Expandable Membrane Flow Balancing for Atrial Pressure Control
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Solution Overview
Problem
Chronic kidney disease and heart failure patients experience elevated right atrium pressure, leading to impaired kidney function and fluid overload due to inefficient diuresis, resulting in increased hospital admissions.
Innovation Solution
Implantable devices with expandable frames and membranes that modulate blood flow through blood vessels, using control wires to adjust the diameter of the membrane to regulate blood flow and reduce atrial pressure, incorporating features to mitigate stasis zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the membrane is radially collapsed to reduce vessel diameter, then blood flow is restricted and atrial pressure is reduced, but kidney perfusion may be compromised
Solution Approach 1:
The device employs a dynamically adjustable membrane that can transition between collapsed and expanded states based on physiological conditions. The control wire system enables real-time modulation of membrane diameter, allowing the system to optimize the balance between reducing atrial pressure and maintaining adequate kidney perfusion pressure.
Solution Approach 2:
The device changes the physical parameter of vessel diameter by controlling membrane collapse/extension. By adjusting the degree of membrane collapse, the system modulates blood flow resistance and pressure gradients, thereby controlling both atrial pressure reduction and kidney perfusion maintenance through parameter optimization.
2Reliability
If the membrane is radially expanded to increase vessel diameter, then kidney perfusion is improved, but atrial pressure increases
Solution Approach 1:
The dynamic control mechanism allows the membrane to be expanded when kidney perfusion is insufficient and collapsed when atrial pressure is elevated. This dynamic adjustment capability enables the system to respond to changing physiological conditions and optimize the trade-off between the two competing requirements.
Solution Approach 2:
The system incorporates feedback mechanisms through pressure sensors and flow monitoring that detect physiological conditions and automatically adjust membrane position. When kidney perfusion pressure drops below a threshold, the system expands the membrane; when atrial pressure rises, the system collapses the membrane, creating a closed-loop control system.
3Adaptability or versatility
If the control wire is actuated to adjust membrane position, then blood flow regulation is achieved, but device complexity increases
Solution Approach 1:
The control wire mechanism extracts the complexity of membrane actuation from the implantable device itself, placing the control function in an external or minimally complex internal system. The control wire serves as a simple mechanical transmission element that converts external actuation forces into membrane position changes, simplifying the overall system architecture.
Solution Approach 2:
The control wire acts as an intermediary element between the actuation mechanism and the membrane. This intermediary transmits mechanical force while allowing independent optimization of the actuation system and the flow regulation system, thereby managing complexity through functional decomposition.
4Productivity
If the membrane is positioned to optimize flow regulation, then blood flow control is improved, but stasis zones may form
Solution Approach 1:
The device incorporates local quality variations through asymmetric membrane positioning or selective collapse patterns that maintain flow velocity in critical regions. By creating different flow characteristics in different zones of the vessel, the system optimizes overall flow control while preventing stasis in thrombus-prone areas through localized flow management.
Solution Approach 2:
The system may incorporate vibration or oscillation mechanisms that create turbulent flow patterns or prevent blood pooling in stagnant zones. Mechanical vibration disrupts laminar flow and prevents the formation of stasis zones while maintaining effective flow regulation through controlled membrane movement.
Data Source
AI summary
Systems and methods are described for modulating blood flow through a blood vessel. Devices may include one or more implantable devices comprising an expandable frame comprising a proximal end and a distal end and a longitudinal axis extending therethrough; a membrane comprising an inflow end and an outflow end, wherein the inflow end is at least partially installed within the distal end of the expandable frame; an actuator coupled to a control wire, the control wire being coupled to a portion of the membrane; a first magnet configured to induce rotation of the actuator to actuate the control wire to activate application of tension to the control wire and cause the membrane to radially collapse at the outflow end; and a second magnet configured to generate a changing magnetic field pole direction to cause rotation of the first magnet to cause the membrane to radially expand at the outflow end.