Patent ID: 8715237

Claim:
A system to detect if a plunger is seated in a reservoir, comprising: an infusion pump case to contain the reservoir and the plunger; a motor within the infusion pump case to drive the plunger into the reservoir; a processor within the infusion pump case, coupled to the motor, the processor further coupled to a memory and configured to execute a software algorithm to control the motor, the software algorithm includes recording current draw to the motor to determine when the plunger is seated in the reservoir, a time difference clock being initiated upon detection via current draw that the plunger is seated in the reservoir; and a force sensor within the infusion pump case coupled to the processor, wherein the software algorithm includes comparing force exerted on the force sensor with a threshold corresponding to the plunger being seated in the reservoir, and a problem with the force sensor is detected when current draw to the motor indicates the plunger is seated in the reservoir and the force sensor fails to independently register that the plunger is seated in the reservoir when the time difference clock exceeds a threshold.