A Wireless ECoG Recording System to Detect Brain Responses to Tactile Stimulation

Many neural recording systems with wired connections to electrodes have suffered from the disadvantage that the wired connections restrict the movement of the subject. To overcome this restriction, wireless neural interfaces have been developed. However, due to the adoption of low transmission rates and protocols in the medical implant communication service band, it has been challenging to develop a high-resolution wireless recording interface that can utilize the functionality of multichannel electrodes at maximum. In this study, we developed a high-throughput wireless recording system assembled using only off-the-shelf components, resulting in a lightweight of 2.1 g. The developed wireless system can transmit 32 channels of neural signals with up to 30 kHz sampling rate per channel and 16-bit analog-to-digital conversion (ADC) resolution seamlessly. The system was connected to a flexible 32-channel electrocorticogram (ECoG) electrode array, and successfully recorded somatosensory evoked potentials (SEPs) from the in vivo brain in response to tactile stimulation, demonstrating a high signal-to-noise ratio (SNR), and high spatial and temporal resolutions in wireless neural signal recording.