g.HIamp: Specs & Features

Groundbreaking technology for brain mapping and BCI

High demands require high level solutions and groundbreaking technology. g.HIamp is a 256 channel biosignal amplifier for invasive and non-invasive measurements of brain functions that is FDA cleared and CE approved. The amplifier has 256 ADC converters with 24 Bit inside for perfect signal resolution and has a wide input sensitivity to measure EEG, ECoG, ECG, EMG, EOG without any saturation. External sensors can also be connected. All channels are DC coupled. Internally, signal processing is performed with the fastest floating point DSP and a sophisticated real-time Kernel. The amplifier relies on a very high oversampling to reduce the noise as much as possible by averaging samples.

256 channels can be analyzed in real-time with the g.tec Highspeed Processing for Simulink toolbox. This leads to faster and more accurate control of brain-computer interface systems that use Common Spatial Patterns (CSP). g.HIamp is powered by a medical mains power supply and the system is connected to the computer via USB. The system is equipped with 16 digital trigger channels and a HOLD input for artifact suppression (e.g. during electrical or magnetic stimulation). g.HIamp provides 80, 144 or 256 channels per unit. Each block of 64 channels is connected via a multi-pole medical safety connector to the electrode interface box. A big advantage is that g.HIamp can be used with passive or active electrodes. The difference is just the electrode connector box (headbox). For ECoG grids and strips, special interface connectors are available.

NEW: A g.HIamp-RESEARCH version for reseach purpose only is available now! More information: g.HIamp-RESEARCH

Product Highlights

  • 80-256 DC coupled wide-range input channels, record any type of signal (EEG, ECoG, EMG, EOG/spikes, connected various sensors)
  • 256 channels perfectly synchronized with 24 Bit
  • Supports active and passive EEG electrodes and ECoG grids
  • Fully integrated into g.tec software components for real-time analysis 
  • Integrated impedance measurement for active and passive electrodes
  • TMS compatible
  • Easy configuration and setup via high-speed online data processing for SIMULINK
  • Driver package/API available
  • FDA cleared and CE certified medical product


"g.HIamp allows us to perform robust intraoperative recordings to ensure cortical and subcortical electrodes are placed in correct functional regions for various clinical applications and research directions at the University of Florida Hospital."

 - Dr. Aysegul Gunduz (University of Florida), US

"The g.HIamp is an absolute workhorse and a critical component of our ECoG program.  Its recording and hardware and software interfacing capabilities make it extremely versatile."

 - Dr. Gerwin Schalk
   (Wadsworth Center, Albany Medical Center), US

"Fused with a variety of rapid prototyping and research software tools, g.HIamp serves as a unique tool in our clinical research applications to record electrocorticogram and local field potentials. The oversampling process executed by the internal DSP provides exceptional SNR and enables capturing higher frequency brain rhythms with superior quality."

  - Dr. Nuri Firat Ince (University of Houston, US)



g.HIamp uses wide-range DC-coupled amplifier technology in combination with 24-bit sampling. The result is an input voltage of +/- 250 mV with a resolution of <60nV! This means that every electrophysiological signal can be recorded directly without additional hardware. Neither high electrode offset voltage nor large artifacts resulting from electrical or magnetic stimulation will saturate the amplifier inputs. This feature is important for various artifact treatment and correction algorithms. The use of digital filters avoids hardware related variations between channels.


The amplifier drives each ADC at 614,4 kHz, which is much higher than the required sampling frequency. Then the floating point DSP internally performs the oversampling and averages samples to increase the signal-to-noise ratio. For example, if the amplifier operates at 256 Hz, then 2400 samples are averaged per data point, which suppresses the noise by a factor of 49. In addition, the floating point DSP also performs real-time bandpass filtering and notch filtering of the data. Several hundred different bandpass filters are predefined. Also, bipolar derivations can be calculated by the DSP to work with a very high CMRR. A steep anti-aliasing filter guarantees a superior signal-to-noise ratio. All these features together allow even to record high-gamma activity in the kHz range! The amplifier uses 256 ADC for the 256 channels, and hence all signals are sampled exactly at the same time point to avoid any time delay between channels. This is especially important for brain mapping procedures.


g.HIamp can be ordered with 64+16, 128+16 or 256 channels initially. The 64+16 channel version comes with one 64 and one 16 channel connector box. The 128+16 version comes with two 64 channel and one 16 channel connector box and the 256 channel version comes with four 64 channel boxes.


g.HIamp uses a new principle for impedance measurement that can determine the skin-electrode impedance for passive and also for active electrodes. It works also for gel or dry electrodes provided by g.tec, and even for ECoG grids. The impedance values are color coded, and all 256 channels are shown in one window, which is updated every few seconds! The impedance check can also beep if an electrode was successfully mounted. This allows very fast assembly of electrodes during real-time impedance control. 


g.tec's philosophy is to provide a broad spectrum of software solutions for different groups of users (e.g. for engineers, researchers & scientists, physiologists, and medical staff, but also for software developers & programmers). From comfortable Windows-based recording software to MATLAB/Simulink based tools and device drivers and APIs, you will find the appropriate tools for your application. Please see the list of related products/software below for more details. g.HIamp is also supported and integrated into the main core of BCI2000 and OpenVIBE. g.HIamp supports also the LSL (lab streaming layer).


We give a full 5-year warranty on g.HIamp. g.HIamp is a safe certified medical device for research in humans, even for invasive recordings such as electrocorticography (ECoG). It must not be used for patient monitoring or determination of brain death. Medical diagnosis and decisions about treatment of diseases must not be based (solely) on results obtained with this device.


Ad-Tech, PMT, Unique Medical and Cortec grid electrodes can be used for ECoG recordings. g.HEADstage can be used for neural spike recordings.


A brilliant feature of the g.HIamp is that the main amplifier unit can be used with different electrode connector boxes. Therefore, the main amplifier unit is only purchased once and can be used for many different applications:

  • passive electrode connector box - comes with 64 channels and is connected to one of the 4 groups of the g.HIamp. It can be used with standard 1.5 mm safety connectors, which are standard for EEG and ECoG electrodes.
  • active electrode connector box - comes with 64 channels and is connected to one of the 4 groups of the g.HIamp. It has 2-pin connectors to support all g.tec active electrodes, such as g.LADYbird or g.SCARABEO (not for medical use).
  • passive electrode connector box with 16 channels - comes with 16 channels and is connected to one of the 4 groups of the g.HIamp. This connector box can provide additional inputs for external sensors.
  • passive TMS box - allows EEG recordings with Transcranial Magnetic Stimulation (TMS). Comes with 64 channels and is connected to one of the 4 groups of g.HIamp. It can be used with standard 1.5 mm safety connectors, which are standard for EEG and ECoG electrodes. The box contains additional filter to suppress artefacts.

Simultaneous Measurement of EEG and tDCS

tDCS is a non-invasive method to stimulate the brain using constant, low current. This technology has been used in patients with brain injuries or psychiatric conditions like major depressive disorder. In addition, tDCS has been explored to alleviate memory deficits in Parkinson’s disease and Alzheimer’s disease, schizophrenia, and pain.

Read the full report on the g.tec blog: Simultaneous Measurement of EEG and tDCS

In summary, the measurement shows that tDCS is compatible with both passive and active electrodes. There is a strong DC component in the raw data with tDCS, but it could be removed with a proper filter.


This figure shows EEG recordings with the g.HIamp during TMS stimulation with a TMS device from Mag&More. A g.GAMMAcap (size M) was prepared with passive g.LADYbird electrodes and the sampling rate was set to 38.400 Hz and no filters were selected. All electrode locations were prepared with abrasive gel to get a low electrode impedance. The TMS stimulation was done with a biphasic single pulse and about 300 repetitions applied with 1.1 Hz. The figure shows also the position of the TMS coil.

Beside g.HIamp, TMS can also be used with g.USBamp and g.Nautilus-PRO. The stimulation artifact with passive electrodes is typically 2 ms long, for active electrodes it is around 6 ms.

As a result of the strong electromagnetic field, transcranial magnetic stimulation (TMS) can cause large discharge artifacts in the EEG due to amplifier characteristics and skin/electrode capacitance/impedance. Therefore, g.tec has developed two remedies for this issue: a dedicated TMS headbox for g.HIamp that minimizes the amplifier-related artifact, and a post-processing artifact removal algorithm integrated in g.BSanalyze software that robustly eliminates discharge artifacts in already contaminated data within seconds.
This figure shows an EEG recording while TMS is performed. The brain signals have been recorded with the new TMS headbox and processed via the articat removal algorithm of g.BSanalyze. This twofold approach, combined with the high dynamic range of g.HIamp, restores the entire EEG data after the stimulation and recovers its physiological content on a µV-scale.

Plugin for DEWESoft X

DEWESoft provides mobile DAQ instruments with high-end signal conditioning, integrated computer, SSD storage, display and battery used in automotive, aerospace, defense and many more applications. This plugin allows you to acquire data with g.HIamp inside the DEWESoft data acquisition system and store it together with all other signals acquired from additional devices in one DEWESoft data file.

Further the plugin allows to configure the g.HIamp and to use its impedance measurement tool. See also www.dewesoft.com

AirRay ECoG Grids

Cortec AirRay ECoG grids with 64, 32 or 16 contacts can be connected via the 64 channel passive headbox or with a direct interface cable.

Available configurations

Hardware and Accessories

Complete Solutions

product no.: 8018 read more g.HIamp 80 bundle — bundle offer consisting of: g.Hiamp 80, g.Power - g.HIamp, g.HEADbox - active, g.HEADbox16 - passive, g.SCARABEO 64 bundle, g.Recorder, trigger cable for g.Hiamp, g.BSanalyze: (Base + EEG), g.GAMMAgelSET
product no.: 8017 read more g.HIamp 144 bundle — bundle offer consisting of: g.Hiamp 144, g.Power - g.HIamp, 2x g.HEADbox - active, g.HEADbox16 - passive, g.SCARABEO 128 bundle, g.Recorder, trigger cable for g.Hiamp , g.BSanalyze: (Base + EEG), g.GAMMAgelSET
product no.: 8016 read more g.HIamp 256 bundle — bundle offer consisting of: g.HIamp 256, g.Power - g.HIamp, 4x g.HEADbox - active, g.HEADbox16 - passive, g.SCARABEO 256 bundle, g.Recorder, trigger cable for g.Hiamp , g.BSanalyze: (Base + EEG), g.GAMMAgelSET
read more g.BCIsys: Specs & Features — Complete MATLAB-based Brain-Computer Interface research/development system
read more g.PHYSIOobserver: Specs & Features — Classify workload, emotions, movements based on physiological parameters in real-time
product no.: 8030 read more RehaBCI for g.HIamp — 80 channels; consisting of: g.HIamp 80; g.HIamp 80 package ACTIVE; g.HIamp SIMULINK High-Speed Online Processing; g.RTanalyze; g.BSanalyze: Base, EEG and Classify-toolbox; g.HIamp common spatial patterns model; g.VRsys; g.UDPinterface; 3D human avatar (g.AVATAR); business PC; bundle offer
product no.: 8006 read more g.HIamp package BCI — upgrade for BCI research consisting of: g.HIamp SIMULINK HIGH-SPEED ONLINE Processing; g.HIamp P300 + Ping Pong + SSVEP model; g.HIamp common spatial patterns; g.RTanalyze; g.BSanalyze (Base + EEG + Classify)
product no.: 8020 read more g.HIamp AEP Setup — complete setup for auditory stimulation experiments with g.HIamp; consisting of: ASSR, BAEP, AEP stimulation unit; audio trigger cable for g.HIamp; Lecture 4: Evoked potentials; bundle offer (0150, 7240_2, 4053)

See some related products

Hardware and Accessories

product no.: 7282 read more g.HIamp USB cable — connection of g.HIamp to USB-port of PC/notebook
product no.: 7225 read more g.HIamp cable for short-cut function (HOLD) — 3m cable with 3pin screw terminal
product no.: 7240_2 read more audio trigger cable for g.HIamp — DIG IN 1 of g.HIamp HA-xxxx.xx.xx to mindBEAGLE audio trigger box
product no.: 7276A read more trigger cable for g.HIamp for DIG IN 1 — trigger cable for g.HIamp for DIG IN 1 (8 digital lines from DIG IN 1 g.HIamp HA-xxxx.xx.xx to D_Sub 25 male (PC-parallel-port pinout), 3 m)
product no.: 7276B read more trigger cable for g.HIamp for DIG IN 2 — trigger cable for g.HIamp for DIG IN 1 (8 digital lines from DIG IN 2 g.HIamp HA-xxxx.xx.xx to D_Sub 25 male (PC-parallel-port pinout), 3 m)
product no.: 7277 read more adapter cable for trigger cable — DSUB25 female to 8xBNC (including 8xBNC to CINCH adapter)
product no.: 7004 read more g.Power - g.HIamp — medical grade-PSU (power supply unit) for g.Hiamp; 110/230 V; 50/60 Hz power line; single 5 V supply
product no.: 7005 read more g.HEADbox - active — electrode interface box for 64 active channels, for usage with g.HIamp; works with g.tec 2 pin safety connector active electrodes; g.INTERfaceHEADbox2HIamp (7008); g.HEADboxPOWER (7009)
product no.: 7006A read more g.HEADbox - passive — electrode interface box for 64 passive channels, for usage with g.HIamp; works with 1.5 mm medical safety connector passive electrodes; g.INTERfaceHEADbox2HIamp (7008)
product no.: 7006B read more g.HEADbox - passive — electrode interface box for 64 passive channels, for usage with g.HIamp or g.USBamp for synchronized recordings of g.tec systems and clinical systems; works with 1.5 mm medical safety connector passive electrodes; 2 grounds; g.INTERfaceHEADbox2HIamp (7008)
product no.: 7006T read more g.HEADbox - TMS — 64 channel electrode connector box for EEG recordings with TMS stimulation
product no.: 7007 read more g.HEADbox16 - passive — electrode interface box for 16 passive channels, for usage with g.HIamp; works with 1.5 mm medical safety connector electrodes
product no.: 7008 read more g.INTERfaceHEADbox2HIamp — interface cable g.HEADbox to g.HIamp with multi pole connector; approx. 165 cm lead
product no.: 7008S read more g.INTERfaceHEADbox2HIamp, short version — interface cable g.HEADbox to g.HIamp with mulit pole connector, approx. 50 cm lead
product no.: 7009 read more g.HEADboxPOWER — power supply cable for g.HEADbox; approx. 165 cm lead
product no.: 7051 read more g.HIamp water-proof heavy duty case — water-proof heavy duty case for g.HIamp equipment
product no.: 0307C read more external trigger button HA — external trigger button for g.HIamp, connected to PIN 1 of DI 1; 2,5 m cable
product no.: 3012 read more medical isolation transformer — 600 VA, REO-MED, 6 outputs

Electrodes and Sensors

read more g.Electrodes: Specs & Features — various active and passive electrodes for electrophysiological recordings
read more g.SAHARA: Specs & Features — active dry EEG electrode system
read more g.GAMMAsys: Specs & Features — active electrode system for EEG/EMG/EOG/ECG
read more g.Sensors: Specs & Features — various sensors for physiological and physical signals
product no.: 0274 read more g.TRIGbox: Specs & Features — multimode trigger conditioner box


read more Software options — choose the best software components for your system

Related Media and Documents

Product Manuals/Handbooks


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gHIamp_InstructionsForUse_USA — 07/27/2017 — 1.36 MB
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gHIamp_64channel_electrode_splitterbox_A_B — 07/26/2016 — 815.01 kB
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gHIamp_64activeBox_InstructionsForUse — 07/26/2016 — 1.19 MB


64-Channel Flash VEP Experiment using g.HIamp — 07/27/2012 — 2.33 MB


Lecture 1: EEG — 11/26/2015 — 6.94 MB
Lecture 2: BCI — 11/26/2015 — 4.23 MB
Lecture 3: ECG — 11/26/2015 — 21.23 MB
Lecture 4: EP — 09/23/2016 — 19.05 MB
Lecture 5: PhysioObserver — 11/26/2015 — 502.23 MB
Lecture 6: g.Nautilus Sports — 11/26/2015 — 106.97 MB