Rotor drive for medical disposables

Abstract

A disposable biomedical rotating filtration system for processing fluids in a closed environment includes a rotor mounted for rotation on a pivot pin, a seal between the rotor and pivot pin, an external permanent magnet drive mechanism, and a star shaped drive element mounted on the rotor for rotating the rotor in response to a magnetic field induced by the permanent magnet of the drive mechanism. The drive element on the rotor is stamped from an inexpensive non-permanent ferromagnetic sheet metal and has a configuration and position in relation to the center of said magnetic field such that said drive element receives sufficient torque for driving said rotor and sufficient seal force is applied on the rotor to provide fluid tight seal between the rotating rotor and the seal. The pivot pin is molded from a hard plastic material such as a polyamide base resin having a low coefficient of friction and good lubriciousness. The pivot pin is irradiated by gamma radiation for sterilization and modifying of the plastic material without degradation or loss of lubricious properties.