Undulating Membrane Pump for LVAD Pulsatility
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Solution Overview
Problem
Current left ventricular assist devices (LVADs) are bulky, energy-intensive, and cause hemolysis and platelet activation due to high shear forces, leading to inefficiencies and potential thrombus formation, while failing to mimic physiological pulsatility effectively.
Innovation Solution
An implantable blood pump system with an undulating membrane driven by a magnetic ring and electromagnetic coils, allowing for adjustable frequency, amplitude, and duty cycle to achieve physiological flow rates and pulsatility with low shear forces, reducing the risk of hemolysis and thrombus formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional LVADs are used to pump blood, then blood flow is achieved, but high shear forces cause hemolysis and platelet activation
Solution Approach 1:
The patent employs a pulsatile flow mechanism where the pump operates in periodic cycles of filling and ejection phases. The diaphragm moves rhythmically to create alternating pressure zones that gently propel blood forward in pulses rather than continuous high-velocity flow, reducing shear forces on blood cells while maintaining adequate flow rates
Solution Approach 2:
The patent utilizes a fluid coupling mechanism where a coupling fluid transmits pressure from the drive mechanism to the diaphragm. This hydraulic system allows for smooth, controlled pressure transmission that avoids mechanical contact with blood, eliminating shear forces generated by direct mechanical components while efficiently transferring energy to pump blood
2Power
If traditional LVADs are used, then pumping function is provided, but devices are bulky and energy-intensive
Solution Approach 1:
The patent integrates multiple functional components within a compact nested structure. The diaphragm is positioned within the pump chamber, the fluid coupling mechanism is contained within the drive assembly, and electronic controls are housed within the same implantable unit. This nesting allows the entire system to fit within a small implantable form factor while maintaining full pumping functionality
Solution Approach 2:
The patent replaces traditional mechanical pump mechanisms (such as rotating impellers or reciprocating pistons) with a flexible diaphragm actuated by fluid pressure. This substitution eliminates complex mechanical linkages, bearings, and seals that add weight and size, while the flexible diaphragm requires minimal structural support, significantly reducing the overall device mass
3Speed
If continuous flow is used, then steady blood delivery is achieved, but physiological pulsatility is not mimicked
Solution Approach 1:
The pump is designed to operate in periodic cycles that mimic the natural heartbeat, with distinct filling and ejection phases. The diaphragm rhythmically changes shape to create pressure variations that generate pulsatile flow, closely replicating physiological blood flow patterns while maintaining continuous forward progression of blood through the circulatory system
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 provides efficient, lightweight, and energy-efficient blood pumping with minimal damage to blood, capable of producing a wide range of physiological flow rates and pulsatile flow, thereby extending patient life and improving quality of life for end-stage heart failure patients.
Implementation Method 1
driven by a magnetic ring and electromagnetic coils
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, 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 pump. The implantable pump includes a flexible membrane coupled to an actuator assembly that is magnetically engagable 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 through 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.