Wideband multichannel differential amplifier with modular design and adjustable analogous commutation.

• Input power: -15, 0, +15 V
• Type: differential
• Input resistance: 1 GOhm
• Noise level at connected inputs:
  • < 0.15 mkV (at 0.3-150 Hz)
  • < 0.8 mkV (at 0.3-1000 Hz)
• Gain coefficient:
  • Input cascade: 1, 10
  • Output cascade: 3, 10, 30, 100, 300, 1000
• Filtering:
  • Intensity: 12 dB/octave
  • LowPass: 35, 70, 150, 300, 1000, 2000, 5000, 10000, 20000 Hz
  • HighPass: 0.1, 0.3, 1, 5, 20, 100, 300 Hz
• Output range: -5V - +5V

The amplifier is composed of two boards: InputAmp and FilterAmp.

Input gain board performs initial commutation of the bipolar signal with reference monopolar input and calibration signal. Next the board amplifies the signal current with 1x/10x gain.

Corresponding directory contains the complete KiCAD project including scheme and PCB.

Preamplified signal is then further amplified inside this board and undergo LowPass and HighPass filtration.

Corresponding directory contains the complete KiCAD project including scheme and PCB.

Calibrator gets 0/+5V input unipolar source and gives 30/300 Hz of 1/0.1 mV square pulse unipolar signal for feeding the amplifier.

Corresponding directory contains the complete KiCAD project including scheme and PCB.

Boards are designed for further geometrical stacking as shown at the how-to-assembly scheme:

The prototype of this amplifier was firstly used by Ilya Kuzmin and colleagues for recording ECG of rats on a tredban:

• Tarasova OS, Borzykh AA, Kuz'min IV, et al. [Dynamics of heart rate changes in rats following stepwise change of treadmill running speed]. Ross Fiziol Zh Im I M Sechenova. 2012; 98(11):1372-9.

Now it is used by Georgy Nikolaev and his students for recording EEG in the research of audiogenic epilepsy on rat model:

• Fedotova IB, Surina NM, Nikolaev GM, Revishchin AV, Poletaeva II. Rodent Brain Pathology, Audiogenic Epilepsy. Biomedicines. 2021; 9(11):1641. https://doi.org/10.3390/biomedicines9111641

The project "Universal Biopotential Amplifier" (I. Kuzmin @kuzmin-ilya, A. Nesterenko @comcon1, G. Nikolaev)
is released under license CC BY-SA 3.0.

Submodules listed as independent projects are not part of this project and are released under their own licenses.