A versatile electrode sorting module for MEAs: Implementation in a FPGA-based real-time system

Extracellular recordings of biological signals using Multi-Electrode Arrays (MEAs) generate large quantities of multichannel data which are not all relevant. Indeed, cultured cells might not cover all electrodes or achieve sufficient electrical contact. In both bench experiments and implant-oriented devices, it is necessary to identify such defects and exclude corresponding electrodes from the processing pool. In the context of a real-time, FPGA-based multichannel signal processing system, this paper presents a versatile electrode sorting module. It uses low-complexity, user-configurable algorithms and supports synchronization, frequency, and amplitude criteria, as well as definable inclusion/exclusion rules. This module relieves the experimenter from constantly monitoring unusual behavior and promotes automatization. The module's efficacy was demonstrated during in vitro experiments on noise-prone pancreatic islets.