4100 near-infrared Spectroscopy (NIRS) System

4100 functional near-infrared spectroscopy (fNIRS) system

MagstimEGI is pleased to offer Hitachi's 4100 Optical Topography System for hemodynamic measurements with near-infrared light. The system transmits near-infrared light through the skull to the cerebral cortex where the light absorbed by hemoglobin. With the aid of the modified Law of Lambert-Beer, changing concentrations in hemoglobin can be determined to pinpoint activated brain areas in the cerebral cortex. A non-invasive measure of brain activity. This system is ideal for use with participants and patients of all ages, neonate through adult.

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About the 4100 fNIRS system: High-quality, real-time imaging of the cerebral cortex

The state-of-the-art 4100 fNIRS system uses the specific absorbance of near-infrared light by hemoglobin to precisely monitor cerebral blood flow.

  • Compact, mobile and user-friendly
    The user-friendly “plug-in and go” system is easily moved from room to room and quickly set up. It has an extremely user-friendly and efficient on-screen user interface and the wide-screen monitor provides a clear view of in-vivo- and analyzed data.

  • Simultaneous multi-channel measurements
    Hitachi developed a unique technology to identify multiple light sources simultaneously. This allows the 4100 to monitor entire brain areas simultaneously, regardless how many light sources and measurement channels are being used and renders the system insensitive to ambient light. The system provides a wide range of fiber holders for simultaneously monitoring several independent brain areas with a capacity of 24 – 52 channels.

  • Versatile and innovative
    Hard- and software features make the system very flexible for a wide range of research and clinical applications. Neonate probes and infant fibers are available as well as customized fibers and fiber holders for specialized applications such as simultaneous NIRS/MRI or NIRS/EEG. The hard- and software have been optimized to meet the increasing demand for multimodal- or multi-distance measurements.

How fNIRS works

Near-infrared light is capable of penetrating tissue and bone. Using an emitter laser diode on the scalp, the light reaches 2–3 cm into the skull and cerebral cortex. In the cerebral cortex, near-infrared light is absorbed by hemoglobin, with any non-absorbed light reflecting back to the surface, where it is measured by a high-sensitivity photodiode.

Oxyhemoglobin and deoxyhemoglobin absorb light differently. By using two different frequency-modulated wavelengths of light (695 nm and 830 nm), one can calculate the ratio between oxy- and deoxyhemoglobin simultaneously.


The 4100 fNIRS system has been engineered for safe and user-friendly use in clinical and research environments. Possible fields of application include cognitive neuroscience, psychology, psychiatry, neurology, rehabilitation, pediatrics and education.

  • Brain Mapping
  • Cognition
  • Psychiatric Disorders (depression, schizophrenia, dementia, ADHD, autism)
  • Pediatrics (development, language- and skill acquisition, social skills, learning difficulties)
  • Neurology (pre-surgical mapping of the hemispheric dominance for language, detectinge epileptic foci, stroke assessment and rehabilitation)