Guide Wire Segmented Surface Friction for Catheter Sliding
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Solution Overview
Problem
Existing guide wires face challenges in achieving high operability due to low grip force and sliding resistance issues, particularly in navigating through indurate stenosis sites and curved blood vessels, as they often compromise between flexibility and pushability/torque transmissibility.
Innovation Solution
A guide wire design featuring a flexible elongate wire body with protruding and non-protruding portions, where the protruding portions have a lower friction coefficient for sliding and the non-protruding portions have a higher friction coefficient for grip, allowing for improved sliding performance within catheters while maintaining effective grip force during manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the guide wire is covered with a fluorinated resin to improve grip force, then the grip force is improved, but the sliding performance with the catheter inner surface deteriorates due to low friction coefficient
Solution Approach 1:
The guide wire surface is segmented into protruding portions and non-protruding portions with different friction coefficients. The protruding portions provide high friction for grip force, while the non-protruding portions provide low friction for sliding performance. This segmentation allows both contradictory requirements to be satisfied simultaneously on different parts of the same surface.
Solution Approach 2:
Different regions of the guide wire surface are given different local qualities - the protruding portions have high friction coefficient material for gripping, while the non-protruding portions have low friction coefficient material for sliding. This local differentiation resolves the contradiction between needing high grip force and good sliding performance.
2Force
If a spiral slip-prevention member is provided on the guide wire to improve grip force, then the grip force is improved, but the sliding performance deteriorates when the slip-prevention member contacts the catheter inner surface
Solution Approach 1:
The surface structure is segmented into protruding portions (providing grip) and non-protruding portions (providing sliding). During insertion, the non-protruding portions contact the catheter inner surface ensuring smooth sliding, while the protruding portions remain engaged with the operator's finger for grip force transmission.
Solution Approach 2:
Instead of making the entire surface slippery or adding external slip-prevention members that interfere with sliding, the invention inverts the approach by creating a textured surface where the high-friction elements (protrusions) are strategically positioned to engage with the finger during gripping operations, while the low-friction valleys ensure catheter sliding.
3Ease of operation
If the guide wire requires both flexibility and pushability/torque transmissibility, then the operability is improved, but the structural design becomes more complex
Solution Approach 1:
The wire body structure is designed with local quality variations - different sections have different structural characteristics to optimize for specific functions. The proximal portion emphasizes torque transmissibility and pushability, while the distal portion emphasizes flexibility and followability, resolving the contradiction without requiring a completely complex multi-component structure.
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 guide wire achieves enhanced sliding performance within catheters and reliable grip force transmission, ensuring improved pushability and torque transmissibility, thereby facilitating easier navigation through complex vascular structures without compromising flexibility or safety.
Implementation Method 1
The protruding portion is formed of a material having a friction coefficient smaller than that of a material forming the non-protruding portion
Implementation Method 2
the non-protruding portion between the adjacent protruding portion... having a friction coefficient smaller than that of a material forming the non-protruding portion
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A guide wire (1A) is comprised of a flexible elongate wire body (10). The wire body has a plurality of protruding portions (34) on the external surface and recessed portions (35) between the adjacent protruding portions. The protruding portions possess a friction coefficient smaller than that of the recessed portions.