Insulin pumps are commonly used in the therapy of children with type 1 diabetes, among other reasons due to the flexible continuous delivery of low basal rates. The standard EN 60601-2-24 describes test settings and procedures for the evaluation of infusion pumps in general; however, no acceptance criteria related to insulin delivery accuracy are stipulated. Most manufacturers’ specifications are limited to the accuracy of basal rates ≥1 U/h, while far lower basal rates are common in children.
In this study, the accuracy of a 0.1 U/h basal rate delivery of different insulin pumps was evaluated in an experimental setting based on EN 60601-2-24. The insulin pumps Accu-Chek® Insight, Accu-Chek® Spirit Combo, Animas® Vibe®, MiniMed® 640G, Paradigm® Veo™ and mylife™ OmniPod® were tested with different infusion sets (IIS). Measurements were based on the determination of weight increase of water-filled, oil-covered beakers placed on balances into which insulin was delivered by the pumps. Pumps were installed outside of the balance with the infusion set or a steel pipe (for the patch pump), respectively, connected to the beaker. After priming, a basal rate of 0.1 U/h was run for 72 h while weight increases were recorded. Each combination of insulin pump and IIS was tested 9 times. The total and the mean delivery over 1-h windows were calculated.
Large differences in total delivery were observed between the tested systems (+4.1% to +24.4% of the expected). During the first 24 h, all deviations were >10% from the expected rate. Evaluation of 1-h windows showed that 31% to 80% of results were within ±15% of the weight increase expected with the set basal rate and large variations between the individual 1-h windows.
With the low basal rate tested in this study, delivery rates calculated from weight increases showed marked deviations from what was expected for this rate. When using insulin pumps in children with low insulin demands, it has to be considered that the basal rate might not be delivered as accurate and as consistent as expected.
R. Ziegler: Advisory Panel; Self; Abbott. Speaker's Bureau; Self; Roche Diabetes Care Health and Digital Solutions. Advisory Panel; Self; Novo Nordisk A/S. Other Relationship; Self; Sanofi-Aventis. Speaker's Bureau; Self; Animas Corporation. U. Kamecke: None. D. Waldenmaier: None. C. Haug: None. G. Freckmann: Speaker's Bureau; Self; Ascensia Diabetes Care. Research Support; Self; Ascensia Diabetes Care. Speaker's Bureau; Self; Roche Diabetes Care Health and Digital Solutions. Advisory Panel; Self; Roche Diabetes Care Health and Digital Solutions. Research Support; Self; Roche Diabetes Care Health and Digital Solutions. Advisory Panel; Self; Abbott, Novo Nordisk Inc.. Consultant; Self; Sensile Medical AG. Speaker's Bureau; Self; Ypsomed AG.
