Blood Pump Speed Control via Conduit Pressure Feedback
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Solution Overview
Problem
Blood pumps require precise control of motor speed to balance blood flow, preventing ventricular collapse and facilitating patient weaning, as existing systems struggle to maintain optimal left and right ventricular pressures and pulsatile flow conversion.
Innovation Solution
Incorporating sensors in inflow and outflow conduits to monitor blood pressure and flow, allowing for continuous adjustment of pump speed based on threshold levels to maintain stable ventricular pressures and gradually reduce support to wean patients off the pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump speed is increased to ensure adequate blood flow to the body, then productivity is improved, but the risk of ventricular collapse increases due to suction in the ventricle
Solution Approach 1:
The system uses pressure sensors to continuously monitor left ventricular pressure and arterial pressure, feeding this information back to the controller. The controller adjusts pump speed based on this feedback to maintain left ventricular pressure above a minimum threshold, preventing ventricular collapse while ensuring adequate blood flow.
Solution Approach 2:
The pump speed is made dynamically adjustable rather than fixed. The controller continuously modifies the pump speed based on real-time pressure measurements, allowing the system to adapt to changing physiological conditions and maintain optimal balance between blood flow and ventricular pressure.
2Reliability
If the pump speed is decreased to prevent ventricular collapse, then safety is improved, but inadequate blood flow to the body occurs
Solution Approach 1:
The pressure sensors provide continuous feedback on left ventricular pressure and arterial pressure to the controller. The controller uses this feedback to adjust pump speed, ensuring that blood flow requirements are met while maintaining ventricular pressure within safe limits.
Solution Approach 2:
The system changes the operational parameters of the pump (speed) based on measured pressure values. By adjusting the pump speed parameter in response to pressure measurements, the system maintains the balance between preventing ventricular collapse and ensuring adequate blood flow.
3Measurement precision
If sensors are added to monitor blood pressure and flow, then measurement precision is improved, but device complexity increases
Solution Approach 1:
Pressure sensors are placed in the inflow and outflow conduits as intermediary measurement points. These sensors indirectly measure left ventricular pressure and arterial pressure without requiring direct intrusion into the ventricle or major arteries, simplifying the overall system while maintaining measurement precision.
4Productivity
If the pump runs at high speed continuously, then productivity is improved, but the ability to facilitate weaning is reduced
Solution Approach 1:
The pump speed is made dynamically adjustable rather than fixed at high levels. The controller can gradually reduce pump speed as the patient's heart recovers, enabling a controlled weaning process while maintaining adequate blood flow at each stage.
Solution Approach 2:
The operational parameter (pump speed) can be changed over time based on patient recovery progress. The system transitions from high-speed continuous operation to gradually reduced speeds, facilitating the weaning process while maintaining therapeutic blood flow support.
Data Source
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AI summary
Materials and methods related to blood pump systems are described. These can be used in patients to, for example, monitor arterial pressure, measure blood flow, maintain left ventricular pressure within a particular range, avoid left ventricular collapse, prevent fusion of the aortic valve in a subject having a blood pump (10), and provide a means to wean a patient from a blood pump (10).