Biodegradable Stent Link Sections for Phase-Adaptive Mechanical Properties

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional stents do not adapt their mechanical properties to different phases post-implantation, such as acute, intermediate, and chronic phases, which limits their effectiveness in maintaining patency and flexibility over time.

Innovation Solution

A stent with linear and wavy-shaped struts connected by link sections made of biodegradable materials with varying decomposition periods, allowing mechanical properties to change over time to suit different phases, enhancing strength and flexibility accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the stent uses uniform biodegradable link sections, then the manufacturing is simple, but the mechanical properties cannot adapt to different phases post-implantation

Engineering Contradiction:
Improveadaptability to different phasesVSAvoidcomplexity of link sections
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The stent is divided into multiple link sections along its length, with each link section having different biodegradation rates. This segmentation allows different portions of the stent to provide structural support for different durations, enabling adaptation to acute, subacute, and chronic phases separately rather than using a uniform structure throughout

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different link sections are assigned different biodegradation characteristics based on their specific location and functional requirements. Fast-degrading link sections provide temporary support in acute phases, while slow-degrading link sections maintain support longer-term, creating local variations in mechanical properties that match localized physiological needs

Inventive Principle:
Principle #3Local quality

2Strength

If the stent maintains high strength continuously, then patency is maintained, but flexibility to follow vessel shape is reduced

Engineering Contradiction:
Improvestent strengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The stent's mechanical properties are made dynamic through time-dependent biodegradation of link sections. Initially, all link sections provide high strength for vessel patency. As biodegradation progresses, link sections sequentially lose strength, allowing the stent to transition from a rigid, high-strength structure to a more flexible configuration that can better conform to vessel geometry

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The biodegradation process creates periodic changes in mechanical properties corresponding to different healing phases. During the acute phase, full structural integrity is maintained. In subsequent phases, as link sections degrade, the stent periodically transitions between states of high and reduced strength, matching the periodic nature of vascular healing and remodeling

Inventive Principle:
Principle #19Periodic action

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

The stent effectively maintains patency and flexibility throughout various phases by altering its mechanical properties, ensuring optimal performance and minimally invasive long-term functionality.

Implementation Method 1

a plurality of link sections each containing a biodegradable material and each connecting two adjacent ones of the linear struts to one another

Methodology Applied
Scientific EffectBiodegradation: Decomposition (biological)

Data Source

PatentEP3143967B1stent
Publication Date: 2021.11.03 TERUMO KK
  • EP3143967B1 patent drawingFigure 1
  • EP3143967B1 patent drawingFigure 2
  • EP3143967B1 patent drawingFigure 3(A)~3(B)

AI summary

A stent has mechanical properties changing in a multistage manner and capable of effectively exhibiting functions thereof in response to a period after indwelling. A stent includes linear struts forming an outer circumference of a cylindrical shape with gaps formed therein and a plurality of link sections each containing a biodegradable material and connecting the struts to each other in each of the gaps, includes at least two link sections having different decomposition periods under identical conditions.