OVERVIEW
Research system for DC EEG acquisition and transcranial electrical stimulation (tDCs/tACs/tRNS)
NVX-36T amplifier is used in training systems, clinical and scientific researches as a part of computer-based system. Each channel has a DIRECT CURRENT input cascade and individual 24-bit ADC for EEG sampling up to 10000 times per second.
Internal high resolution Direct Digital Synthesis (DDS) current stimulator for producing DC or AC current via any EEG electrode or a set of electrodes.
Application software for settings of experiment, recording to EDF+, BDF+ and stimulation. Software library for self-design of user application.
• 32 EEG DC monopolar channels, 4 DC AUX bipolar channels for probes, 9/1 input/output triggers, OLED display, AC/DC DDS current generator. Stimulate using up to 31 electrodes.
• Dual use electrodes for EEG acquisition and stimulation. Used big-area sintered Ag/AgCl electrodes and innovative textile cap.
SOFTWARE
For managing transcranial electrical stimulation (tES) and EEG recording in research and clinical practice, the NeoRec and TetosExpert software solutions are used. NeoRec is designed for EEG recording and analysis in research applications, while TetosExpert is focused on scientific tasks, including stimulation control.
NeoRec allows recording EEG data during scientific and medical studies. It supports data storage in various formats (EDF+ 16-bit, BDF+ 24-bit, GDF 32-bit) and real-time data streaming via Lab Streaming Layer (LSL) for compatibility with external software such as MATLAB, EEGLAB, OpenViBE, and others.
TetosExpert is designed for configuring and managing stimulation in research projects. It enables setting parameters for tDCS, tACS, and tRNS with flexible electrode positioning, using custom waveform signals (.WAV), and real-time process control.
On request, additional software modules are available for clinical applications:
Neurovisor – a clinical EEG software solution supporting IFCN-recommended montages, automatic or semi-automatic EEG recording with voice prompts, built-in artifact suppression algorithms (ICA), and automated report generation.
Neurovisor-tES – a clinical module for transcranial stimulation, including electrode montage selection, real-time current and impedance monitoring, and automated report generation with stimulation graphs.
These software solutions provide researchers and clinicians with precise tools for managing stimulation and EEG recording, ensuring flexibility in procedure setup and control over neurophysiological signals.
SPECIFICATION
EEG recording mode | |
EEG channels | 32 |
Channels of sensors | 4 galvanic isolated from EEG |
Synchronization channels | 9 / 1 |
Display | OLED 3.2", 256 x 64 px |
Input dinamic range of EEG cannels | not less then ± 400 mV |
Input impedance of EEG cannels | > 100 MOhm @ DC |
Noise of EEG cannels | < 1 µV pk-pk (0.17 RMS) @ 0.1‑30 Hz |
Electrode impedance measurement range | 1‑120 kOm (±10%) @ 30 Hz |
EEG test signal | square 250 µV (±1%), 1 Hz |
Input dinamic range of sensor channels | 0‑4 V |
Input impedance of sensor channels | more 20 MOhm @ DC |
Noise of sensor channels | < 15 µV pk‑pk (2.5 µV RMS) @ 0.5‑30 Hz |
Powering of sensors | +5 V, 15 mA per channel with electronic protection |
Digitalization | 24 bit, 6th order delta-sigma modulator with 64x oversampling, one converter per each channel |
Low pass filter | From 0 Hz (DC) followed by filtering by application software |
Sampling rate | 500, 1000, 2000 Hz (TETOS Expert); 250, 500, 1000, 2000, 5000, 10000 Hz (NeoRec); 250‑2000 Hz for all channels: 5000 Hz for the first 24 channels; 10000 Hz for the first 16 channels; |
Data transfer format in real time | Lab Steaming Layer (LSL) |
Input TTL levels of synchronization channels | Low Uil <+0.8 V, Iil > -2.1 mA High Uih > +3.5 V, Iih > -0.1 mA |
Output TTL levels of synchronization channels | Installed programmatically by a command from the PC. Low Uol < +0.4 V, Iol > -1.6 mA High Uoh > +2.8 V, Ioh > 0.5 mA |
Synchronization channel mode | synchronously with the issued channel readings, accuracy ±0.5 reading. |
Galvanic isolation | reinforced |
Stimulation mode | |
Number of current generators | 1 |
Number of stimulation channels | up to 31 (30 ЭЭГ + GND, switching to channels A1 and A2 is not available) Each electrode can be connected to the anode or cathode of the generator |
Current generator | 16 bit Direct Digital Synthesis (DDS) |
Stimulating current range | from 10 µA to 3.9 mA |
Maximum output voltage of the current generator | 30 V |
Stimulation current modes | Direct current (tDCS), Alternating current (tACS), Alternating current monopolar (tACMS), Random noise (tRNS), Custom stimulation mode |
Stage duration | up to 60 min |
Smooth start/end of stimulation | Off, 10 sec, 20 sec, 30 sec |
Sham | Off, 10 / 20 / 30 sec. at the beginning, 10 / 20 / 30 sec. at the beginning and at the end |
Stimulus shapes in tACs and tACMs mode | Sine, square, random noise, ramp, trap, sinc, Gauss, Lorentz, haversine, exponential, custom |
Loading an external stimulus | from a specially prepared WAV file |
Current generator sampling rate | 8000 Hz |
Maximum frequency for a periodic signal | 1000 Hz |
tRNS frequency band selection | Lower cutoff frequency at -3 dB: 0, 10, 50, 100, 200, 300, 500, 1000 Hz; Upper cutoff frequency at -3 dB: 50, 100, 200, 300, 500, 1000, 2000 Hz; |
Measurements during stimulation | total generator current; total load impedance; Local current for each electrode (for all electrodes in AC mode, for the anode in DC mode) |
Stimulation indication | In the program, sound signal, indicator light, output trigger, on the LED screen of the device |
Other | |
Dimensions (LxWxH) | 200 х 155 х 40 mm |
Net weight | < 650 g |
Safety | IEC60601‑1, IEC60601‑1‑6, IEC60601‑2‑10, IEC60601‑2‑26 class II, type BF |
ACCESSORIES
NVX 36T Electrode kit includes
Ag/AgCl sintered electrodes MCScap-NTC – 33 pcs.
• Ag/AgCl electrodes MCScap-CS22 – 33 pcs.
• stainless steel electrodes MCScap-CS22SS – 33 pcs.
• set of ear Ag/AgCl sintered electrodes with fixators – 2 pcs.
• textile cap MCScap 10-10, size L (54-60 cm) – 2 pcs.
• textile cap MCScap 10-10, size M (48-54 cm) – 2 pcs.
• textile cap MCScap 10-10, size S (42-48 cm) – 2 pcs.
• elastic textile belt, size L (54-60 cm) – 2 pcs.
• elastic textile belt, size S (42-48 cm) – 2 pcs.
• starter kit (conductive gel, syringe, needles, brushes for cleaning).