Fig. 1.

Schematic representation of basal insulin suspension/attenuation algorithms. a Schema of algorithms based on detection of hypoglycemia. Measurements of subject’s interstitial glucose (IG) concentration are real-time collected by a CGM sensor. When CGM measurements go below a threshold T, the hypoglycemia detection module detects hypoglycemia. Then, the basal insulin attenuation module calculates the attenuation factor $\varphi (t)$, which is 0 if no hypoglycemia is detected and $0<\varphi (t)\le 1$ if a hypoglycemia is detected. Finally, the nominal basal insulin delivery rate, ${I_b}^{\mathit{nom}}(t)$, is multiplied for $\varphi (t)$ to obtain the final modulated basal insulin delivery rate, ${I_b}^{\mathit{mod}}(t)$, which is given in output by the insulin pump. b Schema of algorithms based on prediction of hypoglycemia. In these algorithms, CGM measurements are used, optionally together with other input data (e.g. insulin), to predict in real-time the occurrence of hypoglycemic events PH min in advance (hypoglycemia prediction module). Such hypoglycemia prediction is then used to calculate a basal insulin attenuation factor, $\varphi (t)$, as in detection-based methods