title: A multichannel EEG acquisition scheme based on single ended amplifiers and digital DRL.
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.
authors.affiliation: CONICET and UNLP, Dto. Electrotecnia, CC 91 (1900) La Plata, Argentina. marcelo.haberman@ing.unlp.edu.ar
authors.forename: Marcelo Alejandro
authors.initials: MA
authors.lastname: Haberman
authors.forename: Enrique Mario
authors.initials: EM
authors.lastname: Spinelli
mesh_terms: D000669:Amplifiers, Electronic; D001698:Biomedical Engineering; D011211:Electric Power Supplies; D004566:Electrodes; D004569:Electroencephalography / Q000295:instrumentation* / Q000706:statistics & numerical data; D004867:Equipment Design; D006801:Humans; D012815:Signal Processing, Computer-Assisted