scholarly journals Advanced Closed-Loop Control System Improves Postprandial Glycemic Control Compared With a Hybrid Closed-Loop System Following Unannounced Meal

2021 ◽  
Author(s):  
Jose Garcia-Tirado ◽  
Jenny L. Diaz ◽  
Rebeca Esquivel-Zuniga ◽  
Chaitanya L. K. Koravi ◽  
John P. Corbett ◽  
...  
Keyword(s):  
Glycemic Control ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Carbohydrate Ingestion ◽  
Loop Control ◽  
Percent Time ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Time In Range ◽  
Design And Methods

<b>Objective:</b> Meals are a major hurdle to glycemic control in type 1 diabetes (T1D). Our objective was to test a fully-automated closed-loop control (CLC) system in the absence of announcement of carbohydrate ingestion among adolescents with T1D, who are known to commonly omit meal announcement. <p><b>Research Design and Methods: </b>Eighteen adolescents with T1D (age 15.6±1.7 years; HbA1c 7.4%±1.5; 9F/9M) participated in a randomized crossover clinical trial comparing our legacy hybrid CLC system (USS-Virginia) with a novel fully-automated CLC system (RocketAP), during two 46h supervised admissions (each with one announced and one unannounced dinner), following 2 weeks of data collection. Primary outcome was the percent time-in-range 70-180mg/dL (TIR) following the unannounced meal, with secondary outcomes related to additional CGM-based metrics.</p> <p><b>Results: </b> Both TIR and time-in-tight-range 70-140mg/dL (TTR) were significantly higher using RocketAP than using USS-Virginia during the 6h following the unannounced meal (83% [64-93] vs. 53% [40-71]; p=0.004 and 49% [41-59] vs. 27% [22-36]; p=0.002, respectively), primarily driven by reduced time-above-range (TAR >180mg/dL 17% [1.3-34] vs. 47% [28-60]), with no increase in time-below-range (TBR <70mg/dL 0% median for both). RocketAP also improved control following the announced meal (mean difference TBR: -0.7%, TIR: +7%, TTR: +6%), overall (TIR: +5%, TAR: -5%, TTR: +8%), and overnight (TIR: +7%, TTR: +19%, TAR: -5%). RocketAP delivered less insulin overall (78±23U vs. 85±20U, p=0.01)</p> <p><b>Conclusions:</b> A new fully-automated CLC system with automatic prandial dosing was proven to be safe and feasible and outperformed our legacy USS-Virginia in an adolescent population with and without meal announcement.</p>

scholarly journals Advanced Closed Loop Control System Improves Postprandial Glycemic Control Compared to a Hybrid Closed-Loop System Following Unannounced Meal

2021 ◽  
Author(s):  
Jose Garcia-Tirado ◽  
Jenny L. Diaz ◽  
Rebeca Esquivel-Zuniga ◽  
Chaitanya L. K. Koravi ◽  
John P. Corbett ◽  
...  
Keyword(s):  
Glycemic Control ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Carbohydrate Ingestion ◽  
Loop Control ◽  
Percent Time ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Time In Range ◽  
Design And Methods

<b>Objective:</b> Meals are a major hurdle to glycemic control in type 1 diabetes (T1D). Our objective was to test a fully-automated closed-loop control (CLC) system in the absence of announcement of carbohydrate ingestion among adolescents with T1D, who are known to commonly omit meal announcement. <p><b>Research Design and Methods: </b>Eighteen adolescents with T1D (age 15.6±1.7 years; HbA1c 7.4%±1.5; 9F/9M) participated in a randomized crossover clinical trial comparing our legacy hybrid CLC system (USS-Virginia) with a novel fully-automated CLC system (RocketAP), during two 46h supervised admissions (each with one announced and one unannounced dinner), following 2 weeks of data collection. Primary outcome was the percent time-in-range 70-180mg/dL (TIR) following the unannounced meal, with secondary outcomes related to additional CGM-based metrics.</p> <p><b>Results: </b> Both TIR and time-in-tight-range 70-140mg/dL (TTR) were significantly higher using RocketAP than using USS-Virginia during the 6h following the unannounced meal (83% [64-93] vs. 53% [40-71]; p=0.004 and 49% [41-59] vs. 27% [22-36]; p=0.002, respectively), primarily driven by reduced time-above-range (TAR >180mg/dL 17% [1.3-34] vs. 47% [28-60]), with no increase in time-below-range (TBR <70mg/dL 0% median for both). RocketAP also improved control following the announced meal (mean difference TBR: -0.7%, TIR: +7%, TTR: +6%), overall (TIR: +5%, TAR: -5%, TTR: +8%), and overnight (TIR: +7%, TTR: +19%, TAR: -5%). RocketAP delivered less insulin overall (78±23U vs. 85±20U, p=0.01)</p> <p><b>Conclusions:</b> A new fully-automated CLC system with automatic prandial dosing was proven to be safe and feasible and outperformed our legacy USS-Virginia in an adolescent population with and without meal announcement.</p>

scholarly journals Advanced Closed-Loop Control System Improves Postprandial Glycemic Control Compared With a Hybrid Closed-Loop System Following Unannounced Meal

2021 ◽  
Author(s):  
Jose Garcia-Tirado ◽  
Jenny L. Diaz ◽  
Rebeca Esquivel-Zuniga ◽  
Chaitanya L. K. Koravi ◽  
John P. Corbett ◽  
...  
Keyword(s):  
Glycemic Control ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Carbohydrate Ingestion ◽  
Loop Control ◽  
Percent Time ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Time In Range ◽  
Design And Methods

<b>Objective:</b> Meals are a major hurdle to glycemic control in type 1 diabetes (T1D). Our objective was to test a fully-automated closed-loop control (CLC) system in the absence of announcement of carbohydrate ingestion among adolescents with T1D, who are known to commonly omit meal announcement. <p><b>Research Design and Methods: </b>Eighteen adolescents with T1D (age 15.6±1.7 years; HbA1c 7.4%±1.5; 9F/9M) participated in a randomized crossover clinical trial comparing our legacy hybrid CLC system (USS-Virginia) with a novel fully-automated CLC system (RocketAP), during two 46h supervised admissions (each with one announced and one unannounced dinner), following 2 weeks of data collection. Primary outcome was the percent time-in-range 70-180mg/dL (TIR) following the unannounced meal, with secondary outcomes related to additional CGM-based metrics.</p> <p><b>Results: </b> Both TIR and time-in-tight-range 70-140mg/dL (TTR) were significantly higher using RocketAP than using USS-Virginia during the 6h following the unannounced meal (83% [64-93] vs. 53% [40-71]; p=0.004 and 49% [41-59] vs. 27% [22-36]; p=0.002, respectively), primarily driven by reduced time-above-range (TAR >180mg/dL 17% [1.3-34] vs. 47% [28-60]), with no increase in time-below-range (TBR <70mg/dL 0% median for both). RocketAP also improved control following the announced meal (mean difference TBR: -0.7%, TIR: +7%, TTR: +6%), overall (TIR: +5%, TAR: -5%, TTR: +8%), and overnight (TIR: +7%, TTR: +19%, TAR: -5%). RocketAP delivered less insulin overall (78±23U vs. 85±20U, p=0.01)</p> <p><b>Conclusions:</b> A new fully-automated CLC system with automatic prandial dosing was proven to be safe and feasible and outperformed our legacy USS-Virginia in an adolescent population with and without meal announcement.</p>

scholarly journals Extended Use of the Control-IQ Closed-Loop Control System in Children With Type 1 Diabetes

2020 ◽  
Author(s):  
Lauren G. Kanapka ◽  
R. Paul Wadwa ◽  
Marc D. Breton ◽  
Katrina J. Ruedy ◽  
Laya Ekhlaspour ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Severe Hypoglycemia ◽  
Substantial Improvement ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Design And Methods

<b>Objective: </b>To further evaluate the safety and efficacy of the Control-IQ closed loop control (CLC) system in children with type 1 diabetes.<b></b> <p><b>Research Design and Methods: </b>Following a 16-week randomized clinical trial (RCT) comparing CLC with sensor augmented pump (SAP) therapy in 101 children age 6 to 13 years old with type 1 diabetes, 22 participants in the SAP group initiated use of the CLC system (referred to as SAP-CLC cohort), and 78 participants in the CLC group continued use of CLC (CLC-CLC cohort) for 12 weeks. </p> <p><b>Results: </b>In the SAP-CLC cohort, mean percentage of time in range 70-180 mg/dL (TIR) increased from 55±13% using SAP during the RCT to 65±10% using CLC (P<0.001), with 36% of the cohort achieving TIR >70% plus time <54 mg/dL <1% compared with 14% when using SAP (P=0.03). Substantial improvement in TIR was seen after the first day of CLC. Time <70 mg/dL decreased from 1.80% to 1.34% (P<0.001). In the CLC-CLC cohort, mean TIR increased from 53±17% pre-randomization to 67±10% during the RCT and remained reasonably stable at 66±10% through the 12-weeks post-RCT. There were no episodes of diabetic ketoacidosis or severe hypoglycemia in either cohort.</p> <p><b>Conclusions: </b> This further evaluation of the Control-IQ CLC system supports the findings of the preceding RCT that use of a closed-loop system can safely improve glycemic control in children 6 to 13 years old with type 1 diabetes from the first day of use and demonstrates that these improvements can be sustained through 28 weeks of use. </p>

Predictors of Time-in-Range (70–180 mg/dL) Achieved Using a Closed-Loop Control System

2021 ◽  
Author(s):  
Melissa J. Schoelwer ◽  
Lauren G. Kanapka ◽  
R. Paul Wadwa ◽  
Marc D. Breton ◽  
Katrina J. Ruedy ◽  
...  
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Time In Range

scholarly journals Extended Use of the Control-IQ Closed-Loop Control System in Children With Type 1 Diabetes

2020 ◽  
Author(s):  
Lauren G. Kanapka ◽  
R. Paul Wadwa ◽  
Marc D. Breton ◽  
Katrina J. Ruedy ◽  
Laya Ekhlaspour ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Severe Hypoglycemia ◽  
Substantial Improvement ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Design And Methods

<b>Objective: </b>To further evaluate the safety and efficacy of the Control-IQ closed loop control (CLC) system in children with type 1 diabetes.<b></b> <p><b>Research Design and Methods: </b>Following a 16-week randomized clinical trial (RCT) comparing CLC with sensor augmented pump (SAP) therapy in 101 children age 6 to 13 years old with type 1 diabetes, 22 participants in the SAP group initiated use of the CLC system (referred to as SAP-CLC cohort), and 78 participants in the CLC group continued use of CLC (CLC-CLC cohort) for 12 weeks. </p> <p><b>Results: </b>In the SAP-CLC cohort, mean percentage of time in range 70-180 mg/dL (TIR) increased from 55±13% using SAP during the RCT to 65±10% using CLC (P<0.001), with 36% of the cohort achieving TIR >70% plus time <54 mg/dL <1% compared with 14% when using SAP (P=0.03). Substantial improvement in TIR was seen after the first day of CLC. Time <70 mg/dL decreased from 1.80% to 1.34% (P<0.001). In the CLC-CLC cohort, mean TIR increased from 53±17% pre-randomization to 67±10% during the RCT and remained reasonably stable at 66±10% through the 12-weeks post-RCT. There were no episodes of diabetic ketoacidosis or severe hypoglycemia in either cohort.</p> <p><b>Conclusions: </b> This further evaluation of the Control-IQ CLC system supports the findings of the preceding RCT that use of a closed-loop system can safely improve glycemic control in children 6 to 13 years old with type 1 diabetes from the first day of use and demonstrates that these improvements can be sustained through 28 weeks of use. </p>

scholarly journals Closed-loop control system for well-defined oxygen supply in micro-physiological systems

2017 ◽  
Vol 3 (2) ◽  
pp. 363-366
Author(s):  
Tobias Steege ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Andrés Fabían Lasagni ◽  
Frank Sonntag
Keyword(s):  
Control System ◽  
Oxygen Supply ◽  
Closed Loop ◽  
Microfluidic System ◽  
Closed Loop Control ◽  
Loop Control ◽  
Cell Vitality ◽  
Closed Loop Control System ◽  
Loop Control System

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

2019 ◽  
Vol 234 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.

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