Magnetic Blood Pump Bearing Layout for Low-Hemolysis Torque Transfer

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Solution Overview

Problem

Magnetically driven blood pumps face issues with wear at bearing surfaces, hemolysis, corrosion, and inefficient magnetic torque generation due to component imbalance, which affect device durability and blood flow rates.

Innovation Solution

A blood pump design with a bearing assembly positioned near the distal side of the driven magnet, aligned with the impeller's center of mass, reduces the number of bearing surfaces and minimizes blood contact, enhancing magnetic torque transfer and durability while using a single bearing assembly for radial and longitudinal control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If bearing surfaces are used to support the impeller assembly, then mechanical stability is improved, but wear at bearing surfaces limits device lifetime

Engineering Contradiction:

Improvemechanical stabilityVSAvoiddevice lifetime

Core Design Contradiction:

Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The patent replaces traditional mechanical bearing surfaces with a magnetic field-based support system. The magnetic field source creates magnetic forces that suspend and position the impeller assembly without physical contact, eliminating mechanical wear at bearing surfaces while maintaining mechanical stability through magnetic field control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If bearing surfaces are used to support the impeller assembly, then mechanical stability is improved, but mechanical interactions with blood at bearing surfaces lead to hemolysis

Engineering Contradiction:

Improvemechanical stabilityVSAvoidhemolysis

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates mechanical bearing surfaces that contact blood by using magnetic field forces to support the impeller assembly. This non-contact support system prevents mechanical interactions between bearing surfaces and blood, thereby eliminating the source of hemolysis while maintaining impeller stability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Power

If magnetic field source is positioned closer to driven magnet, then magnetic torque generation is improved, but component imbalance affects pump performance

Engineering Contradiction:

Improvemagnetic torque generationVSAvoidblood flow rate

Core Design Contradiction:

PowerVSProductivity

Solution Approach 1:

The patent employs asymmetric positioning of the magnetic field source relative to the driven magnet, optimized to maximize magnetic torque generation. The magnetic field source is positioned at a specific offset that creates optimal magnetic coupling while maintaining impeller assembly balance, resolving the conflict between torque generation and pump performance.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent optimizes the distance and positioning parameters between the magnetic field source and driven magnet to achieve maximum magnetic torque generation. By carefully controlling the magnetic field strength, gap distance, and relative positioning, the system achieves high torque output while maintaining impeller balance and optimal blood flow performance.

Inventive Principle:

Principle #35Parameter changes

4Device complexity

If traditional bearing assembly positioning is used, then structural simplicity is maintained, but insufficient magnetic torque transfer occurs

Engineering Contradiction:

Improvestructural simplicityVSAvoidmagnetic torque transfer

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The patent replaces traditional mechanical bearing positioning with magnetic field-based positioning. The magnetic field source creates magnetic forces that both support the impeller assembly and transmit torque, eliminating the need for separate mechanical bearing structures while improving torque transfer efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 design reduces hemolysis and thrombosis risks, improves magnetic torque transfer, and increases blood flow rates by optimizing the positioning of the bearing assembly, allowing for closer proximity of the magnetic field source to the driven magnet, thus enhancing device durability and efficiency.

Implementation Method 1

a magnetic field source; an impeller assembly including a longitudinal axis, an impeller, and a driven magnet, the driven magnet being longitudinally offset and distally disposed relative to the magnetic field source, the driven magnet being rotatable and longitudinally controlled by the magnetic field source

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentUS12576262B2Magnetic propulsion and bearing for a hemodynamic support pump

Publication Date: 2026.03.17 BOSTON SCIENTIFIC SCIMED INC

AI summary

Various aspects of the present disclosure are directed towards apparatuses, systems, and methods that may include a blood pump. The blood pump may include a magnetic field source and an impeller assembly. The impeller assembly includes an impeller and a driven magnet. The driven magnet is longitudinally offset and distally disposed relative to the magnetic field source, and the driven magnet is rotatable and longitudinally controlled by the magnetic field source. The driven magnet includes a distal side, the distal side faces the impeller. The blood pump further includes a bearing assembly near the distal side of the driven magnet.