Experimental Demonstration of the Lower Leg Trajectory Error Framework Using Physiological Data as Inputs
Experimental Demonstration of the Lower Leg Trajectory Error Framework Using Physiological Data as Inputs
复制标题
使用生理数据作为输入的小腿轨迹误差框架的实验演示
DOI：
10.1115/1.4048643
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Winter, Amos G.
中科院分区：
文献类型：
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作者：
Olesnavage, Kathryn M.;Prost, Victor;Johnson, William Brett;Major, Matthew J.;Winter, Amos G.
虽然许多研究试图描述被动假肢脚的机械行为，以了解其对截肢者步态的影响，但机械设计和生物力学性能之间的关系尚未从基础物理学的角度得到充分阐述。一种新的框架，称为小腿轨迹误差（LLTE）框架，提出了一种定量优化假肢脚的本构模型，以匹配参考运动学和动力学数据集的手段。该框架可用于预测假体所需的刚度和几何形状，以产生所需的生物力学响应。一个被动的原型脚与可调踝关节刚度进行了测试，由单侧经胫骨截肢，以评估这个框架。具有LLTE最佳踝关节刚度的足部条件使用户能够在16%的均方根（RMS）误差内复制生理目标数据集。具体而言，测量的运动学变量匹配的目标运动学在4%的RMS误差。由同一用户测试踝关节刚度条件范围（1.5 - 24.4 N·m/deg）表明，LLTE值较低的条件与目标运动学数据的偏差最小。在所有条件下，该框架预测的水平/垂直位置，并在1.0厘米，0.3厘米，和1.5度，分别在中期的小腿的角度方向。这项初步测试表明，采用低LLTE值设计的假肢脚可以为用户提供好处。LLTE框架对于特定的足部设计和运动学/动力学用户目标是不可知的，并且可以用于设计和定制假足。
While many studies have attempted to characterize the mechanical behavior of passive prosthetic feet to understand their influence on amputee gait, the relationship between mechanical design and biomechanical performance has not yet been fully articulated from a fundamental physics perspective. A novel framework, called lower leg trajectory error (LLTE) framework, presents a means of quantitatively optimizing the constitutive model of prosthetic feet to match a reference kinematic and kinetic dataset. This framework can be used to predict the required stiffness and geometry of a prosthesis to yield a desired biomechanical response. A passive prototype foot with adjustable ankle stiffness was tested by a unilateral transtibial amputee to evaluate this framework. The foot condition with LLTE-optimal ankle stiffness enabled the user to replicate the physiological target dataset within 16% root-mean-square (RMS) error. Specifically, the measured kinematic variables matched the target kinematics within 4% RMS error. Testing a range of ankle stiffness conditions from 1.5 to 24.4 N·m/deg with the same user indicated that conditions with lower LLTE values deviated the least from the target kinematic data. Across all conditions, the framework predicted the horizontal/vertical position, and angular orientation of the lower leg during midstance within 1.0 cm, 0.3 cm, and 1.5 deg, respectively. This initial testing suggests that prosthetic feet designed with low LLTE values could offer benefits to users. The LLTE framework is agnostic to specific foot designs and kinematic/kinetic user targets, and could be used to design and customize prosthetic feet.