Adaptive control of a variable-impedance ankle-foot orthosis to assist drop-foot gait
Adaptive control of a variable-impedance ankle-foot orthosis to assist drop-foot gait
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DOI：
10.1109/tnsre.2003.823266
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发表时间：
2004-03-01
影响因子：
4.9
通讯作者：
Herr, H
中科院分区：
文献类型：
--
作者：
Blaya, JA;Herr, H
提出了一种主动踝足矫形器（AAFO），其中矫形关节的阻抗在整个步行周期中进行调节，以治疗足下垂步态。在受控跖屈期间，应用仿生扭转弹簧控制，主动调整矫形关节刚度，以尽量减少前脚与地面的碰撞。在整个站立后期，关节阻抗被最小化，以免妨碍动力跖屈运动，并且在摆动阶段，扭转弹簧阻尼器控制抬起脚以提供脚趾间隙。为了评估可变阻抗控制的临床效果，收集了两名佩戴 AAFO 的下垂参与者的动力学和运动学步态数据。对于每个参与者，评估零、恒定和可变阻抗控制策略，并将结果与三个年龄、体重和身高匹配正常值的力学进行比较。我们发现，与正常情况相比，主动调整关节阻抗可以减少拍打足的发生，从而允许更大的动力跖屈，并在摆动过程中提供更小的运动差异。这些结果表明，与具有零或恒定刚度关节行为的传统踝足矫形器相比，可变阻抗矫形器对于治疗足下垂步态可能具有一定的临床益处。
An active ankle-foot orthoses (AAFO) is presented where the impedance of the orthotic joint is modulated throughout the walking cycle to treat drop-foot gait. During controlled plantar flexion, a biomimetic torsional spring control is applied where orthotic joint stiffness is actively adjusted to minimize forefoot collisions with the ground. Throughout late stance, joint impedance is minimized so as not to impede powered plantar flexion movements, and during the swing phase, a torsional spring-damper control lifts the foot to provide toe clearance. To assess the clinical effects of variable-impedance control, kinetic and kinematic gait data were collected on two drop-foot participants wearing the AAFO. For each participant, zero, constant, and variable impedance control strategies were evaluated and the results were compared to the mechanics of three age, weight, and height matched normals. We find that actively adjusting joint impedance reduces the occurrence of slap foot allows greater powered plantar flexion and provides for less kinematic difference during swing when compared to normals. These results indicate that a variable-impedance ortbosis may have certain clinical benefits for the treatment of, drop-foot gait compared to conventional ankle-foot orthoses having zero or constant stiffness joint behaviors.