Hourly insulin sensitivity variation studied from clinical ICU data Stochastic model developed: probability distribution (likelihood) of coming hour’s insulin sensitivity index can be derived S I at hour n ( I n ) (mU/L/min) +1 ( +1 2 4 6 8 10 12 x 10 -4 1000 2000 3000 4000 5000 6000 7000 8000 potential probability distribution function fitted Figure 1. Fitted hourly SI data and probability distribution function Figure 2. Three-dimensional stochastic model of SI variability
Utilising the derived probability distribution of coming hour’s insulin sensitivity index, probabilistic forecast of change in blood glucose levels can be made, and therefore assist clinical control interventions. Blood Glucose Forecast Time 1 ml insulin injection 2 ml insulin injection 4 ml insulin injection BEST CONTROL Too much insulin Hypoglycemia (blood glucose levels too low) can lead to complications and be potentially fetal!!! Most likely blood glucose forecast Range of 90% likelihood Desirable blood glucose level Hypoglycemic region inter-quartile probability interval 0.90 probability interval 0.95 probability interval raw fitted SI most probable SI forecast