Prosthetic Valve Leaflet Thickness Control via Dip Casting and Humidity Curing

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Solution Overview

Problem

Current techniques for manufacturing prosthetic heart valves with artificial polymeric leaflets are not suitable for large-scale production and lack efficient methods for forming and integrating leaflets with the valve frame, leading to inconsistencies in leaflet thickness and performance.

Innovation Solution

The use of an environmental humidity chamber (EHC) for partial curing of liquid polymer during the manufacturing process, combined with a dip casting method to form leaflets directly on the valve frame, and the application of an identifier for traceability and process control, ensures consistent leaflet thickness and integration with the frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional manufacturing techniques are used for prosthetic heart valves, then manual assembly and traditional polymer processing methods can be applied, but the manufacturing precision and consistency of leaflet thickness are poor

Engineering Contradiction:
Improveleaflet thickness consistencyVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-coating the valve frame with a polymer layer before dip casting the leaflets. This undercoat layer is applied in advance to ensure uniform thickness and proper adhesion, resolving the thickness consistency issue before the main manufacturing step occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary undercoat layer between the valve frame and the leaflet polymer. This intermediate layer acts as a mediator that ensures uniform thickness distribution and proper bonding, solving the manufacturing precision problem while maintaining ease of manufacture through a systematic multi-step process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If polymeric leaflets are formed by conventional coating methods, then traditional polymer processing can be used, but the leaflet thickness and uniformity are inconsistent

Engineering Contradiction:
Improveleaflet thickness uniformityVSAvoidmanufacturing cycle time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements continuity of useful action by using dip casting followed by immediate partial curing in the humidity chamber, then proceeding directly to final curing in the oven without interruption. This continuous process ensures uniform thickness while optimizing time efficiency through seamless transition between manufacturing stages.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent applies parameter changes by controlling humidity levels in the chamber during partial curing, then transitioning to elevated temperature for final curing. This systematic change in environmental parameters (humidity then temperature) ensures consistent leaflet thickness and proper polymer crosslinking, resolving the uniformity issue while managing cycle time through optimized parameter transitions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If polymeric leaflets are formed by conventional coating methods, then traditional processing can be used, but the leaflets show poor adhesion to the valve frame

Engineering Contradiction:
Improveleaflet adhesion to frameVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-coating the valve frame with polymer to create an undercoat layer before forming the leaflets. This preliminary step ensures proper adhesion by creating a bonded interface between the frame and the leaflet polymer, resolving the reliability issue while the added step is offset by the elimination of separate adhesion treatments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the adhesion function and the structural function into a single integrated undercoat layer. This combined layer simultaneously provides bonding to the frame and serves as the base for the leaflets, improving reliability while reducing overall process complexity by eliminating separate adhesion steps.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If manual assembly methods are used for prosthetic valves, then traditional surgical techniques can be applied, but the productivity and scalability are limited

Engineering Contradiction:
Improvemanufacturing scalabilityVSAvoidleaflet-integration consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces manual mechanical assembly with an automated dip casting process. The valve frame is dipped into the polymer solution in a controlled manner, and the leaflets are formed automatically through the dip casting and curing process. This substitution dramatically improves productivity and scalability while maintaining manufacturing precision through consistent process parameters.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses parameter changes (dip depth, dip speed, curing temperature, humidity levels) to control leaflet formation and integration consistency. By systematically controlling these parameters, the process achieves high manufacturing precision while being fully automated for improved productivity and scalability.

Inventive Principle:
Principle #35Parameter changes

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 results in prosthetic heart valves with consistent leaflet thickness and improved manufacturability, allowing for precise control of the manufacturing process and traceability throughout the production stages, enhancing the reliability and quality of the valves.

Implementation Method 1

The use of an environmental humidity chamber (EHC) for partial curing of liquid polymer during the manufacturing process

Methodology Applied
Scientific EffectHumidity-controlled partial curing: Phase Change

Implementation Method 2

combined with a dip casting method to form leaflets directly on the valve frame

Methodology Applied
Scientific EffectDip casting deposition: Deposition (physical)

Data Source

PatentEP3661459B1Methods relating to the manufacture of prosthetic valves
Publication Date: 2024.10.02 FOLDAX INC
  • EP3661459B1 patent drawingFigure 1
  • EP3661459B1 patent drawingFigure 2A~2B
  • EP3661459B1 patent drawingFigure 3A

AI summary

Improved prosthetic heart valves and their methods of manufacture are described. An environmental humidity chamber can be used in the methods of valve leaflet manufacture for a first phase of curing. In some instances, the methods of manufacturing a polymeric valve prosthesis can include applying an identifier to the prothesis. The identifier can be covered by polymer but remain readable through the polymer.