Stented Heart Valve Cooling via Thermal Conductor

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Solution Overview

Problem

Existing methods for compressing stented prosthetic heart valves for delivery systems often require cooling, which can expose the tissue to aqueous solutions, compromising the dry state of the valve material, and lack efficient mechanisms for maintaining the stent frame in a malleable state without direct liquid contact.

Innovation Solution

A method involving a cooling device with a thermally conductive chamber structure that separates the stented prosthetic heart valve from the cooling element, allowing heat transfer through a thermally conductive wall to cool the stent frame to a critical temperature without direct liquid exposure, enabling compression and loading onto a delivery system while maintaining the valve in a dry state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the stent frame is cooled using an ice bath based solution, then the nitinol frame enters the martensitic state and becomes malleable for compression, but the tissue is exposed to aqueous solutions which compromises the dry state of the valve material

Engineering Contradiction:
Improvestent frame temperatureVSAvoidaqueous solution exposure to tissue
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

A thermally conductive container serves as an intermediary between the cooling element and the stent frame. The container allows thermal energy transfer to cool the nitinol frame to martensitic state while physically isolating the tissue from direct contact with aqueous cooling solutions, thus maintaining the dry state of the valve material

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system is segmented into distinct functional zones: a cooling element chamber, a thermally conductive container holding the stent frame, and isolation barriers. This segmentation allows the cooling function to be separated from the tissue protection function, enabling independent optimization of each aspect

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the stent frame is cooled to critical temperature for compression, then the valve becomes malleable and can be loaded into delivery system, but the compression process requires direct contact with cooling solutions

Engineering Contradiction:
Improvecompression and loading capabilityVSAvoidliquid exposure during compression
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The thermally conductive container acts as a mediator that enables compression operations while maintaining thermal isolation. The container can be compressed along with the cooled stent frame inside it, allowing the compression force to be applied without requiring the tissue to contact external cooling solutions

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thermally conductive container functions as a flexible shell that can be compressed while maintaining its thermal isolation properties. This thin-walled container allows mechanical compression forces to transmit to the stent frame while preventing liquid penetration to the tissue

Inventive Principle:
Principle #30Flexible shells and thin films

3Productivity

If traditional cooling methods are used, then the stent frame can be compressed, but the process is complex and requires multiple steps including ice bath immersion and manual compression

Engineering Contradiction:
Improvecompression and loading efficiencyVSAvoidcooling and compression system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The cooling and compression functions are merged into a single integrated device. The thermally conductive container allows both cooling to occur and subsequent compression to be performed on the same platform, eliminating the need for separate ice bath immersion and manual compression steps

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The thermally conductive container serves multiple functions: it acts as a thermal conductor for cooling, a protective barrier for tissue isolation, a compression chamber for reducing the stent frame, and a loading guide for delivering the compressed valve. This multi-functionality simplifies the overall process and reduces device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively cools the stented prosthetic heart valve to a malleable state without exposing it to liquids, ensuring the valve remains in a dry state and facilitating efficient compression and loading onto a delivery system, enhancing the compatibility and stability of the valve during implantation.

Implementation Method 1

Heat is transferred from the first chamber to the second chamber through a thermally conductive wall to cool an interior of the first chamber

Methodology Applied
Scientific EffectHeat transfer through thermal conduction: Conduction (thermal)

Implementation Method 2

The cooling process brings the valve out of the austenitic and into the martensitic phase. While in the martensitic phase, nitinol is more malleable

Methodology Applied
Scientific EffectPhase transition of nitinol from austenitic to martensitic state: Phase Change

Data Source

PatentEP3399948B1Prosthetic heart valve cooling
Publication Date: 2024.12.18 MEDTRONIC VASCULAR INC
  • EP3399948B1 patent drawingFigure 1A
  • EP3399948B1 patent drawingFigure 1B
  • EP3399948B1 patent drawingFigure 2A

AI summary

Methods of compressing a stented prosthetic heart valve are disclosed. The method including inserting a stented prosthetic heart valve having a self-expandable stent frame into a container, initiating a cooling element in the container, transferring heat through a thermal conductor to cool an interior of the container, reducing a temperature of the self-expandable stent frame while located within the container to a critical temperature of not greater than 8° C, and compressing an outer diameter of the stented prosthetic heart valve while the stented prosthetic heart valve is at the critical temperature.