Hybrid Neuroprosthesis with a Variable Knee for Walking in SCI

用于 SCI 行走的具有可变膝关节的混合神经假体

• 批准号: 8977503
• 负责人: Rudi Kobetic
• 金额: --
• 依托单位: LOUIS STOKES CLEVELAND VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8977503
• 关键词: Acceleration; Address; American; Analysis of Variance; Body Weight; Braces-Orthopedic appliances; Chest; Confidence Intervals; Contracts; Dependence; Development; Devices; Electrodes; Employee Strikes; Ensure; Evaluation; Exercise; Experimental Designs; Feedback; Floor; Gait; Gastrocnemius Muscle; Heart; Heel; Hip region structure; Hybrids; Implant; Individual; Injury; Intramuscular; Joints; Knee; Lead; Leg; Lower Extremity; Lung; Measures; Medical; Motion; Muscle; Muscle Contraction; Orthotic Devices; Outcomes Research; Paralysed; Paraplegia; Performance; Persons; Phase; Physiologic pulse; Planning Techniques; Principal Investigator; Recruitment Activity; Research; Resistance; Safety; Shock; Signal Transduction; Skin; Spinal cord injury; Statistical Data Interpretation; Surface; System; Testing; Thigh structure; Thoracic spinal cord structure; Toes; Upper Extremity; Validation; Veterans; Walking; Wheelchairs; Work; ankle joint; base; bone; design; disability; electric impedance; evaluation/testing; exoskeleton; experience; fall risk; foot; functional outcomes; functional restoration; hamstring; improved; neuromuscular stimulation; neuroprosthesis; novel; orthotics; phase 1 study; prevent; prototype; quadriceps muscle; sensor

DESCRIPTION (provided by applicant): Objective - of the proposed research is to determine whether a novel hybrid neuroprosthesis (HNP) combining functional neuromuscular stimulation (FNS) and incorporating an advanced sensor based controlled variable impedance knee mechanism (VIKM) for walking in persons with paraplegia from spinal cord injury (SCI) can: (1) reduce impact forces during loading, improve forward momentum, reduce the fluctuations in vertical trunk motion, and improve foot-ground clearance during walking, and (2) restore stair descent and stand-to-sit functions by controlling the resistance to knee flexion while lowering of the body. Research Plan and Methodology - Three phases of the study are: 1) design, development, and validation of a closed loop control system using our novel variable impedance knee mechanism (VIKM) for modulation of stance phase knee flexion during gait, 2) evaluation of the functional benefits of incorporating knee flexion during stance phase of gait, and 3) evaluation of the ability of the VIKM to control stair descent and stand-to-sit maneuver. Five individuals with thoracic paraplegia from SCI will be recruited to test the VIKM as part of a hybrid neuroprosthesis (HNP). Subjects will be implanted with an eight channel pulse generator and intramuscular electrodes to activate iliopsoas/sartorius for hip/knee flexion, hamstrings for hip extension and quadriceps for knee extension and gastrocnemius for plantar flexion. These are key muscles for standing up, for initiating the swing and for forward propulsion of the body. The ankle joint will be spring loaded to return the foot to neutral during swing after actively plantar flexing for push-off. A prototype VIKM will be incorporated in previously designed exoskeleton and combined with implanted FNS systems to yield a novel HNP. A closed loop controller to modulate knee during gait will be based on feedback from sensors measuring foot-ground contact, hip and knee angles, thigh and leg velocity, and acceleration. A microcontroller will modulate damper current to control the resistance of the VIKM based on phase of the gait cycle. The finite state controller will control the VIKM and modulate stimulation to the paralyzed muscles. It will be first evaluated in two able-bodied individuals to ensure that it can accurately identify phases of gait (controller validation) and provide adequate resistance against knee collapse during stance (VIKM validation). The VIKM is expected to lessen the effect of impact and absorb shock during initial loading, reduce body center of mass displacement and improve toe clearance in early swing by regulating knee flexion. During stair descent and stand-to-sit maneuver the emphasis will be on lowering of the body and weight acceptance when the VIKM will perform most of the work normally performed by the eccentrically contracting muscles impossible to control with FNS. The controller will be optimized to reduce the need for upper extremity support during lowering and landing on the step below and sitting surface. Walking with the VIKM-based HNP will be compared to walking with FNS-only and conventional orthosis. Statistical analysis of the data will be carried out using a within subject experimental design to test effect of VIKM. Impact force at initial contact, average vertical motion of body center of mass, and stance phase knee flexion will be measured. A one-way repeated measure ANOVA will be used to test for significant differences and the Tukey honestly significant difference multiple comparison tests will be used to determine 95% confidence intervals.

描述（由申请人提供）： 拟议研究的目的是确定一种新型混合神经假体（HNP）结合功能性神经肌肉刺激（FNS）和基于先进传感器的受控可变阻抗膝关节机制（VIKM），用于脊髓损伤（SCI）截瘫患者的行走，是否可以：（1）在负重期间减少冲击力，提高向前的动量，减少垂直躯干运动的波动，并提高行走期间的脚-地面间隙，以及（2）通过控制在降低身体的同时对膝弯曲的阻力来恢复下楼梯和站到坐的功能。研究计划和方法-研究的三个阶段是：1）使用我们的新颖的可变阻抗膝关节机构（VIKM）来设计、开发和验证闭环控制系统，用于调节步态期间的站立相膝关节屈曲，2）评估在步态的站立相期间结合膝关节屈曲的功能益处，3）评价VIKM控制下楼梯和站坐动作的能力。 将招募5名脊髓损伤导致胸段截瘫的患者来测试VIKM作为混合神经假体（HNP）的一部分。受试者将植入八通道脉冲发生器和肌内电极，以激活髂腰肌/缝匠肌进行髋关节/膝关节屈曲，激活腿筋进行髋关节伸展，激活四头肌进行膝关节伸展，激活腓肠肌进行跖屈。这些是站立、开始摆动和身体向前推进的关键肌肉。踝关节将是春天 在主动足底屈曲蹬离后，在摆动过程中加载以使脚返回到中立位置。 原型VIKM将被纳入先前设计的外骨骼，并与植入的FNS系统相结合，以产生一种新的HNP。在步态期间调节膝盖的闭环控制器将基于来自测量脚-地面接触、臀部和膝盖角度、大腿和腿部速度以及加速度的传感器的反馈。微控制器将调制阻尼器电流，以基于步态周期的相位控制VIKM的电阻。有限状态控制器 将控制VIKM并调节对麻痹肌肉的刺激。将首先评估 以确保其能够准确地识别步态的阶段（控制器 验证），并提供足够的阻力，防止膝盖崩溃期间的立场（VIKM验证）。预计VIKM将在初始加载期间减轻冲击效应并吸收冲击，减少身体质心位移，并通过调节膝关节屈曲来改善早期摆动中的脚趾间隙。 在下楼梯和站到坐的动作中，重点将放在降低身体和重量接受上，此时VIKM将执行通常由FNS无法控制的偏心收缩肌肉执行的大部分工作。控制器将进行优化，以减少在下降和降落在台阶下方和坐面上时对上肢支撑的需求。 将使用基于VIKM的HNP行走与仅使用FNS和传统矫形器行走进行比较。将使用受试者内实验设计对数据进行统计分析，以检验VIKM的效果。冲击力 在初始接触时，将测量身体质心的平均垂直运动和站立相膝关节屈曲。将使用单向重复测量ANOVA检验显著性差异，并使用Tukey诚实显著性差异多重比较检验确定95%置信区间。