A Programmable System for Concurrent Neural Stimulation and Recording with Artifact Mitigation
Electrical neuromodulation of the brain has enabled innovative treatments for various neurological disorders, yet the biophysical mechanisms underlying therapeutic benefits are not fully understood. Neural recording hardware is sensitive to large voltage transients and often saturates when proximal to stimulating electrodes, preventing the acquisition of direct evoked responses. Here, we developed a system with low-noise, high-input-range recording amplifiers and programmable stimulation current sources to investigate the neural responses typically masked by stimulation artifacts. The device design enables concurrent recording and stimulation through the same electrode for capturing evoked responses at the site and time of stimulation. Circuit testing was conducted to verify device specifications, and in vitro testing in phosphatebuffered saline using platinum-iridium microprobes and microelectrocorticography (μ ECoG) electrodes elucidated the capability of recording neural responses directly after stimulation. We found that currents above 200 μ A could be delivered without saturating the recording on the same channel for both microprobes and μ ECoG electrodes in saline. By applying artifact removal techniques, simulated neural data could be recovered approximately 50 μ s after stimulation. Investigation with this system in vivo could provide critical insight for understanding modulated cortical circuit dynamics, enhancing our knowledge of the therapeutic mechanisms underlying neural stimulation and advancing neuromodulation therapies.
