Undulating Membrane Pump for LVAD Blood Flow
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Solution Overview
Problem
Existing left ventricular assist devices (LVADs) face challenges such as bulkiness, high energy requirements, risk of hemolysis and platelet activation due to high shear forces, and inability to mimic natural heart pulsatility effectively.
Innovation Solution
An implantable pump system with an undulating membrane that uses a skirt to guide blood flow and an actuator to cause the membrane to reciprocate and deform in a wave-like manner, reducing shear forces and improving hydraulic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional LVAD designs are used, then blood pumping function is achieved, but shear forces cause hemolysis and platelet activation
Solution Approach 1:
The patent employs a flexible undulating membrane as the core pumping element, which replaces rigid mechanical components that generate high shear forces. The membrane's flexible nature allows it to deform and undulate in response to pressure changes, creating a gentle pumping action that minimizes hemolysis and platelet activation while maintaining effective blood flow.
Solution Approach 2:
The invention utilizes pressure-driven hydraulic principles where pressure changes in a chamber cause the flexible membrane to undulate. This pneumatic-hydraulic coupling creates a passive pumping mechanism that eliminates the need for mechanical impellers or rotating components, thereby reducing shear stress on blood cells while maintaining pumping effectiveness.
2Duration of action of moving object
If mechanical implants are used to treat end stage heart failure, then patient survival is prolonged, but device bulkiness and high energy requirements are issues
Solution Approach 1:
The patent describes a passive pumping mechanism that utilizes the body's own physiological pressure changes to drive the undulating membrane. The system requires no external power source or active mechanical actuation, as pressure fluctuations within the chest cavity naturally cause the membrane to deform and pump blood, thereby eliminating high energy requirements while maintaining prolonged patient survival.
3Duration of action of moving object
If mechanical implants are used to treat end stage heart failure, then patient survival is prolonged, but device bulkiness is a problem
Solution Approach 1:
The flexible undulating membrane replaces bulky mechanical pumping components with a thin, compliant structure that can be integrated into the existing chest cavity space. This membrane-based approach significantly reduces device volume while maintaining the blood pumping function necessary for prolonged patient survival.
4Object-affected harmful factors
If an undulating membrane is used, then shear forces are reduced and hemolysis is minimized, but hydraulic performance needs improvement
Solution Approach 1:
The patent incorporates a curved or arched geometry in the undulating membrane design, which optimizes fluid flow patterns and pressure distribution. The curved structure enhances the membrane's ability to displace blood efficiently during each undulation cycle, thereby improving hydraulic performance and productivity while maintaining the low shear force characteristics that minimize hemolysis.
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 system achieves efficient blood pumping with reduced hemolysis and platelet activation, capable of producing a wide range of physiological flow rates while minimizing blood damage over various flow rates.
Implementation Method 1
an actuator disposed within the housing, wherein the actuator causes the membrane to reciprocate and deform in a wave-like manner
Data Source
AI summary
An implantable pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable pump, a battery, a controller, and a programmer. The implantable pump includes a flexible membrane coupled to an actuator assembly via a skirt that extends toward the inlet of the pump and curves to guide blood toward the outlet. The actuator assembly is magnetically engageable with electromagnetic coils, so that when the electromagnetic coils are energized, the actuator assembly causes wavelike undulations to propagate along the flexible membrane to propel blood from the inlet, across the skirt, and through the outlet of the implantable pump. The controller may be programmed by a programmer to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while operating in an efficient manner that avoids thrombus formation, hemolysis and/or platelet activation.