Restoring Proprioception to Improve Balance and Gait in Lower-Limb Amputees

摘要 下肢截肢者可能会遭受各种各样的步态障碍， 补偿性运动，以大大高于平均人群的跌倒风险。这 增加的跌倒风险可以部分归因于触觉的减少或完全缺乏， 来自假肢的本体感受反馈。最近有很大的兴趣， 通过传感器化的神经假体提供感觉反馈。然而，这些研究 主要专注于恢复上肢截肢者的触觉反馈。本研究的目的是 为下肢截肢者提供自然的本体感觉反馈， 脊髓刺激（SCS）。实验将作为正在进行的NIH资助的 使用经FDA批准的SCS电极导线植入外侧腰椎硬膜外的项目 空间为了确定引起关节运动的自然感知所需的参数，我们 将首先评估刺激模式对诱发本体感受的自然性的影响 感觉使用适应性跨模态一致性效应（CCE）测试作为代理， 自然性，我们将量化哪些刺激模式（恒定频率或仿生） 创造更自然的感觉，如更高的CCE分数所示。的效果进行评价 为了刺激受试者将这些感知作为本体感觉纳入的能力，我们将使用 各种刺激模式与不同程度的自然和评估 静态或动态感知的本体感受准确性。我们亦会研究 诱发本体感觉对使用传感器假体改善步态和功能的作用 以提供关于关节角度的实时反馈。我们将使用临床和科学 本体感觉和步态功能的测量，以评估刺激的功效。我们 假设本体感觉的更自然的感觉将提供更大的准确性， 本体感觉的临床测试以及在更复杂的运动控制任务中的更大改善， 例如步态，从而改善下肢截肢者的活动性和安全性。

Abstract Lower-limb amputees can suffer from a wide range of gait impairments, ranging from compensatory movements to a substantially higher fall risk than the average population. This increased fall risk can be partially attributed to reduced or complete lack of tactile and proprioceptive feedback from the prosthetic limb. There has been significant recent interest in providing sensory feedback via sensorized neuroprostheses. However, these studies have primarily focused on restoring tactile feedback in upper-limb amputees. The aim of this study is to provide natural proprioceptive feedback in lower-limb amputees through lumbosacral spinal cord stimulation (SCS). Experiments will be conducted as an addition to an ongoing NIH-funded project using FDA-cleared SCS leads implanted percutaneously into the lateral lumbar epidural space. To determine the parameters required to evoke naturalistic percepts of joint motion, we will first evaluate the effects of stimulus patterning on the naturalness of evoked proprioceptive sensations. Using an adapted cross-modal congruency effect (CCE) test as a proxy for naturalness, we will quantify which stimulation patterns (constant frequency or biomimetic) create a more natural percept, as indicated by a higher CCE score. To evaluate the effect of stimulation on the subject’s ability to incorporate these percepts as proprioception, we will use a variety of stimulation patterns with varying degrees of naturalness and evaluate the proprioceptive accuracy for either static or dynamic percepts. We will also study the effect of evoked proprioceptive sensations on improving gait and function using a sensorized prosthesis to provide real-time feedback about joint angles. We will use both clinical and scientific measures of proprioception and gait function to evaluate the efficacy of stimulation. We hypothesize that more natural sensations of proprioception will provide greater accuracy in clinical tests of proprioception and greater improvements in more complex motor control tasks, such as gait, thereby improving the mobility and safety of lower-limb amputees.