Department of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University, Tel-Aviv, Israel.
PLoS One. 2012;7(8):e44587. doi: 10.1371/journal.pone.0044587. Epub 2012 Aug 31.
Insulin resistance (IR) is one of the most widespread health problems in modern times. The gold standard for quantification of IR is the hyperinsulinemic-euglycemic glucose clamp technique. During the test, a regulated glucose infusion is delivered intravenously to maintain a constant blood glucose concentration. Current control algorithms for regulating this glucose infusion are based on feedback control. These models require frequent sampling of blood, and can only partly capture the complexity associated with regulation of glucose. Here we present an improved clamp control algorithm which is motivated by the stochastic nature of glucose kinetics, while using the minimal need in blood samples required for evaluation of IR. A glucose pump control algorithm, based on artificial neural networks model was developed. The system was trained with a data base collected from 62 rat model experiments, using a back-propagation Levenberg-Marquardt optimization. Genetic algorithm was used to optimize network topology and learning features. The predictive value of the proposed algorithm during the temporal period of interest was significantly improved relative to a feedback control applied at an equivalent low sampling interval. Robustness to noise analysis demonstrates the applicability of the algorithm in realistic situations.
胰岛素抵抗(IR)是现代最普遍的健康问题之一。定量胰岛素抵抗的金标准是高胰岛素-正常血糖钳夹技术。在测试过程中,通过静脉内输注调节的葡萄糖来维持恒定的血糖浓度。目前用于调节这种葡萄糖输注的控制算法基于反馈控制。这些模型需要频繁采集血液样本,并且只能部分地捕捉与葡萄糖调节相关的复杂性。在这里,我们提出了一种改进的钳夹控制算法,该算法的动机是葡萄糖动力学的随机性,同时使用评估 IR 所需的最少血液样本。基于人工神经网络模型的葡萄糖泵控制算法得到了开发。该系统使用从 62 个大鼠模型实验中收集的数据库进行训练,使用反向传播勒文贝格-马夸特优化。遗传算法用于优化网络拓扑和学习特征。与在等效低采样间隔下应用的反馈控制相比,所提出的算法在感兴趣的时间期间的预测值得到了显著提高。对噪声分析的稳健性证明了该算法在实际情况下的适用性。