ETG-4000 Optical Topography System

EGI is pleased to offer Hitachi's advanced near-infrared spectroscopy system for hemodynamic measurements. Near-infrared light penetrates brain tissue and is absorbed differentially by hemoglobin and deoxyhemoglobin, providing 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 ETG-4000

This all-in-one system provides everything you need to get started with NIRS in your care center. The system features:

  • Compact and portable design — all components fit onto a wheeled cart, which can be moved easily up to the bedside or around the clinic
  • Patient-friendly — individual probes are easily mounted in a fiber holder and have spring-loaded fiber tips for comfortable and secure positioning
  • Versatile probe configurationalt the modular design allows 24, 48, or 52 simultaneous measurements anywhere on the scalp
  • High-performance technology — frequency-modulated 695 nm and 830 nm laser diodes provide high sensitivity, even in normal room light
  • Intuitive software — a user-friendly interface and multimode display rapidly generates accurate test results
  • Multimodal imaging support — the system features several ways to communicate with external devices allowing the synchronization of the ETG-4000 with other modalities, such as EEG, MEG, TMS, external video, etc.

How NIRS works

altNear-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.



Over 130 research papers have been published using the Hitachi ETG-4000 Optical Topography System in fields such as developmental neuroscience, cognitive neuroscience, multimodal imaging, and clinical research. 


ETG-4000 Optical Topography System

Systems are sold as complete packages with everything you will need to start work immediately. Systems include:

  • altwheeled cart
  • software
  • computer and monitor
  • probe modules of your choice
  • system manuals
  • 1 year Support Contract


  • neonate/infant probes
  • video system
  • 3-D positioning unit for sensor registration

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The sale of medical devices is strictly regulated by national laws. Please contact Philips Neuro for further details. Not all products are available in all markets. This page is not an offer to sell a medical device in any country where its sale would be prohibited by law.