Guidewire Thermal Segmentation for Shaping and Durability
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Solution Overview
Problem
Existing guidewires made of superelastic materials face challenges in shaping performance, particularly in forming a hook shape, and durability issues such as folding during use.
Innovation Solution
A guidewire design featuring a core shaft with a thermally-transformed segment and a sparsely-wound coil on the distal end, combined with a shorter or non-transformed segment on the rear end, enhances shaping performance and durability by controlling superelastic characteristics and flexural rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the core shaft is made of superelastic material throughout, then durability is improved, but shaping performance deteriorates
Solution Approach 1:
The core shaft is divided into multiple segments with different thermal transformation states: a first segment (distal end) that is thermally transformed to reduce superelasticity for easy shaping, and a second segment (proximal end) that is not thermally transformed or has shorter thermal transformation to maintain superelasticity for durability. This segmentation allows each segment to fulfill different functional requirements.
Solution Approach 2:
Different portions of the core shaft are given different properties through selective thermal transformation. The distal end portion (first segment) undergoes thermal transformation to become more formable, while the proximal end portion (second segment) retains or regains superelastic properties for durability, creating local quality differences along the shaft.
2Ease of operation
If the entire core shaft is thermally transformed, then shaping performance is improved, but durability deteriorates
Solution Approach 1:
The thermal transformation is applied selectively to segments rather than the entire core shaft. The first segment at the distal end is thermally transformed to improve shaping, while the second segment at the proximal end is excluded or partially excluded from thermal transformation to preserve durability through maintained superelasticity.
Solution Approach 2:
The core shaft exhibits non-uniform properties along its length, with the distal end having thermally transformed characteristics for formability and the proximal end having non-transformed or partially transformed characteristics for durability, achieving local quality optimization.
3Strength
If the coil is densely wound, then structural integrity is improved, but shaping performance deteriorates
Solution Approach 1:
The coil winding density varies along the guidewire length. The distal end portion has sparsely wound coils to allow bending and shaping, while other portions maintain densely wound coils for structural integrity, creating local quality differences in mechanical properties.
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 allows for easy shaping into desired configurations, improves flexibility, and maintains durability by reducing sudden changes in rigidity and thermal conductivity, facilitating easier navigation through complex vascular structures.
Implementation Method 1
a first segment consisting of a thermally-transformed portion in which the superelastic material has been thermally transformed
Implementation Method 2
the coil has a sparsely-wound portion on a distal end portion in which a gap is formed between portions of the wire that are adjacent to each other
Data Source
Figure 1
Figure 2
Figure 2
AI summary
This guidewire is provided with a core shaft made of a superelastic material, and a coil formed of a wire that has been spirally wound around the outer periphery of the distal end portion of the core shaft. A section of the core shaft positioned on an inner side of the coil has a first segment consisting of a thermally-transformed portion in which the superelastic material has been thermally transformed, and a second segment that is positioned on a rear end side of the first segment. In the second segment, a thermally-transformed portion having a shorter length than the first segment is formed, or no thermally-transformed portion is formed. The distal end portion of the coil has a sparsely-wound portion in which gaps are formed between portions of the wire that are adjacent to each other.