...convenient, accurate, and affordable 3D electrode position measurement

Finally, a solution for 3D electrode localization that everyone can afford - Patriot! It's smaller, lighter, more compact and less expensive than previous models, yet the Patriot sports accuracy and resolution that are well matched to the task of electrode position measurement. Best of all, Patriot, when coupled with the Locator software, is a very fast way to measure electrode positions. Consider this -- your total time commitment for electrode position measurement is approximately 2 seconds per electrode (roughly 2 minutes for 64 channels or 4 1/2 minutes for 128 channels.

  • Perfect solution for localization of electrodes and head landmarks in preparation for the co-registration of EEG with MRI or other anatomical imaging modalities in EMSE Suite or BESA.
  • Least expensive electrode position measurement solution on the market.
  • No need to worry about maintaining a clear line-of-sight between receiver and transmitter, due to patented low-frequency magnetic transducing technology.
  • Patriot is controlled by our EMSE Locator software, which acquires and displays 3D position measurements for electrodes, fiducial landmarks and other points on the head surface.
  • Adds only a few minutes to a study.
  • Electrode coordinates are compatible with almost all research EEG analysis programs, including BESA, EMSE Suite, Analyzer and those made by competitors.
  • Resolution of 0.0015 inch and 0.01 degree; static accuracy of 0.1 inch RMS for the X, Y, Z position and .75 degrees RMS of orientation.
  • 20 ms latency updated at 60 Hz.
  • Accuracy of 0.1" RMS with a resolution of 0.0015 in./in.
  • Standard range is up to 5 feet.
  • From the pioneer in 3D position/orientation measuring devices, in business since 1970.
  • Factory calibrated, never needs adjustment.

Technical Specifications

UPDATE RATE 60Hz per sensor simultaneous sampling
INTERFACE RS-232 with selectable baud rates up to 115.2 K USB 2.0 (high speed)
LATENCY Less than 18.5 milliseconds
STATIC ACCURACY 0.06 in. RMS for X, Y, Z position; 0.40º RMS for sensor orientation. The system will provide the specified performance in a non-distorting environment when standard (RX2) sensors are within 36 inches of the standard (TX2) source; 42 inches with the optional TX4 source (Non-standard, smaller, sensors may reduce the specified range slightly). Operational out to 60 inches with slight degradation in performance.
OPERATING TEMPERATURE 10ºC to 40ºC at a relative humidity of 10% to 95%, noncondensing
SOFTWARE TOOLS PiMgr GUI for Microsoft Windows® USB driver package for Microsoft Windows® PDI SDK for Microsoft Windows® GUI for Linux®
REGULATORY FCC Part 15, class B EN61326-1: 2013 Emissions EN61326-1: 2013 Immunity, Basic Environment
REGULATORY (Patriot M) FCC Class B and CE Certified Tested to IEC 60601-1 Ed. 3.1: 2012 and IEC 60601-1-3rd Ed. 2007


Physical Specifications


The SEU contains the hardware and software necessary to generate and sense magnetic fields, compute position and orientation, and interface with the host computer via an RS 232 or USB interface. A small lightweight cube (RX2). The sensor’s position and orientation is precisely measured as it is moved. The source generates the magnetic field in which the sensor is tracked.
DIMENSIONS: 6.75 in (17.1 cm) x 6.25 in (15.9 cm) x 1.75 in (4.4 cm) WEIGHT: 0.32 oz (9.1 g)
DIMENSIONS: .9 in (2.29 cm) x 1.11 in (2.82 cm) x .6 in (1.52 cm)
TX2 - WEIGHT: 8.8 oz (250 g) DIMENSIONS: 2.3 in (5.84 cm) x 2.2 in (5.08 cm) x 2.3 in (5.84 cm)
TX4 - WEIGHT: 1.60 lbs (726 g) DIMENSIONS: 4.07 in (10.33 cm) x 4.07 in (10.33 cm) x 4.04 in (10.16 cm)
TX1 - WEIGHT: 0.36 oz (10.2 g) DIMENSIONS: .9 in (2.29 cm) x 1.11 in (2.82 cm) x .6 in (1.52 cm)


Range Versus Resolution

Patriot Range Versus Resolution

PATRIOT is the leading cost-effective solution for 6 Degree-Of-Freedom motion tracking and 3D digitizing. Available with stand alone system electronics unit or compact PC drive bay configuration (see PATRIOT DB PDF link above), it's an expandable system that can accommodate up to two sensors, making it perfect for a wide array of applications. From head tracking, biomechanical analysis and computer graphics to cursor control and stereotaxic localization, PATRIOT delivers a sweet spot combination of performance and value.

Expandable, Versatile and Easy to Use

PATRIOT includes a system electronics unit (SEU), a power supply, one sensor and one source. The system's capabilities can be expanded by simply adding an additional sensor or an optional stylus. Measuring in at only 6.75 by 6.25 by 1.75 inches (LWH), the electronics unit is compact for easy installation in any environment. PATRIOT interfaces with the host computer via RS-232 or USB. It's fully compatible with Windows™ XP/Vista/Win7 (open-source application for Linux® also available).  PATRIOT's intuitive PiMgr graphical user interface makes it easy to use.

PATRIOT utilizes AC tracking technology, which has been perfected through multiple generations to deliver the industry's highest level of performance and reliability. The source and sensor contain electromagnetic coils enclosed in plastic shells. The source emits magnetic fields, which are detected by the sensor. The sensor's position and orientation are precisely measured as it is moved. Because the sensor is completely passive, it's safe for use in any application.

PATRIOT provides dynamic, real-time measurements of position (X, Y and Z Cartesian coordinates) and orientation (azimuth, elevation and roll). PATRIOT can update data continuously, discretely (point by point), or incrementally. With the optional stylus, trace the outline of a physical object or collect polygon facets and get pinpoint accuracy of unlimited X, Y and Z data points.

PATRIOT is designed for unrivaled ease of use. Within a few minutes after unpacking the box, the system will be up and running. Data can readily be output to third-party applications for custom functionality to meet virtually any need. The system is factory calibrated and never requires adjustment.

Low Latency, High Stability

PATRIOT is designed to deliver reliability in demanding real world applications. It offers low latency and high stability to ensure precise, uninterrupted tracking at all times. PATRIOT boasts an update rate of 60Hz per sensor and an operating range (radius) of five feet.

Quiet and stable, the system is essentially unaffected by facility power grid fluctuations. Update rates are always maintained, because AC magnetics offer superior signal to noise ratios. Sophisticated digital signal processing helps provide optimal signal. In addition, adaptive filtering is available as a standard feature.

Advanced AC Technology

Polhemus pioneered AC motion tracking and has refined and perfected the technology through numerous generations. Unlike products based on pulsed DC technology, Polhemus trackers are not negatively affected by the earth's magnetic field, power outlets or electric motors. Because AC tracking is also more accurate and faster, it's clearly the superior choice. In fact, Polhemus originated pulsed DC technology, but chose not to pursue it because of performance shortcomings.

There is no need to worry about maintaining a clear line-of-sight between the sensor and source. Unlike sonic or laser devices, PATRIOT is not affected by signal blocking and interference.

We recommend the following components when using Patriot for electrode position measurement:

  • System Electronics Unit - Contains the hardware and software necessary to generate and sense the magnetic fields, compute position and orientation, and interface with the host computer via an RS-232.
  • Source (transmitter) - The transmitter is a triad of electromagnetic coils, enclosed in a plastic shell, that emits the magnetic fields. The transmitter is the system's reference frame for receiver measurements.
  • Receiver - The receiver is a small triad of electromagnetic coils, enclosed in a plastic shell, that detects the magnetic fields emitted by the transmitter. The receiver is a lightweight cube whose position and orientation are precisely measured as it is moved. The receiver is completely passive and highly reliable.
  • Stylus - The stylus is a pencil-like device that contains a triad of electromagnetic coils, and is used for digitizing electrode locations and collecting the contours of a subject's head.  We provide the system with the stylus in an 8" length, with a round nib.
  • Head-band - The head-band is a proprietary sensor mount that conveniently holds the head-motion correction receiver at a rigidly fixed position and orientation with respect to the head-mounted electrode cap / array.
  • Tripod - This is a carefully chosen and customized tripod that conveniently holds the Source near the head so that you get the most accurate measurements.
  • Serial to USB adapter cable - This cable makes it simple to connect the Patriot device to a computer over USB for reliable operation with EMSE Locator.
  • EMSE Locator software - Locator is a stand-alone module from our EMSE Suite Software that allows you to create electrode digitization templates for virtually any electrode cap / layout, provides an easy to use wizard with audible prompts to collect electrode position data from the Patriot, and stores electrode coordinate data in all of the most common formats and converts saved data between all supported formats.