A multichannel EEG acquisition scheme based on single ended amplifiers and digital DRL

IEEE Trans Biomed Circuits Syst. 2012 Dec;6(6):614-8. doi: 10.1109/TBCAS.2012.2190733.

Abstract

Single ended (SE) amplifiers allow implementing biopotential front-ends with a reduced number of parts, being well suited for preamplified electrodes or compact EEG headboxes. On the other hand, given that each channel has independent gain; mismatching between these gains results in poor common-mode rejection ratios (CMRRs) (about 30 dB considering 1% tolerance components). This work proposes a scheme for multichannel EEG acquisition systems based on SE amplifiers and a novel digital driven right leg (DDRL) circuit, which overcome the poor CMRR of the front-end stage providing a high common mode reduction at power line frequency (up to 80 dB). A functional prototype was built and tested showing the feasibility of the proposed technique. It provided EEG records with negligible power line interference, even in very aggressive EMI environments.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amplifiers, Electronic
  • Biomedical Engineering
  • Electric Power Supplies
  • Electrodes
  • Electroencephalography / instrumentation*
  • Electroencephalography / statistics & numerical data
  • Equipment Design
  • Humans
  • Signal Processing, Computer-Assisted