Single-Piece Heart Valve Stent Frame Without Weld Seams
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Solution Overview
Problem
Existing stent manufacturing methods face challenges such as high cost and labor intensity, particularly when using shape memory materials like Nitinol, and the presence of weld seams which can be a weakness in stent constructions.
Innovation Solution
The development of stent frames formed from a single piece of material using methods like heat treatment and deep forming, eliminating the need for welds and allowing for the creation of tubular structures without attachment methods, enabling the production of stents with various configurations that can accommodate different valve types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If stents are made from multiple wire or metal frame components arranged in predetermined patterns, then the stent can provide sufficient structural support and compression characteristics, but the manufacturing process becomes tedious and labor intensive requiring crimping or welding
Solution Approach 1:
The patent merges multiple separate wire or metal frame components into a single integrated stent structure. The stent is formed as one continuous piece with all structural elements (struts, bars, arcs) created from a single blank, eliminating the need for crimping or welding operations while maintaining the required structural support and compression characteristics.
Solution Approach 2:
The stent structure is segmented into multiple functional regions (commissural regions, strut regions, arc regions) that are all formed from a single continuous piece of material. This segmentation allows each region to provide specific structural functions while avoiding the need for separate components and their associated assembly complexities.
2Ease of operation
If large portions of material are removed from a cylinder to provide apertures and structural features, then the stent can achieve desired compression characteristics for percutaneous delivery, but manufacturing large tubes becomes difficult and expensive
Solution Approach 1:
Instead of starting with a solid cylinder and removing material to create apertures and features, the patent inverts the approach by forming the stent directly from a flat blank with the desired aperture patterns already present. The blank is then formed into a cylindrical shape, achieving the desired compression characteristics without the difficulty of manufacturing and modifying large tubes.
3Ease of manufacture
If a flat sheet of material is used to make a stent, then manufacturing may be simplified, but a weld seam is required to join the two ends into a tubular stent creating a potential weakness
Solution Approach 1:
The patent merges the two ends of the flat sheet into a continuous seamless structure by forming the blank into a cylinder. The edges of the blank are brought together and joined without creating a weld seam, resulting in a tubular stent with uniform strength throughout and no potential weakness points from welding operations.
4Length of stationary object
If Nitinol wires are arranged and attached to each other to make a stent structure, then large diameter stents can be manufactured, but the process requires crimping or welding wire ends which is very labor intensive
Solution Approach 1:
The patent combines all wire elements into a single integrated blank structure that is formed into the final stent shape. This eliminates the need to arrange, attach, crimp, or weld separate wire ends together, dramatically reducing labor intensity while enabling the production of large diameter stents with consistent structural 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
This approach reduces material costs and labor intensity while eliminating potential weaknesses from weld seams, providing a robust and versatile stent frame suitable for various applications, including heart valves.
Implementation Method 1
The stent blank can then be formed into a cylinder shape using heat treatment in a stepwise method, thereby forming a tubular stent frame.
Implementation Method 2
Alternatively, the stent blank can be formed into a cylinder shape using a deep forming or shaping process to form a tubular stent frame.
Data Source
AI summary
A single piece stent construction having a plurality of commissure posts, each of which extends upwardly from a solid ring along a bend line and generally along a central longitudinal axis of the stent.