Shoe Insole Force Sensor Feedback for Foot Load Monitoring

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Solution Overview

Problem

Existing devices for monitoring and preventing excessive loads on the human foot during walking are either too expensive, bulky, impractical for everyday use, or lack a direct feedback mechanism, making them unsuitable for rehabilitation and physiotherapy applications.

Innovation Solution

A device integrated into a shoe insert with force sensors, an evaluation unit, an electrical energy source, a feedback control signal generator, and a feedback output unit, which provides tactile feedback specifically in the area of the foot's longitudinal arch to alert the user of improper loading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a treadmill and support frames with sensors are used to monitor foot load, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvefoot load measurementVSAvoidsystem structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential measurement function from the complex treadmill system and implements it directly in the shoe insole using simple force sensors. This removes the need for bulky support frames and treadmill equipment while retaining the core capability of monitoring foot load during walking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The shoe insole system is self-contained with integrated sensors, power source, and feedback mechanisms. It independently monitors foot load and provides real-time feedback without requiring external treadmill equipment or complex support infrastructure, enabling practical everyday use.

Inventive Principle:
Principle #25Self-service

2Device complexity

If sensor units are integrated into a narrow shoe sole, then device complexity is reduced, but the sensor system becomes vulnerable and lacks readout capabilities

Engineering Contradiction:
Improvesystem integrationVSAvoidsensor durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines multiple functions (sensing, power supply, feedback generation, and feedback delivery) into a single integrated shoe insole system. The force sensors are protected within the insole structure, and the feedback mechanism delivers information directly to the user's foot, eliminating the need for external cables and vulnerable exposed components.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of information

If an RF transmitter is used to send measurement signals, then feedback range is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvesignal transmissionVSAvoidpower consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent implements a closed-loop feedback system where force sensors detect foot load, the microcontroller processes the data, and the feedback signal is delivered through the insole to the user's foot. This direct feedback mechanism eliminates the need for RF transmitters and external receivers, significantly reducing power consumption while maintaining effective communication of load information to the user.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If a wide shoe sole is used to integrate sensors, then measurement accuracy is improved, but comfort during wear deteriorates

Engineering Contradiction:
Improvesensor accuracyVSAvoidwear comfort
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent places force sensors only at specific critical locations within the shoe insole where foot load measurement is most important, rather than distributing sensors across the entire wide sole area. This localized sensing approach maintains measurement accuracy for foot load assessment while keeping the insole narrow and comfortable for everyday wear.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables direct and effective feedback to prevent excessive loads on the foot, promoting safe walking patterns and reducing the risk of injury, while being affordable and suitable for everyday use.

Implementation Method 1

at least one force sensor (3) arranged on or in the shoe insole (2) to generate a measurement signal that indicates loads and/or partial loads on the foot

Methodology Applied
Scientific EffectForce sensing: Piezoresistive Effect

Implementation Method 2

The feedback output unit (21) is designed as an actuator (22), which receives the feedback control signal and generates tactile feedback in the area of the longitudinal arch of the foot

Methodology Applied
Scientific EffectTactile feedback generation: Electromagnetic Induction

Data Source

PatentEP3348185B1Device for preventing excessive loads on the human foot during walking and method for the operation thereof
Publication Date: 2020.11.11 DOLL WALTER
  • EP3348185B1 patent drawingFigure 1
  • EP3348185B1 patent drawingFigure 2
  • EP3348185B1 patent drawingFigure 3

AI summary

A device for preventing excessive stress on the human foot during walking comprises a shoe insole with at least one force sensor for generating a measurement signal that indicates loads and/or partial loads on the foot; an evaluation unit electrically connected to at least one force sensor to evaluate the measurement signal from the at least one force sensor; an electrical power source to provide current for the evaluation unit; and furthermore, a feedback control signal generator which, based on the evaluation by the evaluation unit, generates a feedback control signal to enable the monitoring of loads and/or partial loads on the foot, e.g., by an actuator, wherein the sensitive components are arranged in a housing to protect them, in particular from water and/or pressure loads. A method for operating the device is also provided.