When used together with Polhemus™ digitizing hardware, LOCATOR allows you to measure accurately electrode locations an external head shape in 3 dimensions. These data may then be used for MRI coregistration and more accurate source estimation. LOCATOR currently supports three Polhemus products: ISOTRAK, FASTRAK, and PATRIOT.*


3D Digitization

  • Electrode locations may be determined by touching with a stylus. Head movement is automatically compensated with 1-3 head mounted sensors.
  • External head shape locations may be determined by “drawing” over the head surface with a stylus. Head movement is automatically compensated with 1-3 head mounted sensors. Location of named points (such as nasion, inion, etc) may be obtained and stored.
  • BESA, Curry, and EMSE formats are supported.*
  • Other sensors (including optical sensors and magnetic sensors) may also be digitized.
  • Setup functions for Polhemus hardware (PATRIOT and FASTRAK) are available through the LOCATOR menu.


  • Interactive 3D display permits viewing of digitized points as they are added or offline. A manual editing function allows error correction.


  • User Interface. A conventional Microsoft Windows style graphical user interface is used throughout.
  • Audio prompt allows you to digitize electrodes from a sequence file without looking at the screen.

Intermodule Communication

  • Input: None
  • Output: Measured locations may be used for 3D rendering of sensors on a head surface in VISUALIZER, and for source estimation in SOURCE ESTIMATOR.

File I/O

  • Input: ASCII setup files may be used to store commonly used sequences (e.g. electrode names).
  • Output: ASCII (EMSE format) probe and headshape files; BESA and Curry ASCII export formats*

Other I/O

  • Graphics may be transferred to clipboard for use by other graphics programs or for insertion into word processors.


  • Printed. User manual, including file formats.
  • Online documentation is bundled with the software.
Digitizing electrode positions in Locator
Digitizing electrode positions in Locator
Head surface points and rendered surface.
Visualization of electrode position data

Requirements minimum required  recommended
CPU Laptop-grade Intel or AMD processor  
RAM 512 Mbyte  
Port RS232 serial port or USB port with an included USB-to-serial adaptor  
Operating System Windows XP/7/8 Windows 7
Display SVGA  
Installation medium CD-ROM or web package installer  
Other hardware Polhemus Isotrak*, Fastrak* & Patriot*  
Input modules none