A wireless optogenetic headstage with multichannel neural signal compression

This paper presents a multichannel wireless op-togenetic headstage providing neural recording and optical stimulation capabilities simultaneously. The proposed headstage, which is entirely built using commercial off-the-shelf components, includes 32 electrophysiological recording channels and up to 32 high-power optical stimulation channels. It can process 32 neuronal signals in real-time with high compression ratio using an embedded digital signal processor performing spike detection and data compression in-situ. The presented headstage is small and lightweight rendering it suitable for conducting in-vivo experiments with freely moving transgenic rodents. We report results obtained from in-vivo experiments showing that the proposed wireless headstage can collect, detect and compress the microvolts amplitude neuronal signals evoked by light stimulation with a high averaged peak-signal-to-noise ratio of 22.4 dB and a high averaged signal-to-noise distortion ratio of 17.0 dB. The design of this headstage is using a rigid-flex printed circuit board, resulting into a lightweight (2.8 g) and compact device (17×18×10 mm3).