EMSE Locator 2.0

EMSE Locator 2.0 is a specialized software solution designed to integrate electroencephalography (EEG) data with structural and functional imaging modalities such as MRI, CT, and SPECT. Its primary function is to accurately measure and map electrode locations on the scalp, enabling realistic head modeling that accounts for anatomical geometry, tissue thickness, and conductivity differences among skin, bone, cerebrospinal fluid, and brain tissue.

By combining 3D head-shape acquisition, fiducial marking, and precise electrode digitization, Locator 2.0 allows EEG researchers to co-register electrophysiological data with MRI or CT datasets. This integration supports advanced modeling workflows such as Boundary Element Method (BEM) and Finite Element Method (FEM) simulations for precise source localization.

Locator 2.0 includes built-in visualization tools for real-time 3D feedback, geometric alignment, and error reporting, ensuring reliable spatial correspondence between measured electrodes and anatomical structures. The software supports standard EEG data formats, making it compatible with major neuroimaging and electrophysiology toolchains.

Locator 2.0 is compatible with Windows 10 and Windows 11 as well as the Polhemus Patriot device. Compatibility with Polhemus Fastrak is currently under development.

Key Features

• Real-time 3D Digitization: Capture electrode positions and head-shape data with visual feedback.
• Head-Shape Modeling: Generate detailed wireframe models of the scalp and skull surface.
• Fiducial-Based Coordinate System: Define nasion and preauricular reference points for consistent spatial alignment.
• Digitization Accuracy Reports: Automatic TRE (Target Registration Error) and electrode alignment visualization.
• Standardized Head Mapping: Align digitized data with templates (e.g., New York Head) for group analyses.
• MRI/CT Integration: Co-register electrode data with MRI or CT anatomical layers for unified modeling.
• Geometric Surface Tools: Merge cortical meshes and apply transformations for BEM/FEM modeling.
• Photogrammetry Integration: Crop and clean 3D scans from devices such as iPhones with Polycam.
• Multi-Format Export: Output compatible with EMSE, EEGLAB, BESA, Curry, CTF, 4D, and BIDS.
• Cross-Platform Visualization: View and export 3D coordinates in ASCII or neuroimaging formats.

Technical Specifications / Prerequisites

Licensing Options

One-Year Subscription License (Machine Code): Tied to a single computer via unique hardware handshake.

Perpetual License (USB Key): Portable physical license enabling use across multiple systems.

Application Note

Locator 2.0 is intended for EEG researchers and neuroscientists requiring high-precision co-registration between scalp-measured electrical data and anatomical imaging. For optimal performance:

1. Perform electrode digitization using compatible 3D scanning hardware (e.g., Polhemus Fastrak or Patriot).
2. Define fiducial landmarks accurately before co-registration.
3. Use integrated visualization tools to validate spatial alignment.
4. Export data in preferred formats for integration with analysis platforms such as EEGLAB, BESA, or Curry.
5. By accurately merging electrophysiological and anatomical datasets, EMSE Locator 2.0 streamlines advanced EEG source modeling and multimodal neuroimaging research.