Cannula Retention Anchor With Locking Washer Against Retropulsion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surgical access devices often experience longitudinal movement issues during minimally invasive procedures, such as retropulsion and over-insertion, due to the lack of effective anchor mechanisms that prevent the cannula from backing out of the tissue opening, compromising the integrity of the pneumoperitoneum and the surgical site access.
Innovation Solution
A retention anchor system comprising an annular body and a washer, where the washer transitions between a first configuration allowing slidable movement and a second configuration engaging the cannula shaft to secure the anchor, providing a counterforce to prevent longitudinal movement and enhance fixation force, is integrated with the surgical access device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an anchor mechanism is added to prevent longitudinal movement, then stability and reliability are improved, but device complexity increases
Solution Approach 1:
The anchor mechanism is divided into separate functional components: an expandable anchor element with arms that can be independently deployed, and a locking mechanism with a locking element that engages with the cannula shaft. This segmentation allows each component to perform its specific function while keeping the overall device manageable in complexity.
Solution Approach 2:
The anchor mechanism transitions from a compressed state during insertion to an expanded state after deployment. The arms of the anchor element are movable between a compressed configuration (during insertion) and an expanded configuration (after deployment), allowing the device to adapt its structure dynamically to achieve secure fixation while maintaining ease of insertion.
2Strength
If the anchor mechanism is made more secure to prevent movement, then fixation force is improved, but the force required to deploy or adjust the anchor increases
Solution Approach 1:
The locking element engages with the cannula shaft through a partial engagement mechanism rather than requiring complete interlocking. The locking element has a locking surface that contacts a corresponding surface on the cannula shaft, providing sufficient fixation force without requiring excessive deployment force. This partial engagement approach achieves adequate strength while minimizing the force needed for deployment.
Solution Approach 2:
The locking element acts as an intermediary between the expandable anchor element and the cannula shaft. It translates the expansion motion of the anchor arms into a locking action that secures the anchor to the cannula, distributing the forces involved in both deployment and fixation in a controlled manner.
3Reliability
If the cannula is secured firmly to prevent backing out, then reliability is improved, but ease of operation during insertion and adjustment is reduced
Solution Approach 1:
The anchor mechanism is designed to be dynamic during insertion and deployment, allowing easy sliding and positioning. The arms are movable and the locking element can engage or disengage from the cannula shaft as needed. Once positioned and locked, the mechanism becomes static and secure, providing firm prevention of backing out while maintaining ease of operation during the insertion and adjustment phases.
Solution Approach 2:
The anchor element is pre-configured in a compressed state that allows it to slide easily along the cannula shaft during insertion. The locking mechanism is pre-positioned to engage automatically or with minimal action after the anchor reaches its desired position, eliminating the need for complex manual adjustment operations while ensuring reliable fixation.
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 system effectively secures the surgical access device to the tissue, minimizing movement and maintaining the integrity of the pneumoperitoneum, thereby stabilizing the cannula and ensuring reliable access for surgical instruments during procedures.
Implementation Method 1
The inner side surface of the annular body may frictionally engage the elongated shaft of the cannula
Data Source
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.