Spiral-Wire Dilator Structure to Prevent Coil Detachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dilators face the risk of the spirally-arranged protruding portion detaching from the hollow shaft due to drag forces during expansion or withdrawal, which can damage tissues.
Innovation Solution
A dilator design featuring a hollow shaft with a tapered portion and a spirally-arranged protruding portion formed by winding a wire, where the inner peripheral radius of the protruding portion is smaller than the outer peripheral radius of the distal tip, ensuring gaps between adjacent portions along the longitudinal direction to prevent detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a wire is simply wound around the outer peripheral surface of the shaft to form a coil body, then the coil body can be easily formed, but the coil body may detach from the shaft due to drag force from tissues or tensile force upon withdrawal
Solution Approach 1:
The invention transitions from a two-dimensional surface winding to a three-dimensional interlocking structure. The wire is wound around the tapered portion and then the distal tip is inserted into the hollow shaft, creating a spatial interlocking configuration where the wire passes through the shaft's hollow interior. This dimensional transition prevents detachment by establishing mechanical interlocking in multiple spatial dimensions simultaneously.
Solution Approach 2:
The distal tip of the wire is inserted into the hollow shaft, creating a nested configuration where one component (distal tip) is contained within another (hollow shaft). This nesting structure provides secure attachment by utilizing the hollow interior space of the shaft to anchor the wire, preventing detachment during expansion or withdrawal operations.
2Reliability
If the inner peripheral radius of the protruding portion is made smaller than the outer peripheral radius of the distal tip, then gaps are created to prevent detachment, but the structural complexity increases
Solution Approach 1:
The invention utilizes parameter changes in the radial dimensions to create functional gaps. By making the inner peripheral radius of the protruding portion smaller than the outer peripheral radius of the distal tip, radial gaps are created that allow the structure to expand and contract while maintaining attachment. This parameter-based solution achieves detachment prevention through dimensional relationships rather than complex mechanical features.
Solution Approach 2:
The wire structure is segmented into distinct functional portions: the spirally-wound coil body on the tapered portion and the distal tip inserted into the hollow shaft. This segmentation allows each portion to perform its specific function - the coil body provides expansion force while the distal tip provides secure anchoring - and simplifies the overall structure by dividing it into manageable, functionally-independent segments.
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 design effectively prevents the spirally-arranged protruding portion from detaching from the hollow shaft, allowing smooth operation and reducing tissue damage during expansion and withdrawal.
Implementation Method 1
a dilator that is provided with a coil body on the outer peripheral surface of the tapered portion of a shaft for expansion, so as to supplement the propulsive force by the use of the screwing action resulting from rotation
Data Source
AI summary
A dilator includes: a hollow shaft having a tapered portion whose outer diameter of the distal end is smaller than the outer diameter of the proximal end; a distal tip, whose proximal end is located at the distal end of the tapered portion, and which is provided to extend toward the distal end direction; and a spirally-arranged protruding portion provided on at least the outer peripheral surface of the tapered portion. The spirally-arranged protruding portion is formed by winding a wire and has gaps between portions adjacent to each other along the longitudinal direction of the hollow shaft. The inner peripheral radius CIDmin of a portion, which is the minimum inner peripheral radius of the spirally-arranged protruding portion, is smaller than the outer peripheral radius TODmax of a portion, which is the maximum outer peripheral radius of the distal tip.