Intravascular Blood Pump Bearing for High-Speed Low-Friction Support
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Solution Overview
Problem
Intravascular blood pumps face challenges in providing low friction and high durability for the rotor and drive shaft, particularly during high-speed rotation, which affects their efficiency and longevity.
Innovation Solution
The design incorporates a proximal bearing with a bearing sleeve and outer bearing ring, where the bearing sleeve forms an axial and radial bearing with the outer ring, and is connected to the flexible drive shaft, allowing for low friction and high durability through the use of a purge fluid and sealant, and materials like ceramic and metal for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bearing is used to support the drive shaft and rotor at high rotational speeds, then friction is reduced and durability is improved, but the complexity of the device increases due to the additional bearing structure
Solution Approach 1:
The bearing structure is integrated into the housing, with the bearing sleeve and outer bearing ring forming a unified support system. The proximal portion of the bearing sleeve forms an axial bearing with the outer bearing ring, while the distal portion forms a radial bearing, combining multiple bearing functions into a single integrated structure that reduces overall device complexity while maintaining reliability
Solution Approach 2:
A purge fluid is introduced as an intermediary substance that flows through the gap between the bearing components. This purge fluid acts as a mediator that reduces friction between the bearing surfaces, cools the bearing, and prevents blood from entering the bearing, thereby improving durability without requiring more complex sealing mechanisms
2Productivity
If the rotor and drive shaft rotate at significant speeds to maintain pump function, then blood circulation support is improved, but friction increases and durability decreases
Solution Approach 1:
A purge fluid delivery system is implemented that uses hydraulic principles to force purge fluid through the bearing gap. The purge fluid flows in the opposite direction to blood flow, creating a pressure barrier that prevents blood from entering the bearing while enabling the rotor to rotate at high speeds. This hydraulic approach allows high-speed rotation for improved blood circulation while maintaining bearing durability through continuous lubrication and cooling
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 configuration reduces friction, prevents blood from entering the bearing, and allows for higher rotational speeds, lower power consumption, and increased durability of the blood pump, leading to improved performance and longevity.
Implementation Method 1
a purge fluid is provided to flow through the gap defined by the radial bearing
Implementation Method 2
the proximal portion of the bearing sleeve forms an axial bearing with a proximal surface of the outer bearing ring. The bearing sleeve further comprises a distal portion extending from the proximal portion of the sleeve distally into the outer bearing ring, wherein the distal portion of the bearing sleeve forms a radial bearing with the outer bearing ring
Data Source
AI summary
An intravascular blood pump comprises a catheter, a rotor, a housing in which the rotor is housed and a flexible drive shaft extending through the catheter and rotatably supported in a proximal bearing located proximally of the rotor. The proximal bearing comprises a bearing sleeve and an outer bearing ring. The bearing sleeve comprises a proximal portion located proximally of the outer bearing ring, the proximal portion of the bearing sleeve forming an axial bearing with a proximal surface of the outer bearing ring. The bearing sleeve further comprises a distal portion extending from the proximal portion of the bearing sleeve distally into the outer bearing ring, wherein the distal portion of the bearing sleeve forms a radial bearing with the outer bearing ring.