Stent Manufacturing Using Protective Shields
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Solution Overview
Problem
Current stent manufacturing methods face inefficiencies and surface damage issues during the process, particularly with the use of mandrels, which can compromise the integrity of the stent and its therapeutic coatings.
Innovation Solution
A stent manufacturing assembly comprising an outer shield, a patterned metal sheet, and an inner shield, where the patterned metal sheet is positioned between the shields to protect both surfaces during rolling and welding, using alignment holes and cutout portions to facilitate alignment and minimize contact with the mandrel, thereby preventing surface damage and allowing for easier inspection and coating uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mandrel is used to fold the metal sheet into a tubular shape, then the stent can be efficiently formed with both sides inspectable, but the internal surface of the stent may be damaged during mandrel contact and removal
Solution Approach 1:
A protective shield is introduced as an intermediary component between the mandrel and the stent's internal surface. The shield contacts the stent during mandrel removal, preventing direct contact between the mandrel and the stent surface, thus eliminating surface damage while maintaining the efficiency benefits of mandrel-based manufacturing.
2Shape
If the metal sheet is deformed around a cylindrical mandrel, then the stent takes on the desired tubular shape, but the coating on the internal surface may be damaged by contact, friction, and pressure
Solution Approach 1:
The protective shield serves as a mediator that absorbs contact, friction, and pressure during the deformation process. By positioning the shield between the mandrel and the coated surface, the coating is protected from direct mechanical stress, maintaining its integrity while the stent achieves its required tubular shape.
3Manufacturing precision
If laser etching is used to cut the pattern into a metal tube, then the stent pattern can be formed, but the process is time-consuming and the inner surface cannot be adequately inspected
Solution Approach 1:
Instead of cutting the pattern into a pre-formed tube (inside-out approach), the invention inverts the process by first creating the pattern on a flat sheet where both surfaces are accessible for inspection, then forming the tube. This outside-in approach allows complete inspection of both sides before deformation, eliminating inspection limitations while maintaining pattern precision.
4Measurement precision
If both sides of the patterned sheet are inspected prior to deformation, then defects can be detected, but the process complexity increases with the addition of protective shields
Solution Approach 1:
The protective shield, while adding a component to the assembly, actually simplifies the overall process by enabling complete inspection of both surfaces. The shield's simple geometry and easy attachment/detachment design minimize the increase in complexity while providing substantial benefit in defect detection capability.
Data Source
AI summary
The present disclosure is directed to a stent manufacturing assembly including an inner shield, a patterned metal sheet, and an outer shield. The patterned metal sheet may include a polymer coating with an embedded therapeutic agent. The inner shield, patterned metal sheet, and outer shield are arranged in a layered configuration and placed in a stent rolling mechanism with a mandrel. In particular, the patterned metal sheet is disposed on the outer shield and the inner shield is disposed on the patterned metal sheet in the layered configuration. In the layered configuration, the stent manufacturing assembly is rolled by the rolling mechanism into a tubular shape and welded to form a tubular stent.