CAREER: Modeling Human Gait to Optimize Exoskeleton Control and Understand How the Goal Changes across Walking Tasks

职业：模拟人类步态以优化外骨骼控制并了解步行任务中目标如何变化

• 批准号: 1943561
• 负责人: Anne Martin
• 金额: $ 50万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1943561&HistoricalAwards=false
• 关键词: CAREER; Modeling; Human; Gait; Optimize

Robotic leg exoskeletons, wearable devices that act as amplifiers to enhance, reinforce or restore human performance, could improve the quality of life for individuals who have trouble walking by helping the user walk more normally. Because humans frequently change speeds while walking, it is important to understand how these speed changes occur and for the exoskeleton to provide appropriate assistance during both steady and variable speed walking. Thus, the objective of this CAREER project is to determine if the human goal, i.e., the human’s subconscious thoughts about the best way to walk, is the same for constant speed walking, changing speeds, and exoskeleton assisted walking for both healthy and post-stroke individuals. This will be accomplished by developing a physics-based predictive computer model of human walking that includes deriving a mathematical function that describes the subconscious goal of human walking. Studies are designed to provide fundamental insight into human gait control and to provide a tool to design optimal exoskeleton controllers. The integrated educational plan will use the appeal of exoskeletons to humanize engineering by producing professional videos highlighting how engineering can help improve impaired walking. An exoskeleton-based project will be developed to improve undergraduate engineers' ability to model a system, something with which many students struggle. The principal investigator's overarching research goal is to study how people walk and to use that knowledge to improve rehabilitation techniques for individuals who have trouble walking. Towards this goal, this CAREER project will determine if the human goal is the same for constant speed walking, changing speeds, and exoskeleton assisted walking for both healthy and post-stroke individuals, which will provide fundamental insight into human gait control and a tool to design optimal exoskeleton controllers. Novel physics-based (sagittal six-link model with revolute hip, knee, and ankle joints connecting the thighs, shanks, and feet), predictive models will be developed that can account for the highly nonlinear and non-intuitive nature of human-device interaction and create controllers that correctly account for this interaction. The models developed will better predict human gait, including transition between speeds, and quantify how people change walking speed. Model development requires determination of an objective function that mathematically describes the subconscious goal of human walking. Initially, the objective will be based on the assumption that humans minimize energetic effort while walking. If minimum effort does not correlate well with chosen gaits, incorporating fall risk into the function will be considered. Participants in the studies include healthy young adults (30), healthy elderly adults (12), slow elderly adults (12), and post-stroke elderly adults (12) who walk with difficulty but are able to walk without an assistive device and can follow directions. The Research Plan is organized under four tasks: 1) Quantify the spatial-temporal (step length, duration and speed) and kinematic properties of speed transitions for young, elderly, and post-stroke adults for the first time, and generate human-like speed transitions for the model by combining several methods from robotic control in a novel manner; 2) Determine if the same objective function can predict healthy human joint kinematics for steady, variable speed, and exoskeleton-assisted walking, providing novel insights into how humans react to exoskeleton assistance; 3) Determine how advanced age and stroke alter the objective function used to predict walking, providing novel insights into how age and stroke affect walking priorities and 4) Create a method to design exoskeleton controllers in simulation that accounts for the nonlinear human-device interactions and produces the desired human gait without additional tuning.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

机器人腿外骨骼，可穿戴设备，作为放大器，以提高，加强或恢复人类的表现，可以提高生活质量的个人谁有困难的步行，帮助用户走得更正常。因为人类在行走时频繁地改变速度，所以重要的是理解这些速度变化如何发生并且外骨骼在稳定和变速行走期间提供适当的辅助。因此，这个职业项目的目标是确定人类的目标，即，对于健康的和中风后的个体而言，人类关于最佳行走方式的潜意识想法对于恒速行走、变速行走和外骨骼辅助行走是相同的。 这将通过开发一个基于物理学的人类步行预测计算机模型来实现，该模型包括推导出一个描述人类步行潜意识目标的数学函数。 研究旨在提供对人类步态控制的基本见解，并提供设计最佳外骨骼控制器的工具。该综合教育计划将利用外骨骼的吸引力，通过制作专业视频，突出工程如何帮助改善步行障碍，使工程人性化。将开发一个基于exoschon的项目，以提高本科工程师对系统建模的能力，这是许多学生都在努力的事情。首席研究员的首要研究目标是研究人们如何行走，并利用这些知识来改善行走困难的个人的康复技术。 为了实现这一目标，这个CAREER项目将确定人类的目标是否与健康和中风后个体的恒速行走、变速行走和外骨骼辅助行走相同，这将为人类步态控制提供基本见解，并为设计最佳外骨骼控制器提供工具。将开发基于物理学的新型预测模型（具有连接大腿、小腿和脚的旋转髋关节、膝关节和踝关节的矢状六连杆模型），这些模型可以解释人机交互的高度非线性和非直观性质，并创建正确解释这种交互的控制器。 开发的模型将更好地预测人类步态，包括速度之间的过渡，并量化人们如何改变步行速度。 模型开发需要确定一个目标函数，该函数在数学上描述了人类行走的潜意识目标。最初，目标将基于人类在行走时最小化能量消耗的假设。 如果最小努力与所选择的步态没有很好的相关性，则将考虑将跌倒风险纳入功能中。研究参与者包括健康的年轻人（30人），健康的老年人（12人），缓慢的老年人（12人）和中风后老年人（12人），他们行走困难，但能够在没有辅助设备的情况下行走，并且可以遵循指示。研究计划分为四个任务：1）量化时空（步长，持续时间和速度）和年轻人，老年人和中风后成年人的速度转换的运动学特性，并通过以新颖的方式结合机器人控制的几种方法为模型生成类似人类的速度转换; 2）确定相同的目标函数是否可以预测用于稳定、可变速度和外骨骼辅助行走的健康人类关节运动学，从而提供对人类如何对外骨骼辅助做出反应的新颖见解; 3）确定高龄和中风如何改变用于预测行走的目标函数，为年龄和中风如何影响行走优先级提供了新的见解，以及4）创建一种方法来设计模拟中的外骨骼控制器，该方法考虑了非线性人类-该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Developing Equations of Motion for a Planar Biped Walker with Nonuniform Foot Shape

开发具有不均匀足部形状的平面双足步行器的运动方程

• DOI: 10.1016/j.ifacol.2021.11.215
• 发表时间: 2021
• 期刊: IFAC-PapersOnLine
• 作者: Rodman, Claire H.;Martin, Anne E.
• 通讯作者: Martin, Anne E.

Correlation of Comfort, Metabolic Cost & Muscle Activation for an Ankle Exoskeleton

舒适度与代谢成本的相关性

• 发表时间: 2022
• 期刊: North American Congress on Biomechanics
• 作者: Maberry, Axl;El Husaini, Mohammed Mohammed;Martin, Anne E.
• 通讯作者: Martin, Anne E.

A Method to Detect Changes in Joint Angles Before and After a Speed Change

一种检测速度变化前后关节角度变化的方法

• 发表时间: 2022
• 期刊: North American Congress on Biomechanics
• 作者: Murray, Greggory F.;Martin, Anne E.
• 通讯作者: Martin, Anne E.