为BrainGate 2试点临床试验的一部分，这些参与者将已经接受了a）两个皮质内 微电极，植入控制手臂和手运动的运动皮层区域，和B）经皮 FES系统由植入手臂和手部各种肌肉的小型细线电极组成， 通过电刺激恢复伸手和抓握功能。因此，该提案将允许直接 在瘫痪退伍军人中测试控制概念。如果成功，拟议的工作将1）导致 大脑控制的高度灵巧的手神经假体瘫痪的退伍军人，和2）提供定量的见解 关于iBCIs为退伍军人指挥复杂神经假肢手功能的长期潜力 考虑在神经损伤或疾病后使用皮质内植入物进行功能性抓握恢复。

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.