Contact Us  I  Home 

T1DM Services

The First Computer Tool Accepted by the FDA as a Substitute for Animal Trials in Pre-clinical Testing

 

The UVa/Padova T1DM Metabolic Simulator is a computer simulator of the human metabolic system based on the Meal Model of glucose-insulin dynamics [1] [2] [3]. In January 2008, the full version of the UVa/Padova Metabolic Simulator became the first computer tool accepted by the FDA as a substitute for animal trials in the pre-clinical testing of certain control strategies in T1DM.  The Distributed/Training Version of The UVa/Padova T1DM Metabolic Simulator is now licensed to The Epsilon Group for distribution. Epsilon distributes and supports the T1DM training version with the aim to simplify access to the model and to training in the use of the T1DM Metabolic Simulator for the wider diabetes research community.

 

The UVa/Padova T1DM Metabolic Simulator, implemented in Simulink®/MATLAB®, uses a well-defined set of interfaces for testing of closed loop user-defined treatment scenarios in the Simulink® controller block with user prescribed meal profiles.  Insulin pump injection parameters and realistic sensor noise are reflected for several devices in the simulator.

 

Realistic computer simulations can provide invaluable information about the safety and the limitations of proposed glucose control strategies, can guide and focus the emphasis of clinical studies, and can rule-out ineffective scenarios and strategies prior to human use.  The simulator gives researchers a validated tool to assess results of a proposed closed loop system early in the development phase of treatment strategies and/or proposed closed loop controls and assist the researcher in choosing the direction of continuing research.

Features
 

In Silico Population

  • 30 in silico subjects

  • 10 Adults

  • 10 Adolescents

  • 10 Children

Basic User-Defined Simulation Input

  • Meal profiles

  • Insulin Treatment

  • Time of simulation and regulation

  • Control Law definition*

* several standard controller blocks are provided; users may develop simple to complex closed loop controls that may include manual insulin injections in addition to insulin dosing controlled by a user-defined algorithm.

In Silico Subject-Specific data available to tune treatment options

  • Age

  • Body Weight (kg)

  • ‘Optimal’ subject-specific basal rate (U/hr)

  • ‘Optimal’ subject-specific carbohydrate ratio (CR, g/U)

  • ‘Optimal’ subject-specific maximum drop (MD, mg/dl per Unit insulin)

  • Total Daily Insulin, a measure of insulin sensitivity (TDI, U/day)

  • Metabolic Testing results may be simulated for individual subjects and incorporated
    into treatment plans prior to the regulated model run

Simulation Output (per subject)

  • Blood Glucose (BG) values (mg/dl per minute)

  • Simulated sensor BG readings (mg/dl per minute)

  • Simulated Time
    Insulin Injections (pmol/minute)

  • CHO – carbohydrate meal dose and timing

  • Subject Identification

  • Subject system states

* Additional model output may be collected as implemented by the user

 

Population & “Per Subject” Analysis

  • Creates user selected population or “per subject” Glucose Control-relevant plots.

    • BG Trace

      • Traditional plot of blood glucose data versus time

    • BG density function

      • Probability distribution of BG values with calculated probabilities of values below/within/above a preset target range

    • Glucose Risk Trace

      • Includes fluctuations of LBGI (plotted as < zero) and HBGI (plotted as > zero) computed hourly; emphasizes large glucose excursions and suppresses fluctuations within target to highlight essential BG variances

    • Aggregated BG Trace

      • Corresponds to time spent below/within/above a preset target range

    • Histogram of BG rate of change

      • Represents the spread and range of glucose transitions (mg/dl per minute)

    • Poincaré Plot

      • Spread of data indicates system (subject) stability; more widespread data data points are associated with unstable diabetes and rapid glucose fluctuations

    • Control Variability Grid Analysis (CVGA)

      • Event-based analysis representing the effectiveness of glycemic control
         

  • Creates user selected “per subject” Glucose Control-relevant outcomes that
    can be imported into Excel to create a Safety & Efficacy Table for the population:

    • Mean blood glucose reading

    • Mean pre-meal and post-meal blood glucose values

    • Per cent time in Severe Hypoglycemia (BG ≤ 50 mg/dL),

    • Per cent time in Hypoglycemia (BG ≤ 70 mg/dL) (user-selected low target)

    • Per cent time in Euglycemia (70 mg/dL < BG ≤ 180 mg/dL) (user-selected target zone)

    • Per cent time in Hyperglycemia (BG > 180 mg/dL) (user-selected high target)

    • Per cent time in Severe Hyperglycemia (BG > 300 mg/dL)

    • Low BG Index (LBGI)

    • High BG Index (HBGI)

    • BG Risk Index (BGRI)

    • SD of BG Rate of Change

Documentation

  • Comprehensive user guide

  • Technical Support and Training

System Requirements

  • PC with Windows7® or Windows XP® (SP2 or later)

  • 1 Gb of Ram

  • 10 Mb free space on hard disk

Software Requirements

  • Matlab® 2009b (or later) (32-bit or 64-bit) with Simulink® and the Curve Fitting Toolbox™

  • Parallel Computing Toolbox™ required for multi-core processing (not required to run model)

 How To Order

References

  1. Chiarra Dalla Man, Robert A. Rizza, and Claudio Cobelli Meal Simulation Model of the Glucose-Insulin System IEEE Transactions of Biomedical Engineering, 2007 54(10): 1740-1749

  2. Dalla Man C, Camilleri M, Cobelli C. A system model of oral glucose absorption: validation on gold standard data. IEEE Trans Biomed Eng. 2006 53(12): 2472-2478.

  3. Marc Breton, Ph.D. and Boris Kovatchev, Ph.D. Analysis, Modeling, and Simulation of the Accuracy of Continuous Glucose Sensors J Diabetes Sci Technol 2008; 2(5): 853-862

  4. Boris P. Kovatchev, Ph.D., Marc D. Breton, Ph.D., Chiarra Dalla Man, Ph.D., and Claudio Cobelli, Ph.D. In Silico Preclinical Trials: A Proof of Concept in Closed-Loop Control of Type 1 Diabetes J. Diabetes Sci Technol 2009 3(1): 44-45

  5. Stephen D. Patek, PhD., Wayne Bequette, PhD., Marc Breton, PhD., Bruce A. Buckingham, M.D., Eyal Dassau, PhD., Francis J. Doyle III, PhD., John Lum, Lalo Magni, PhD., and Howard Zisser, M.D. In Silico Preclinical Trials: Methodology and Engineering Guide to Closed-Loop Control in Type I Diabetes Mellitus J. Diabetes Sci Technol 2009 3(2): 269-282.

  6. William Clarke, M.D. and Boris P. Kovatchev, Ph.D. Statistical Tools to Analyze Continuous Glucose Monitor Data Diabetes Technol Ther. 2009 11(S1): S45-S54

  7. Lalo Magni, Ph.D., Davide M. Raimondo, M.S., Chiarra Dalla Man, Ph.D., Marc Breton, Ph.D., Steven Patek, Ph.D., Guissepe De Nicolao, Ph.D., Claudio Cobelli, Ph.D., and Boris P. Kovatchev, Ph.D. Evaluating the Efficacy of Closed-Loop Glucose Regulation via Control-Variability Grid Analysis J. Diabetes Sci Technol 2008 2(4): 630-635.

 

Back to Top

Features

How to Order

References

© 2011 The Epsilon Group., Charlottesville, VA USA. All rights reserved.