Biocybernetics Laboratory
THYROSIM is a tool for simulating a well-validated human thyroid hormone (TH) feedback regulation system model*. Users can simulate common thyroid system maladies by adjusting TH secretion/absorption rates on the interface. Oral input regimens, also selectable on the interface, simulate common hormone treatment options. Bolus and intravenous infusion inputs also can be added, for exploratory research and teaching demonstrations. For easy comparisons, the interface includes facility for superimposing two sets of simulation results.

Minimum Usage:
  1. To see normal thyroid hormone behavior: click "Simulate".
  2. To simulate hypo/hyperthyroidism: change T 3 /T 4 secretion.
  3. To modify oral input absorption: change T 3 /T 4 absorption.
  4. Simulate treatment options:
    1. Click the Oral Input Oral Input IV Input IV Input or Infusion Input Infusion Input icons to add as input.
    2. Fill in the required dosage, start and end times.
  1. x icon: click to delete an input.
  2. ON OFF icons: click to turn input on or off for the next run.
  3. plus minus icons: click to show or hide scrollbars.
  4. info icon: hover mouse over to see additional info.
The Euthyroid Example uses default thyroid hormone secretion/absorption values without any input doses. Simulated for 5 days. Default Example The DiStefano-Jonklaas 2019 Example-1 reproduces Figure 1 of the DiStefano-Jonklaas 2019 paper. Specifically, the simulated hypothyroidic individual (25% thyroid function) is given 123 µg T 4 and 6.5 µg T 3 daily for 30 days. DiStefano-Jonklass Example 1
The main Thyroid Simulator. Thyroid Simulator Junior is optimized for babies. Advanced simulators contain parameter editors for fine-tuning. Junior and Advanced simulators are available upon request.
THYROSIM is intended as an educational and research tool only. Information provided is not a substitute for medical advice and you should contact your doctor regarding any medical conditions or medical questions that you have.

T 4 and T 3 secretion are capped at 125% because the model is not validated for hyperthyroid conditions.

The full implemented Thyrosim model (ver. Dec 2015) is described here.
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Input Manager
Add T 3 and T 4 inputs to adjust quantity and frequency:
Control Panel
Simulation Time: Days
T 4 Secretion
T 4 Absorption
T 3 Secretion
T 3 Absorption
Recalculate Initial Conditions:
Set Next Run Color: