Biodegradable Double-Tube Scaffold for Prosthetic Implants

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Solution Overview

Problem

Current prosthetic heart valves and vessels are prone to mechanical weakness, delicacy, and difficulty in reproducibility due to their single-tube structure and suture-based construction, which can lead to increased risk of failure and require multiple surgeries as patients grow, especially in younger patients.

Innovation Solution

A biodegradable scaffold comprising coaxially arranged tubular components with secured overlapped edges at different positions to avoid structural weaknesses, and a method of assembly using a jig set to create a robust, three-layered scaffold structure for heart valves, enhancing mechanical strength and reproducibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a single-tube scaffold structure is used, then the device complexity is reduced, but the mechanical strength and stiffness are insufficient

Engineering Contradiction:
Improvemechanical strengthVSAvoidscaffold structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The scaffold is divided into multiple tubular components (first tubular component, second tubular component, and optionally third tubular component) that are co-axially arranged and secured together. This segmentation allows each tube to contribute to the overall mechanical strength while maintaining a relatively simple individual structure, resolving the contradiction between strength and complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The scaffold employs a composite structure where multiple biodegradable tubular components are combined co-axially. This composite approach creates a structure with enhanced mechanical properties compared to a single tube, as each layer contributes to the overall strength and stiffness without requiring complex individual components.

Inventive Principle:
Principle #40Composite materials

2Reliability

If overlapped edges are secured at the same position in all tubular components, then the assembly is simplified, but structural weaknesses occur at the secured positions

Engineering Contradiction:
Improvestructural reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The secured positions of overlapped edges are intentionally asymmetrically distributed among the tubular components. The first tubular component has its overlapped edge secured at a first position, the second tubular component at a second position different from the first, and the third tubular component at a third position different from both. This asymmetric distribution prevents concentration of stress at single points, enhancing structural reliability.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the scaffold are designed with different characteristics - the secured positions of overlapped edges are strategically placed at different locations around the circumference to create localized strength distribution. This ensures that no single location bears excessive stress, improving overall structural reliability without significantly complicating the manufacturing process.

Inventive Principle:
Principle #3Local quality

3Strength

If conventional suture-based construction is used, then the ease of manufacture is maintained, but mechanical weakness and delicacy increase

Engineering Contradiction:
Improvemechanical strengthVSAvoidconstruction complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The construction process is segmented into distinct steps: forming individual tubular components with secured overlapped edges, then co-axially arranging and securing multiple components together. This segmentation allows each component to be manufactured and secured independently, maintaining ease of manufacture while building up mechanical strength through layering.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The overlapped edges of each tubular component are secured together in advance before the final co-axial assembly. This preliminary action creates pre-formed, structurally sound components that can be easily handled and assembled, reducing the complexity of the overall construction process while ensuring mechanical strength is established at each stage.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If inorganic or fixed organic material is used, then the structural stability is improved, but the capacity for repair, reconfiguration or growth is lost

Engineering Contradiction:
Improvecapacity for growthVSAvoidstructural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The scaffold employs biodegradable materials whose physical and chemical parameters change over time in a controlled manner. The material gradually degrades as the patient's own tissue grows and replaces the scaffold, allowing the structure to transition from a stable artificial form to a living, adaptable tissue structure, thus achieving both initial stability and long-term adaptability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1968660B1Biodegradable scaffold
Publication Date: 2010.11.24 UNIVERSITY OF ZURICH
  • EP1968660B1 patent drawingFigure 1~2
  • EP1968660B1 patent drawingFigure 3~4
  • EP1968660B1 patent drawingFigure 5~6

AI summary

A biodegradable scaffold 1; 11 for a prosthetic implant, the scaffold comprising: first and second tubular scaffold components 3, 7; 17, 15 co-axially arranged one inside the other and secured one to the other, each said tubular scaffold component being fabricated from a sheet of biodegradable material having two generally parallel peripheral edges that are overlapped and secured one to the other to form a tube.