Medical Guide Wire Torsional Rigidity Optimization
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Solution Overview
Problem
Existing guide wires for treating vascular lesions lack significant improvement in rotation transmission performance from the proximal end to the distal end, due to inadequate torsional rigidity ratios between tubular connectors and metal wires, which hinders insertion and passage through vascular lesions.
Innovation Solution
A guide wire design featuring a tubular connector that connects cores with pseudoelastic and strain-induced martensitic transformation properties, optimizing torsional rigidity ratios to enhance rotation transmission performance, with a hydrophilic coating for improved slidability and operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a tubular connector is used to connect different kinds of metal wires, then connection strength is improved, but rotation transmission performance deteriorates due to inadequate torsional rigidity ratios
Solution Approach 1:
The patent optimizes the torsional rigidity ratio by carefully selecting the wall thickness and material properties of the tubular connector. The connector's torsional rigidity is adjusted to satisfy a specific relationship with the torsional rigidities of the first and second cores, ensuring efficient rotation transmission while maintaining connection strength.
Solution Approach 2:
The guide wire employs a composite structure consisting of different kinds of metal wires (first core and second core with different material properties) connected by a tubular connector. This composite design allows each component to contribute its unique mechanical properties, achieving both strong connection and effective rotation transmission.
2Ease of operation
If the guide wire is inserted into the vascular lesion, then passability is improved, but twist at the connection portion increases causing poor rotation transmission
Solution Approach 1:
The patent controls the twist at the connection portion by optimizing the torsional rigidity ratio of the tubular connector. The connector is designed with specific dimensional parameters (wall thickness, length) to maintain appropriate torsional rigidity, preventing excessive twist accumulation during insertion while enabling smooth passage through the vascular lesion.
3Ease of operation
If a hydrophilic coating is applied, then slidability is improved, but manufacturing complexity increases
Solution Approach 1:
The hydrophilic coating utilizes hydraulic principles by forming a water-based lubricating layer on the guide wire surface. This coating reduces friction between the guide wire and blood vessel walls through fluid lubrication, significantly improving slidability during insertion and retrieval operations.
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 improved reachability and passability through vascular lesions by optimizing torsional rigidity ratios and reducing twist at the connection portion, while the hydrophilic coating enhances slidability and ease of release from vessel walls.
Implementation Method 1
the first core (2A) has a pseudoelastic property
Implementation Method 2
the second core (2B) has a strain-induced martensitic transformation phase
Data Source
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AI summary
In a medical guide wire having a connecting structure formed by three members: a tubular connector; a first core; and a second core, when a torsional rigidity of one member is lower than the torsional rigidity of the materials of both end portions, for example, the twist is unevenly generated between the members and the rotation transmission performance to the distal end side is significantly reduced. In such a case, there is a technical problem for improving the rotation transmission performance to the distal end side. In the connecting structure formed by three members, as a result of focusing on the torsional rigidity of the three members and considering the torsional rigidity ratios between the members, the technical problem for improving the rotation transmission performance to the distal end side can be solved when the torsional rigidity ratios satisfy a predetermined relation.