External Fixator Adjustment Knob with Detachable Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing external fixation devices are difficult to adjust and prone to unintentional misadjustments, making them challenging for patients to use effectively and safely.
Innovation Solution
An external fixation device with a detachable adjusting knob and complementary stop members that allows for defined length adjustments through rotation, providing a tactile stop position and preventing unintentional actuation, combined with a torsion-resistant design and a calibrated scale for precise length measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the adjusting knob is permanently attached to the adjusting member, then the device is protected against unintentional misadjustments, but the device becomes more complex and harder to adjust for patients
Solution Approach 1:
The adjusting knob is designed with a detachable connection to the adjusting member, allowing it to transition between a locked state (preventing unintentional adjustments) and a detached state (enabling easy adjustment by patients). This dynamic configuration resolves the contradiction by providing both security and ease of use at different times.
2Ease of operation
If the adjusting knob is detachable, then the device is easier to adjust for patients, but the risk of unintentional misadjustments increases
Solution Approach 1:
The adjusting knob can be detached when adjustment is needed and reattached when adjustment is complete, dynamically changing the device's state between easy adjustment and secure locking, thereby resolving the contradiction between ease of operation and reliability.
3Device complexity
If the internal rod is rotatable in relation to the axis of the rectangular internal rod, then the adjustment mechanism is simpler, but the torsional stability is reduced
Solution Approach 1:
The internal rod has a rectangular cross-section instead of a circular one, creating an asymmetric shape that provides torsional stability while still allowing for simple adjustment through the adjusting member. The rectangular geometry prevents unwanted rotation while maintaining ease of adjustment.
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 device is simplified for patient use, reducing the risk of unintentional adjustments and allowing for easy extension of bone length, while ensuring secure immobilization of the desired distance between clamping members.
Implementation Method 1
an adjusting member (10) which can be attached to the other end (5b) of housing (5), wherein an engagement knob (36) is disposed, by means of which the axial position of internal rod (4) can be adjusted in relation to housing (5) by means of rotation of the adjusting member (10)
Implementation Method 2
Adjusting knob (2) and housing (5) each have at least one complementary stop member (8, 39) so that a stop position with an altered length can be reached through the number and arrangement of the complementary stop members (8, 39) according to a predefined angle of rotation of adjusting knob (2)
Implementation Method 3
A similar device is known from FR 2,557,933. It is used particularly in the context of an external fixator. It comprises a rectangular internal rod and a hollow tube surrounding the same, which are thus movable in one another in a torsion-resistant manner.
Data Source
AI summary
An external fixation device for the extension of the distance between two clamping members of an external fixator has a central internal rod and an outer hollow housing. The internal rod is movable axially. One end of the internal rod projects over the one end of the housing, and serves to fix the one clamping member. An adjusting member is provided disposed at the other end of the housing and is connected with internal rod and/or the outer hollow housing, whereby the axial position of the interior shaft can be adjusted in relation to the housing by means of rotation of the adjusting member. Furthermore, an adjusting knob is provided that can be detachably attached to the adjusting member with an essentially positive fit.