Two-Stage Rotodynamic Blood Pump Self-Balancing Rotor
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Solution Overview
Problem
Current blood pumping devices for congestive heart failure patients lack effective balancing mechanisms for left and right circulations, leading to potential accumulation of blood in organs and increased risk of heart failure, as they rely on electronic intervention and do not self-regulate inlet pressures.
Innovation Solution
A valveless, sensorless, pulsatile, continuous flow total artificial heart with a two-stage rotodynamic pump configuration that self-balances left and right circulations by adjusting the axial position of a rotor assembly within a brushless DC motor winding, using hydraulic forces to modulate the performance of the impellers and balance inlet pressures without electronic intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electronic intervention is used to control blood pumping devices, then precise control of blood flow is achieved, but device complexity and reliability are worsened due to electronic components failure risk
Solution Approach 1:
The pump system performs self-regulation of inlet pressures through hydraulic forces acting on the rotor assembly, automatically balancing left and right circulations without external electronic control. The system serves itself by using the pumped fluid's pressure to adjust its own operation.
Solution Approach 2:
Electronic control systems are replaced with a purely mechanical/hydraulic self-regulation mechanism. The rotor assembly's axial position is controlled by hydraulic forces from pressure differentials rather than electronic actuators, eliminating sensors and electronic intervention.
2Device complexity
If valveless and sensorless design is implemented, then device complexity is reduced, but measurement precision and control accuracy are worsened
Solution Approach 1:
The system eliminates sensors and measurement devices by using direct hydraulic coupling where pressure differentials physically move the rotor assembly to the position needed for balance. The system self-regulates without needing to measure pressures electronically.
Solution Approach 2:
Hydraulic forces generated by the blood pressure differentials between left and right circulations directly act on the rotor assembly to adjust its axial position. The hydraulic system provides both the driving force and the measurement function through physical displacement.
3Reliability
If axial position of rotor assembly is adjusted to balance inlet pressures, then reliability is improved by eliminating electronic components, but device complexity increases due to movable rotor mechanism
Solution Approach 1:
The motor rotor and pump impeller are merged into a single rotating assembly that performs both functions. The rotor assembly combines the motor's rotating component with the pump's impeller, eliminating the need for separate mechanical coupling mechanisms.
Solution Approach 2:
The rotor assembly serves multiple functions: it is driven by electromagnetic forces from the motor windings, acts as the pump impeller to move blood, and simultaneously functions as the pressure-balancing mechanism through its axial movement capability.
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 enables balanced systemic and pulmonary blood flows and atrial pressures, reducing the risk of organ failure by passively adjusting the pump stages' performance in response to pressure differentials, eliminating the need for electronic control and enhancing the reliability and efficiency of blood pumping.
Implementation Method 1
The rotor assembly is free to move axially in response to the hydraulic environment, thereby changing clearances in the two opposed rotodynamic pumping stages, affecting relative performance to balance the inlet pressures
Implementation Method 2
a single moving part, which revolves within a brushless, sensorless DC motor winding
Data Source
AI summary
A pump includes a housing, a stator supported in the housing, and a rotor assembly including a rotor supported in the housing for rotation relative to the stator about an axis. The stator includes a stator core, a first lamination wound around an axial portion of the stator core, and a second lamination wound around a second axial portion of the stator core. The first and second laminations are spaced from each other along the length of the stator core. The rotor includes a rotor core, a first magnet assembly that extends around an axial portion of the rotor core, and a second magnet assembly that extends around a second axial portion of the rotor core. The first and second magnet assemblies are spaced from each other along the length of the rotor.