US Patent 8937509 Multi-channel biopotential signal acquisition systems

A multi-channel biopotential signal acquisition system is disclosed. In the system, a plurality of biopotential channels is corrected for common-mode interference. In one aspect, each biopotential channel includes an electrode for providing a biopotential input signal and an associated amplifier for amplifying the biopotential input signal and providing a biopotential output signal. The output signal is processed in a processor. Each biopotential output signal is passed to a common-mode feedback system, which determines an average common-mode signal and feeds that signal back to each of the amplifiers in each of the biopotential channels to enhance common-mode rejection ratio of the system.