Patent ID: 7338470

Claim:
An air-bubble-monitoring medication assembly comprising: a) a drug infusion subassembly having a tube for administering therein a liquid to a patient at a dose rate; b) a bubble-size determinator which is disposed to sense an air bubble entrained in the liquid in the tube and which determines the volume of the sensed air bubble; and c) an analyzer which logs the time the bubble-size determinator senses an air bubble and the volume of the sensed air bubble, which calculates a first running sum of a total air volume of all air bubbles sensed over a first time interval, where the first time interval is dependent upon the dose rate, and the analyzer compares the first running sum with a first preselected limit, and which generates an output when the first running sum exceeds the first preselected limit, and which further calculates a second running sum of a total air volume of all air bubbles sensed over a second time interval; compares the second running sum with a second preselected limit; and generates the output when the second running sum exceeds the second preselected limit, wherein the second time interval is longer than the first time interval, wherein the second preselected limit equals the first preselected limit times a multiplier, and wherein the second time interval does not equal the first time interval times the multiplier.