Exosuit Control Parameter Tuning for Personalized Gait Assistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Soft exosuits exhibit high variability in efficacy across different individuals due to the need for individualized assistance patterns, leading to inconsistent metabolic benefits, as a one-size-fits-all approach fails to optimize actuation parameters effectively for each wearer.

Innovation Solution

The development of systems and methods that adjust actuation parameters such as timing, amplitude, rate, and profile shape of actuation to optimize objective functions related to physical assistance, interaction between the wearer and exosuit, and exosuit operation, using wearable sensors to evaluate and adjust these parameters in real-time to maximize efficacy and minimize variability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a one-size-fits-all control approach is used for exosuits, then device complexity is reduced and ease of operation is improved, but efficacy and metabolic benefit vary significantly across different individuals

Engineering Contradiction:
Improveease of operationVSAvoidefficacy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control system dynamically adapts actuation parameters in real-time based on individual wearer characteristics and gait patterns. The controller continuously adjusts timing, amplitude, and profile shape of actuation signals to optimize assistance for each user, transforming a static one-size-fits-all approach into a dynamic personalized system that maintains both ease of operation and high efficacy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system optimizes multiple actuation parameters including timing relative to gait cycle, amplitude of actuation force, rate of actuation, and profile shape. By varying these parameters based on individual wearer data collected during operation, the system achieves personalized control without requiring complex manual configuration, resolving the contradiction between operational simplicity and treatment effectiveness

Inventive Principle:
Principle #35Parameter changes

2Reliability

If actuation parameters are optimized for each individual wearer, then efficacy and metabolic benefit are maximized, but device complexity and control complexity increase

Engineering Contradiction:
ImproveefficacyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The exosuit control system performs self-adjustment by automatically collecting wearer data during operation and using this data to optimize actuation parameters in real-time. The system serves itself by eliminating the need for external manual configuration or complex setup procedures, achieving personalized optimization while maintaining relatively simple device architecture

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements closed-loop control by continuously monitoring wearer responses and gait patterns, then using this feedback to adjust actuation parameters. This automated feedback mechanism enables personalized optimization without requiring complex manual intervention, as the system self-regulates based on real-time performance data

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If real-time optimization is implemented during walking, then metabolic cost reduction is maximized for each subject, but computational requirements and control complexity increase

Engineering Contradiction:
Improvemetabolic costVSAvoidcontrol complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system performs preliminary data collection and analysis during initial wear periods to establish baseline wearer characteristics and gait patterns. This preliminary action enables the controller to make informed real-time adjustments without requiring complex computational processing during actual walking, as much of the optimization work is prepared in advance based on collected data

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11498203B2Controls optimization for wearable systems
Publication Date: 2022.11.15 PRESIDENT & FELLOWS OF HARVARD COLLEGE
  • US11498203B2 patent drawing
  • US11498203B2 patent drawing
  • US11498203B2 patent drawing

AI summary

A wearable system includes an exosuit or exoskeleton; an actuator(s) configured to generate force in the exosuit or exoskeleton; a sensor(s) configured to measure information for evaluating an objective function associated with providing physical assistance to the wearer, an interaction between the wearer and the exosuit or exoskeleton, and/or an operation of the exosuit or exoskeleton; and a controller(s) configured to: actuate the actuator(s) according to an actuation profile(s), evaluate the objective function based on the information measured by the at least one sensor to determine a resulting change in the objective function, adjust a parameter(s) of the actuation profile(s) based on the resulting change in the objective function, and continue to actuate, evaluate, and adjust to optimize the actuation parameter(s) for maximizing or minimizing the objective function. Wearable systems configured to assist or promote an improvement in the wearer's gait and optimized using a gradient descent or Bayesian approach.