Optical Topography Options

3D Topographic Image Display System

The 3D Topographic Image Display System combines the results from NIRS measurements with structural MRI images to generate a sophisticated 3-dimensional and dynamic model of changing hemoglobin concentrations on the surface of the brain.

The system consists of the integrated 3D Positioning Unit for the determination of the 3D coordinates for the head and the optode positions, and the 3D Composite Display Unit which combines 3-dimensional maps of NIRS data with structural MRI images.

The 3D Positioning Unit is integrated into the ETG-4000 and determines the 3D coordinates in real-time, thus allowing precise probe navigation. 3D coordinates are stored in an experiment-specific file and the data can be used in future experiments to navigate the probe(s) into exactly the same position.

Together with the recorded NIRS data, the 3D coordinates can be transformed into a 3-dimensional image of hemodynamic activity projected on a wire-frame head.

Importing the 3D data into the 3D Composite Display Unit allows the co-registration of 3-dimensional NIRS data and structural MRI images of the subject.

Video Interface

The video interface provides the possiblity of observing and recording video footage of the subject during measurements. After connectiong a video camera to the ETG-4000, the systemsoftware automatically controls and synchronizes the recordings of video footage and hemoglobin data.

“3x11” Fiber Holder

The “3x11” fiber holder combines all optical fibers in a single array and allows the simultaneous measurement of extended brain areas. By combining all optial fibers in the “3x11” configuration, the number of measurement channels increase from 48 to 52.

Neonate Probe

Light-weght probes designed for use with neonates and young infants (up to 9 months) are available. The optical fibers are embedded in soft silicon cushions, keeping the probes ligh and a

Video Interface

The video interface provides the possibility of observing and recording video footage of the subject during measurements. After connecting a video camera to the ETG-4000, the system software automatically controls and synchronizes the recordings of video footage and hemoglobin data.

“3x11” Fiber Holder

The “3x11”fiber holder combines all optical fibers in a single array and allows the simultaneous measurement of extended brain areas. By combining all optical fibers in the “3x11” configuration, the number of measurement channels increases from 48 to 52.

Neonate Probe

Light-weight probes designed for use with neonates and young infants (up to 9 months) are available. The optical fibers are embedded in soft silicon cushions, keeping the probes light and avoiding any discomfort. Two different fiber configurations are offered: a dual “3x3” configuration (24 channels) or a single “3x5” configuration (22 channels); a 48 channel system is required for using a dual “3x5” configuration.

Infant Probes

The new infant probes have been developed for infants 9 months and older. Removable fibers provide access to the scalp and allow the manipulation of interfering hair. The size of the head cap is adjustable and allows the accommodation of 24, 34, 36 or 46 measurement channels.

MRI-compatible Optical Fibers

For simultaneous NIRS/MRI-measurements optical fibers free of ferromagnetic metals are available. The standard length of these fibers is 7 meters (23 ft). The length of the fibers can be customized but should not exceed 10 meters (32 ft).

Simultaneous NIRS/EEG-measurements

The newly developed NIRS/EEG cap integrates functional near-infrared spectroscopy with electroencephalography. Optical fibers are arranged in a bilateral “3x3” (2x 12 channels) or “3x5” (2x 22 channels) configuration. The head cap can accommodate up to 32 EEG-channels in the standard “10/20” positions.

Direct triggering between the two modalities or remote control of both devices via customized computer programs* make the simultaneous NIRS/EEG-measurements easy.

(* customized PC programs are the user’s responsibility)

Double-Density Arrays

Doubling the spatial resolution of fNIRS with the new double-density arrays.

Two interlocking fiber holders with a standard fiber distance of 3cm increase the spatial resolution 2-fold in a single measurement.

Note: Double-density arrays require a higher light intensity and can be performed onlywith ETG-4000 systems manufactured after January 2010.