A MULTI-CHANNEL ECG RECORDING SYSTEM WITH FDM TECHNIQUE FOR 12-LEAD APPLICATIONS

Abstract

In this thesis, a dual-loop 8-channel Electrocardiogram (ECG) recording system is proposed for wireless real-time 12-lead ECG applications. It employs frequency division multiplexing (FDM) technique to achieve multi-channel IA (MCIA). The FDM technique allows using smaller input capacitor and sharing of PGA, buffer, and ADC to achieve smaller area. To suppress the DC offset of bio-signal with faster settling, dual DC servo loops are proposed. The main loop employs the least-mean-square (LMS) algorithm in the digital domain to extract DC offsets for different frequency channels. An auxiliary fast settling loop (FSL) in analog domain can be enabled to shorten the settling time from 14 s down to only 0.6 s. The MCIA achieves 112.5-dB CMRR, 113.0-dB PSRR, and 1.44-μVrms noise performance. The MCIA occupies only 0.3 mm2 and consumes 60μW for 8 channels. The whole ECG recording system was implemented in 130-nm CMOS technology.