• SimNIBS 2.1 is a free software package for the Simulation of Non-invasive Brain Stimulation. It allows for realistic calculations of the electric field induced by transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS).

• A SimNIBS 2.1 workflow consists of three main parts:
  • Command line scripts are used for the automatic generation of high-quality tetrahedral volume meshes of the head from MR images (Note: We included the new script headreco in 2.1 which offers an extended coverage including the neck, see also Nielsen 2018).
  • These volume meshes are then used in the electric field calculations based on finite elements. A graphical user interface (GUI) is provided to set up the calculations. Setting up and running a simulation is done quickly, and usually requires less than 5 minutes.
  • The simulation results can be visualized in Gmsh or freeview. In addition, they can be loaded into Python or Matlab for further analyses. Example matlab scripts are provided. This comprises both analyses of the electric field strengh or the normal component of the field relative to the cortical sheet. The analyses can be carried out in subject space or in template spaces (MNI or fsaverage).

• The Installation section describes how to download and set up SimNIBS under Linux, Mac OSX, and now Windows.

• The Documentation section guides you through SimNIBS in a step-by-step fashion based on an example data set.

• The new example data set can be downloaded here.

• SimNIBS 2.1 is incompatible with simulation set-ups (.simnibs and .mat files) and head meshes (.msh files) generated with SimNIBS 2.0. When you started a project in SimNIBS 2.0, stick to 2.0 for that project!

• Contact us when you experience problems, need information or want to contribute code!

• Note: SimNIBS is a research tool. Clinical usage is not supported or advised. In particular, SimNIBS was not tested to give accurate results in the presence of pathological condition.

SimNIBS was created at the Max-Planck Institute for Biological Cybernetics (Tübingen, Germany), the Danish Research Center for Magnetic Resonance (Copenhagen, Denmark) and the Technical University of Denmark (Kgs Lyngby, Denmark) (Contributors and Acknowledgements). SimNIBS is distributed under the GNU GPL v3. When you publish results based on SimNIBS 2.0 or 2.1, or parts of it, please cite:

• Thielscher, A., Antunes, A. and Saturnino, G.B. (2015), Field modeling for transcranial magnetic stimulation: a useful tool to understand the physiological effects of TMS? IEEE EMBS 2015, Milano, Italy

• 21/12/2018 Preprint on SimNIBS 2.1 now available at https://doi.org/10.1101/500314. This preprint covers the architecture of SimNBS 2.1, head models and group analysis.
• 20/11/2018: Version 2.1.2 is now available. The main feature in this release is an expanded MATLAB library (see the changelog for details)
• 19/09/2018: SimNIBS now supports windows, please see the installation page for more information
• 29/08/2018: Version 2.1.1 is now available. It features a simplified installation and simulation set-up (see the changelog for details)
• 03/07/2018: Version 2.1 is now available. It is a major update of SimNIBS 2. More detailed descriptions can be found in the help documents included in the download package. The Installation procedure is described here. SimNIBS 2.1 also comes with a new example data set. We will update the rest of the SimNIBS homepage soon.