Deep Brain Stimulation (DBS) is an established technique for symptomatic treatment of some neurological disorders such as Parkinson’s disease and essential tremor. Finite Element Method (FEM) simulations of the electric field magnitude (EF) can be used to estimate which structures in the brain that are affected by DBS, where an EF of 0.2 V/mm has been estimated to affect the structures when using a pulse width of 60 µs [1, 2]. We are developing a Matlab-based application named ELMA [3] for tissue classification and electric conductivity assignment to use in the FEM software Comsol Multiphysics (CM). Preoperative MR images are used to classify tissue into grey matter, white matter, blood and cerebrospinal fluid and this classification is then used to assign the electric conductivity for the FEM simulations. We are also developing a CM application for easy electrode placement and simulations of the EF. It is currently containing the Medtronic 3389 lead but will be expanded with other lead types such as segmented leads for directional stimulation. Both applications will be free and available for download at

https://liu.se/en/research/dbs

The CM application does require a CM license at the moment though.

References

[1]          J. D. Johansson, F. Alonso, and K. Wårdell, "Modelling details for electric field simulations of deep brain stimulation," in World Congress on Medical Physics & Biomedical Engineering, Prague, 2018, vol. 68, no. 1: Springer, pp. 645-648.

[2]          M. Åström, E. Diczfalusy, H. Martens, and K. Wårdell, "Relationship between Neural Activation and Electric Field Distribution during Deep Brain Stimulation," (in English), IEEE T Bio-Med Eng, vol. 62, no. 2, pp. 664-672, Feb 2015.

[3]          J. D. Johansson, F. Alonso, and K. Wårdell, "Patient-Specific Simulations of Deep Brain Stimulation Electric Field with Aid of In-house Software ELMA " in the 41st International Engineering in Medicine and Biology Conference, Berlin, 2019.