Occlusion of insulin delivery due to bubble formation in infusion pump therapy

Abstract

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.Various models of insulin pumps were used in this in-vitro experimental study to investigate the delivery performance when operating at various pre-set basal flow rates. The effect of insulin type on the measured delivery performance was also investigated by using three different types of insulin derivatives, namely: Humalog (“lispro”), Novolog (“aspart”), and Apidra (“glulisine”). Experiments were performed in a controlled laboratory environment in which data were collected using an automated computerized data acquisition setup, with temperature control to simulate body contact, and agitation to simulate typical activity levels. Each experiment ran for up to 5 days. Statistical analysis was performed on the data collected to determine significant differences and deviations in insulin delivery rates that might be due to factors such as: pump type, the set basal flow rate, insulin type, vibration, and possible insulin occlusion due to air bubble formation within the infusion line. Results of the study showed that insulin occlusion due to bubble formation occurred in about 7% of experimental runs and could last for 8 to 10 hours, depending on the flow rate and other conditions.