INTEGRATED CLOSED-LOOP MEDICATION DELIVERY WITH ERROR MODEL AND SAFETY CHECK

摘要

A closed-loop system for insulin infusion overnight uses a model predictive control algorithm (“MPC”). Used with the MPC is a glucose measurement error model which was derived from actual glucose sensor error data. That sensor error data included both a sensor artifacts component, including dropouts, and a persistent error component, including calibration error, all of which was obtained experimentally from living subjects. The MPC algorithm advised on insulin infusion every fifteen minutes. Sensor glucose input to the MPC was obtained by combining model-calculated, noise-free interstitial glucose with experimentally-derived transient and persistent sensor artifacts associated with the FreeStyle Navigator® Continuous Glucose Monitor System (“FSN”). The incidence of severe and significant hypoglycemia reduced 2300- and 200-fold, respectively, during simulated overnight closed-loop control with the MPC algorithm using the glucose measurement error model suggesting that the continuous glucose monitoring technologies facilitate safe closed-loop insulin delivery.

主权项

1. A system for the delivery of insulin to a patient, the system comprising:
a glucose sensor configured to provide a sensor glucose measurement signal representative of sensed glucose; an insulin delivery device configured to deliver insulin to a patient in response to control signals; and a controller programmed to receive the sensor glucose measurement signal and to provide a delivery control signal to the delivery device as a function of the received sensor glucose measurement signal in accordance with a control model and a glucose measurement error model; wherein the glucose measurement error model is derived from actual glucose sensor measurement data.