Occlusion resolution in medication delivery devices, systems, and methods
Methods, devices, and systems of delivering infusion fluid (e.g., medication such as insulin) can detect, at multiple times during a dispensation period of time, a pressure level of the infusion fluid in an infusion fluid pathway, either directly or indirectly. Based on the detected pressure levels, one or more actual dispensation times that are after an intended dispensation time can be determined. In some cases, methods, devices, and systems provided herein can use variable occlusion alarm thresholds, which can depend on variables such as an age of an infusion set and/or a current analyte level. In some cases, methods, devices, and systems provided herein can automate medication delivery and use the actual dispensation times in a control algorithm determining medication deliveries.
1. A method of operating a portable infusion pump system, the method comprising:
initiating a dispensation of an infusion fluid by a pump of the portable infusion pump system;
identifying an intended dispensation time at which the dispensation of the infusion fluid is initiated;
detecting, at multiple times during a dispensation period of time, pressure measurements of the infusion fluid in an infusion fluid pathway of the pump;
identifying pressure data predetermined for the infusion pump system, the pressure data indicative of a pressure change of the infusion fluid pathway in an occluded condition, the pressure data including one or more threshold pressure values;
comparing each of pressure measurements detected at the multiple times during the dispensation period to the one or more threshold pressure values; and
determining, based on one or more of the detected pressure measurements exceeding the one or more of the threshold pressure values of the pressure data, that the dispensation occurred at an actual dispensation time that is delayed from the intended dispensation time due at least in part to the occluded condition; and
determining an amount of the infusion fluid delivered from the actual dispensation time.
2. The method of claim 1 , wherein the infusion fluid is insulin.
3. The method of claim 2 , wherein control circuitry of the infusion pump system calculates an estimate of insulin-on-board based on the amount of the infusion fluid delivered from the actual dispensation time.
4. The method of claim 2 , further comprising receiving, from a blood glucose detection device, at least one blood glucose level, wherein an amount of insulin in the dispensation is determined based at least in part upon the at least one blood glucose level and an estimate of insulin-on-board.
5. The method of claim 4 , wherein the one or more pressure threshold values include a variable alarm threshold, the method further comprising outputting an occlusion alarm if one or more of the detected pressure measurements exceeds the variable alarm threshold, the variable alarm threshold being dependent upon at least one detected blood glucose value.
6. The method of claim 5 , wherein the variable alarm threshold is further dependent on a timing of one or more recent dispensations, amount of one or more recent dispensations, type of one or more recent dispensations, or a combination thereof.
7. The method of claim 2 , further comprising predicting a future blood glucose level based on the actual dispensation time and the amount of the infusion fluid delivered from the actual dispensation time.
8. The method of claim 2 , further comprising determining an amount of insulin that is stuck in transit in the infusion fluid pathway of the pump due to the occluded condition based on the pressure data, wherein the actual dispensation time is determined based on a time that the detected pressure decreases to a predetermined level, wherein an amount of insulin stuck in transit is excluded from an insulin-on-board calculation performed by control circuitry of the portable infusion pump system.
9. The method of claim 1 , wherein, in response to determining that the dispensation occurred at an actual dispensation time that is after the intended dispensation time, delaying or reducing a subsequent dispensation of the infusion fluid.
10. The method of claim 1 , wherein the pressure level is determined or estimated using a pressure sensor or a force sensor.