A device and method for controlling operation of an ambulatory infusion device drive. The drive may have a spindle drive with a stepper motor, a drive member operatively coupled to a rotary encoder, and a driver controller that executes several steps, including actuating the stepper motor to execute a requested number of steps in a current drive control sequence, receiving a drive member position that indicates an actual position of a drive member following the actuation, computing an executed steps number from the drive member position, computing a missed steps number for the current drive control sequence, which is the difference between the requested number of steps and the executed steps number, determining when the ambulatory infusion device drive is blocked based on a statistical evaluation of a time-distribution of the missed steps number over a history of drive control sequences, and generating a blockage alarm signal.
