Compact Closed-loop EEG/fNIRS Recording and TMS Neuromodulation System

Transcranial magnetic stimulation (TMS) is a clinic-proven neuromodulation technique to treat various neurological and psychological diseases. However, existing TMS devices are bulky, expensive, and open loop. Therefore, they can only be used in fixed locations, and the modulation effects cannot be measured. In this paper, a wearable close-loop neuromodulation system that integrates real-time EEG/fNIRS recording and TMS is proposed. The system’s real-time signal monitoring and analysis function allows the inducing of magnetic stimulation and helps measure its effects after stimulation. The proposed system can measure and analyze 23 channel EEG and 64 channel fNIRS signals simultaneously in real-time. The dimensions of the fabricated TMS device are 330mm × 148mm × 112mm, with peak voltage and current values of 1100 V and 2400A, respectively, resulting in peak magnetic stimulation of 620 mTesla and bidirectional current pulse width of 311 μs.