Pod Pumps for Cardiopulmonary Bypass to Reduce Blood Shear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cardiopulmonary bypass (CPB) systems face challenges in minimizing priming volume, reducing shear forces on blood, and preventing microembolization, which can lead to complications such as hemolysis, inflammatory responses, and neurological impairments during cardiac surgery.
Innovation Solution
The use of pod pumps with a geometry that reduces shear forces on blood, combined with a modular and flexible extracorporeal blood flow system that includes actively controlled valves and a heat exchanger system, allows for precise control of blood flow and temperature, minimizing trauma to blood and reducing the risk of microembolization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a centrifugal pump or roller pump is used for high flow-rate main circuit, then the flow rate requirement is met, but high shear forces are created on cellular elements of blood leading to hemolysis
Solution Approach 1:
The patent replaces traditional centrifugal or roller pumps with a membrane pump system that uses flexible membranes to move blood. This substitution eliminates the high shear forces and turbulence generated by centrifugal and roller pumps, thereby preventing hemolysis while maintaining the required flow rates through the membrane's controlled expansion and contraction.
Solution Approach 2:
The patent changes the pumping mechanism from rigid mechanical compression (centrifugal/roller) to flexible membrane displacement. This parameter change in the pump operation method reduces shear forces on blood cells while maintaining adequate flow rates, directly addressing the contradiction between productivity and harmful shear forces.
2Ease of operation
If peristaltic or roller pumps are used for branch circuits and medication infusion lines, then the required flow control is achieved, but high shear forces are created leading to platelet activation
Solution Approach 1:
The patent replaces peristaltic and roller pumps with a membrane pump system in branch circuits and medication infusion lines. This substitution maintains the ability to control flow rates while eliminating the high shear forces that cause platelet activation, as the membrane pump moves fluid through gentle displacement rather than mechanical compression.
3Quantity of substance
If the priming volume of CPB circuit is minimized by shortening interconnections and reducing tubing diameter, then the volume of extra fluid is reduced, but the system becomes more complex and harder to assemble
Solution Approach 1:
The patent merges multiple CPB circuit components (pumps, membranes, flow control elements) into an integrated modular assembly. This consolidation reduces the number of separate interconnections and tubing pieces needed, thereby reducing priming volume while actually simplifying the overall system assembly process despite the reduced component count.
Solution Approach 2:
The patent segments the CPB system into modular units with standardized connection interfaces. This segmentation allows for reduced priming volume through shorter interconnections while maintaining ease of assembly through standardized modular components that can be quickly connected and configured.
4Measurement precision
If actively controlled valves are used to alter fluid flow paths among several pumps, then flow path control precision is improved, but device complexity increases
Solution Approach 1:
The patent incorporates flow sensors and control algorithms that enable the membrane pump system to automatically detect flow conditions and adjust pump operation accordingly. This self-regulating capability provides precise flow path control without requiring complex externally controlled valves, as the system monitors and adjusts itself based on real-time flow measurements.
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
This approach reduces hemolysis, minimizes the risk of microembolization, and enhances the reliability and precision of CPB operations, while also providing the flexibility to introduce pulsatile flow and reducing overall treatment costs.
Implementation Method 1
heat exchanger system for systems, devices and methods of cardiopulmonary treatment and procedures
Implementation Method 2
pods having a geometry that reduces shear forces on the blood
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A cardiopulmonary bypass system utilizing membrane-based reciprocating positive displacement blood pumps ("pod pumps"). In one aspect, the pod pumps are constructed to provide reduced shear forces on the blood being pumped. In another aspect blood flow through the pod pumps can be controlled by a controller using information from pressure sensors in the control chamber of the pod pumps. In another aspect, the pod pumps are included on a disposable unit that can be received and held by a receptacle means on a base unit, the base unit also providing pressurized control fluid to the pod pumps on the disposable unit through the receptacle means.