The Geodesic EEG system can acquire a 256 channel EEG.
Acquisitions can be done through two available networks:
- HydroCel GSN Sensor NETs, MR compatible (available sizes: 54-56 cm, 56-58cm)
- HydroCel GSN Sensor NETs, not MR compatible (available sizes: 54-56 cm, 56-58cm)
Networks are connected to a Net Amps 400 amplifier:
| Feature | Net Amps 400 |
| Coupling | DC |
| Chip for A/D conversion | ADS1298 |
| A/D resolution | 24 bits |
| On-board microprocessor | Intel ATOM 1.6 GHz 32-bit |
| FPGA | DSP FIR filter signal processor |
| Embedded operating system | Linux |
| I/O connection | Fiber optic ethernet |
| Digital (TTL) inputs | 16 bits (8 supported in hardware) |
| Input impedance | ≥ 1 G ohm |
| Sensitivity (AC model)/precision | 0.023 µV/bit |
| Bandwidth | DC to 2000 Hz |
| Input noise | < 0.8 µVRMS |
| Input range | ± 200 mV |
| Common mode rejection rate | ≥ 90 dB |
| Isolation mode rejection rate | ≥ 120 dB |
| Sampling rate supported | 8 KHz* (available: 0.25, 0.5, 1 KHz) |
| Power consumption | 15 Watts |
Also available are:
- 2 GES Clock Sync I/O
- 2 MR compatible electrodes for ECG measurements
- E-Prime Experiment Control System for stimulus presentation
- Faraday Cage