A modeling tool for multilevel physiological systems


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Flint is a simulator of bio-physiological models written in PHML and SBML. It parses those languages, compiles internally and execute simulations. Flint can also interpret PHML-SBML hybridized multilevel models, which can be created on PhysioDesigner. Flint uses SOSlib to parse SBML.

In the framework of PhysioDesigner platform, the tasks for model construction and for simulation are clearly separated. Users can focus on the structure and logic of models without being troubled by implementation of algorithms of numerical calculations, because Flint takes care all such issues instead of users.

On the main window of Flint, users can select a numerical integration algorithm (for now, there are two choices, i.e. Euler method and 4-th order Runge-Kutta method), set the simulation duration, time step with unit of time, and sampling interval to record the values in a data file. Users also can select physical quantities to dump the simulation result into a file.

The simulation results are written in CSV or ISD format which is a binary format to describe time series. ISD format specification can be found

On Flint, it is possible to perform a parameter scan, a batch job to run a number of simulations with changing the parameter values in given ranges.

There is a cloud based flint service called
Flint K3. If you want to perform simulations in the cloud, please visit


Latest version

Download site was moved to GitHub.

The latest version of Flint is available at