  In recent years, non-invasive neuro-modulation methods such as Focused
Ultrasound (FUS) have gained popularity. The aim of this work is to introduce
the use of existing open-source technology for surgical navigation to the field
of multimodal non-invasive brain stimulation. Unlike homegrown and commercial
systems, the use of well-documented, well maintained, and freely available
open-source components minimizes the learning curve, maximizes technology
transfer outcome, and fosters reproducible science for complex, guided
neuromodulation systems. The described system significantly lowers the entry
bar to clinical research and experimentation in the field of non-invasive brain
stimulation. Our contribution is two-fold. First, a high-level overview of the
components of the descried system is given in this manuscript. Second, all
files are made available online, with a comprehensive step-by-step manual,
quickly allowing researchers to build a custom system. A spatial accuracy of
0.93 mm was found through validation using a robotic positioning system.
