PHASE-BASED CONTROL OF LOCOMOTION FOR HIGH-PERFORMANCE PROSTHESES AND ORTHOSES

描述(申请人提供)：高性能的下肢假体和矫形器可以显著改善近100万美国截肢者的生活质量，甚至更多中风幸存者的生活质量，他们的行走速度慢，稳定性差，效率低于健全人。尽管最近的机动假体和矫形器有可能恢复受损人群的行动能力，但关键的障碍仍然限制了它们的临床应用。 生存能力。目前的动力腿独立控制不同的关节和步态的时间周期。 周期，限制了对环境不确定性的稳健性，并要求临床医生花费大量时间来调整每个控制模型以适应个人。这种顺序控制方法是当前将人类步态模式视为时间函数的范例的直接结果。然而，最近的两足机器人可以通过一种控制模型稳定地行走、奔跑和爬楼梯，该控制模型作为机械变量的函数来驱动关节模式，机械变量不断地表示机器人在步态周期中的前进，也就是说，有一种“相位感”。机器人控制理论的这些新突破为解决假肢技术中的关键障碍提供了一个新的机会，改变了人们对人类步态周期的看法：作为阶段变量的函数，而不是时间的函数。然后，可以用单一的控制模型来设计假肢，该模型测量生物启发的相位变量，以匹配人类的意志运动或对扰动做出反应。这一挑战的核心是在关于人类神经肌肉系统如何保持相位感的知识方面存在根本差距。该项目旨在通过1)确定用于人类运动的生物力学相位变量，以及2)设计用于假肢和矫形器的统一控制模型来解决这一差距。我假设人类的关节模式是由压力中心(COP)从脚跟到脚趾的运动驱动的，COP是脚底累积反作用力施加在地面上的点。我将通过观察行走在机器人平台上时人类关节对COP扰动的反应来检验这一假设。然后，我将利用这种相位感在动力膝关节-脚踝假体上实施一种新的控制策略，并将在人体截肢受试者身上进行验证。这项研究将对我们理解运动过程中的神经肌肉系统、分析步态周期的研究方法以及设计临床可行的假肢控制系统具有重要意义。这项工作的创新包括1)一种新的人类运动阶段依赖范式，它挑战了现有的时间依赖范式，以及2)一种新的控制方法，将加速电动假肢和矫形器的临床应用。从这一大胆的新范式中获得的知识和概念将在物理医学和康复方面产生广泛影响，促进中风、脊髓损伤和周围神经病变后恢复活动能力的技术进步。我在机器人控制方面的专业知识和修复学方面的博士后培训使我独一无二地有资格成功执行这项高度创新的工作。

DESCRIPTION (provided by applicant): High-performance lower-limb prostheses and orthoses could significantly improve the quality of life for nearly a million American amputees and even more stroke survivors, whose ambulation is slower, less stable, and less efficient than that of able-bodied persons. Although recent motorized prostheses and orthoses have the potential to restore mobility in impaired populations, critical barriers still limit their clinical viability. Current powered legs independently control different joints and time periods of the gait cycle, limiting robustness to environmental uncertainty and requiring clinicians to spend significant amounts of time tuning each control model to the individual. This sequential control methodology is a direct consequence of the current paradigm for viewing human gait patterns as functions of time. However, recent bipedal robots can stably walk, run, and climb stairs with one control model that drives joint patterns as functions of a mechanical variable, which continuously represents the robot's progression through the gait cycle, i.e., a sense of "phase." These new breakthroughs in robot control theory present an emerging opportunity to address a key roadblock in prosthetic technology with a paradigm shift in how the human gait cycle is viewed: as a function of a phase variable rather than time. Prosthetic legs could then be designed with a single control model that measures a biologically-inspired phase variable to match the human's volitional movement or respond to perturbations. Central to this challenge is a fundamental gap in knowledge about how the human neuromuscular system might maintain a sense of phase. This project aims to address this gap by 1) identifying a biomechanical phase variable used in human locomotion, and 2) designing a unifying control model for lower-limb prostheses and orthoses. I hypothesize that human joint patterns are driven by the heel-to-toe movement of the center of pressure (COP)-the point on the foot sole where the cumulative reaction force is imparted against the ground. I will test this hypothesis by observing the response of human joints to perturbations of the COP while walking over a robotic platform. I will then implement a novel control strategy using this sense of phase on a powered knee-ankle prosthesis, which will be validated with human amputee subjects. This investigation will be significant to our understanding of the neuromuscular system during locomotion, research methods for analyzing the gait cycle, and the design of clinically viable prosthetic control systems. The innovation of this work is encompassed in 1) a new phase-dependent paradigm of human locomotion that challenges the existing time-dependent paradigm, and 2) a novel control methodology that will accelerate the clinical adoption of powered prostheses and orthoses. The knowledge and concepts gained from this bold new paradigm will have a broad impact in physical medicine and rehabilitation, catalyzing technological advances for restoring mobility after stroke, spinal cord injury, and peripheral neuropathy. My expertise in robot control and postdoctoral training in prosthetics make me uniquely qualified to successfully execute this highly innovative work.