Two-Stage Rotodynamic Blood Pump Axial Adjustment
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Solution Overview
Problem
Current blood pumping devices for congestive heart failure patients lack an efficient mechanism to balance systemic and pulmonary arterial blood flows and atrial pressures, often requiring electronic intervention and complex control systems.
Innovation Solution
A valveless, sensorless, pulsatile blood pump with a two-stage rotodynamic 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, or employing external electronic control via a solenoid-type element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage blood pump is used, then the device structure is simple, but it cannot balance systemic and pulmonary arterial blood flows and atrial pressures
Solution Approach 1:
The pump is divided into two independent pumping stages: a first stage for systemic circulation and a second stage for pulmonary circulation. Each stage has its own impeller and housing, allowing independent optimization of blood flow to each circulation pathway while maintaining overall device functionality
Solution Approach 2:
Two complete pumping stages are merged into a single integrated rotor assembly that shares a common drive mechanism. The rotor contains both impellers and rotates within a housing that provides both pump housings, combining multiple functions into unified structures to achieve flow balance without proportionally increasing device complexity
2Measurement precision
If electronic control systems are used to balance blood flows, then flow balance precision is improved, but device complexity and reliability are worsened
Solution Approach 1:
The pump design allows the rotor assembly to automatically self-adjust its axial position in response to pressure differentials between the two circulation stages. This passive self-regulation mechanism eliminates the need for electronic sensors and control systems, achieving flow balance through inherent hydraulic principles while maintaining device simplicity and reliability
3Measurement precision
If electronic sensors and control systems are used, then inlet pressure balancing is improved, but device complexity increases
Solution Approach 1:
The rotor assembly automatically adjusts its axial position in response to pressure differentials between the two circulation stages. This passive self-regulation mechanism eliminates the need for electronic sensors and control systems, achieving pressure balance through inherent hydraulic principles while maintaining device simplicity
Solution Approach 2:
The pump utilizes hydraulic forces generated by the blood flow itself to drive the self-regulation mechanism. Pressure differentials between the systemic and pulmonary circulation stages create axial forces on the rotor assembly, causing it to move to positions that automatically balance the flows without requiring external electronic 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
The pump achieves balanced systemic and pulmonary flows and atrial pressures through self-adjusting hydraulic performance characteristics, reducing the need for complex control systems and enhancing the efficiency and reliability of blood flow management.
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
Implementation Method 3
external electronic control is employed to control the position of the rotating assembly via an electromotive force, such as a solenoid-type element
Data Source
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AI summary
A pump (10) includes a stator housing (22), a stator (20) supported in the housing, and a rotor assembly (30). The rotor assembly (30) includes a rotor (32) supported in the housing for rotation relative to the stator (20) about an axis (12). The rotor assembly (30) also includes a first impeller (34) operatively coupled to a first axial end of the rotor (32) for rotation with the rotor about the axis (12). The rotor assembly further includes a second impeller (36) operatively coupled to a second axial end of the rotor (32), opposite the first axial end, for rotation with the rotor about the axis (12). The rotor assembly (30) is movable along the axis (12) relative to the housing to adjust hydraulic performance characteristics of the pump (10).