Intelligent Tuner for Powered Prosthesis Impedance Control

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Solution Overview

Problem

Current methods for tuning powered prostheses impedance control parameters are manual, time-consuming, and require unique calibration for each patient, lacking precision and being resource-intensive, while existing simplification approaches like reducing parameters or associating with biomechanical measures are imprecise and unsuitable for dynamic ambulation tasks.

Innovation Solution

A system comprising a powered prosthesis with an intelligent tuner that adjusts impedance control parameters using a rule base, linked to sensors measuring gait parameters, and an impedance controller to output torque adjustments based on measured parameters, optionally employing fuzzy logic to achieve target gait characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual tuning of impedance control parameters is performed by prosthetists based on qualitative observations, then the prosthesis can be customized for each patient, but the process becomes time-consuming and resource-intensive

Engineering Contradiction:

Improvecustomization for each patientVSAvoidtuning time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system enables self-service through automatic parameter tuning. The intelligent tuner autonomously adjusts impedance control parameters by analyzing sensor data from the patient's gait, eliminating the need for manual tuning by prosthetists while still providing personalized customization for each patient.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical tuning process with an automated computational system. The intelligent tuner uses sensor measurements and algorithmic processing to determine optimal parameters, substituting human expert judgment with an automated decision-making system that analyzes objective gait data.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If the number of control parameters is reduced to simplify tuning, then the tuning burden is reduced, but the precision and suitability for dynamic ambulation tasks may be compromised

Engineering Contradiction:

Improvetuning burdenVSAvoidparameter tuning precision

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system replaces manual parameter selection with automated computational determination. The intelligent tuner uses sensor data and algorithms to precisely calculate optimal parameter values, maintaining high precision while simplifying the overall tuning process through automation rather than parameter reduction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system employs feedback from sensor measurements during gait to automatically adjust parameters. The intelligent tuner continuously monitors gait parameters and uses this feedback to optimize impedance control settings, ensuring precision is maintained through data-driven adjustments rather than simplified parameter sets.

Inventive Principle:

Principle #23Feedback

3Productivity

If impedance control parameters are manually fine-tuned based on qualitative observations until gait looks good, then the prosthesis can achieve acceptable performance, but the process lacks precision and objectivity

Engineering Contradiction:

Improvetuning efficiencyVSAvoidparameter tuning precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent substitutes subjective qualitative assessment with objective quantitative measurement. The intelligent tuner uses sensor data to precisely measure gait parameters and automatically adjusts impedance control settings based on objective criteria rather than subjective visual evaluation, improving both precision and efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements closed-loop feedback where sensor measurements of actual gait performance continuously inform parameter adjustments. The intelligent tuner uses this objective feedback to precisely tune parameters, replacing the imprecise trial-and-error process of manual visual assessment with data-driven optimization.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10335294B2Systems and methods for automatically tuning powered prosthesis impedance control parameters

Publication Date: 2019.07.02 NORTH CAROLINA STATE UNIV

AI summary

An example system for tuning powered prosthesis impedance control parameters can include a powered prosthesis and intelligent tuner operably connected to the powered prosthesis. The powered prosthesis can include a joint, a motor that is mechanically coupled to the joint, a plurality of sensors configured to measure a plurality of gait parameters associated with a subject, and an impedance controller. The motor of the powered prosthesis can be configured to drive the joint, and the impedance controller of the powered prosthesis can be configured to output a control signal for adjusting a torque of the motor, where the torque is adjusted as a function of the measured gait parameters and a plurality of impedance control parameters. The intelligent tuner can be configured to adjust at least one of the impedance control parameters using a rule base.