fNIR System

FNIR System

Functional NIRS equipment Spectratech OEG-17H

Spectratech OEG-17H is the Functional NIRS equipment, to measure the change in blood amount in each part in the not-so-deep in vivo part at the same time in a multichannel method utilizing the light absorption characteristics in the vicinity of near infrared to red light where the in vivo hemoglobin (Hb) changes by its oxygen bonding state.

The spread spectrum modulation system, which is one of the latest digital technologies, we originally developed is adopted as the light modulation/ demodulation technology which forms the basis of this equipment. It has achieved the further high performance, downsizing, and cost reduction compared with the former technologies.


  1. Newly developed for whole-head measurement.

  2. Expandable number of channels (from 14 to 57ch) to meet each purpose.

  3. Dedicated sensor pallets selectable to be easily mounted at an objective measuring part.

  4. Small-sized main unit excellent in portability(as small as notebook PC).

  5. Spread spectrum modulation method (most advanced light modulation) is adopted.

  6. Connection to a monitor PC via 100M Ethernet LAN.

  7. Various event input is available.

  8. Synchronous operation with other measuring device is possible.

  9. Equipped with 3 general-purpose analog signal input channels as standard.

  10. AC100-240V operation is possible.


Spectratech OEG-17H Sensor cable (In basic configuration)

1) Light emitting part

Light source:

2-wavelength embedded type LED (Wavelength1: 840nm

Wavelength 2: 770nm) Equipped with 6pcs of them

Output power:

12mW/770nm, 12mW/840nm (Max) on the surface of light-emitting part

2) Light-receiving part

APD (Avalanche photo diode) Equipped with 6pcs of them.

3) Number of channels at simultaneous measurement

14、16 or 17 channels (Expandable to 34、37、51 and 57 channels)

4) Distance between light-emitting part and light-receiving part


5) Length of Sensor cable


6) To be used by mounting to Sensor palette (sold separately) prepared for each measurement region.


OEG-17H has been developed for the whole-head measurement, however please note that there still might be the case where the whole head could not be measured depending on the subject.

Spectratech OEG-17H main unit (In basic configuration)

1) Measurement method of biological signal

By Modified Lambert-Beer Law

3 kinds of hemoglobin change signals Unit: mM・mm

Oxy hemoglobin change

ΔCoxy ・ L (or ΔCo ・ L)

Deoxy hemoglobin change

ΔCdeoxy ・ L (or ΔCd ・ L)

Total hemoglobin change

ΔCtota l・ L (or ΔC ・ L)

Note: To express each hemoglobin change, it is expected to use ΔCo ・ L, ΔCd ・ L, and ΔC ・ L as standard in the future.

2) Optical multiplex modulation method

Modulation method: Spread spectrum modulation DS (Direct Sequence) method Note 1

PN CODE: M-sequence code

Effective biological signal bandwidth:

(1) Fine Mod: 0.76Hz (Sampling interval: 0.65535 sec)

(2) Fast Mode: 6.10Hz (Sampling interval: 0.08192 sec)

3) Event input function

A manual event trigger can be input (with LED to confirm the acceptance) at an optional time using the accompanying Spectratech OEG-16-05 BOX for manual event trigger input.

4) External trigger input function


It is equipped with 2 systems of the photo-isolated “External trigger input terminal” to operate together with the external device. It is connected to the external device via the optional Spectratech OEG-16-04 BNC cable, and can be used with both the external event trigger input and the external measurement/record start trigger.

Input condition: TTL level (Photo-isolated by photo coupler in the main unit) Note 2


It can be input from other PC via the network (use of UDP protocol).

How to use from the network is described in §10 of Software edition in detail.

5) Input function of general-purpose analog signal

It is equipped with 3 channels of the general-purpose analog signal input which can be measured together with the biological signal (hemoglobin change signal).

It is convenient to measure simultaneously with sphygmograph and thermometer, etc. which has an analog signal output function.

Input voltage range:

0 to +5V (High impedance input)

Number of input channels:



12 Bit

Sampling interval:

Identical to the biological signal’s sampling interval

(0.65535 or 0.08192 sec)

6) Measurement time

Continuous measurement for about 2 to 6 hours depending on the number of measurement channels.

7) Connection with PC

It is connected with PC with the network function (100M-ethernet) via the network, on which Windows 7, Windows 8, or Windows 10 is running. Installing the accompanying Spectratech OEG-17APD-07 application software makes it possible to output various commands, send the measured data to the PC, and record or display it.

For the use, please select a PC with Intel I5 CPU or above, 8GB main memory or above, and a monitor in resolution of 1368 x 768 or above.

8) Battery equipped

For the photo isolation part:

CR2032 Lithium battery (Continuous operation for about 3-5 years)

For the internal calendar clock:

CR2032 Lithium battery (Continuous operation for about 3-5 years)

9) The latest firmware can be downloaded from our website as needed.

Note 1:

The DS (Direct Sequence) method is one of the spread spectrum signal generation methods, called direct diffusion method as well, and modulates by using the random numbers called spread code sequence (PN sequence). In addition, there is FH method (Frequency Hopping) method.

Note 2:

TTL input means +3 to +5V digital signal input at high impedance.




47 CFR Part 15 Subpart B


This equipment consists of the following components.

1) Spectratech OEG-17H Main unit ------------------------------------------------ 1-3 set

2) Spectratech OEG-17APD-00-D30 Sensor cable (Detector) ------------------------- 1 set / 1 unit

3) Spectratech OEG-17APD-00-E30 Sensor cable (Emitter) -------------------------- 1 set / 1 unit

4) Spectratech OEG-17APD-01-50 Light-blocking cap ------------------------------- 1 pc

5) Spectratech OEG-17APD-02 Optical phantom ------------------------------------- 1 set / 1 unit

6) Spectratech OEG-17APD-06 GEN-LOCK cable -------------------------------------- 1-2 pc

7) Spectratech OEG-17H-07 CD-ROM for Application software ----==---------------- 1 pc

8) Spectratech OEG-16-05 BOX for manual event trigger input -------------------- 1 pc

9) AC adaptor TR60M05-26E13 CINCON -------------=-------------------------------- 1-3 pc

10) Operation manual ------------------------------------------------------------ 1 set

11) Spectratech OEG-17ME-06 LAN cable 0.5m×2 with isolator ---------------------- 1 set

12) Spectratech OEG-17H-302 Protective earth 3.6m (2 or 3units) ------------------ 1 set

Sensor palette, PC, and Network HUB are not included. Please purchase separately.

※ The component beginning with Spectratech OEG-16- is in common with Spectratech OEG-16

※ The component beginning with Spectratech OEG-17APD- is in common with Spectratech OEG-17APD.

1) Spectratech OEG-17H Main unit -------------------------------------------------------------------------- 1-3 set

2) Optical multi-modulation method Modulation method: Spread spectrum modulation DS (Direct Sequence) method Note 1 PN CODE: M-sequence code (Code length: 65535 bits (Max)) Effective bandwidth of biological signal: Fine Mode: 0.76 Hz (Sampling interval: 0.65535sec) Fast Mode: 6.10 Hz (Sampling interval: 0. 08192sec)

Sensor palette

Various sensor palettes are prepared. You may select it for your measurement purpose.

1) Spectratech OEG-17APD-01-06 Sensor palette Type 2x3W

14 CH by 2 x (2 lines 3 rows) for measuring parietal region

2) Spectratech OEG-17APD-01-02 Sensor palette Type 2x6

16 CH by 2 lines 6 rows for measuring frontal and parietal regions

3) Spectratech OEG-17APD-01-03 Sensor palette Type 3x4

17 CH by 3 lines 4 rows for measuring parietal and occipital regions

4) Spectratech OEG-17APD-01-01 Sensor palette Type 3x4W

34 CH by 3 lines 4 rows for measuring temporal region

5) Spectratech OEG-17APD-01-01-02 

Sensor palette Type 3x4W cloth SNEW

Spectratech OEG-17APD-01-01-03 Sensor palette Type 3x4W cloth L

34 CH by 3 linesx 4 rows for measuring temporal region

6) Spectratech OEG-17APD-01-09 Sensor palette Type 2x12

34 CH by 2 lines 12 rows for measuring frontal/temporal region

7) Spectratech OEG-17APD-01-04 Sensor palette Type 3x8

37 CH by 3 lines 8 rows for measuring frontal and parietal regions

8) Spectratech OEG-17APD-01-07 Sensor palette Type 3x4Tri

51 CH by 3 x (3 lines 4 rows) for measuring frontal/temporal region

9) Spectratech OEG-17APD-01-05-02 

Sensor palette Type 3x12 cloth SNEW

Spectratech OEG-17APD-01-05-03 Sensor palette Type 3x12 cloth L

57 CH by 3 x 12 rows for measuring frontal/temporal region

You may need to expand Spectratech OEG-17H according to the sensor palettes you will select to use. The expanding connection is called the stackable connection.

3D Digtizer- for digitizing 3D electrode positions on scalp and head shape for accurate source localization.

Patriot, Fastrak or Liberty 3D Digitizers can be used to digitize 3D eeg electrode or fNIR system's optodes positions on scalp and also for head

shape digitizing for accurate source localization in EEG/ERP, Cognition studies. Digitized electrode head positions and ahead points can be exported in many standard formats compatible with popular EEG/ERP analysis softwares like Neuroscan, EEGLab, CAR Tools etc..