Cannula Retention Anchor Structure for Anti-Retropulsion Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surgical access devices lack effective mechanisms to prevent retropulsion and over-insertion during the insertion, manipulation, and withdrawal of surgical instruments, compromising the stability and integrity of the cannula within the body.
Innovation Solution
A retention anchor with an annular body and fixation body, featuring wings and a compressible collar, is used to secure the cannula to tissue, limiting longitudinal movement and stabilizing the device during surgical procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an anchor mechanism is added to prevent retropulsion, then the cannula stability is improved, but the device complexity increases
Solution Approach 1:
The retention anchor is nested within the cannula structure, with the annular body positioned inside the cannula lumen and the fixation body extending outward. This nested configuration allows the anchor mechanism to be integrated into the existing cannula design without requiring separate external components, thereby improving stability while minimizing increases in overall device complexity.
Solution Approach 2:
The anchor mechanism is divided into distinct functional segments: the annular body that interfaces with the cannula, the fixation body with wings that engages tissue, and the compressible collar that provides incremental adjustment. This segmentation allows each component to perform its specific function efficiently while maintaining modularity that simplifies manufacturing and assembly.
2Stability of the object's composition
If a retention mechanism is added to prevent over-insertion, then the cannula stability is improved, but the device complexity increases
Solution Approach 1:
The retention anchor is nested within the cannula structure, with the annular body positioned inside the cannula lumen and the fixation body extending outward. This nested configuration allows the anchor mechanism to be integrated into the existing cannula design without requiring separate external components, thereby improving stability while minimizing increases in overall device complexity.
Solution Approach 2:
The retention anchor is pre-positioned on the cannula before insertion, with the fixation body oriented to engage tissue at the desired depth. The compressible collar is pre-loaded to provide immediate resistance against over-insertion forces, preventing the need for additional control mechanisms during the procedure.
3Reliability
If the retention anchor structure is made more complex to improve securing effectiveness, then the anti-retropulsion capability is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The compressible collar provides adjustable compression force that can be incrementally increased to optimize tissue engagement. By varying the compression parameter, the system achieves reliable securing effectiveness without requiring complex mechanical interlocking structures, thereby simplifying manufacturing while maintaining high reliability.
Solution Approach 2:
The compressible collar is constructed as a flexible, elastomeric component that can be compressed radially to engage tissue. This flexible shell design provides effective securing through elastic deformation rather than rigid mechanical structures, simplifying manufacturing processes while ensuring reliable retention.
Data Source
Figure 1
Figure 2
Figure 3~6
AI summary
A surgical access assembly includes a cannula including an elongated shaft and a retention anchor movably positionable along the elongated shaft. The retention anchor includes an annular body and a fixation body. The annular body includes a proximally-facing surface, a distally-facing surface, an inner side surface defining an opening therethrough, and an outer side surface. The fixation body includes a disc secured to the distally-facing surface of the annular body and wings extending radially outwardly from the disc beyond the outer side surface of the annular body. The disc defines an opening therethrough and the elongated shaft extends through the openings in the annular body and the fixation body.