Intravascular Blood Pump Bearing With Ancillary Flow Cooling
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Solution Overview
Problem
Existing intravascular blood pumps are bulky and inefficient due to the need for significant axial construction space and issues with blood clotting and heat management, particularly in blood-immersed bearings.
Innovation Solution
A compact blood pump design featuring an ancillary impeller with radial sliding bearings and an ancillary blood flow through the axial gap between the stator and rotor, utilizing ceramic materials for improved heat conduction and reduced friction, along with a separated ancillary blood flow to minimize hydraulic losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a blood-purged radial sliding bearing with ancillary impeller is used, then heat management and blood clotting prevention are improved, but axial construction space increases making the pump voluminous
Solution Approach 1:
The ancillary impeller serves dual functions: it generates ancillary blood flow for cooling the stator and rotor while simultaneously forming the inner rotor bearing surface of the radial sliding bearing. This multi-functionality eliminates the need for separate cooling and bearing components, reducing axial construction space while maintaining blood clotting prevention through effective cooling.
Solution Approach 2:
The invention merges the cooling function and bearing function into a single integrated system. The ancillary impeller both generates the cooling blood flow and forms the bearing surface, combining what would traditionally be separate components into one unified structure that reduces overall pump volume.
2Force
If ceramic materials are used in the bearing, then friction and heat are reduced, but manufacturing complexity increases
Solution Approach 1:
Ceramic materials are applied specifically to the rotor bearing surface (inner rotor bearing surface) where friction and heat generation are most critical. This localized application of ceramic coating or ceramic material construction reduces friction and heat in the bearing zone without requiring the entire pump to be manufactured from ceramic, thereby managing manufacturing complexity while achieving friction reduction.
3Temperature
If an ancillary impeller is added to generate blood flow through the axial gap, then heat management is improved, but device complexity increases
Solution Approach 1:
The ancillary impeller is designed to perform multiple functions simultaneously: generating ancillary blood flow for cooling, forming the inner rotor bearing surface, and contributing to the overall structural integrity of the rotating assembly. This multi-functionality justifies the additional component by eliminating or reducing the need for separate cooling channels and bearing structures.
Solution Approach 2:
The ancillary impeller utilizes the rotation of the rotor itself to generate the ancillary blood flow for cooling, without requiring an independent power source or control system. The rotational motion of the rotor directly drives the ancillary impeller, creating a self-service cooling system that reduces overall device complexity despite the additional component.
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 achieves a compact and reliable blood pump that effectively manages heat and reduces blood clotting, enhancing efficiency and throughput while maintaining a small diameter suitable for intravascular use.
Implementation Method 1
The radial sliding rotor bearing comprises an inner rotor bearing surface and an outer rotor bearing surface
Implementation Method 2
utilizing ceramic materials for improved heat conduction
Data Source
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AI summary
This invention relates to an intravascular blood pump (1), comprising a pumping device (11) with a pump section (3) and a drive section (4), wherein the pump section (3) comprises a pump casing (2) having a primary blood flow inlet (211) and a primary blood flow outlet (22) hydraulically connected by a primary passage (30) and the drive section (4) comprises a stator (40) and a rotor (41) rotatable about an axis of rotation (10) and configured to rotate a primary impeller (31), the primary impeller (31 ) being configured to convey a primary blood flow from the primary blood flow inlet (211) to the primary blood flow outlet (22) along the primary passage (30), the drive section (49) further comprises an ancillary blood flow inlet (23) and an ancillary blood flow outlet (24) hydraulically connected by an ancillary passage extending through an axial gap (401) between the rotor (41) and the stator (40) and an ancillary impeller (42) arranged at a drive section end (DSE) of the rotor (41) and rotatable about the axis of rotation (10) along with the rotor, the ancillary impeller (42) comprising one or more ancillary impeller vanes (421) configured to convey an ancillary blood flow (ABF) from the ancillary blood flow inlet (23) to the ancillary blood flow outlet (24) along the ancillary passage in a direction toward a pump section end (PSE) of the pumping device (11), and the rotor (41) is mounted in a blood-purged radial sliding rotor bearing (47) with an inner rotor bearing surface (4211) and an outer rotor bearing surface (4311), and the ancillary impeller (42) forms the inner rotor bearing surface (4211) of the radial sliding rotor bearing (47).