Patent ID: 9344024
Filing Date: 2016-05-17
CPC Classification: A61M,F04B,H02P

Claim Text:
1. A method of detecting an occlusion in a fluid path of an infusion device, the method comprising: applying a modulated voltage to a stepper motor to produce a commanded number of motor steps of rotation of a rotor of the stepper motor, the rotation of the rotor resulting in delivery of fluid via the fluid path; determining an expected number of incremental rotations expected to be detected by a sensor coupled to the stepper motor in response to applying the modulated voltage to the stepper motor to produce the commanded number of motor steps based on the commanded number of motor steps; obtaining a measured number of incremental rotations of the rotor from the sensor in response to applying the modulated voltage to the stepper motor to produce the commanded number of motor steps; adjusting a duty cycle of the modulated voltage to achieve the commanded number of motor steps in response to a difference between the expected number and the measured number; and identifying an occlusion condition based on the duty cycle.