Start your analysis with clean signals from BioSemi systems !


The ActiveTwo system sets new standards for multi channel, high resolution biopotential measurement systems for research applications. The system is a further development of our successful ActiveOne system, the first commercially available system with active electrodes. Advances in technology have allowed us to significantly increase the number of channels, digital resolution, input range, and sample rate, without any increase in size, power-consumption or costs. Second generation active electrodes are smaller in size with less cable weight, while offering even better specs in terms of low-frequency noise and input impedance. The new system confirms the solid lead that BioSemi has build over competing designs during the last years.


-Headcap system with the fastest application time.

-Up to 256+8 electrode + 7 sensor channels in a single ultra compact box.

-Reliable measurements without skin preparation.

-Second generation active electrode: smaller size & less weight.

-Battery powered front-end with fiber optic data transfer.

-Flexible colored electrode labeling system.

-Suitable for EEG, ECG as well as EMG measurements.

-24 bit ADC per channel, unsurpassed S/N ratio and linearity.

-Graphical programming (LabVIEW) on PC and Mac.

-Improved digital resolution, LSB value is 31nV.

-Full range of auxiliary sensors available.

-Full DC operation, largest input range in the industry (524mVpp).

-MEG/MCG compatible digital system.

-User selectable sample-rate 2, 4, 8, 16 kHz/channel.

  • ?DATA SHEET? (Specifications)
Sample-rate options:?(sample rate is adjustable by user) 2048 Hz 4096 Hz 8192 Hz 16,384 Hz
Max. number of channels @ selected sample rate:
280 280 280 152
Bandwidth (-3dB): DC – 400 Hz? DC – 800 Hz DC – 1600 Hz DC – 3200 Hz
Low-pass response 5th order sinc digital filter
High-pass response fully DC coupled
Digitalization: 24 bit, 4th order Delta-Sigma modulator with 64x oversampling,
one converter per channel
Sampling skew: < 10 ps
Absolute sample rate accuracy (over temp range: 0-70 C) 0.1 Hz 0.2 Hz 0.4 Hz 0.8 Hz
Relative sample rate accuracy (jitter) < 200 ps
Quantization-resolution LSB = 31.25 nV, guaranteed no missing codes
Gain accuracy: 0,1 %
Anti aliasing filter fixed first order analog filter, -3dB at 3.6 kHz?
Total input noise (Ze < 10 kOhm):, full bandwidth 0.8 uVRMS
(5 uVpk-pk)
1.0 uVRMS
(6 uVpk-pk)
1.4 uVRMS
(8 uVpk-pk)
2.0 uVRMS
(12 uVpk-pk)
1/f noise (Ze < 1 MOhm): 1 uVpk-pk @ 0.1..10Hz
Amplifier current noise: < 30 fArms
Input bias current: < 100 pA per channel
Input impedance Active Electrode 300 MOhm @ 50 Hz (1012 Ohm // 11 pF)
DC offset: < 0.5 mV
DC drift < 0.5 uV per degree Celsius
Input range +262 mV to -262 mV
Distortion < 0.1 %
Channel separation > 100 dB
Common Mode Rejection Ratio > 100 dB @ 50 Hz
Isolation Mode Rejection Ratio > 160 dB @ 50 Hz
Power Consumption 4 Watt @ 280 channels
inversely proportional with the number of installed channels
Battery capacity, standard battery 25 Watt-hour, 3 cell sealed lead-acid
(double capacity battery is available as an option)
Battery life on standard battery > 5 hours @ 280 channels
inversely proportional with the number of installed channels
Battery charge time (with external fast charger): < 3.5 hours for a 100% charge
Leakage current, normal operation: < 1 uA rms.
Leakage current, single fault? < 50 uArms
Trigger inputs: 16 inputs on optical receiver (isolated from subject section) , TTL level?
Trigger outputs: 15 outputs on optical receiver (isolated from subject section) , TTL level?
PC interface: USB2.0
Size of front-end, including battery-box (H x W x D) 120 x 150 x 190 mm
Weight of front-end, including battery-box 1.1 kg
Warranty 3 years




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