Stent Strand-End Coupling for Reliable Laser Welding
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Solution Overview
Problem
Existing medical devices, such as stents, face challenges in securely joining strand ends to maintain structural integrity and consistency, particularly when made from nickel-titanium wires, as existing methods fail to ensure reliable and consistent welding of coupling structures across the device.
Innovation Solution
The method involves securing a coupling structure to aligned strand end portions of medical devices using laser welding, where the coupling structure is not a strand of the device, and is configured with a passageway for direct contact before welding, ensuring alignment and stability, even when the device is axially compressed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing methods are used to join strand ends, then the device can be manufactured, but the structural integrity and consistency are compromised due to unreliable welding
Solution Approach 1:
A coupling structure serves as an intermediary component between strand ends, providing a dedicated welding interface that is optimized for laser welding. This coupling structure includes a coupling surface specifically designed to contact and weld to the strand ends, ensuring reliable and consistent welding without compromising the parent material of the strands.
Solution Approach 2:
The joining system is segmented into distinct components: the coupling structure with its coupling surface, and the strand ends. This segmentation allows the coupling structure to be specifically optimized for welding operations while the strands maintain their original properties, resolving the contradiction between welding reliability and structural integrity.
2Reliability
If the coupling structure is made larger to ensure stable welding, then welding reliability improves, but the device length increases and proportionality is lost
Solution Approach 1:
The coupling structure dimensions are carefully controlled within specific parameter ranges (length 0.1-5mm, width 0.01-1mm, thickness 0.01-0.5mm) to provide sufficient welding surface area for reliable welding while maintaining proportionality to the overall device and avoiding excessive length increase.
3Manufacturing precision
If the coupling structure is placed into direct contact with strand end portions before welding, then alignment precision improves, but the complexity of positioning increases
Solution Approach 1:
The coupling structure includes self-aligning features such as the coupling surface that automatically positions itself relative to the strand ends during assembly. The geometric configuration of the coupling surface and strand end interface enables self-alignment, reducing positioning complexity while maintaining high alignment precision for welding.
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
This approach enhances the structural integrity and consistency of medical devices by creating reliable welded regions that maintain device shape and functionality, even under compression, using nickel-titanium coupling structures that are proportionally sized relative to the device length.
Implementation Method 1
securing the coupling structure to the first and second strand end portions using laser welding
Data Source
AI summary
A woven, self-expanding stent device has one or more strands and is configured for insertion into an anatomical structure. The device includes a coupling structure secured to two different strand end portions that are substantially aligned with each other. The two different strand end portions include nickel and titanium. The coupling structure is not a strand of the device.