Schlotthauer Gastón, Gamero Lucas G, Torres María E, Nicolini Guido A
Universidad Nacional de Entre Ríos, Facultad de Ingeniería, Bioingeniería, C.C. 47, Suc. 3, Paraná (3100), E.R. Argentina.
Med Eng Phys. 2006 Apr;28(3):240-50. doi: 10.1016/j.medengphy.2005.04.009. Epub 2005 Jun 16.
Patients with type I diabetes nearly always need therapy with insulin. The most desirable treatment would be to mimic the operation of a normal pancreas. In this work a patient affected with this pathology is modeled and identified with a neural network, and a control strategy known as Nonlinear Model Predictive Control is evaluated as an approach to command an insulin pump using the subcutaneous route. A method for dealing with the problems related with the multiple insulin injections simulation and a multilayer neural network identification of the patient model is presented. The controller performance of the proposed strategy is tested under charge and reference disturbances (setpoint). Simulating an initial blood glucose concentration of 250 mg/dl a stable value of 97.0 mg/dl was reached, with a minimum level of 76.1 mg/dl. The results of a simulated 50 g oral glucose tolerance test show a maximum glucose concentration of 142.6 mg/dl with an undershoot of 76.0 mg/dl. According to the simulation results, stable close-loop control is achieved and physiological levels are reached with reasonable delays, avoiding the undesirable low glucose levels. Further studies are needed in order to deal with noise and robustness aspects, issues which are out of the scope of this work.
I型糖尿病患者几乎总是需要胰岛素治疗。最理想的治疗方法是模拟正常胰腺的运作。在这项工作中，对一名患有这种病症的患者进行建模并用神经网络进行识别，并评估一种称为非线性模型预测控制的控制策略，作为一种通过皮下途径控制胰岛素泵的方法。提出了一种处理与多次胰岛素注射模拟相关问题的方法以及患者模型的多层神经网络识别方法。在所提出策略的控制器性能在负荷和参考干扰（设定点）下进行测试。模拟初始血糖浓度为250mg/dl时，达到了97.0mg/dl的稳定值，最低水平为76.1mg/dl。模拟的50g口服葡萄糖耐量试验结果显示最大葡萄糖浓度为142.6mg/dl，下冲量为76.0mg/dl。根据模拟结果，实现了稳定的闭环控制，并在合理延迟下达到了生理水平，避免了不良的低血糖水平。为了处理噪声和鲁棒性方面的问题，还需要进一步研究，这些问题超出了本工作的范围。
