CMOS-based microelectrode arrays (MEAs) enable the recording of electrical activities from biological cells, i.e., neurons or cardiac cells, at multiple sites with single-cell resolution. However, biological and electronic noise sources impair the detection of extracellular voltages. Reliable detection of so-called action potentials (small voltage deflections) would be significantly improved with real-time data processing. Therefore, we present here a Field Programmable Gate Array (FPGA) that filters the data stream and extracts the relevant electrophysiological information. In addition to single-cell activity, we analyze the CMOS MEA area covered by biological tissue using electrical imaging via adhesion voltage noise spectroscopy. Electrical imaging enables the recording of selected areas at unprecedented spatiotemporal resolution.