47 research outputs found

    Intelligent Control with Artificial Neural Networks for Automated Insulin Delivery Systems

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    Type 1 diabetes mellitus is a disease that affects millions of people around the world. Recent progress in embedded devices has allowed the development of artificial pancreas that can pump insulin subcutaneously to automatically regulate blood glucose levels in diabetic patients. In this work, a Lyapunov-based intelligent controller using artificial neural networks is proposed for application in automated insulin delivery systems. The adoption of an adaptive radial basis function network within the control scheme allows regulation of blood glucose levels without the need for a dynamic model of the system. The proposed model-free approach does not require the patient to inform when they are going to have a meal and is able to deal with inter- and intrapatient variability. To ensure safe operating conditions, the stability of the control law is rigorously addressed through a Lyapunov-like analysis. In silico analysis using virtual patients are provided to demonstrate the effectiveness of the proposed control scheme, showing its ability to maintain normoglycemia in patients with type 1 diabetes mellitus. Three different scenarios were considered: one long- and two short-term simulation studies. In the short-term analyses, 20 virtual patients were simulated for a period of 7 days, with and without prior basal therapy, while in the long-term simulation, 1 virtual patient was assessed over 63 days. The results show that the proposed approach was able to guarantee a time in the range above 95% for the target glycemia in all scenarios studied, which is in fact well above the desirable 70%. Even in the long-term analysis, the intelligent control scheme was able to keep blood glucose metrics within clinical care standards: mean blood glucose of 119.59 mg/dL with standard deviation of 32.02 mg/dL and coefficient of variation of 26.78%, all below the respective reference values.</p

    Receding Horizon Control of Type 1 Diabetes Mellitus by Using Nonlinear Programming

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    Receding Horizon Controllers are one of the mostly used advanced control solutions in the industry. By utilizing their possibilities we are able to predict the possible future behavior of our system; moreover, we are able to intervene in its operation as well. In this paper we have investigated the possibilities of the design of a Receding Horizon Controller by using Nonlinear Programming. We have applied the developed solution in order to control Type 1 Diabetes Mellitus. The nonlinear optimization task was solved by the Generalized Reduced Gradient method. In order to investigate the performance of our solution two scenarios were examined. In the first scenario, we applied “soft” disturbance—namely, smaller amount of external carbohydrate—in order to be sure that the proposed method operates well and the solution that appeared through optimization is acceptable. In the second scenario, we have used “unfavorable” disturbance signal—a highly oscillating external excitation with cyclic peaks. We have found that the performance of the realized controller was satisfactory and it was able to keep the blood glucose level in the desired healthy range—by considering the restrictions for the usable control action

    Mastering Endo-Laparoscopic and Thoracoscopic Surgery

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    This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents

    Mastering Endo-Laparoscopic and Thoracoscopic Surgery

    Get PDF
    This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents

    Mechanobiology of the basement membrane

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    The microenvironment (ME) of epithelial cells lies at the heart of the function and architecture of most organs. Epithelial cells define the function of the organ. The stroma ensures that the highly specialized MEs within an organ are correctly assembled. A key organising element of the ME is the rather stiff basement membrane (BM), which is the structural part that passively, through its mechanical rigidity and actively through signalling via its components separates the luminal epithelia from the stromal fibroblasts, creating and maintaining tissue polarity to ensure proper function of the organ. The primary goal of this work is to find universal features of the BM and epithelial cells across organs and to understand how the cells mechanobiology is influenced by the BM. The cells mechanobiology is defined by the interaction of the cells integrins with the BMs proteins, notably laminin, perlecan and collagen IV. Disturbing either of the interaction partners quickly leads to distinct new mechanobiological phenotypes of the epithelial cells, without the need for genetic modifications. Further, I will show that changes to the BM by cancer cells are a key step in forming invasive carcinomas which goes together with recent research that shows that the mechanics of epithelial cells and extra-cellular matrix (ECM) are fundamentally altered. In the case of BMs and the extracellular matrix in general, the mechanical properties are governed by the type of fibres and the state of cross-linking. The only tool available for characterizing this physical properties of cells and ECM components under physiological conditions is the atomic force microscope. It gives insight about stiffness and E-modulus on a sub-micrometer scale and is very sensitive to changes in the low Pascal-range. The combination with confocal light microscopy allows one to correlate changes in ridigity to cytoskeletion localisation, to understand what part of the cytoskeleton defines the mechanics and how this is changed by disturbing cell-BM interactions

    Advanced Sensing and Image Processing Techniques for Healthcare Applications

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    This Special Issue aims to attract the latest research and findings in the design, development and experimentation of healthcare-related technologies. This includes, but is not limited to, using novel sensing, imaging, data processing, machine learning, and artificially intelligent devices and algorithms to assist/monitor the elderly, patients, and the disabled population
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