Method and apparatus for detection and management of air-in-line

摘要

In an infusion pump operable to deliver fluid to a patient at a programmed therapy flow rate, air-in-line sensing is improved by commanding the pumping mechanism to deliver a bolus volume of fluid at a flow rate higher than the therapy flow rate when an uninterrupted volume of air is detected that exceeds a first threshold. In many cases, the bolus will be effective to clear microbubbles from an observation zone of the air-in-line sensor to avoid an air-in-line alarm condition. If the uninterrupted volume of air continues to grow beyond a second threshold in spite of the bolus, then an alarm may be triggered. The invention reduces false alarms.

主权项

1. A method of detecting an air-in-line condition with respect to flow of liquid through tubing connected to an infusion pump, the method comprising:
providing an air-in-line sensor at a sensing location along the tubing, the air-in-line sensor generating a signal indicating whether a volume of fluid observed by the sensor at a given time is air or liquid; operating the pump to deliver fluid at a therapy flow rate; sampling the sensor signal as fluid flows past the sensor; calculating a total volume of air observed by the sensor since the sensor last observed liquid; operating the pump to deliver a bolus volume of fluid at a bolus flow rate greater than the therapy flow rate when the total volume of air exceeds a first threshold, wherein the bolus volume is delivered automatically by the pump, prior to stopping the pump or signaling an alarm, when the total volume of air exceeds the first threshold; detecting the air-in-line condition when the total volume of air exceeds a second threshold greater than the first threshold, wherein the air-in-line condition is basis for stopping the pump or signaling the alarm.