PUMP MONITOR APPARATUS IN PATIENT TREATMENT SYSTEM BY OPTICAL ACTIVATION

摘要

A preferred patient blood treatment system for the photoactivation of reagents in contact with a patient's blood employs an infusion pump for adding anti-coagulation reagent to the blood during extracorporeal operations. The infusion pump is preferably driven by a stepper motor and monitored by a periodic photo chopper employing a plurality of sensors. The spacing of the sensors and the spacing of the photo choppers work in concert to detect rotation of the stepper motor and to discriminate such from stutter or other characteristic nonrotational faults associated with stepper motors.