Myoelectric Prosthesis Setup Using Surface Electrode Mapping

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Solution Overview

Problem

Existing prosthetic systems struggle to determine the appropriate treatment and configuration for patients quickly after limb loss, as wound healing and swelling complicate immediate fitting, and complex devices require multiple electrodes for reliable control.

Innovation Solution

A method involving a surface electrode array around the limb stump to detect and evaluate myoelectric signals for signal quality, allowing determination of optimal electrode positioning and control method selection, followed by positioning fixed electrodes on the prosthetic socket based on the array's findings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a complex prosthetic device with multiple drives and functions is provided, then the prosthesis can perform more functions of the missing limb, but it requires eight or more electrode pairs for reliable control via pattern recognition

Engineering Contradiction:
Improvefunctional capability of prosthesisVSAvoidnumber of electrode pairs required
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/electrical system of multiple electrode pairs with a capacitive touch sensor system that detects muscle activity through capacitive coupling. This allows complex prosthetic control without requiring multiple physical electrode connections, thus reducing device complexity while maintaining functional capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control unit is designed to perform multiple functions: it can operate with simple two-channel control for basic movements, pattern recognition with multiple electrodes for complex movements, and capacitive touch sensing for additional control modes. This multi-functionality allows the same device to adapt to different user needs without requiring separate systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If immediate prosthetic fitting is provided after limb loss, then early prosthetic integration is achieved, but wound healing and swelling prevent accurate socket fitting

Engineering Contradiction:
Improvespeed of prosthetic integrationVSAvoidaccuracy of socket fitting
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies the prosthetic socket and recording electrodes to the limb stump before final wound healing and swelling resolution. The system performs preliminary assessment and setup, allowing the socket to be fitted early while the limb is still changing, rather than waiting for complete healing which would delay integration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system is designed to adapt to dynamic changes in the limb stump. The control unit can adjust to varying muscle activity patterns and the socket can accommodate changes in limb volume and shape as swelling subsides, maintaining functional capability throughout the healing process.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple recording electrodes are positioned on the prosthetic socket for complex control, then reliable control of powered components is achieved, but assembly effort and potential interference increase

Engineering Contradiction:
Improvecontrol reliability of prosthetic deviceVSAvoidassembly effort and interference
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional wired electrode connections with capacitive touch sensors that detect muscle activity through capacitive coupling without requiring physical contact or complex wiring. This reduces assembly effort and eliminates interference issues associated with multiple electrodes positioned on the socket.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts the essential function of muscle activity detection from the complex electrode system and implements it through simplified capacitive sensing. This removes the need for multiple recording electrodes positioned on the prosthetic socket while maintaining the ability to detect and respond to muscle activity for reliable control.

Inventive Principle:
Principle #2Taking out (Extraction)

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 rapid assessment of a patient's suitability for prosthetic systems, ensuring accurate control and efficient fitting of prosthetic components with minimal assembly effort and reduced interference, facilitating early prosthetic integration.

Implementation Method 1

several recording electrodes for detecting electrical muscle activity

Methodology Applied
Scientific EffectElectromyographic signal detection: Electrical Impedance Tomography

Data Source

PatentEP3790515B1Method for setting up a myoelectric-controlled prosthesis system and prosthesis system
Publication Date: 2026.04.01 OTTO BOCK HEALTHCARE PROD GMBH
  • EP3790515B1 patent drawingFigure 1~2
  • EP3790515B1 patent drawingFigure 3~4
  • EP3790515B1 patent drawingFigure 5

AI summary

Method for setting up a myoelectric-controlled prosthesis system with a prosthesis shaft (20) and a plurality of pick-up electrodes (10) for detecting electrical muscle activities, said method having the steps of: placing a surface electrode arrangement (200) with a plurality of surface electrodes (100) about the circumference of a limb stump (1), detecting electrical muscle activity at muscles of the limb stump (1) as electromyographic signals through the surface electrodes (100), evaluating the myoelectric signals in terms of their signal differentiation, selecting the control method, by which the prosthesis system is controlled, on the basis of the evaluation of the signal differentiation, and fastening the pick-up electrodes (10) to the prosthesis shaft (20).