Intravascular Blood Pump Magnetic Core for High Flux, Low Heat
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Solution Overview
Problem
Existing intravascular blood pumps face challenges in achieving a compact design with high pumping power due to limitations in magnetic flux and heat generation, particularly when powered by batteries for long-term applications.
Innovation Solution
The blood pump incorporates a magnetic core with discontinuous soft magnetic material, where the posts and back plate are made of a single block of material, reducing magnetic resistance and eddy currents, and using slotted or laminated structures to minimize heat generation and energy consumption, while maintaining strong magnetic flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If large magnets or high current are supplied to the drive unit to provide sufficiently strong magnetic coupling, then the magnetic flux is improved, but the overall diameter of the blood pump becomes large
Solution Approach 1:
The patent employs a composite magnetic core structure combining ferromagnetic material (for magnetic flux conduction) and non-conductive material (for mechanical support and eddy current reduction). This composite approach enables achieving strong magnetic coupling without requiring large magnet dimensions, thus resolving the contradiction between magnetic flux strength and pump size.
Solution Approach 2:
The patent optimizes magnetic flux density distribution by carefully designing the geometry and material properties of the magnetic core components. By changing parameters such as core cross-sectional area, magnetic path length, and material permeability, the patent achieves sufficient magnetic coupling with a compact overall diameter.
2Power
If continuous soft magnetic material is used in the magnetic core, then magnetic flux is improved, but eddy currents increase leading to heat generation and energy consumption
Solution Approach 1:
The magnetic core is segmented into ferromagnetic material regions (for flux conduction) and non-conductive material regions (for breaking eddy current paths). This segmentation maintains sufficient magnetic flux while interrupting eddy current circulation, thereby reducing energy losses and heat generation.
Solution Approach 2:
Different materials are used in different regions of the magnetic core: ferromagnetic material where high magnetic flux density is needed, and non-conductive material where eddy current suppression is prioritized. This local differentiation of material properties optimizes both magnetic performance and energy efficiency.
3Volume of moving object
If the blood pump is designed to be compact for intravascular insertion, then the device size is reduced, but the pumping power is limited
Solution Approach 1:
The composite magnetic core structure enables a compact pump design by efficiently utilizing magnetic flux paths and reducing the need for large magnets, while still achieving sufficient pumping power through optimized magnetic coupling between the drive unit and impeller.
Solution Approach 2:
The patent optimizes multiple parameters including magnetic flux density, core geometry, and coil winding configuration to maximize pumping power within the constrained volume of an intravascular pump, achieving high power density without increasing overall size.
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 results in a more compact blood pump with reduced energy consumption and heat generation, enabling efficient operation at high speeds and allowing for battery-powered mobility without the need for purging, suitable for long-term use.
Implementation Method 1
A control unit sequentially supplies a voltage to the coil windings to create the rotating magnetic field
Implementation Method 2
Due to attracting forces between the magnets in the impeller and in the motor, rotation of the motor is transmitted to the impeller
Implementation Method 3
material of at least a portion of at least one of the posts of the magnetic core is integral with the material of an intermediate area of the magnetic core's back plate... magnetic resistance at the transition between the posts and the back plate is minimized and, thus, magnetic flux is improved
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
This invention concerns an intravascular blood pump (1) for percutaneous insertion into a patient's blood vessel. The blood pump (1) comprises a pump casing (2) having a blood flow inlet (21) and a blood flow outlet (22), an impeller (3) arranged in said pump casing (2) so as to be rotatable about an axis of rotation (10). The impeller (3) has blades (31) sized and shaped for conveying blood from the blood flow inlet (21) to the blood flow outlet (22). The blood pump (1) comprises a drive unit (4) for rotating the impeller (3), the drive unit (4) comprising a magnetic core (400) including a plurality of posts (40) arranged about the axis of rotation (10) and a back plate (50) connecting the posts (40) and extending between the posts (40) in an intermediate area (59). A coil winding (44) is disposed around each of the posts (40). The coil windings (44) are controllable so as to create a rotating magnetic field, wherein the impeller (3) comprises a magnetic structure (32) arranged to interact with the rotating magnetic field so as to cause rotation of the impeller (3). A material of at least a portion of at least one of the posts (40) is integral with a material of the intermediate area (59) of the back plate (50). Further, the invention concerns a method of manufacturing a magnetic core (400) and a method of manufacturing an intravascular blood pump (1).