Blood Pump Impeller Housing Bonding for Reduced Hemolysis

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Solution Overview

Problem

Existing methods for manufacturing a housing for an impeller of a blood pump do not effectively address the challenge of ensuring a smooth inner surface to reduce hemolysis and prevent structural damage from the impeller and axial shaft.

Innovation Solution

A method involving treating a frame to enhance bonding with an inner lining, coupling the inner lining to the frame, placing a mandrel inside the inner lining, and heating the assembly while applying pressure to couple a pump-outlet tube to the frame, ensuring a secure and smooth assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an inner lining is coupled to the frame to provide a smooth inner surface, then hemolysis is reduced and blood flow is improved, but the manufacturing complexity increases due to additional bonding steps

Engineering Contradiction:
ImprovehemolysisVSAvoidmanufacturing process
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The frame is treated with a surface treatment (e.g., plasma treatment or coating) before coupling the inner lining, to enhance bonding. This preliminary action ensures strong adhesion between the frame and inner lining, reducing the risk of delamination while maintaining a smooth inner surface to minimize hemolysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A bonding agent or adhesive layer is introduced as an intermediary between the frame and the inner lining to ensure strong coupling. This mediator enhances the bonding strength while allowing the inner lining to maintain its smooth surface properties for blood compatibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the frame and pump-outlet tube are heated and pressed together to ensure secure coupling, then bonding strength is improved, but the risk of thermal damage to blood-related components increases

Engineering Contradiction:
Improvebonding strengthVSAvoidthermal damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

Heating is applied locally and selectively to specific regions of the frame and pump-outlet tube assembly, rather than uniformly heating the entire device. This ensures adequate bonding strength at the coupling interfaces while avoiding thermal exposure of heat-sensitive components such as the inner lining and blood channels.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The heating process is segmented into controlled stages or zones, with temperature and duration optimized for each specific bonding location. This allows precise control over thermal exposure, ensuring strong bonds where needed while protecting sensitive components from thermal damage.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the strut junctions are kept open during assembly to facilitate impeller insertion, then ease of assembly is improved, but structural stability deteriorates until the securing element is applied

Engineering Contradiction:
Improveease of assemblyVSAvoidstructural stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The strut junctions are designed to be dynamically changeable between open and closed states. During assembly, they remain open to facilitate impeller insertion, and then transition to a closed, secured state using securing elements (e.g., screws, clips, or interference fits) to achieve the required structural stability for operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The open configuration of strut junctions is maintained temporarily during the assembly process as a preliminary state, allowing easy access for impeller insertion. Once assembly is complete, the junctions are promptly secured to transition to the stable closed state, minimizing the period of reduced structural stability.

Inventive Principle:
Principle #10Preliminary 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

This method provides a secure and smooth inner surface for the blood pump housing, reducing hemolysis and preventing structural damage, while ensuring effective blood flow and device functionality.

Implementation Method 1

heating the inner lining, the frame and the portion of the elongate tube, via the mandrel

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

applying pressure from outside the portion of the elongate tube, such as to cause the portion of the elongate tube to become coupled to the frame

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP4218898B1Ventricular assist device
Publication Date: 2025.05.07 MAGENTA MEDICAL LTD
  • EP4218898B1 patent drawingFigure 1A
  • EP4218898B1 patent drawingFigure 1B
  • EP4218898B1 patent drawingFigure 1C

AI summary

A method, comprising: manufacturing a housing for an impeller (50) of a blood pump by: treating a frame (34) in order to enhance bonding between an inner surface of the frame (34) and an inner lining (39); subsequently, coupling the inner lining (39) to the inner surface of the frame (34) along at least a portion of a central cylindrical portion of the frame (34), the central cylindrical portion of the frame (34) including struts that define a generally cylindrical shape; subsequent to coupling the inner lining (39) to the inner surface of the frame (34) along at least a portion of the central cylindrical portion of the frame (34): placing a mandrel inside the inner lining (39); placing a portion of an elongate tube (24) around at least a portion of the frame (34), the elongate tube including a proximal portion that defines at least one blood outlet opening (109); while the portion of the elongate tube (24) is disposed around at least the portion of the frame (34), heating the inner lining (39), the frame (34) and the portion of the elongate tube (24), via the mandrel; and while heating the inner lining (39), the frame (34), and the portion of the elongate tube (24), applying pressure from outside the portion of the elongate tube (24), such as to cause the portion of the elongate tube (24) to become coupled to the frame (34).