Blood Pump Impeller With Curved Blades for Low-Shear Flow
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Solution Overview
Problem
Existing centrifugal blood pumps experience turbulence, non-physiological shear stress, flow stagnation zones, and thrombosis due to high-speed rotation, leading to blood damage and rotor instability, which are exacerbated by magnetically coupling drive mechanisms.
Innovation Solution
A centrifugal impeller design featuring banana-shaped blades with a wrap angle greater than or equal to 90° and a supporting structure with opposite-bending blades, which enhance flow regulation, reduce shear stress, and maintain rotor balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the centrifugal impeller rotates at high speed to improve blood circulation efficiency, then the productivity increases, but turbulence and non-physiological shear stress occur causing blood damage
Solution Approach 1:
The patent employs curved centrifugal blades with optimized wrap angles (≥90°) and banana-shaped geometry instead of straight blades. This curvature design guides blood flow smoothly through the impeller, reducing turbulence and non-physiological shear stress while maintaining high-speed rotation efficiency
Solution Approach 2:
The patent optimizes critical geometric parameters including blade wrap angle (≥90°), blade thickness distribution (thick in middle, thin at ends), and blade curvature radius. These parameter changes reduce flow separation and turbulence, allowing high-speed operation without excessive shear stress on blood cells
2Productivity
If the centrifugal impeller rotates at high speed to improve blood circulation efficiency, then the productivity increases, but flow stagnation zones form leading to thrombosis
Solution Approach 1:
The curved blade design with optimized wrap angle ensures continuous blood flow along the blade surface, preventing flow separation and stagnation zones that would lead to thrombosis, while maintaining high circulation efficiency
Solution Approach 2:
The supporting structure with opposite-bending supporting blades is designed to counteract flow stagnation before it occurs. The supporting blades generate a counter-flow that prevents blood from stagnating in the secondary flow path region, eliminating thrombosis risk
3Device complexity
If a magnetically coupling drive mechanism is used to drive the centrifugal impeller, then the device complexity is reduced, but huge lift force is generated causing rotor instability
Solution Approach 1:
The supporting blades are designed with opposite bending direction to the centrifugal blades, creating a counterbalancing effect. This opposite-bending configuration generates forces that counteract the huge lift force from magnetic coupling, maintaining rotor dynamic balance without increasing drive mechanism complexity
Solution Approach 2:
The patent optimizes the supporting blade geometry parameters including wrap angle (≥10°), thickness distribution, and bending curvature to precisely balance the lift force. By adjusting these parameters, the supporting structure achieves accurate force balancing while maintaining simple magnetic coupling drive
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
The design reduces blood damage, thrombosis risk, and improves hydraulic performance by minimizing flow stagnation and enhancing structural stability and dynamic balance.
Implementation Method 1
a centrifugal impeller for a blood pump... the centrifugal impeller inside the pump head to rotate and thus promote the blood circulation... The high-speed rotation of the centrifugal impeller of the blood pump leads to the occurrence of turbulence in the impeller
Implementation Method 2
a magnetic-coupling driven blood pump, in which a magnetically coupling drive motor outside a pump head drives a centrifugal impeller inside the pump head to rotate... when the rotor is started, or the rotational speed changes, it is very easy to generate a huge lift force
Data Source
AI summary
A centrifugal impeller for a blood pump, and a blood pump are provided. The centrifugal impeller comprises a circular base plate, centrifugal blades, and a supporting structure. A through hole is formed in the middle of the base plate to form a secondary flow path. The centrifugal blades are arranged on the upper surface of the base plate, each centrifugal blade is a banana-shaped blade which is thick in middle and thin at both ends, and a wrap angle of each centrifugal blade is greater than or equal to 90°, and the centrifugal blades extend radially from the outer edge of the through hole to the periphery of the base plate. The supporting structure comprises a supporting shaft arranged at the center of the through hole and supporting blades, one end of each supporting blade is connected to the supporting shaft, and another end is connected to the base plate.