Endoscopic Clip Helical Arms Buckling Prevention
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Solution Overview
Problem
Conventional endoscopic clips experience buckling under loads, limit arm size and shape due to tangential loading, and fail to securely capture tissue or maintain precision, leading to potential loosening over time.
Innovation Solution
The design includes a handle with a mounting hub and helically shaped arms that retract into the hub upon user activation, using axial strength to securely close wounds by constraining arms to move toward a center axis, enhancing mechanical advantage and precision control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the size of the arms is increased to increase strength, then the arms' strength is improved, but the arms cannot pass through the lumen of the endoscope which may be as small as 2.8 millimeters
Solution Approach 1:
The clip arms are designed to nest within the delivery catheter lumen during delivery, then deploy outward to engage tissue. The arms can be contained within the 2.8mm catheter in a collapsed state, then expand to provide sufficient strength for tissue capture and closure.
Solution Approach 2:
The arms transition from a constrained, compact configuration during delivery to an expanded, load-bearing configuration during use. This dynamic transformation allows the arms to be small during delivery but large and strong during tissue engagement.
2Device complexity
If conventional endoscopic clips are used, then the device structure is simple, but the clips experience buckling under loads and fail to securely capture tissue
Solution Approach 1:
The arms incorporate curved or helical sections that provide structural strength and resistance to buckling loads. The curved geometry distributes stresses more effectively than straight arms, allowing the clip to securely capture tissue without requiring overly complex reinforcement.
Solution Approach 2:
The clip may utilize composite material structures combining different material properties to achieve both strength and flexibility. This allows the arms to resist buckling while maintaining the simplicity of the overall device structure.
3Ease of manufacture
If conventional endoscopic clips are used, then the manufacturing process is straightforward, but the clips do not offer sufficient mechanical advantage or precision control
Solution Approach 1:
The clip is divided into distinct functional segments including the mounting hub, arms with specific curvature zones, and engagement tips. This segmentation allows each component to be optimized for its specific function while maintaining manufacturability through modular construction.
Solution Approach 2:
The arm geometry incorporates specific curvature radii, lengths, and material properties that provide mechanical advantage and precision control. By carefully selecting these parameters, the clip achieves superior tissue engagement control while remaining manufacturable using conventional processes.
Data Source
AI summary
An endoscopic clip apparatus includes a clip sleeve defining an interior passage along a longitudinal axis and having a distal end with a plurality of openings defined in the distal end. A clip including a plurality of arms is disposed in the clip sleeve, and each arm includes a distal tip extending from the clip sleeve through one of the plurality of openings. Each arm includes a convex curved section oriented away from the longitudinal axis. The clip sleeve and clip are axially moveable relative to each other such that when the clip sleeve travels over the convex curved section of each arm toward the distal tip of each arm, each arm is constrained by the clip sleeve and each distal tip advances toward the longitudinal axis to grasp tissue.