Flexible Prosthetic Liner With Magnetic Locking for Easy Donning

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Solution Overview

Problem

Existing prosthetic systems are cumbersome for geriatric patients due to the tedious process of threading the free end of the traction device through the prosthetic socket, and there is a need for a more efficient and secure attachment mechanism.

Innovation Solution

A flexible prosthetic liner with a distal end and a flexible traction element that uses a tool-free magnetic locking mechanism for attachment to the prosthetic socket, featuring positive locking elements and a magnetic orientation system to facilitate easy connection and secure fixation, allowing for tool-less detachment and replacement of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional locking system with straps and threading is used, then the prosthetic socket can be securely attached, but the process becomes tedious and difficult for geriatric patients

Engineering Contradiction:

Improvesecure attachmentVSAvoidease of donning

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the traditional mechanical threading system with a magnetic locking mechanism. The magnetic attraction force automatically secures the prosthetic socket to the liner without requiring manual threading or complex strap manipulation, thus maintaining secure attachment while dramatically improving ease of operation for geriatric patients

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic locking system enables self-service attachment where the prosthetic components automatically lock together through magnetic attraction when brought into proximity. The patient simply needs to align and approach the components, and the magnetic force completes the secure attachment without requiring manual threading or assistance

Inventive Principle:

Principle #25Self-service

2Ease of operation

If the traction element remains attached to the prosthetic socket during removal, then the patient can step out easily, but the existing system requires tedious threading to remove the strap

Engineering Contradiction:

Improveease of removalVSAvoidtime for strap manipulation

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The magnetic locking mechanism replaces the time-consuming mechanical threading and unthreading process. When removal is needed, the magnetic attraction is simply overcome by pulling the components apart, eliminating the tedious strap manipulation and significantly reducing the time required for prosthetic removal

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If a tool-free locking system is used, then the patient can easily attach and detach components, but the locking mechanism must still prevent unintentional unlocking

Engineering Contradiction:

Improvetool-free operationVSAvoidlocking security

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The magnetic locking system provides tool-free operation while ensuring locking security through the inherent strength and directionality of magnetic attraction. The magnetic force securely holds the components together during normal use but can be reliably overcome by intentional pulling, preventing unintentional unlocking while maintaining ease of operation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic locking mechanism utilizes changes in magnetic field strength and direction to provide secure locking during attachment while allowing controlled release during intentional removal. The magnetic parameters are optimized to prevent accidental disengagement while enabling tool-free operation

Inventive Principle:

Principle #35Parameter changes

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

The system simplifies the insertion process by eliminating the need for threading and ensures secure attachment, enabling easy removal and replacement of prosthetic components without tools, while preventing unintentional detachment.

Implementation Method 1

a friction-fit, particularly magnetic, locking mechanism, or at least securing of the form-fit locking mechanism, can be achieved by a friction-fit, particularly magnetic, locking mechanism. Magnetic forces can also serve to facilitate threading, approximation, and/or orientation of the connecting components.

Methodology Applied

Scientific EffectMagnetic locking mechanism: Magnetism

Implementation Method 2

a friction-fit, particularly magnetic, locking mechanism, or at least securing of the form-fit locking mechanism, can be achieved by a friction-fit, particularly magnetic, locking mechanism

Methodology Applied

Scientific EffectFriction-fit: Friction

Data Source

PatentEP3432840B1Flexible prosthetic liner and prosthetic shaft system

Publication Date: 2026.05.06 OTTOBOCK SE & CO KGAA

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AI summary

The invention relates to a flexible prosthetic liner (10) having a proximal access opening (11) for a stump of a limb and a distal end region (12) as well as a flexible tension means (30) which is arranged in the distal end region (12) on the prosthetic liner (10). The tension means (30) is detachably fastened to the prosthetic liner (10) by means of a closure system (40) that can be actuated without a tool. The invention also relates to a prosthetic shaft system formed by such a prosthetic liner and a prosthetic shaft.