Rectangular Membrane Blood Pump for Low-Shear Partial Support
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Solution Overview
Problem
Existing partial-support assist devices for heart failure patients face issues such as thrombosis risk due to high shear stress, cannula leakage, and aesthetic concerns due to cylindrical shape, among others.
Innovation Solution
An implantable pump system with a rectangular membrane and electromagnetic actuation, which induces wave-like deformations to propel blood with low shear forces, reducing hemolysis and platelet activation, and is designed for minimal invasiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a rotary pump with impeller is used to provide partial flow support, then the pump can move blood effectively, but high shear stress is generated causing thrombosis risk
Solution Approach 1:
The patent replaces the rotary impeller mechanism with a linearly reciprocating plunger that directly displaces blood in a linear direction. This substitution eliminates the rotational shear forces generated by impellers while maintaining effective blood flow propulsion through linear reciprocation, thereby reducing thrombosis risk while preserving productivity
Solution Approach 2:
Instead of rotating blood in a circular path as done by impellers, the patent inverts the approach by moving blood in a linear reciprocating motion. The plunger moves linearly back and forth, directly pushing blood forward without the rotational component that generates harmful shear stress, thus resolving the contradiction between flow rate and shear stress
2Ease of operation
If a cylindrical pump device is implanted in the chest, then the pump can be positioned effectively, but aesthetic concerns arise due to the cylindrical shape
Solution Approach 1:
The patent transitions from a symmetric cylindrical shape to an asymmetric rectangular configuration. The rectangular shape with distinct length, width, and height dimensions allows for more flexible positioning and orientation within the chest cavity, while also presenting a different aesthetic profile that may be more acceptable to patients, thus resolving the contradiction between ease of positioning and aesthetic appearance
3Device complexity
If a smaller pump is used for partial-support assist, then less invasive surgery is required, but the pump must be highly efficient in a compact space
Solution Approach 1:
The patent employs a flexible diaphragm as the pumping element, which can be actuated by a magnet assembly. This flexible membrane design allows for effective blood displacement in a compact volume, enabling the pump to achieve required flow rates in a smaller, less invasive configuration while maintaining high efficiency through the elastic deformation of the diaphragm
Solution Approach 2:
The patent utilizes the rectangular geometry to optimize space utilization in three dimensions. By arranging the pumping chambers and diaphragms in a rectangular configuration rather than cylindrical, the design achieves more efficient packing and utilization of the available implantation space, allowing compact size without sacrificing blood flow support efficiency
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 partial circulatory support with reduced blood damage and thrombosis risk, offering a more aesthetically pleasing and effective alternative to existing devices.
Implementation Method 1
The electromagnetic assembly may generate, when electrically activated, a magnetic field applied to the one or more magnets to induce wave-like deformation of the rectangular membrane, thereby pumping blood from the inlet, along the rectangular membrane, and out the outlet
Data Source
AI summary
An implantable pump system is provided, including an implantable blood pump suitable for use as a partial support assist device, the system further including 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 electromagnetic actuator including a magnetic assembly and electromagnetic assembly, so that when the electromagnetic assembly is energized, the electromagnetic assembly causes wavelike undulations to propagate along the flexible membrane to propel blood 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.