Catheter Pump Impeller Design for High Flow Low Hemolysis

The patent changes the operational parameters of the pump by optimizing impeller blade geometry, number of blades, and rotational speed to achieve higher flow rates without proportionally increasing shear stress. The impeller is designed with specific blade angles and curvatures that allow efficient blood propulsion at lower rotational speeds, thereby maintaining productivity while reducing hemolysis and thrombosis risks.

The patent replaces traditional high-speed rotary mechanical pumping with a magnetically driven impeller system that uses magnetic fields to rotate the impeller without direct mechanical connection to the blood flow path. This substitution reduces mechanical shear stress on blood cells while maintaining effective pumping action, thus improving productivity without increasing harmful factors.

The patent segments the ventricular assist device into multiple components: a percutaneous access portion, a drive shaft, a magnetically coupled impeller assembly, and control systems. This segmentation allows the device to be inserted through small percutaneous access points while the expanded impeller assembly provides near full heart flow rates once positioned in the ventricle, resolving the contradiction between size and productivity.

The patent employs a nested configuration where the impeller assembly and drive components are contained within a percutaneous access sheath during insertion. The drive shaft passes through the catheter body, and the impeller is magnetically coupled to the drive mechanism. This nesting allows the large-flow device to be delivered through small access points, reducing device complexity for insertion while maintaining high productivity capability.