The Experts below are selected from a list of 112500 Experts worldwide ranked by ideXlab platform

Roman Hovorka - One of the best experts on this subject based on the ideXlab platform.

  • New Closed-Loop insulin Systems
    Diabetologia, 2021
    Co-Authors: Charlotte K. Boughton, Roman Hovorka
    Abstract:

    Advances in diabetes technologies have enabled the development of automated Closed-Loop insulin delivery Systems. Several hybrid Closed-Loop Systems have been commercialised, reflecting rapid transition of this evolving technology from research into clinical practice, where it is gradually transforming the management of type 1 diabetes in children and adults. In this review we consider the supporting evidence in terms of glucose control and quality of life for presently available Closed-Loop Systems and those in development, including dual-hormone Closed-Loop Systems. We also comment on alternative ‘do-it-yourself’ Closed-Loop Systems. We remark on issues associated with clinical adoption of these approaches, including training provision, and consider limitations of presently available Closed-Loop Systems and areas for future enhancements to further improve outcomes and reduce the burden of diabetes management. Graphical abstract

  • Is an artificial pancreas (Closed‐Loop system) for Type 1 diabetes effective?
    Diabetic medicine : a journal of the British Diabetic Association, 2018
    Co-Authors: Charlotte K. Boughton, Roman Hovorka
    Abstract:

    The artificial pancreas is now a viable treatment option for people with Type 1 diabetes and has demonstrated improved glycaemic outcomes while also reducing the onus of self-management of Type 1 diabetes. Closed-Loop glucose-responsive insulin delivery guided by real-time sensor glucose readings can accommodate highly variable day-to-day insulin requirements and reduce the hypoglycaemia risk observed with tight glycaemic control in Type 1 diabetes. In 2011, the James Lind Alliance research priorities for Type 1 diabetes were produced and priority 3 was to establish whether an artificial pancreas (Closed-Loop system) for Type 1 diabetes is effective. This review focuses on the progress that has been made in the evolution of Closed-Loop Systems as an effective treatment option for Type 1 diabetes. Development of Closed-Loop Systems has advanced from feasibility evaluations in highly supervised settings over short periods, to clinical studies in free-living, unsupervised conditions lasting several months. The approval in the USA of the first hybrid Closed-Loop system (MiniMed® 670G pump, Medtronic, Northridge, CA, USA) in 2016 for use in Type 1 diabetes reflects these advancements. We discuss the evidence from clinical studies that Closed-Loop Systems are effective with improved glycaemic outcomes, reduced hypoglycaemia and had positive end-user acceptance in children, adolescents, adults and pregnant women with Type 1 diabetes. We also present the outlook for future Closed-Loop Systems in the treatment of Type 1 diabetes and identify the challenges facing the wide-spread clinical adoption of this technology.

  • Coming of age: the artificial pancreas for type 1 diabetes
    Diabetologia, 2016
    Co-Authors: Hood Thabit, Roman Hovorka
    Abstract:

    The artificial pancreas (Closed-Loop system) addresses the unmet clinical need for improved glucose control whilst reducing the burden of diabetes self-care in type 1 diabetes. Glucose-responsive insulin delivery above and below a preset insulin amount informed by sensor glucose readings differentiates Closed-Loop Systems from conventional, threshold-suspend and predictive-suspend insulin pump therapy. Insulin requirements in type 1 diabetes can vary between one-third–threefold on a daily basis. Closed-Loop Systems accommodate these variations and mitigate the risk of hypoglycaemia associated with tight glucose control. In this review we focus on the progress being made in the development and evaluation of Closed-Loop Systems in outpatient settings. Randomised transitional studies have shown feasibility and efficacy of Closed-Loop Systems under supervision or remote monitoring. Closed-Loop application during free-living, unsupervised conditions by children, adolescents and adults compared with sensor-augmented pumps have shown improved glucose outcomes, reduced hypoglycaemia and positive user acceptance. Innovative approaches to enhance Closed-Loop performance are discussed and we also present the outlook and strategies used to ease clinical adoption of Closed-Loop Systems.

  • Progress with Closed-Loop Systems in Type 1 Diabetes
    US Endocrinology, 2010
    Co-Authors: Lalantha Leelarathna, Roman Hovorka
    Abstract:

    Automated insulin delivery by means of a glucose-responsive Closed-Loop system has often been cited as the ‘holy grail’ of type 1 diabetes management. Reflecting the technological advances in interstitial glucose measurements and wider use of continuous glucose monitoring, recent research in Closed-Loop glucose control has focused on the subcutaneous route for glucose measurements and insulin delivery. The primary aim of such Systems is to keep blood glucose within the target range while minimizing the risk of hypoglycemia with minimal input from the user. This article examines recent developments in the field of interstitial glucose measurement, limitations of the current generation of devices and implications on the performance of Closed-Loop Systems. Clinical results and the advantages and disadvantages of different Closed-Loop configurations are summarized. Potential future advances in Closed-Loop Systems are highlighted.

  • Continuous glucose monitoring and Closed-Loop Systems
    Diabetic medicine : a journal of the British Diabetic Association, 2006
    Co-Authors: Roman Hovorka
    Abstract:

    Background  The last two decades have witnessed unprecedented technological progress in the development of continuous glucose sensors, resulting in the first generation of commercial glucose monitors. This has fuelled the development of prototypes of a Closed-Loop system based on the combination of a continuous monitor, a control algorithm, and an insulin pump. Method  A review of electromechanical Closed-Loop approaches is presented. This is followed by a review of existing prototypes and associated glucose sensors. A literature review was undertaken from 1960 to 2004. Results  Two main approaches exist. The extracorporeal s.c.–s.c. approach employs subcutaneous glucose monitoring and subcutaneous insulin delivery. The implantable i.v.–i.p. approach adopts intravenous sampling and intraperitoneal insulin delivery. Feasibility of both solutions has been demonstrated in small-scale laboratory studies using either the classical proportional–integral–derivative controller or a model predictive controller. Performance in the home setting has yet to be demonstrated. Conclusions  The glucose monitor remains the main limiting factor in the development of a commercially viable Closed-Loop system, as presently available monitors fail to demonstrate satisfactory characteristics in terms of reliability and/or accuracy. Regulatory issues are the second limiting factor. Closed-Loop Systems are likely to be used first by health-care professionals in controlled environments such as intensive care units.

Joe S Qin - One of the best experts on this subject based on the ideXlab platform.

Raghunathan Rengaswamy - One of the best experts on this subject based on the ideXlab platform.

  • On the Detection of Valve Nonlinearities in Otherwise Linear Closed-Loop Systems
    IEEE Transactions on Automatic Control, 2017
    Co-Authors: Tim Spinner, Babji Srinivasan, Raghunathan Rengaswamy
    Abstract:

    Previous works introduced control valve stiction detection and quantification methods for Closed-Loop Systems based on the identification of a Hammerstein element between the feedback controller and plant output signals. These techniques each rely upon the fact that the presence of valve stiction introduces nonlinearities in the Closed-Loop system, yet, little theoretical discussion has been presented which explains the conditions under which these methods will succeed or fail in properly detecting valve stiction. Therefore, the present work uses frequency domain analysis to provide a theoretical investigation of the identification of stiction in otherwise linear Closed-Loop Systems. In this way, the failure of Hammerstein stiction detection techniques to positively identify valve stiction in certain Systems in which it known to be present can be explained accordingly.

  • An integrated approach for oscillation diagnosis in linear Closed Loop Systems
    Chemical Engineering Research and Design, 2015
    Co-Authors: Babji Srinivasan, Ulaganathan Nallasivam, Raghunathan Rengaswamy
    Abstract:

    Abstract In industrial plants with non-oscillatory set points, oscillation detection and diagnosis are key steps to improve plant performance and safety. Oscillations in linear Closed Loop Systems can occur due to one or more of the following reasons: (i) changes in process/controller settings, (ii) stiction in control valves, (iii) external oscillatory disturbances, (iv) quantization effects, and (v) presence of saturation and hysteresis in Closed Loop Systems. Though there are techniques to address oscillation diagnosis problem, there are gray areas such as the identification of multiple sources that cause oscillations in the process output. In this work, this problem is addressed through the development of an algorithm to identify multiple sources of oscillations in Single Input Single Output (SISO) Loops. Further, an integrated approach to diagnose both single/multiple root causes in SISO Loops is presented. Simulation and industrial case studies are provided to show the applicability of the proposed algorithms.

Joseph Rinehart - One of the best experts on this subject based on the ideXlab platform.

  • feasibility of fully automated hypnosis analgesia and fluid management using 2 independent Closed Loop Systems during major vascular surgery a pilot study
    Anesthesia & Analgesia, 2019
    Co-Authors: Alexandre Joosten, Joseph Rinehart, Maxime Cannesson, Vincent Jame, Brenton Alexander, Thierry Chazot, Ngai Liu, Luc Barvais
    Abstract:

    Automated titration of intravenous anesthesia and analgesia using processed electroencephalography monitoring is no longer a novel concept. Closed-Loop control of fluid administration to provide goal-directed fluid therapy has also been increasingly described. However, simultaneously combining 2 independent Closed-Loop Systems together in patients undergoing major vascular surgery has not been previously detailed. The aim of this pilot study was to evaluate the clinical performance of fully automated hypnosis, analgesia, and fluid management using 2 independent Closed-Loop controllers in patients undergoing major vascular surgery before implementation within a larger study evaluating true patient outcomes.

  • Principles of pharmacologic hemodynamic management and Closed-Loop Systems.
    Best practice & research. Clinical anaesthesiology, 2014
    Co-Authors: Esther Banh, Wei Der Wu, Joseph Rinehart
    Abstract:

    Every day, physicians in critical-care settings are challenged with the hemodynamic management of patients with severe cardiovascular derangements. There is a potential role for Closed-Loop (automated) Systems to assist clinicians in managing these patients and growing interest in the possible applications. In this review, we discuss the basic principles of critical-care hemodynamic management and the Closed-Loop Systems that have been developed to help in this setting.

  • Closed Loop Systems and automation in the era of patients safety and perioperative medicine
    Journal of Clinical Monitoring and Computing, 2014
    Co-Authors: Maxime Cannesson, Joseph Rinehart
    Abstract:

    In 2013, General Motors, BMW, Mercedes-Benz, and Tesla all announced that they would bring self-driving cars to market for the general population before 2020 [1]. Some expectations suggest that by 2040, 75 % of all cars will be autonomous [2] and that this may reduce traffic accidents by a factor 10 [3]. In looking ahead at this possibility, three US states have already enacted laws addressing autonomous vehicles (California, Florida, and Nevada). We’ve come a long way since the model T first rolled off the assembly line. A moment’s reflection will show that automation has flourished in nearly every part of our daily lives. It has made aviation safer and more fuel efficient, modern life more comfortable with the widespread adoption of air conditioning, and has transformed the food industry with the invention of the refrigerator. The whole concept of life and homeostasis, described by Claude Bernard decades ago, relies essentially on feedback control; mammalian physiology may be the most sophisticated series of Closed Loop Systems to ever exist. In looking at our specialty, it is likely that forms of

  • review article Closed Loop Systems in anesthesia is there a potential for Closed Loop fluid management and hemodynamic optimization
    Anesthesia & Analgesia, 2012
    Co-Authors: Joseph Rinehart, Brenton Alexander, Ngai Liu, Maxime Cannesson
    Abstract:

    Closed-Loop (automated) controllers are encountered in all aspects of modern life in applications ranging from air-conditioning to spaceflight. Although these Systems are virtually ubiquitous, they are infrequently used in anesthesiology because of the complexity of physiologic Systems and the difficulty in obtaining reliable and valid feedback data from the patient. Despite these challenges, Closed-Loop Systems are being increasingly studied and improved for medical use. Two recent developments have made fluid administration a candidate for Closed-Loop control. First, the further description and development of dynamic predictors of fluid responsiveness provides a strong parameter for use as a control variable to guide fluid administration. Second, rapid advances in noninvasive monitoring of cardiac output and other hemodynamic variables make goal-directed therapy applicable for a wide range of patients in a variety of clinical care settings. In this article, we review the history of Closed-Loop controllers in clinical care, discuss the current understanding and limitations of the dynamic predictors of fluid responsiveness, and examine how these variables might be incorporated into a Closed-Loop fluid administration system.

Sue A Brown - One of the best experts on this subject based on the ideXlab platform.