Adaptive ankle robot control system to reduce foot-drop in chronic stroke

自适应踝关节机器人控制系统可减少慢性中风患者的足下垂

• 批准号: 9901442
• 负责人: STEVEN J KITTNER
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9901442
• 关键词: Address; Ankle; Biomechanics; Canes; Caring; Chronic; Consensus; Custom; Elements; Equilibrium; Event; Floor; Foot-drop; Gait; Health Status; Hour; Impairment; Inferior; Joints; Laws; Lead; Learning; Lower Extremity; Measures; Mediating; Mission; Modeling; Musculoskeletal Equilibrium; Neurologic; Outcome; Paresis; Participant; Patient Care; Pattern; Phase; Physical therapy; Posture; Quality of life; Randomized; Recovery; Risk; Robot; Robotics; Safety; Self-Help Devices; Severities; Standardization; Stroke; System; Testing; Time; Training; Translations; Upper Extremity; Veterans; Walking; base; chronic stroke; compare effectiveness; disabling disease; fall risk; falls; foot; hemiparetic stroke; improved; improved mobility; indexing; leg paresis; motor learning; novel; orthotics; post stroke; pressure; public health relevance; robot control; stroke survivor; treadmill training; treatment as usual; walking speed

 DESCRIPTION (provided by applicant): This proposal investigates a novel ankle robot (anklebot) adaptive control approach integrated with treadmill training to reduce foot drop and improve mobility function in chronic hemiparetic stroke survivors. Currently, stroke survivors with foot drop are trained to live with a cane or othr assistive device, and often ankle foot orthotics (AFO's) for safety. Neither mediates task-practice or neuromotor recovery. We have developed an adaptive anklebot controller that detects gait cycle sub-events for precise timing of graded robotics assist to enable deficit severity adjusted ankle motor learning in the context of walking. Our Merit pilot findings show that 6 weeks treadmill training with robot (TMR) timed to assist swing phase dorsiflexion only, is more effective than TM alone to improve free-walking swing dorsiflexion at foot strike (+400%, +9.7°, N=4/group), floor-walking speed (21% vs. 9%), and the benefits are retained at 6 weeks post- training such that 3 of 4 participants no longer required their AFO's. Notably, swing-phase TMR training improved paretic leg push-off (277% vs. 2%), and center-of-pressure (CoP) sway on standing balance (-25% vs. +30%), indicating generalized benefits to other elements of gait and balance, beyond those robotically targeted toward foot drop. This randomized study investigates the hypothesis that 6 weeks TMR is more effective to durably improve gait biomechanics, static and dynamic balance, and mobility function in chronic stroke survivors with dorsiflexion deficits, compared to TM alone. Aims are to determine the compare effectiveness of 6 weeks TMR vs. TM alone on: 1) Independent gait function indexed by gait velocity, swing-phase DF, terminal stance push off, and 48- hour free-living mobility profiles. 2) Balance function indexed by measures of postural sway (CoP), asymmetric loading in quiet standing, peak paretic A-P forces in non-paretic gait initiation, and standardized scales (Berg Balance, Dynamic Gait Index, and ABC for Falls Efficacy and; 3) Long-term mobility outcomes, assessed by repeated measures of all key gait and balance outcomes at 6 weeks and 6 months after formal training cessation. While upper extremity robotics has proven effective, and altered national care standards for stroke, in contrast, lower extremity robotics that has primaril focused on repetitive, multi-joint patterning of gait cycles, remains controversial, with consensus that current approaches are inferior to usual care, or even deleterious. We challenge this paradigm by testing an adaptively controlled anklebot guided by sensorimotor learning models to focus specifically on complications due to impaired paretic DF control. The profile of ankle motor learning based on repeat measures of unassisted walking reveals a power law pattern with ~80% of gains <3 weeks. Hence, TMR may prove effective within the time-frame of usual physical therapy, which increases potential for translation into VA care. Results of this study wil establish a new paradigm for diverse deficit severity customized gait-integrated adaptive modular LE robotics to improve mobility function in stroke and other neurological conditions.

 描述（由申请人提供）： 本研究旨在探讨一种新颖的踝关节机器人自适应控制方法，结合跑步机训练，以减少慢性偏瘫中风幸存者的足下垂，并改善其移动功能。目前，患有足下垂的中风幸存者被训练与拐杖或其他辅助设备一起生活，并且通常使用踝足矫形器（AFO）以确保安全。两者都不介导任务练习或神经运动恢复。 我们已经开发了一种自适应踝关节机器人控制器，它可以检测步态周期子事件，以精确计时分级机器人辅助，从而在行走的背景下实现缺陷严重程度调整的踝关节运动学习。我们的Merit试点研究结果表明，使用机器人（TMR）进行为期6周的跑步机训练，时间仅用于辅助摆动阶段背屈，比单独使用TM更有效地改善足部撞击时的自由行走摆动背屈（+400%，+9.7°，N=4/组），地板行走速度（21%对9%），并且益处在训练后6周保留，使得4名参与者中的3名不再需要他们的AFO。值得注意的是，摆动阶段TMR训练改善了麻痹腿的蹬离（277% vs. 2%）和站立平衡时的压力中心（CoP）摆动（-25% vs. +30%），表明对步态和平衡的其他元素的普遍益处，超出了机器人针对足下垂的目标。 这项随机研究调查了以下假设：与单独TM相比，6周TMR可更有效地持久改善具有背屈缺陷的慢性卒中幸存者的步态生物力学、静态和动态平衡以及移动功能。目的是确定6周TMR与TM单独治疗在以下方面的比较有效性：1）独立步态功能，以步态速度、摆动相DF、末端站立蹬离和48小时自由生活活动性曲线为指标。 2)通过姿势摇摆（CoP）、安静站立时的不对称负荷、非轻瘫步态起始时的轻瘫A-P峰值力和标准化量表（贝格平衡、动态步态指数和福尔斯疗效ABC）和3）长期活动性结局（通过在正式训练停止后6周和6个月重复测量所有关键步态和平衡结局进行评估）来索引平衡功能。 虽然上肢机器人技术已被证明是有效的，并改变了中风的国家护理标准，但相比之下，下肢机器人技术主要集中在步态周期的重复性，多关节模式，仍然存在争议，达成共识 目前的方法不如通常的护理，甚至有害。我们通过测试自适应控制的踝关节机器人的感觉运动学习模型的指导下，专门专注于由于受损的轻瘫DF控制的并发症，挑战这种范式。基于重复测量的无辅助行走的踝关节运动学习的概况揭示了幂律模式，其中约80%的增益<3周。因此，TMR可能在常规物理治疗的时间范围内有效，这增加了转化为VA护理的可能性。这项研究的结果将建立一个新的范例，不同的缺陷严重程度定制的步态集成自适应模块化LE机器人，以改善中风和其他神经系统疾病的移动功能。