Medical Guide Wire with Inclined Outer Coil for Occluded Lesions
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Solution Overview
Problem
Existing medical guide wires face challenges in safely navigating through microchannels with small pore diameters in occluded blood vessels, particularly in avoiding vessel wall damage and ensuring accurate placement during vascular treatments like stent indwelling.
Innovation Solution
A guide wire design featuring a core with a tapered diameter and an outer coil with a flat-shaped, inclined coil portion, where each turn of the coil wire is continuously inclined, allowing for a larger cross-sectional area ratio and improved flexibility, enabling safe passage through tiny blood vessels and facilitating operator feedback through tissue interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the outer coil has a small outer diameter to pass through microchannels, then the guide wire can navigate tiny blood vessels, but the cross-sectional area for operator feedback and tissue interaction is reduced
Solution Approach 1:
The patent applies dimensionality change by transitioning the coil cross-section from a conventional circular shape to an elliptical shape. This allows the coil to have a smaller dimension in one direction (to pass through microchannels) while maintaining or increasing the cross-sectional area in another direction (for operator feedback). The elliptical cross-section with major diameter larger than minor diameter enables the guide wire to navigate tiny blood vessels while providing sufficient surface area for tactile feedback during operation.
2Stability of the object's composition
If the coil wire is made rigid to maintain shape stability, then the guide wire structure is stable, but the flexibility to navigate occluded lesions is reduced
Solution Approach 1:
The patent applies local quality by creating regions of different flexibility within the coil structure. The coil comprises multiple turns with varying pitch distances, where some regions have smaller pitch distances (more rigid) and other regions have larger pitch distances (more flexible). This allows the guide wire to have both shape stability in certain sections and adaptability in others, enabling it to maintain overall structural integrity while navigating complex occluded lesions.
3Adaptability or versatility
If the distal end portion is made more flexible to pass through microchannels, then the guide wire can navigate tiny vessels, but the penetrating performance to reach occluded lesions is reduced
Solution Approach 1:
The patent applies segmentation by dividing the guide wire into distinct functional segments: a distal end portion with higher flexibility for navigating microchannels and a proximal portion with greater rigidity for providing penetrating force. The coil structure is segmented with varying pitch distances along its length, creating a gradient of flexibility that allows the distal end to conform to tiny vessels while the proximal end maintains the force necessary to reach occluded lesions.
Data Source
AI summary
Conventionally, a coil formed in an irregular shape is used on a distal end side of the coil of a guide wire or a distal joining section is used on the tip of the guide wire to shorten a length in a longitudinal direction of a rigid joint portion for improving the passing performance to the occluded lesion. However, it is not enough especially in the completely occluded lesion. Thus, it is an important technical problem to improve both the passing performance and safety. An outer coil having a coil inclined portion and a distal joining section connected with the coil inclined portion are provided on a distal end portion of the guide wire. In the coil inclined portion, each one turn of a coil wire is continuously inclined in a longitudinal direction. Thus, both the passing performance and safety can be remarkably improved especially in the completely occluded lesion.