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In this paper a proposal is made in order to avoid hypoglycemic events in glycemic closed-loop control. Within the development of closed-loop glucose controllers (referred to as “Artificial Pancreas”), one of the major risks is the insulin induced hypoglycemia that can be produced due to controller overreaction. Here, a supervisory methodology on a main controller is proposed to avoid excessive rates...
Subjects suffering from Type 1 diabetes mellitus need to constantly receive insulin injections. To improve their life quality, a desirable solution is represented by the implementation of an artificial pancreas. In this paper we move a preliminary step towards this goal. Namely, we work at the knowledge base for such a device. One of the main problems is to estimate the Blood Glucose (BG) values,...
In this work we consider the local sampled-data stabilization of human plasma glycemia. It is proved theoretically that the implementation by sampling and holding, for suitable small sampling period, of a state feedback which is shown in the literature to yield local stabilization when applied in a continuous time basis, yields local practical stabilization, with arbitrarily small final target ball...
The focus of this paper is on the characterization of the uncertainties in the evolving states of a diabetic model, to permit a study of the impact of the time interval between insulin bolusing and meal initiation on hypo- and hyperglycemic events. A polynomial chaos based approach is used to characterize the independent uncertainties in the initial condition and meal size. Galerkin projection of...
This study compares recent Control Algorithms of Artificial Pancreas; Proportional-Integral-Derivative (PID) and Model Predictive Control (MPC). PID controller is applicable to many controls problem, often performs satisfactorily and eliminates the offset. However, it can perform poorly in some applications, does not in general provide optimal control and is unstable with integral control. On the...
This paper describes the communication challenges associated with implementation of a multi-sensor artificial pancreas system on a smartphone device and presents solutions for potential communication losses. In particular, a standardized development framework on an Android device supporting multiple sensors is introduced in order to facilitate a multi-variable closed-loop AP algorithm. Package losses...
In healthy individuals, blood glucose concentrations are tightly controlled by the pancreas through the secretion of two hormones, insulin and glucagon. Insulin is secreted by pancreatic beta cells and reduces blood glucose concentrations, and glucagon is secreted by pancreatic alpha cells and increases blood glucose concentrations [1], [2]. In type 1 diabetes, insulin secretion is lost due to the...
This paper proposes a novel fault-tolerant human-implantable artificial pancreas integrated circuit achieving high dependability. The main objective of this work is to provide fault-tolerance to this safety-critical application and extend its lifetime similar to existing techniques such as Dual Modular Redundancy (DMR) and Triple Modular Redundancy (TMR). The key idea is to explore a hybrid-substrate...
In Type 1 Diabetes Mellitus (T1DM), external administration of insulin is needed due to absolute deficiency of insulin production in pancreas. Model reference adaptive control (MRAC) is considered because of possibility of time varying parameters of insulin-glucose system. T1DM simulator is individualized by parameter identification of nonlinear model on the basis of continuous glucose monitoring...
Insulin pump is a device for continuous subcutaneous infusion of insulin. Insulin pump is reliable, small, light, and is becoming more and more sophisticated. Insulin pump can control the blood glucose more steadily and reduce the complications mostly. In this paper, an intelligent insulin pump is designed. It can infuse the insulin precisely using a stepper motor. The device adopts Chinese-displaying...
We propose an optimisation method for parameter setting of a MRAC-based adaptive controller of blood glucose (glycemia) in the human body. The glycemia dynamics is a complex process, which can be controlled by external bio-cybernetic devices as Artificial Pancreas. The artificial pancreas consists of glycemia sensor, controller and insulin pump. Such systems are using complex algorithms with many...
The design of a Model Predictive Control (MPC) strategy for the closed-loop operation of an Artificial Pancreas (AP) to treat type 1 diabetes mellitus is considered. The contribution of this paper is to propose a velocity-weighting mechanism, within an MPC problem's cost function, that facilitates penalizing predicted hyperglycemic blood-glucose excursions based on the predicted blood-glucose levels'...
The aim of this work is the evaluation of two state-estimators in a glucose estimation in a diabetes control setting. Technological solutions leading to the design of an artificial pancreas heavily rely on the availability of glucose subcutaneously. Practical solutions for these measurements often suffer from significant time-delays and direct measurements of the required states is often impossible...
Individuals with type 1 Diabetes Mellitus (T1DM) must inject insulin to regulate blood glucose concentrations. The artificial pancreas project seeks to automate the delivery of insulin in response to continuous glucose monitor (sensor) signals. Most medical devices must go through extensive animal studies before human studies can be conducted, but regulatory authorities (FDA, in the United States)...
A closed-loop artificial pancreas has been the “Holy Grail” of efforts to improve the medical care and lifestyle of individuals with type 1 diabetes. In this talk we provide an overview of research activities related to an artificial pancreas, beginning with a history of glucose sensing technologies, insulin delivery systems, and algorithms to connect sensor signals and insulin delivery rates. Current...
Diabetes Mellitus is a widespread chronic disease that affects more than 220 million people worldwide. We have been developing an implantable artificial pancreas that can regulate blood glucose level by delivering appropriate dosage of insulin when necessary. By sensing the blood glucose from and injecting insulin directly into the vein, the implantable device aims to remove delays from subcutaneous...
Good control of glucose in diabetes requires minimisation of high and low blood glucose excursions and is critical to reducing the incidence of complications and improving quality of life. A closed-loop insulin delivery system consisting of a glucose sensor, a controller and an insulin pump, has the potential to achieve this and be life changing. We present the Bio-inspired Artificial Pancreas (BiAP),...
The development of control systems for medical applications poses particular challenges, distinct from the applications in electrical engineering, mechanical engineering, and chemical engineering. Physiological systems involve a myriad of networked subsystems, with multiple feedforward and feedback loops, and interactions at many levels. There is both interpatient dynamic variability as well as intrapatient...
The design of a Model Predictive Control (MPC) strategy for the closed-loop operation of an Artificial Pancreas (AP) for treating Type 1 Diabetes Mellitus (T1DM) is considered in this paper. The contribution of this paper is to propose two changes to the usual structure of the MPC problems typically considered for control of an AP. The first proposed change is to replace the symmetric, quadratic input...
Diabetes mellitus is a serious and widespread disease currently affecting 25.8 million people in the United States. Its treatments including exercise, diet, hypoglycemic pills, and insulin often are not sufficient to mitigate the symptoms of the disease or prevent its progression over time. An artificial pancreas capable of continuously monitoring and adjusting blood glucose levels through closed-loop...
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