Speed adaptation in a powered transtibial prosthesis controlled with a neuromuscular model
Speed adaptation in a powered transtibial prosthesis controlled with a neuromuscular model
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DOI：
10.1098/rstb.2010.0347
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发表时间：
2011-05-27
影响因子：
6.3
通讯作者：
Herr, Hugh
中科院分区：
文献类型：
--
作者：
Markowitz, Jared;Krishnaswamy, Pavitra;Herr, Hugh
动力踝足假肢的控制方案将大大受益于一种使它们天生适应不同步行速度的方法。为了实现这一目标，人们可以尝试模仿完整的人类脚踝，因为它能够无缝适应。人类的运动是由腿部动力学、形态和神经控制（包括脊髓反射）之间的相互作用控制的。有人认为，反射会导致踝关节动力学的变化，这与不同速度的行走相对应。在这里，我们使用数据驱动的肌肉肌腱模型，该模型对跨越脚踝的主要肌肉的激活、力量、长度和速度进行估计，以得出局部反馈回路，这对于步行过程中控制这些肌肉可能至关重要。这种纯粹的反射方法忽略了非反射神经驱动的来源，并且不一定反映生物控制方案，但仍然可以准确地再现从生物数据估计的肌肉动力学。由此产生的神经肌肉模型用于控制动力踝足假肢，并由截肢者以三种速度行走进行测试。控制器产生速度自适应行为；净踝关节功随着步行速度的增加而增加，凸显了应用神经肌肉原理控制自适应假肢的好处。
Control schemes for powered ankle-foot prostheses would benefit greatly from a means to make them inherently adaptive to different walking speeds. Towards this goal, one may attempt to emulate the intact human ankle, as it is capable of seamless adaptation. Human locomotion is governed by the interplay among legged dynamics, morphology and neural control including spinal reflexes. It has been suggested that reflexes contribute to the changes in ankle joint dynamics that correspond to walking at different speeds. Here, we use a data-driven muscle-tendon model that produces estimates of the activation, force, length and velocity of the major muscles spanning the ankle to derive local feedback loops that may be critical in the control of those muscles during walking. This purely reflexive approach ignores sources of non-reflexive neural drive and does not necessarily reflect the biological control scheme, yet can still closely reproduce the muscle dynamics estimated from biological data. The resulting neuromuscular model was applied to control a powered ankle-foot prosthesis and tested by an amputee walking at three speeds. The controller produced speed-adaptive behaviour; net ankle work increased with walking speed, highlighting the benefits of applying neuromuscular principles in the control of adaptive prosthetic limbs.