School of Electrical Engineering and Computer Science (SEECS), National University of Sciences and Technology (NUST), Islamabad, Pakistan.
IET Syst Biol. 2021 Apr;15(2):72-82. doi: 10.1049/syb2.12015.
Destruction of β-cells in pancreas causes deficiency in insulin production that leads to diabetes in the human body. To cope with this problem, insulin is either taken orally during the day or injected into the patient's body using artificial pancreas (AP) during sleeping hours. Some mathematical models indicate that AP uses control algorithms to regulate blood glucose concentration (BGC). The extended Bergman minimal model (EBMM) incorporates, as a state variable, the disturbance in insulin level during medication due to either meal intake or burning sugar by engaging in physical exercise. In this research work, EBMM and proposed finite time robust controllers are used, including the sliding mode controller (SMC), backstepping SMC (BSMC) and supertwisting SMC (second-order SMC or SOSMC) for automatic stabilisation of BGC in type 1 diabetic patients. The proposed SOSMC diminishes the chattering phenomenon which appears in the conventional SMC. The proposed BSMC is a recursive technique which becomes robust by the addition of the SMC. Lyapunov theory has been used to prove the asymptotic stability of the proposed controllers. Simulations have been carried out in MATLAB/Simulink for the comparative study of the proposed controllers under varying data of six different type 1 diabetic patients available in the literature.
胰岛β细胞的破坏导致胰岛素产生不足，从而导致人体糖尿病。为了解决这个问题，胰岛素要么在白天口服，要么在睡眠期间使用人工胰腺 (AP) 注射到患者体内。一些数学模型表明，AP 使用控制算法来调节血糖浓度 (BGC)。扩展的 Bergman 最小模型 (EBMM) 将药物治疗期间由于进食或进行体育锻炼而消耗糖分导致的胰岛素水平的干扰作为状态变量纳入其中。在这项研究工作中，使用了 EBMM 和提出的有限时间鲁棒控制器，包括滑模控制器 (SMC)、回溯 SMC (BSMC) 和超螺旋 SMC (二阶 SMC 或 SOSMC)，用于自动稳定 1 型糖尿病患者的 BGC。所提出的 SOSMC 减少了在传统 SMC 中出现的抖动现象。所提出的 BSMC 是一种递归技术，通过添加 SMC 变得鲁棒。Lyapunov 理论已被用于证明所提出的控制器的渐近稳定性。在 MATLAB/Simulink 中进行了仿真，以比较在文献中可用的 6 个不同 1 型糖尿病患者的不同数据下提出的控制器。
