Blood Pump Impeller Rinse via Axial Oscillation
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Solution Overview
Problem
Existing blood pumps lack a system to effectively dislodge and remove foreign particles, such as thrombus, that can lodge on hydrodynamic bearings and impede their operation, posing a hazardous risk to patients.
Innovation Solution
A method using a vector control method to control the axial motion of an impeller within the blood pump, causing it to oscillate and dislodge foreign particles by temporarily displacing it between specific axial positions, utilizing a hydraulic and magnetic suspension system and a three-phase sensorless field-oriented control method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydrodynamic bearing is used to support the rotor, then mechanical wear is eliminated, but foreign particles can lodge on the bearing surface and impede operation
Solution Approach 1:
The patent applies mechanical vibration by causing the impeller to oscillate between a first axial position (normal operating position) and a second axial position (displaced position). This oscillating motion creates vibrational forces that dislodge foreign particles from the hydrodynamic bearing surface, preventing thrombus accumulation while maintaining the contactless bearing configuration.
Solution Approach 2:
The patent implements periodic action through controlled oscillations of the impeller between axial positions. The control circuit periodically displaces the impeller to the second axial position and returns it to the first axial position, creating repeated cyclic motion that continuously prevents particle adhesion and removes deposited material from the bearing surface.
2Stability of the object's composition
If the impeller operates at a fixed axial position, then pump performance is stable, but foreign particles accumulate on the bearing surface
Solution Approach 1:
The patent transitions from a static impeller position to a dynamic position control system. The control circuit actively adjusts the impeller's axial position between two distinct positions based on operational conditions. This dynamic positioning allows the system to maintain stable pump performance during normal operation while enabling particle removal through controlled displacement to the second axial position.
3Reliability
If a contactless bearing system is implemented, then mechanical wear is prevented, but foreign particles can still accumulate and cause thrombus
Solution Approach 1:
The patent combines the contactless bearing operation with mechanical vibration through impeller oscillation. The hydrodynamic bearing maintains contactless operation to prevent mechanical wear, while the controlled oscillation of the impeller between axial positions generates vibrational forces that prevent foreign particle accumulation and remove thrombus from the bearing surface.
Solution Approach 2:
The system employs self-service by using the impeller's own oscillating motion to clean the bearing surface. The control circuit activates the oscillation mechanism that utilizes the impeller's mass and the hydraulic suspension system to create self-cleaning action, dislodging particles without requiring external cleaning mechanisms or contactless physical intervention.
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
Effectively dislodges foreign particles from the blood pump, preventing mechanical wear and ensuring safe operation by using controlled oscillating motion to direct particles away from the impeller, thus maintaining pump efficiency and patient safety.
Implementation Method 1
a hydraulic and magnetic suspension system of the blood pump causes the positive and a negative displacement of the impeller
Implementation Method 2
a hydraulic and magnetic suspension system of the blood pump causes the positive and a negative displacement of the impeller
Implementation Method 3
a three-phase sensorless field-oriented control method including a set of three stator windings and a set of three alternating currents
Data Source
AI summary
A method of controlling a blood pump including executing a control command to temporarily displace an impeller of the blood pump within a pump housing from a first axial position relative to the pump housing to a second axial position a distance away from the first axial position using a vector control method, and causing the impeller to move from the second axial position to a third axial position, the third axial position including a positive and a negative displacement of the impeller relative to the first axial position.