Patent ID: 7944366

Claim:
A method for detecting a malfunction in an infusion pump having a non-mechanically driven movable partition, comprising: (a) for each of a plurality of instances: (i) activating the infusion pump for a first pre-determined amount of time to induce movement of the movable partition of the pump and to release a shot of fluid from the pump, (ii) de-activating the infusion pump for a second pre-determined amount of time, and (ii) determining a position of the movable partition using a sensor; (b) calculating a derivative for each of the plurality of instances, the derivative being based on a change in position of the movable partition with respect to a change in the number of shots released; (c) calculating a moving average using calculated derivative values corresponding to each of the plurality of instances; and (d) comparing the calculated moving average with a predetermined threshold value, to determine whether the infusion pump is malfunctioning.