Micro Catheter with Braid-to-Helix Transition
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Solution Overview
Problem
Traditional micro catheters are not adaptable to intracranial distal blood vessels due to insufficient flexibility, torque transmission, follow-up characteristics, supporting property, and kink resistance, and their size and design are not suitable for navigating the complex and tortuous paths of these vessels.
Innovation Solution
A micro catheter design featuring a catheter wall structure with a smooth layer, a reinforcing layer, and an outer covering layer, where the reinforcing layer transitions from a braid structure at the proximal end to a helix structure at the distal end, with increasing braid pitch points and decreasing helix pitch, allowing for improved flexibility, torque transmission, and kink resistance, and a decreasing outer diameter to accommodate smaller vessel sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional micro catheter structure is used, then the catheter can maintain sufficient pushing property, but it cannot achieve sufficient flexibility and torque transmission for intracranial distal blood vessels
Solution Approach 1:
The catheter body is divided into multiple sections with different wall structures. The proximal portion has a multi-layer wall structure with braid reinforcement for pushing strength, while the distal portion has a simpler wall structure for flexibility. This segmentation allows each section to be optimized for its specific functional requirements.
Solution Approach 2:
Different portions of the catheter are given different structural qualities. The proximal portion features a complex multi-layer wall with braid and coil reinforcements for strength, while the distal portion has a simpler structure for flexibility. The wall structure transitions from proximal to distal to balance pushing property and flexibility locally.
2Adaptability or versatility
If the catheter size is reduced to fit intracranial distal blood vessels, then the catheter can access smaller vessels, but it loses torque transmission and kink resistance
Solution Approach 1:
The catheter employs different wall structures at different locations. The proximal portion has a robust multi-layer wall with braid and coil reinforcements for torque transmission and kink resistance, while the distal portion has a simpler structure that maintains adequate properties at smaller sizes. This local differentiation allows the catheter to maintain reliability where needed while adapting to small vessel dimensions.
Solution Approach 2:
The catheter wall incorporates composite structures combining multiple materials and layers. The proximal portion uses combinations of polymer layers with metallic braid and coil reinforcements to achieve high torque transmission and kink resistance. The distal portion uses simplified composite structures that maintain adequate performance at reduced size.
3Strength
If the catheter wall is made thicker to improve supporting property, then the catheter gains kink resistance, but it reduces flexibility and follow-up characteristics
Solution Approach 1:
The catheter wall structure is segmented into proximal and distal portions with different thicknesses and compositions. The proximal portion has a thicker, multi-layer wall with reinforcements for supporting property and kink resistance. The distal portion has a thinner, simpler wall structure that provides flexibility and follow-up characteristics. This segmentation resolves the contradiction by providing different wall characteristics in different locations.
Solution Approach 2:
Different wall thicknesses and structures are applied locally to different portions of the catheter. The proximal portion features a thicker wall with braid and coil reinforcements for supporting property, while the distal portion has a thinner wall for flexibility. This local quality differentiation allows the catheter to have both strong supporting property where needed and good follow-up characteristics where required.
Data Source
Figure 1~2
Figure 3~4B
Figure 5A~5C
AI summary
A catheter and a micro catheter (10) for nerve intervention are provided, and the catheter wall of the catheter comprises a smooth layer (23), a reinforcing layer (24) and an outer covering layer (25) in the order from inside to outside. The smooth layer (23) and the outer covering layer (25) are both made of polymer materials. The reinforcing layer (24) is a supporting layer, which is connected with the smooth layer (23) and the outer covering layer (25) respectively, so as to connect the respective layers of the catheter together. The catheter comprises a proximal portion (11) and an extension portion in the direction from the proximal end to the distal end. The reinforcing layer (24) assumes a braid structure at the proximal portion (11), and assumes a helix structure at the extension portion.