An Improved Strategy for Blood Glucose Control Using Multi-Step Deep Reinforcement Learning

TL;DR

This paper introduces a multi-step deep reinforcement learning approach with prioritized experience replay for more effective and faster blood glucose control in type 1 diabetes, accounting for drug delay effects.

Contribution

It proposes a novel multi-step DRL algorithm that models BG control as an MDP, improving convergence speed and control accuracy over existing methods.

Findings

Faster convergence of the proposed method.

Higher time-in-range (TIR) in evaluations.

Improved BG control performance compared to benchmarks.

Abstract

Blood Glucose (BG) control involves keeping an individual's BG within a healthy range through extracorporeal insulin injections is an important task for people with type 1 diabetes. However,traditional patient self-management is cumbersome and risky. Recent research has been devoted to exploring individualized and automated BG control approaches, among which Deep Reinforcement Learning (DRL) shows potential as an emerging approach. In this paper, we use an exponential decay model of drug concentration to convert the formalization of the BG control problem, which takes into account the delay and prolongedness of drug effects, from a PAE-POMDP (Prolonged Action Effect-Partially Observable Markov Decision Process) to a MDP, and we propose a novel multi-step DRL-based algorithm to solve the problem. The Prioritized Experience Replay (PER) sampling method is also used in it. Compared to single-step bootstrapped updates, multi-step learning is more efficient and reduces the influence from biasing targets. Our proposed method converges faster and achieves higher cumulative rewards compared to the benchmark in the same training environment, and improves the time-in-range (TIR), the percentage of time the patient's BG is within the target range, in the evaluation phase. Our work validates the effectiveness of multi-step reinforcement learning in BG control, which may help to explore the optimal glycemic control measure and improve the survival of diabetic patients.