Ceramic Thrust Bearing for Blood Pump Axial Stability
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Solution Overview
Problem
Current ventricular assist devices face challenges in maintaining axial stability of the impeller during variations in pressure gradients, leading to potential axial motion and reduced efficiency in blood pumping.
Innovation Solution
Incorporation of a thrust bearing with a ceramic interface and a distal bearing housing that houses the thrust bearing, which prevents axial motion of the axial shaft and maintains a low-friction interface, along with a design that includes an inlet guard with specific geometrical features for efficient blood flow and minimal space occupation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a thrust bearing is added to prevent axial motion of the axial shaft, then axial stability is improved, but device complexity increases
Solution Approach 1:
The thrust bearing is integrated within the distal bearing housing, which itself is positioned within the pump head assembly. This nested arrangement allows the thrust bearing to be incorporated without significantly increasing the overall device footprint or structural complexity, while still providing the necessary axial stability to prevent impeller motion during pressure gradient variations.
2Loss of energy
If a ceramic interface is used in the thrust bearing, then friction is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The thrust bearing employs a ceramic interface, likely combining ceramic materials with metallic components. This composite material approach reduces friction and wear at the bearing interface, improving energy efficiency. The design accommodates the tighter tolerances required for ceramic components through proper integration with the distal bearing housing and axial shaft, balancing the increased manufacturing precision requirements with the benefits of reduced friction loss.
3Volume of moving object
If the inlet guard is made flat and perpendicular to the axial shaft, then space occupation is reduced, but flow direction control becomes more challenging
Solution Approach 1:
The inlet guard is designed as a flat structure positioned perpendicular to the axial shaft, utilizing the radial dimension to control flow direction rather than extending axially. This dimensional approach allows the guard to effectively redirect blood flow toward the impeller while occupying minimal axial space within the pump head, optimizing the balance between compactness and flow control functionality.
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 stabilizes the axial shaft, enhances blood flow efficiency, and reduces the risk of axial motion due to pressure gradient variations, thereby improving the overall performance of the ventricular assist device.
Implementation Method 1
a thrust bearing with a ceramic interface and a distal bearing housing that houses the thrust bearing, which prevents axial motion of the axial shaft and maintains a low-friction interface
Data Source
AI summary
Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a body of a subject. An impeller is coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. A thrust bearing includes a proximally-facing ceramic surface disposed distally from the axial shaft so as to inhibit distal movement of the axial shaft beyond the thrust bearing, and a distally-facing ceramic cover that covers a distal end of the axial shaft, such that the ceramic cover contacts the ceramic surface as the axial shaft rotates. Other applications are also described.