Rotational Locking Mechanism for Prosthetic Adjustment Tools
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Solution Overview
Problem
Current tools for adjusting prosthetic anatomical devices, such as annuloplasty rings, lack the necessary precision and control for in situ adjustments post-implantation, leading to potential complications like incomplete coaptation and blood flow issues due to the lack of a reliable and minimally invasive adjustment mechanism.
Innovation Solution
A minimally invasive adjustment tool featuring a handheld design with a center shaft and internally threaded knob system, combined with a rotational locking device that securely attaches to the prosthetic device, allowing controlled adjustment of the annuloplasty ring's size and shape through a compression mechanism to prevent unintended rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a minimally invasive adjustment tool is used for in situ adjustment of prosthetic devices, then the invasiveness is reduced and patient recovery is improved, but the precision and control of adjustment are compromised
Solution Approach 1:
The tool employs nested hypotubes where an inner hypotube containing the shaft is received within an outer hypotube. The inner hypotube can rotate independently within the outer hypotube, allowing the shaft to rotate for adjustment while the outer hypotube remains stationary or rotates minimally, thus maintaining precision while reducing invasiveness
Solution Approach 2:
The tool is divided into multiple functional segments: a handle portion, an outer hypotube, an inner hypotube, and a shaft with locking mechanism. Each segment performs a specific function - the handle provides ergonomic grip, the hypotubes provide rotational control, and the shaft with locking mechanism provides precise positioning. This segmentation allows the tool to achieve both minimally invasive delivery and precise adjustment capability
2Manufacturing precision
If a rotational locking device is added to prevent unintended rotation, then the control and precision are improved, but the device complexity increases
Solution Approach 1:
The locking mechanism is pre-configured with a locking element on the shaft and a corresponding recess in the inner hypotube. Before rotation occurs, the locking element is positioned to engage with the recess. This preliminary positioning ensures that unintended rotation is prevented before it can cause imprecision, while the locking action itself is simple and does not add complex mechanisms
Solution Approach 2:
The locking element acts as an intermediary between the shaft and the inner hypotube. It provides a simple mechanical interface that either allows rotation (when disengaged) or prevents rotation (when engaged). This intermediary component simplifies the overall design by providing a clear binary state rather than requiring complex control mechanisms
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 precise and controlled adjustment of prosthetic devices like annuloplasty rings, reducing the risk of blood flow issues by allowing surgeons to securely and effectively modify the device's size and shape post-implantation, thereby improving coaptation and minimizing complications.
Implementation Method 1
The hypotube is rotated by an internally threaded knob received about an externally threaded cylinder
Implementation Method 2
A compression member is arranged within the housing for engaging a portion of the hypotube for retarding its unrestricted rotation
Implementation Method 3
Movement of the sleeve to the first position engages the locking elements thereby precluding rotation of the sleeve and preventing rotation of the shaft
Data Source
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AI summary
An adjustment tool enables manipulation of a prosthetic anatomical device such as an annuloplasty ring. The tool includes a compression member which is operative for retarding rotation of the adjustment shaft to preclude inadvertent rotation thereof during use of the tool by the surgeon. A locking device is associated with the adjustment tool to enable the releasable attachment of the tool to the anatomical device during its adjustment by manipulation of the tool. The locking device is oriented into operative and inoperative positions by the engagement and disengagement of locking elements. A scale may be provided on the adjustment tool to assist a surgeon in determining the size or amount of adjustment to the size of the anatomical device during its adjustment.