System for predicting a patient's blood glucose level

An automated system for controlling a patient's blood glucose, comprising a processing and control unit configured to:

• predict, based on a first mathematical model, a future trend of the patient's blood glucose over a prediction period, and
• regulate, based on the prediction, insulin delivered to the patient, wherein the regulating comprises controlling an insulin injection device, wherein the first mathematical model takes as inputs:
• a variable EE(t) representative of a time variation of the patient's energy expenditure;
• a variable IOB(t) representative of a time variation of the patient's quantity of insulin on board;
• and
• a variable COB(t) representative of a time variation of the patient's quantity of carbohydrate on board,
• and wherein the first mathematical model is physiological model only defined by the observation of the effects of input variables EE(t), IOB(t) and COB(t) on the patient's blood glucose, without taking into account different known physiological mechanisms operating in the patient's body,
• wherein, in operation, the processing and control unit receives a signal CHO(t), representative of a time variation of the quantity of carbohydrates ingested by the patient, and a signal I(t) representative of a time variation of the quantity of insulin injected to the patient, and wherein the processing and control unit is configured to calculate the input variables IOB(t) and COB(t) of the first mathematical model as follows:
• IOB(t)=Σk=0KI(t−k)*hIOB(k) and
• COB(t)=Σk=0KCHO(t−k)*hCOB(k),
• where K is an integer greater than 1, k is an integer in the range from 0 to K, hIOB is an action function representing a time variation of an effect of the injected insulin on the absorption of blood glucose, and hCOB is an action function representing a time variation of an effect of the ingested carbohydrates on the blood glucose.