Intravascular Blood Pump Magnetic Coupling Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing intravascular blood pumps face challenges in achieving a balance between mechanical and magnetic coupling, leading to either loose or tight fits that require precise tolerances, making manufacturing expensive and affecting magnetic flux efficiency.
Innovation Solution
The blood pump design features posts with rear end surfaces perpendicular to their longitudinal axis, allowing for a magnetic connection independent of mechanical fastening, using discontinuous soft magnetic material to reduce eddy currents and heat generation, and a back plate with recesses for improved magnetic flux transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the posts are mechanically fastened to the back plate with tight fit, then good mechanical coupling is achieved, but manufacturing cost increases due to required precise tolerances
Solution Approach 1:
The patent separates the mechanical coupling function from the magnetic coupling function. The posts are mechanically fastened to the back plate through recesses that provide form-fitting mechanical support, while the magnetic coupling is achieved through magnetic attraction between the posts and back plate. This segmentation allows each function to be optimized independently, reducing manufacturing tolerances and costs.
Solution Approach 2:
The patent combines mechanical fastening and magnetic coupling in a unified structure where the posts are both mechanically supported by recesses in the back plate and magnetically attracted to it. This dual coupling approach provides both structural support and magnetic field continuity, resolving the contradiction between mechanical strength and manufacturing ease.
2Ease of manufacture
If the posts are mechanically fastened to the back plate with loose fit, then manufacturing is easier, but magnetic coupling efficiency deteriorates
Solution Approach 1:
The patent merges mechanical support and magnetic coupling functions so that the same recess structure that provides mechanical support also ensures optimal magnetic coupling. The form-fitting recesses maintain close proximity between posts and back plate, ensuring efficient magnetic flux transfer without requiring tight tolerances.
Solution Approach 2:
The recesses in the back plate act as intermediaries that simultaneously provide mechanical support and optimize magnetic coupling. By designing the recesses to receive the posts in a form-fitting manner, the structure ensures both mechanical stability and efficient magnetic flux transfer, eliminating the need to choose between loose fit and tight fit.
3Force
If large magnets are used to provide strong magnetic coupling, then magnetic forces are sufficient, but pump diameter increases
Solution Approach 1:
The patent replaces traditional mechanical coupling mechanisms with magnetic coupling between the posts and back plate. The magnetic attraction forces provide both mechanical support and field continuity, eliminating the need for large physical magnets and reducing the overall pump diameter while maintaining sufficient coupling strength.
Solution Approach 2:
The patent uses composite magnetic structures where the posts and back plate are made of magnetically permeable materials that enhance magnetic coupling efficiency. This allows strong magnetic forces to be generated with smaller dimensions, reducing the pump diameter while maintaining adequate magnetic coupling.
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 enhances magnetic coupling efficiency, reduces energy consumption, and minimizes heat generation, enabling smaller pump sizes and longer battery-powered operation without purging, suitable for intravascular applications.
Implementation Method 1
A control unit sequentially supplies a voltage to the coil windings to create the rotating magnetic field
Implementation Method 2
The impeller comprises magnets which are disposed adjacent to magnets in the electric motor. 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
utilizing discontinuous soft magnetic material in the posts and/or in the back plate, in order to reduce eddy currents and heat generation
Data Source
AI summary
This invention concerns an intravascular blood pump for percutaneous insertion into a patient's blood vessel. The blood pump comprises a pump casing having a blood flow inlet and a blood flow outlet, and an impeller arranged in said pump casing so as to be rotatable about an axis of rotation. The impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump comprises a drive unit for rotating the impeller, the drive unit comprising a plurality of posts arranged about the axis of rotation and a back plate. A coil winding is disposed around each of the posts and has an impeller-side end pointing towards the impeller. The coil windings are controllable so as to create a rotating magnetic field, wherein the impeller comprises a magnetic structure arranged to interact with the rotating magnetic field so as to cause rotation of the impeller. The rear end surfaces of the posts contact the back plate.