3D motion tracking system by Polhemus
Haoyun Zhang, Assistant Director of Human Imaging
SLEIC Human Electrophysiology Facility
University Park, PA 16802
Used to capture EEG net sensor locations when registering to MRI data. FASTRAK tracks the position (X, Y, and Z Cartesian coordinates) and orientation (azimuth, elevation, and roll) of a small sensor as it moves through space by using electro-magnetic fields to determine the position and orientation of a remote object.
- Used to capture EEG net sensor locations when registering to MRI data
- Degrees-of-Freedom – 6 DOF
- Number of Sensors – 1-4
- Update rate - 120 Hz (divided by number of sensors)
- Position Coverage – specified accuracy when standard receivers are located within 30 inches (76 cm.) of the standard transmitter.
- Angular Coverage - all-attitude
- Static Accuracy - 0.03” (0.08 cm) RMS for the X,Y,or Z receiver position, and 0.15° RMS for receiver orientation.
- Resolution - 0.0002 inches/inch of range (0.0005 cms/cm of range), and .025°.
- Latency - 4.0 milliseconds
The FASTRAK tracking system from Polhemus uses electro-magnetic fields to determine the position and orientation of a remote object. The technology is based on generating near field, low frequency magnetic field vectors from a single assembly of three concentric, stationary antennas called a transmitter, and detecting the field vectors with a single assembly of three concentric, remote sensing antennas called a receiver. The sensed signals are input to a mathematical algorithm that computes the receiver’s position and orientation relative to the transmitter.