Catheter with Variable Rigidity for Branch Vessel Insertion
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Solution Overview
Problem
Existing catheters face challenges in securely inserting the distal end into small-diameter branch blood vessels due to the rigidity of the catheter, causing the guide wire to separate from the branch blood vessel during the procedure.
Innovation Solution
A branch blood vessel insertion catheter with a catheter body featuring a wire-wound reinforcing member and a physical property change point 3.0 to 7.0mm from the distal end, allowing for a transition from a more rigid to an easily bendable region, preventing the guide wire from separating and facilitating secure insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the catheter distal region has high rigidity to maintain structural stability, then the catheter can resist external forces, but the guide wire distal end portion separates from the branch blood vessel during insertion
Solution Approach 1:
The catheter is designed with non-uniform rigidity distribution: the distal region (within 3mm from tip) has low rigidity to follow the guide wire into the branch blood vessel, while the proximal region has high rigidity for structural stability. This local differentiation resolves the contradiction by allowing the distal tip to be compliant while maintaining overall catheter strength.
Solution Approach 2:
The catheter shaft is segmented into multiple regions with different rigidity characteristics. The distal region (0-3mm) has low rigidity, the intermediate region (3-15mm) has moderate rigidity, and the proximal region (>15mm) has high rigidity. This segmentation allows each region to perform its specific function: the distal segment follows the guide wire, while proximal segments provide structural support.
2Stability of the object's composition
If the catheter distal region has high rigidity to maintain shape, then the catheter structure is stable, but the catheter cannot easily follow the guide wire into the branch blood vessel
Solution Approach 1:
The catheter exhibits local quality variation in rigidity along its length. The distal 3mm region has low rigidity enabling it to bend and follow the guide wire's path into the branch blood vessel, while maintaining overall shape stability through the higher rigidity of proximal regions.
Solution Approach 2:
The catheter's rigidity is dynamically adapted to the operational requirements: the distal region is designed to be flexible for navigation, while the proximal region remains rigid for support. This dynamic rigidity distribution allows the catheter to simultaneously achieve ease of insertion and shape stability.
3Ease of operation
If the catheter is made highly flexible to follow the guide wire, then insertion into branch blood vessel is easy, but the catheter cannot maintain structural stability
Solution Approach 1:
The catheter is segmented into distal, intermediate, and proximal regions with progressively increasing rigidity. The distal segment provides flexibility for easy insertion by following the guide wire, while the proximal segments provide structural stability through higher rigidity, resolving the contradiction between flexibility and strength.
Solution Approach 2:
The rigidity parameter of the catheter is changed along its length, with the distal region having lower rigidity for flexibility and the proximal region having higher rigidity for structural stability. This parameter gradient allows the catheter to simultaneously achieve ease of insertion and maintain strength.
Data Source
Figure 1
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AI summary
A branch blood vessel insertion catheter (1) is inserted into a small-diameter branch blood vessel branching from a first blood vessel. The catheter (1) has a catheter body (2) having a lumen (20) penetrating therethrough from a distal end thereof to a proximal end thereof to allow a guide wire (15) to be inserted therethrough. The catheter body (2) has an inner layer (3), a wire-wound reinforcing member (5) mounted on an outer surface of the inner layer (3), and an outer layer (4) covering both the inner layer (3) and the wire-wound reinforcing member (5). The catheter body (2) has a first physical property change point (6) located at a position apart from the distal end of the catheter body (2) at a distance of 3.0 to 7.0mm. The rigidity of a portion of the catheter body (2) located proximally from the first physical property change point (6) is set higher than that of a portion of the catheter body (2) located distally therefrom.