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是否有一种新型混合神经假体（HNP）结合了功能性神经肌肉刺激（FNS）并结合了基于先进传感器的受控可变阻抗膝关节机构（VIKM），用于脊髓损伤（SCI）截瘫患者的行走）可以：（1）减少装载过程中的冲击力，提高前进动力，减少垂直躯干运动的波动，并提高步行过程中脚部离地间隙，（2）通过控制膝盖阻力身体下降时屈曲。研究计划和方法 - 研究的三个阶段是：1）使用我们新颖的可变阻抗膝盖机构（VIKM）来设计、开发和验证闭环控制系统，以调节步态期间的站立阶段膝盖弯曲，2）评估在步态的站立阶段结合膝关节屈曲的功能优势，以及 3) 评估 VIKM 控制楼梯下降和从站到坐的操作的能力。 将招募 5 名因 SCI 导致胸椎截瘫的患者来测试 VIKM，作为混合神经假体 (HNP) 的一部分。受试者将被植入八通道脉冲发生器和肌内电极，以激活髂腰肌/缝匠肌以实现髋部/膝部屈曲、腘绳肌以实现髋部伸展、股四头肌以实现膝部伸展以及腓肠肌以实现跖屈。这些是站立、开始摆动和身体向前推进的关键肌肉。踝关节将呈弹簧状 在主动跖屈以推出后，加载以在挥杆过程中将脚返回到中立位置。 VIKM 原型将被纳入先前设计的外骨骼中，并与植入的 FNS 系统相结合，形成一种新型 HNP。在步态过程中调节膝盖的闭环控制器将基于测量脚与地面接触、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，以根据步态周期的相位控制 VIKM 的电阻。有限状态控制器 将控制 VIKM 并调节对瘫痪肌肉的刺激。将首先评估 在两个身体健全的人身上，以确保它能够准确识别步态的阶段（控制器 验证）并在站立期间提供足够的抵抗膝盖塌陷的能力（VIKM 验证）。 VIKM 有望在初始加载过程中减轻冲击力并吸收震动，减少身体质心位移，并通过调节膝关节屈曲来改善挥杆初期的脚趾间隙。 在下楼梯和从站到坐的动作期间，重点将放在降低身体和承受重量上，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。控制器将经过优化，以减少在下降和降落在台阶下方和坐面时对上肢支撑的需求。 使用基于 VIKM 的 HNP 行走将与仅使用 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，以测试 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阶段膝关节弯曲度。单向重复测量方差分析将用于测试显着性差异，Tukey 真实显着性差异多重比较测试将用于确定 95% 置信区间。