Coaxial Ventricular Cannula for LVAD Blood Delivery
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Solution Overview
Problem
Current left ventricular assist devices (LVADs) face inefficiencies due to the need for a return line extending from the left ventricle to the aorta, which reduces system efficiency, increases the risk of blood damage, and leads to complications like thrombosis and barotrauma.
Innovation Solution
An implantable cardiovascular blood pump system with coaxial cannulas and a vibrating membrane pump that eliminates the need for an external return line by using a coaxial design to deliver blood directly from the left ventricle to the aorta, applying low shear forces to minimize hemolysis and platelet activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external return line is used to deliver blood from the left ventricle to the aorta, then blood delivery is achieved, but system efficiency is reduced and the risk of blood damage increases
Solution Approach 1:
The outflow cannula is positioned coaxially within the inflow cannula, with the outflow cannula's outer surface in sliding engagement with the inflow cannula's inner surface. This nested configuration allows blood to flow directly from the left ventricle through the outflow cannula to the aorta without requiring an external return line, thereby improving blood delivery efficiency while minimizing blood damage through reduced exposure to external surfaces and lower shear forces.
2Reliability
If an external return line is used, then blood delivery is achieved, but complications like thrombosis and barotrauma occur
Solution Approach 1:
The nested coaxial configuration eliminates the external return line that would otherwise be exposed to blood flow, removing the surface that generates thrombosis and barotrauma complications. Blood flows directly from the left ventricle through the outflow cannula to the aorta within the protected nested structure.
Solution Approach 2:
The harmful external return line is extracted from the system and replaced with the integrated nested coaxial cannula design, removing the source of thrombosis and barotrauma complications while maintaining blood delivery function.
3Reliability
If a conventional LVAD design with separate inflow and outflow cannulas is used, then blood pumping is achieved, but system complexity and external components are increased
Solution Approach 1:
The inflow and outflow cannulas are merged into a single integrated assembly where the outflow cannula is positioned within the inflow cannula. This unified structure reduces device complexity by eliminating the need for separate external cannula connections while maintaining effective blood pumping from the left ventricle to the aorta.
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 delivery with reduced hemolysis and platelet activation, enhancing the safety and efficacy of LVADs by eliminating the need for an external return line and minimizing complications.
Implementation Method 1
a vibrating membrane pump that eliminates the need for an external return line by using a coaxial design to deliver blood directly from the left ventricle to the aorta, applying low shear forces to minimize hemolysis and platelet activation
Data Source
AI summary
An implantable cardiovascular blood pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable cardiovascular pump, an extracorporeal battery and a controller coupled to the implantable pump, and a programmer selectively periodically coupled to the controller to configure and adjust operating parameters of the implantable cardiovascular pump. The implantable cardiovascular blood pump includes a coaxial inflow cannula and outflow cannula in fluid communication with one another and with a pumping mechanism. The pumping mechanism may be a vibrating membrane pump which may include a flexible membrane coupled to an electromagnetic actuator assembly that causes wavelike undulations to propagate along the flexible membrane to propel blood through the implantable cardiovascular pump. The implantable cardiovascular pump may be programmed to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while avoiding thrombus formation, hemolysis and/or platelet activation.