Background: Accuracy of continuous subcutaneous insulin infusion (CSII) is essential for glycaemic control. Our study presents results of accuracy assessment of three off-the-shelves CSII under fluctuating temperature at 0,5UI/h.

Methods: CSII systems accuracy was assessed by a double measurement approach utilizing a direct mass flow meter and a time-stamped micro-gravimetric test bench combined with a Kalman mathematical filter. CSII was placed inside a chamber of fluctuating temperature: 8h-tests were composed of successions of 1h at 32°C, 1h at 5°C, and compared to 8-hour tests at a 22°C fixed temperature. Accuracy was evaluated using mean of dose error. Mean absolute relative dispersion (MARD) of error was also computed for 15min time-windows. Stroke regularity was assessed in terms of frequency and volume. Tests were conducted both with insulin and medical water.

Results: Delivery errors follow temperature profile. MARD of error is significantly higher with fluctuating temperature (85.2%, 44.4%, 20.4% according to each of the 3 CSII pump models) vs. fixed temperature (13.3%, 9.5%, 12.7%). No difference was observed between insulin and medical water. Stroke volume is affected by temperature changes rather than stroke frequency.

Conclusion: Temperature and its fluctuations may affect the accuracy and amounts of insulin delivered by CSII. The clinical impact of the difference in insulin intake requires clinical investigations.


S. Girardot: Employee; Self; Air Liquide. Employee; Spouse/Partner; Air Liquide. P. Jacquemier: Employee; Self; Air Liquide. F. Mousin: Employee; Self; Air Liquide. C. Rendekeu: Employee; Self; Air Liquide. S. Hardy: None. J. Riveline: None.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at