Blood Pump Bearing Assembly for Washed Flow and Clot Reduction
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Solution Overview
Problem
Blood pumps face challenges with blood clots and hemolysis due to stagnation in bearing areas, which existing designs fail to adequately address, particularly in terms of fluid flow, lubrication, and pressure-volume characteristics.
Innovation Solution
A modular bearing system incorporating unique sleeve and cone bearing designs with modified geometries to enhance fluid flow, reduce thrombosis, and promote full washing of bearing surfaces, including features like thrust rings and segmented cone bearings to minimize contact points and ensure continuous blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional sleeve bearings are used to provide radial confinement, then radial support is improved, but blood stagnation and clotting occur in bearing areas
Solution Approach 1:
The bearing surface is segmented into multiple discrete contact points rather than a continuous surface. The cone bearing features multiple circumferential ridges that create separate contact zones with the rotor, allowing blood to flow between the segments rather than stagnate in a continuous bearing interface.
Solution Approach 2:
The bearing design utilizes hydraulic principles by allowing blood itself to serve as the lubricating fluid. The geometry of the bearing surfaces and the presence of circumferential grooves facilitate hydrodynamic lubrication, where blood flow patterns are optimized to maintain a lubricating film while preventing stagnation.
2Object-affected harmful factors
If bearing surfaces are designed for full washing by blood flow, then thrombosis risk is reduced, but bearing confinement capability may be compromised
Solution Approach 1:
Different regions of the bearing surface have different functions. The circumferential ridges create zones of high contact pressure for confinement, while the grooves between ridges create zones of enhanced blood flow for washing. This spatial variation in local quality allows simultaneous achievement of confinement and flushing.
Solution Approach 2:
The bearing design exploits the dynamic rotation of the rotor to generate hydrodynamic effects. As the rotor rotates, blood is dynamically pumped through the bearing interface by the geometry of the cone bearing surfaces, ensuring continuous washing without compromising the static confinement structure.
3Object-affected harmful factors
If modified sleeve bearing geometry is used to reduce thrombosis, then thrombosis risk is reduced, but axial confinement capability is weakened
Solution Approach 1:
The invention combines the radial confinement function of a sleeve bearing with the axial confinement function of a cone bearing into a single integrated thrust ring structure. This merged component provides both radial support through its cylindrical portion and axial support through its conical surface, while maintaining modified geometry to reduce thrombosis.
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 solution effectively reduces thrombosis and hemolysis risks by improving fluid dynamics and lubrication within the bearing regions, enhancing the overall performance and safety of blood pumps.
Implementation Method 1
maintaining the pressure-volume characteristics of the bearing interfaces within favorable ranges, and minimizing forces on the blood that can lead to thrombosis or hemolysis
Data Source
AI summary
A blood flow assist system can include an impeller assembly including an impeller shaft and an impeller on the impeller shaft, a primary flow pathway disposed along an exterior surface of the impeller. The system can include a rotor assembly at a proximal portion of the impeller shaft. A secondary flow pathway can be disposed along a lumen of the impeller shaft. During operation of the blood flow assist system, blood can be pumped proximally along the primary flow pathway and the secondary flow pathway. The system can include a sleeve bearing distal the impeller. The system can include a drive unit having a distal end disposed distal a proximal end of the second impeller. The drive unit comprising a drive magnet and a drive bearing between the drive magnet and the impeller assembly.