A5089437051- Diabetes Management and Research
- Pancreatic function and diabetes
- Diabetes and associated disorders
- Diabetes Treatment and Management
- Hyperglycemia and glycemic control in critically ill and hospitalized patients
- Cardiovascular Function and Risk Factors
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Diet and metabolism studies
- Heart Rate Variability and Autonomic Control
- Diabetes Management and Education
- Formal Methods in Verification
- Mobile Health and mHealth Applications
- Health and Lifestyle Studies
- Receptor Mechanisms and Signaling
- Pharmacology and Obesity Treatment
- Advanced Control Systems Optimization
- Electrochemical sensors and biosensors
- Adipose Tissue and Metabolism
- Metabolism, Diabetes, and Cancer
- Cardiovascular Syncope and Autonomic Disorders
- Health Systems, Economic Evaluations, Quality of Life
- Ultrasound and Hyperthermia Applications
- Medication Adherence and Compliance
- Cardiovascular and exercise physiology
- Advanced Database Systems and Queries
University of Virginia
2016-2025
Charlottesville Medical Research
2020-2024
University of Virginia Health System
2005-2022
Diabetes Care Center
2022
Centre Hospitalier Universitaire de Montpellier
2021
Université de Montpellier
2015-2021
Stanford University
2020
Yale University
2020
Jaeb Center for Health Research
2020
National Institute of Diabetes and Digestive and Kidney Diseases
2020
Arguably, a minimally invasive system using subcutaneous (s.c.) continuous glucose monitoring (CGM) and s.c. insulin delivery via pump would be most feasible step to closed-loop control in type 1 diabetes mellitus (T1DM). Consequently, technology is focusing on developing an artificial pancreas algorithms link CGM with delivery. The future development of the will greatly accelerated by employing mathematical modeling computer simulation. Realistic simulation capable providing invaluable...
Recent studies have provided new insights into nonlinearities of insulin action in the hypoglycemic range and glucagon kinetics as it relates to response hypoglycemia. Based on these data, we developed a version UVA/PADOVA Type 1 Diabetes Simulator, which was submitted FDA 2013 (S2013). The model glucose hypoglycemia has been improved, implementing notion that insulin-dependent utilization increases nonlinearly when decreases below certain threshold. In addition, secretion models...
A closed-loop system of insulin delivery (also called an artificial pancreas) may improve glycemic outcomes in children with type 1 diabetes.
Integrated closed-loop control (CLC), combining continuous glucose monitoring (CGM) with insulin pump (continuous subcutaneous infusion [CSII]), known as artificial pancreas, can help optimize glycemic in diabetes. We present a fundamental modular concept for CLC design, illustrated by clinical studies involving 11 adolescents and 27 adults at the Universities of Virginia, Padova, Montpellier. tested two constructs: standard to range (sCTR), designed augment plus CGM preventing extreme...
Abstract The significant and growing global prevalence of diabetes continues to challenge people with (PwD), healthcare providers, payers. While maintaining near-normal glucose levels has been shown prevent or delay the progression long-term complications diabetes, a proportion PwD are not attaining their glycemic goals. During past 6 years, we have seen tremendous advances in automated insulin delivery (AID) technologies. Numerous randomized controlled trials real-world studies that use AID...
Background: A new version of the UVA/Padova Type 1 Diabetes (T1D) Simulator is presented which provides a more realistic testing scenario. The upgrades to previous simulator, was accepted by Food and Drug Administration in 2013, are described. Method: Intraday variability insulin sensitivity (S I ) has been modeled, based on clinical T1D data, accounting for both intra- intersubject daily S . Thus, time-varying distributions subject’s basal infusion insulin-to-carbohydrate ratio were...
The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the permitting non-adjunct CGM use) is a topic ongoing debate. Assessment this in clinical experiments virtually impossible because magnitude errors cannot be manipulated and related prospectively to outcomes.A combination archival data (parallel CGM, pump, self-monitoring blood [SMBG] records, meals 56 pump users with type 1 diabetes) silico was used "replay" real-life treatment...
Background: The t:slim X2™ insulin pump with Control-IQ® technology from Tandem Diabetes Care is an advanced hybrid closed-loop system that was first commercialized in the United States January 2020. Longitudinal glycemic outcomes associated real-world use of this have yet to be reported. Methods: A retrospective analysis Control-IQ users who uploaded data Tandem's t:connect® web application as February 11, 2021 performed. Users age ≥6 years, >2 weeks continuous glucose monitoring (CGM) pre-...
Background: A composite metric for the quality of glycemia from continuous glucose monitor (CGM) tracings could be useful assisting with basic clinical interpretation CGM data. Methods: We assembled a data set 14-day 225 insulin-treated adults diabetes. Using balanced incomplete block design, 330 clinicians who were highly experienced analysis and ranked best to worst glycemia. used principal component multiple regressions develop model predict clinician ranking based on seven standard...
Closed-loop control systems of insulin delivery may improve glycemic outcomes in young children with type 1 diabetes. The efficacy and safety initiating a closed-loop system virtually are unclear.In this 13-week, multicenter trial, we randomly assigned, 2:1 ratio, who were at least 2 years age but younger than 6 had diabetes to receive treatment or standard care that included either an pump multiple daily injections plus continuous glucose monitor. primary outcome was the percentage time...
Advancements in subcutaneous continuous glucose monitoring and insulin delivery are stimulating the development of a minimally invasive artificial pancreas that facilitates optimal glycemic regulation diabetes. The key component such system is blood controller for which different design strategies have been investigated literature. In order to evaluate compare efficacy various algorithms, several performance indices proposed.A new tool-control-variability grid analysis (CVGA)-for measuring...
In 2008-2009, the first multinational study was completed comparing closed-loop control (artificial pancreas) to state-of-the-art open-loop therapy in adults with type 1 diabetes mellitus (T1DM).The design of algorithm done entirely silico, i.e., using computer simulation experiments N=300 synthetic "subjects" T1DM instead traditional animal trials. The clinical recruited 20 at Universities Virginia (11); Padova, Italy (6); and Montpellier, France (3). Open-loop admission scheduled 3-4 weeks...
Background: Continuous glucose monitors (CGMs) collect detailed blood (BG) time series, which carry significant information about the dynamics of BG fluctuations. In contrast, methods for analysis CGM data remain those developed infrequent self-monitoring. As a result, important temporal structure is lost during translation raw sensor readings into clinically interpretable statistics and images. Methods: The following mathematical are introduced field interpretation: (1) rate change; (2)...
Background: Recent progress in the development of clinically accurate continuous glucose monitors (CGMs), automated insulin infusion pumps, and control algorithms for calculating doses from CGM data have enabled prototypes subcutaneous closed-loop systems controlling blood (BG) levels type 1 diabetes. The use a new personalized model predictive (MPC) algorithm to determine achieve maintain BG between 70 140 mg/dl overnight postprandial is presented. Methods: Eight adults with diabetes were...
Continuous glucose monitors (CGMs) collect a detailed time series of consecutive observations the underlying process fluctuations. To some extent, however, high temporal resolution data is accompanied by increased probability error in any single point. Due to both physiological and technical reasons, structure these errors complex their analysis not straightforward. In this article, we describe methods needed obtain description sensor that enough for simulation.Data were provided Abbott...
OBJECTIVE To evaluate the feasibility of a wearable artificial pancreas system, Diabetes Assistant (DiAs), which uses smart phone as closed-loop control platform. RESEARCH DESIGN AND METHODS Twenty patients with type 1 diabetes were enrolled at Universities Padova, Montpellier, and Virginia Sansum Research Institute. Each trial continued for 42 h. The United States studies conducted entirely in outpatient setting (e.g., hotel or guest house); Italy France hybrid hospital–hotel admissions. A...
OBJECTIVE We estimate the effect size of hypoglycemia risk reduction on closed-loop control (CLC) versus open-loop (OL) sensor-augmented insulin pump therapy in supervised outpatient setting. RESEARCH DESIGN AND METHODS Twenty patients with type 1 diabetes initiated study at Universities Virginia, Padova, and Montpellier Sansum Diabetes Research Institute; 18 completed entire protocol. Each patient participated two 40-h sessions, CLC OL, randomized order. Sensor (Dexcom G4) (Tandem t:slim)...
Modularity plays a key role in many engineering systems, allowing for plug-and-play integration of components, enhancing flexibility and adaptability, facilitating standardization. In the control diabetes, i.e., so-called "artificial pancreas," modularity allows step-wise introduction (and regulatory approval for) algorithmic starting with subsystems assured patient safety followed by higher layer components that serve to modify patient's basal rate real time. this paper, we introduce...
Intense exercise is a major challenge to the management of type 1 diabetes (T1D). Closed-loop control (CLC) systems (artificial pancreas) improve glycemic during limited intensity and short duration physical activity (PA). However, CLC has not been tested extended vigorous outdoor common among adolescents.Skiing presents unique metabolic challenges: intense prolonged PA, cold, altitude, stress/fear/excitement. In randomized controlled trial, 32 adolescents with T1D (ages 10-16 years)...
Background: In the past few years, artificial pancreas—the commonly accepted term for closed-loop control (CLC) of blood glucose in diabetes—has become a hot topic research and technology development. summer 2014, we initiated 6-month trial evaluating safety 24/7 CLC during free-living conditions. Research Design Methods: Following an initial 1-month Phase 1, 14 individuals (10 males/4 females) with type 1 diabetes at three clinical centers United States one Italy continued 5-month 2, which...
Background: We present a clinical trial establishing the feasibility of control-to-range (CTR) closed-loop system informed by heart rate (HR) and assess effect HR information added to CTR on risk for hypoglycemia during after exercise. Subjects Methods: Twelve subjects with type 1 diabetes (five men, seven women; weight, 68.9±3.1 kg; age, 38±3.3 years; glycated hemoglobin, 6.9±0.2%) participated in randomized crossover comparing versus CTR+HR two 26-h admissions, each including 30 min mild...
To determine the safety and efficacy of an automated unified system (USS) in providing overnight closed-loop (OCL) control children adolescents with type 1 diabetes attending summer camps.The Diabetes Assistant (DIAS) USS used Dexcom G4 Platinum glucose sensor (Dexcom) t:slim insulin pump (Tandem Care). An initial inpatient study was completed for 12 participants to evaluate safety. For main camp study, 20 were randomized either OCL or sensor-augmented therapy (control conditions) per night...