Programmable External Fixation Strut Adjustment With Sensor Feedback

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Solution Overview

Problem

Existing external fixation devices face challenges in precise and efficient strut length adjustment due to cumbersome patient interaction, potential human errors, and difficulties in wireless data communication, leading to frame instability and incorrect adjustments.

Innovation Solution

A programmable tool that automatically adjusts external fixation struts by communicating with a cloud unit, using a position sensor for feedback, and ensuring correct strut identification through data exchange, eliminating the need for manual measurement and reducing human error.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual adjustment of strut length is performed by patient or practitioner, then ease of operation is improved, but measurement precision and reliability deteriorate due to human errors and inability to accurately monitor small adjustments

Engineering Contradiction:
Improveease of strut adjustmentVSAvoidprecision of strut length measurement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent incorporates a feedback mechanism where the system monitors and tracks the actual strut length adjustments made by the patient or practitioner. The system provides feedback to verify that adjustments match the prescribed protocol, ensuring both ease of operation and measurement precision are maintained simultaneously.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical measurement with an automated electronic measurement system that uses sensors and digital displays to precisely measure strut length. This substitution eliminates human error in measurement while maintaining the simplicity of the adjustment process for the user.

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

2Reliability

If automated programmable tool is used for strut adjustment, then measurement precision and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvereliability of strut adjustmentVSAvoidcomplexity of adjustment system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the adjustment system into separate functional modules: a programmable controller, a sensor system for measurement, a display interface, and the mechanical adjustment mechanism. This segmentation allows each component to perform its specific function independently, improving reliability while keeping the overall system manageable in complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a self-service feature where the system automatically verifies and confirms adjustments without requiring complex user intervention. The programmable tool autonomously monitors the adjustment process and validates results, improving reliability while minimizing the operational burden on the user.

Inventive Principle:
Principle #25Self-service

3Productivity

If wireless data communication is implemented for strut adjustment, then ease of operation and productivity are improved, but reliability deteriorates due to communication errors and lack of feedback

Engineering Contradiction:
Improveefficiency of adjustment processVSAvoidreliability of data transmission
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent incorporates feedback mechanisms in the wireless communication system that continuously verify data transmission accuracy. The system receives adjustment data wirelessly, validates it against prescribed protocols, and provides confirmation feedback to ensure reliability while maintaining the efficiency benefits of wireless operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces wired mechanical data transmission with wireless communication technology, improving productivity and ease of operation. The wireless system uses encrypted digital communication to maintain reliability, eliminating the physical constraints of wired connections while ensuring accurate and secure data transfer.

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

Data Source

PatentEP4643798A1Improved programmable tool for external fixation strut adjustment
Publication Date: 2025.11.05 ORTHOFIX SRL
  • EP4643798A1 patent drawingFigure 1~3
  • EP4643798A1 patent drawingFigure 4~5
  • EP4643798A1 patent drawingFigure 6

AI summary

The present disclosure relates to an external fixation strut having an elongated body comprising at least a first shaft and a second shaft moveable with respect to each other to modify the length of said elongated body, an adjustment mechanism for moving the second shaft with respect to the first shaft thereby modifying the length of the elongated body, a second coupling portion of the adjustment mechanism adapted to releasably engage with a first coupling portion of a tool for adjusting said external fixation strut, to enable torque transmission, at least one sensor adapted to perform at least a measurement which is indicative of the length of the elongated body, and a second connecting portion of the adjustment mechanism which is in electrical communication with a first connecting portion of the tool when the first coupling portion is engaged with the second coupling portion and which is adapted to enable transmission of data from the sensor to the tool. A related medical assembly is also disclosed.