Mixed reality assisted target localization for transcranial magnetic stimulation navigation: a feasibility study

Area of Science:

• Neuroscience
• Medical Technology
• Biomedical Engineering

Background:

• Transcranial magnetic stimulation (TMS) is a non-invasive technique for modulating brain activity, used for conditions like depression and OCD.
• Accurate targeting is critical for TMS effectiveness, but current methods like EEG systems offer only rough localization, causing errors.
• Mixed reality (MR) technology presents opportunities for developing improved, user-friendly navigation systems for TMS.

Purpose of the Study:

• To introduce and validate a portable MR navigation system, TMS-Guide, for precise non-invasive neural modulation target localization.
• To evaluate the system's localization accuracy and operational efficiency in preclinical settings.
• To offer a high-precision, simplified workflow solution for TMS and other non-invasive brain stimulation technologies.

Main Methods:

• The system utilizes Microsoft HoloLens 2 with custom interaction tools for target localization.
• Five distinct simulated head models with ten target points each were used for testing.
• Researchers performed target localization using CT-imaged models in both standing and lying positions to assess accuracy and efficiency.

Main Results:

• Localization errors were low, with standing positions showing errors between 2.3-2.6 mm (IQR) and lying positions between 1.9-2.5 mm (IQR).
• A significant difference in accuracy was observed between different researchers (p < 0.05).
• No significant difference in accuracy was found within the same researcher across repetitions (p > 0.05).

Conclusions:

• The MR-based TMS-Guide system provides a portable, simple, and accurate solution for TMS targeting.
• It demonstrates superior localization accuracy compared to traditional manual targeting methods.
• The system shows significant potential for broader use in non-invasive neural modulation and brain-computer interfaces.