Cannula Retention Anchor With Transitioning Washer Fixation
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Solution Overview
Problem
Current surgical access devices lack an effective mechanism to securely anchor themselves within tissue during minimally invasive procedures, particularly in laparoscopic surgeries, which can lead to instability and potential withdrawal of the cannula during instrument manipulation.
Innovation Solution
A retention anchor comprising an annular body with a washer that transitions between convex and concave configurations, providing a friction fit with the cannula shaft to securely anchor the device within the tissue, combining a flexible annular body with a more rigid washer for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple cannula structure is used, then the device is easy to manufacture and operate, but it lacks effective anchoring mechanism leading to instability and potential withdrawal during surgery
Solution Approach 1:
The retention anchor is divided into functionally distinct segments: an annular body for basic anchoring and a separate washer component for enhanced security. The washer can be independently positioned or removed, allowing flexible configuration. This segmentation enables the device to provide reliable anchoring through multiple components while maintaining ease of manufacture by using simple, separate parts that can be produced independently and assembled straightforwardly.
2Reliability
If the washer extends radially inwardly (second configuration), then friction fit with cannula shaft is enhanced for secure anchoring, but the device complexity increases
Solution Approach 1:
The washer is designed to be dynamically positionable between two configurations: extending radially inwardly (second configuration) for maximum friction fit and secure anchoring, or positioned outwardly (first configuration) for easier cannula insertion and removal. This dynamic positioning capability allows the device to adapt its complexity level based on the operational phase, providing enhanced security when needed while maintaining simplicity during insertion and withdrawal operations.
3Strength
If a rigid washer is used, then structural strength and friction fit are improved, but the overall device flexibility is reduced
Solution Approach 1:
The device employs local quality by using a rigid washer material specifically at the interface where friction fit is required, while the annular body and cannula shaft can be made of more flexible materials. This localized rigidity provides the necessary structural strength and friction fit security at the critical anchoring point without compromising the overall flexibility and adaptability of the cannula system, allowing the device to conform to tissue while maintaining secure anchoring.
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 retention anchor effectively secures the cannula in place, preventing longitudinal movement and ensuring stability during surgical procedures, while allowing easy removal post-use by transitioning between configurations.
Implementation Method 1
the washer transitionable between a first configuration in which the inner terminal edge of the washer is coincident with or disposed radially outwardly of the inner side surface of the annular body, and a second configuration in which the inner terminal edge of the washer extends radially inwardly of the inner side surface of the annular body
Data Source
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AI summary
A surgical access assembly includes a cannula and a retention anchor including an annular body and a washer secured to the annular body. The annular body includes an inner side surface defining an opening therethrough, and the washer includes an inner terminal edge defining an opening therethrough that is aligned with the opening of the annular body. The elongated shaft of the cannula extends through the openings. The washer is transitionable between a first configuration in which the inner terminal edge of the washer is coincident with or disposed radially outwardly of the inner side surface of the annular body so that the retention anchor is slidable along the elongated shaft, and a second configuration in which the inner terminal edge of the washer extends radially inwardly of the inner side surface of the annular body and engages the elongated shaft to fix the retention anchor to the elongated shaft.