Skin-Mounted Joint Restraint with Pivot-Triggered Electrical Alert

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Solution Overview

Problem

Current movement restraining devices for medical purposes either provide excessive resistance in allowed directions or fail to prevent movements in forbidden directions, and there is a need for a device that allows free movement in allowed directions while blocking further movement beyond a certain pivot position, with the added feature of alerting healthcare workers if the patient attempts to move the restrained body part into a forbidden position.

Innovation Solution

A movement restraining device that attaches to the skin at a body joint, allowing free pivoting in one direction while blocking further movement in the opposite direction, with electrical contact elements that activate an indicator when the abutting pivot position is reached, alerting healthcare workers of attempted forbidden movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cast or splint is applied to prevent movement of the body part, then movement restriction is achieved, but the device presents resistance even in allowed movement directions

Engineering Contradiction:
Improvemovement restrictionVSAvoidmovement freedom
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The splint incorporates a hinge mechanism that allows dynamic movement in permitted directions while maintaining restriction in forbidden directions. The hinge enables the splint to adapt to physiological movements without providing resistance, achieving both reliability in restriction and ease of operation in allowed movements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The restraining device is divided into multiple stopper elements that can pivot independently relative to each other. This segmentation allows different parts of the device to perform different functions - some elements allow movement while others provide blocking, resolving the contradiction between movement freedom and restriction

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a splint allows movement in allowed directions, then movement freedom is improved, but it fails to provide hard resistance in forbidden directions

Engineering Contradiction:
Improvemovement freedomVSAvoidmovement restriction
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The hinge mechanism provides dynamic adaptation - it remains flexible and allows movement during normal physiological ranges, but becomes rigid and provides hard resistance when movement exceeds the permitted range. This resolves the contradiction by making the resistance characteristic dependent on the movement direction and magnitude

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The abutment surface and abutting surface are pre-positioned to engage before harmful movement can occur. When the body part attempts to move beyond the permitted range, these surfaces immediately provide blocking resistance, preventing the harmful movement before it can cause damage

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If traditional restraining devices block movement completely, then harmful movements are prevented, but healing is delayed due to excessive immobilization

Engineering Contradiction:
Improveharmful movement preventionVSAvoidhealing time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The device enables dynamic healing by allowing controlled movement in directions that promote healing while blocking movements that would cause harm. This partial immobilization approach reduces healing time compared to complete immobilization while maintaining protection against harmful movements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The restraining device applies restriction locally only to forbidden movement directions while leaving allowed directions unrestricted. This selective restriction prevents harmful movements without impeding healing processes that require movement, thereby reducing overall healing time

Inventive Principle:
Principle #3Local quality

4Device complexity

If no monitoring system is provided, then device complexity is reduced, but healthcare workers cannot be alerted of attempted forbidden movements

Engineering Contradiction:
Improvedevice simplicityVSAvoidmovement monitoring
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The electrical contact elements provide immediate feedback when the abutting pivot position is reached. This feedback mechanism alerts healthcare workers to attempted forbidden movements without significantly increasing device complexity, as it uses simple electrical contacts rather than complex electronic systems

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The electrical contact elements act as intermediaries between the mechanical movement restriction system and the monitoring function. When the stopper elements pivot to the abutting position, the contact elements transfer this mechanical state into an electrical signal that can be monitored, adding monitoring capability without requiring direct integration of complex electronic systems

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3184090B1Movement restraining device
Publication Date: 2020.01.22 3M INNOVATIVE PROPERTIES CO
  • EP3184090B1 patent drawingFigure 1~2
  • EP3184090B1 patent drawingFigure 3~4

AI summary

Movement restraining device (1) for partially immobilizing a body joint (10) facilitating rotation of a body part (20) about a joint axis (40). The device comprises a) a first stopper element (50) having an abutment surface (70); b) a second stopper element (60), comprising an abutting surface (100), pivotable, relative to the first stopper element. The second stopper element can be pivoted into an abutting pivot position, in which position the abutting surface is in surface contact with the abutment surface; c) skin attachment means (90) for attaching the stopper elements to skin at the body joint; and d) electrical contact elements (310, 320), connectable to an indicator device for providing an indication when the contact elements are in electrical contact with each other. The first contact element can be brought into electrical contact with the second contact element by pivoting the second stopper element into the abutting pivot position.