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

摘要 下肢截肢者可能会遭受广泛的步态损伤，范围从 补偿性流动导致的跌倒风险大大高于平均人口。这 跌倒风险的增加可以部分归因于减少或完全缺乏触觉和 假肢本体感觉反馈。最近有很大的兴趣 通过感觉化神经假体提供感觉反馈。然而，这些研究已经 主要集中在恢复上肢截肢者的触觉反馈。这项研究的目的是 经腰骶椎为下肢截肢者提供自然本体感觉反馈 脊髓刺激(SCS)。实验将作为正在进行的NIH资助的一项补充进行 使用FDA清除的SCS导联经皮植入腰椎外侧硬膜外的项目 太空。为了确定唤起对关节运动的自然主义感知所需的参数，我们 我将首先评估刺激模式对诱发本体感觉自然性的影响 轰动一时。使用自适应的跨模式一致性效应(CCE)测试作为 自然性，我们将量化哪种刺激模式(恒定频率或仿生) 创造一种更自然的感知，如较高的CCE分数所示。评估……的效果 刺激受试者将这些知觉合并为本体感觉的能力，我们将使用 具有不同自然度的刺激模式的多样性，并评估 静态或动态感知的本体感觉准确性。我们还将研究 使用感觉化假体改善步态和功能的本体感觉 提供有关关节角度的实时反馈。我们将使用临床和科学两种方法 测量本体感觉和步态功能以评估刺激的效果。我们 假设本体感觉的更自然感觉将提供更高的准确性 本体感觉的临床测试和在更复杂的运动控制任务中的更大改进， 例如步态，从而提高了下肢截肢者的机动性和安全性。

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.