Calibration of insulin pumps

Nowadays, several types of infusion pumps are commonly used for medical drug delivery, such as insulin pumps, and present different measuring features and capacities according to their use and therapeutic application. In order to ensure the metrological traceability of these equipment, it is necessary to use suitable calibration methods and standards.

During the research herein presented, two different calibration methods were used to determine the flow rates of an insulin pump. One of these was the gravimetric method, considered as a primary method, and commonly used by the National Metrology Institutes; the other calibration method used was an optical method, which relies on the measurement of the variation of volume of a drop during a period of time.

The suitability of each calibration method mentioned earlier was assessed by testing an insulin pump at a flow rate of 10 μL/h and for a volume of 10 μL, that in the tested device corresponds to 1 unit of insulin. Experimental results revealed a non-continuous functioning of the insulin pumping device under test, which was unexpected, and could lead the patient not to receive a continuous dose of medicine.