Glycemic Safety Tube: A Provably Safe Control Framework for Artificial Pancreas Systems under Parametric Uncertainty

TL;DR

Glycemic Safety Tube Control (GSTC) is a model-free, computationally efficient framework that guarantees safety bounds for glucose levels in artificial pancreas systems, even under uncertainties and disturbances.

Contribution

GSTC introduces a provably safe control method that does not rely on patient-specific models, ensuring glucose safety with formal guarantees and robustness.

Findings

GSTC maintains glucose safety across various meal patterns and patient conditions.

GSTC outperforms existing control methods in safety and computational efficiency.

The framework guarantees safety despite bounded disturbances and estimation errors.

Abstract

Type 1 diabetes eliminates the body's ability to produce insulin, making glucose regulation entirely dependent on external insulin delivery and the control algorithm. Existing closed-loop methods either rely on accurate patient-specific models or do not provide formal safety guarantees, and are often computationally demanding for wearable devices. This paper proposes Glycemic Safety Tube Control (GSTC), a model-free and computationally efficient control framework for automated insulin delivery. The method enforces clinically relevant safety bounds on glucose levels by design, ensuring that glucose remains within a prescribed safe range. We also derive feasibility conditions that guarantee safety and input constraint satisfaction under bounded meal disturbances and estimation errors. The performance of GSTC is evaluated against state-of-the-art methods, including linear and nonlinear model predictive control and sliding mode control. The results demonstrate that GSTC maintains safety under varying meal patterns and patient conditions, highlighting its robustness and computational efficiency. Overall, GSTC provides a safe, efficient, and patient-independent approach for next-generation artificial pancreas systems.