Occlusion detection for a fluid infusion device

In a fluid infusion device comprising a drive motor assembly and a force sensor associated with the drive motor assembly, a method of detecting occlusions in a fluid path of the fluid infusion device, the method comprising:

• determining a plurality of force measurements for a fluid delivery action of the drive motor assembly, the plurality of force measurements indicating measures of actuation force imparted to the force sensor for the fluid delivery action;
• determining a plurality of quantity measurements for the fluid delivery action, each of the plurality of quantity measurements being determined relative to a reference quantity measurement;
• calculating a first slope of force-versus-quantity based upon the current one of the plurality of force measurements, a current one of the plurality of quantity measurements, corresponding to the current one of the plurality of force measurements, a previous one of the plurality of force measurementsand a previous one of the plurality of quantity measurements, corresponding to the previous one of the plurality of force measurements;
• indicating an occlusion when the first slope of force-versus-quantity for a large sample of the plurality of quantity measurements is greater than or equal to a first threshold slope value;
• and
• indicating an occlusion when both:
• (a) a second slope of force-versus-quantity for a small sample of the plurality of quantity measurements is greater than or equal to a second threshold slope value;
• and (b) a current one of the plurality of force measurements is greater than or equal to a threshold force value.