Low Noise Biopotential Amplifier and the Future Use of Energy Scavengers for Biomedical Instrumentation

Biopotentials are electrical signals generated by living organisms; they provide valuable information about the physiological processes occurring within the body. In several cases, such as electroencephalography, the level of the output biopotential signals is in the order of microvolts, and the measurements are easily corrupted by external interferences. This paper introduces a low-noise EEG (electroencephalography) amplifier design. The amplifier comprises a low-noise instrumentation amplifier with a Driven Right Leg (DRL) circuit, a bandpass filter, and a programmable gain amplifier. Simulation results demonstrate a low input-referred noise of 0.174µVrms integrated from 0.1 to 100 Hz. Post analog processing and filtering, the signal undergoes sampling and digitization by a commercial data acquisition card connected to a PC. Furthermore, the paper suggests the development of a wireless EEG acquisition system powered by a thermoelectric energy scavenger.