Bendable Guidewire With Nested Oblique Slits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Guidewires with slits formed to impart flexibility often crack due to poor stress distribution when bending, as the bending stress is not adequately managed in the uncut portions of the outer tube.
Innovation Solution
The slits are designed with angled ends and increased density distally, and the ends of the slits are nested between other slits to distribute bending stress, allowing for flexible navigation without cracking, with features such as oblique slit-ends and varying slit density along the tube length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If slits are formed in the outer tube to impart flexibility, then the guidewire can bend more easily, but the uncut portions crack due to poor stress distribution
Solution Approach 1:
The outer tube is divided into multiple segments by forming slits that extend circumferentially around the tube. These slits create discrete uncut portions that can independently deform, distributing the bending stress across multiple segments rather than concentrating it in a single location, thereby preventing cracking while maintaining flexibility
Solution Approach 2:
The slits are designed with varying characteristics along the length of the guidewire - including variations in slit length, spacing, and orientation - to create different local stress distribution patterns. This local differentiation allows the structure to optimize both flexibility in distal regions and cracking resistance in proximal regions with thicker uncut portions
2Adaptability or versatility
If the guidewire is made more flexible to navigate hard-to-reach areas, then navigation capability improves, but the structure becomes weaker and more prone to damage
Solution Approach 1:
The guidewire structure transitions from a static rigid tube to a dynamic flexible structure through the addition of slits. The uncut portions can dynamically adjust their deformation during bending, allowing the guidewire to adapt to various navigation requirements while maintaining structural integrity through the distributed stress pattern created by multiple uncut portions
Solution Approach 2:
Multiple uncut portions are nested along the length of the guidewire, with each uncut portion providing structural support within the overall flexible structure. This nested arrangement of reinforcing uncut portions within the slit-patterned tube allows the guidewire to achieve high flexibility while maintaining strength through the hierarchical distribution of structural elements
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An apparatus includes a tube (29) configured for insertion into a body of a subject, the tube comprising a plurality of strips (28), which are angled obliquely with respect to a longitudinal axis of the tube, by virtue of the tube being shaped to define a plurality of slits (32) having respective oblique proximal ends and respective oblique distal ends. The distal end of each of the slits is nested between the proximal end of a first other one of the slits and the proximal end of a second other one of the slits such that (i) one of the strips is disposed between the distal end of the slit and the proximal end of the first other one of the slits, and (ii) another one of the strips is disposed between the distal end of the slit and the proximal end of the second other one of the slits.