System and method for detecting presence of an infusion cartridge in an infusion pump

A method for detecting a presence of an infusion cartridge in an infusion pump, comprising:

• installing the infusion cartridge in the infusion pump;
• initiating an infusion cartridge loading sequence;
• recording loading pulse width modulation (PWM) commands applied to an infusion pump motor during the infusion cartridge loading sequence;
• setting a value of threshold PWM commands based on the loading PWM commands applied to the infusion pump motor during the infusion cartridge loading sequence;
• generating operational PWM commands as electrical command input into the infusion pump motor causing the infusion pump motor to operate a drive mechanism of the infusion pump;
• controlling a velocity output of the infusion pump motor with a velocity loop algorithm by the generating the operational PWM commands as the electrical command input into the infusion pump motor;
• comparing values of the operational PWM commands that are generated as the electrical command input into the infusion pump motor during pumping operations to the value of the threshold PWM commands;
• and
• generating a missing cartridge indication if the values of the operational PWM commands drop below the value of the threshold PWM commands by a predetermined amount.