Conical Peristaltic Pump Design for Reduced Hemolysis

The patent applies asymmetry by transitioning from a conventional cylindrical stator to a conical stator with varying radius. The pressor element similarly transitions from a cylindrical roller to a conical shape. This asymmetric geometry creates a more uniform distribution of compression forces along the tube, reducing peak shear stress values that cause hemolysis while maintaining effective pumping action through the conical cavity.

The conical stator and pressor element design implements local quality by varying the compression characteristics along the length of the contact area. The radius of the stator increases from the small base to the large base, creating zones of different compression intensity. This allows the system to apply gentler compression at certain locations and stronger compression at others, optimizing both tube protection and pumping efficiency locally throughout the peristaltic cycle.

The conical stator with its progressively increasing radius from base to apex creates a self-aligning geometry. When the flexible tube is inserted, the conical surfaces naturally guide the tube into the correct position through the tapering walls. The pressor element similarly uses its conical shape to self-position against the tube, eliminating the need for complex external positioning mechanisms and ensuring repeatable alignment without manual adjustment.

The conical geometry of both the stator and pressor element provides curved surfaces that naturally guide and position the flexible tube. The tapered conical walls create a funnel-like effect that directs the tube into proper alignment, while the curved contact surfaces ensure consistent positioning through geometric constraint rather than mechanical fastening or complex adjustment mechanisms.