System and method for detecting occlusions in an infusion pump

摘要

Occlusions in a delivery line of an infusion pump can be detected by measuring pressure differentials in the pump over short periods of time in order to minimize the effects of long term systematic sensor changes. In a delivery mode such as basal insulin delivery where a small portion of a volume of fluid is delivered, pressure readings can be obtained before and after the motor move to deliver each portion and compared. The differentials after one or more motor moves can be compared to determine whether an occlusion is present. In a delivery mode such as bolus insulin delivery in which an entire volume of fluid is delivered, pressure differentials can be obtained for consecutive deliveries at a common point in the delivery cycle of each delivery. Comparison of these pressure values can be used to determine whether an occlusion is present.

主权项

1. An ambulatory infusion system, comprising:
a disposable infusion cartridge, the infusion cartridge including a collapsible reservoir for containing a fluid and a substantially rigid shell disposed over the collapsible reservoir and forming, an interior volume between an outside surface of the collapsible reservoir and an inside surface of the shell, the disposable infusion cartridge further including a delivery mechanism having a spool slidingly disposed in a bore, the spool including as main section and a distal section axially displaceable relative to the main section with a collapsible volume formed between a seal on the main section and a seal on the distal section; a pump device configured to selectively receive the infusion cartridge and cooperate with the infusion cartridge to deliver fluid from the reservoir to the patient, the pump device including a drive mechanism powered by a motor and selectively engageable with the spool to impart controlled axial movements to the spool to deliver fluid from the cartridge to the patient a pressure sensor located in one of the infusion cartridge and the pump, the pressure sensor in communication with the interior volume of the infusion cartridge; and a processor located in one of the infusion cartridge and the pump wherein the processor is adapted to:
obtain a first pressure reading of the pressure in the interior volume of the cartridge from the pressure sensor;obtain a second pressure reading of the pressure in the interior volume of the cartridge from the pressure sensor following an operation configured to deliver fluid from the cartridge to a patient;compare the first pressure reading to the second pressure reading;determine, from the comparison, of the first pressure reading to the second pressure reading, whether the distal section of the spool moved axially at time during the operation configured to deliver fluid from the cartridge to the patient when the distal section should have remained stationary;selectively generate an occlusion alarm based on the comparison of the first pressure reading to the second pressure reading if it is determined that the distal section moved at the time it should have remained stationary.