An Intra-oral EEG System with Accelerometer For Motion Artifact Free EEG Recording.

Electroencephalography (EEG) has been reported to be acquired intra-orally from the palate region. Although different types of motions such as gulping, tongue movements, teeth grinding can occur intra-orally, the motion artifacts in intra-oral EEG signals have not been studied. In this work, we propose a sensor-fusion of EEG electrodes and an accelerometer integrated with a mandibular device and demonstrate an algorithm to generate motion artifacts free intra-oral EEG signal by removing the motion corrupted EEG segments. The EEG electrodes and the accelerometer simultaneously record intra-oral EEG signals and motion signals, respectively. The signal recording instrument is implemented on a breadboard for this study. The algorithm implemented in MATLAB identifies the motion events from the accelerometer data, removes the motion corrupted EEG data segments using the accelerometer information, and finally reconstructs the EEG signals after the removal of the corrupted EEG segments. The effectiveness of the sensor-fusion and algorithm is demonstrated for the detection of 'eye open' and 'eye close' activity from intra-oral EEG signals in the presence of tongue movements, teeth grinding and gulping. The device along with the algorithm will have potential for motion artifacts free intra-oral EEG signal monitoring.