A Multichannel Reconfigurable EEG Acquisition System Design with Felt-based Soft Material Electrodes

摘要

The electroencephalogram (EEG) is a weak electrical signal generated by the activity of neurons located in the cerebral cortex or scalp surface neurons which is very important to brain disease diagnosis, rehabilitation and so on. However, the traditional acquisition equipment is usually large in size, difficult to configure, and complicated to use. To overcome these problems, a novel 8-channel EEG acquisition system based on the analog front end ADS1299, which can be also extended to 32-channel is proposed. A novel flexible and replaceable electrode based on felt material without the requirement of the conductive paste is designed. The proposed system is able to adjust the sampling rate from 250 Hz to 16 kHz. Moreover, with the advantage of a programmable gain amplifier, the proposed system can be applied not only for EEG signal acquisition, but also for most of the physiological signals acquisition like the electrocardiogram (ECG), electromyogram (EMG) and so on. In order to evaluate the performance of the EEG acquisition system, input noise level experiment and comparison experiment with the commercial product are performed. Moreover, spontaneous EEG signals (open-closed eyes) and evoked EEG signals (the steady-state visual evoked potentials, SSVEP) tasks are conducted. Experimental results indicate that the system satisfies the requirements of multi-channel EEG acquisition with high signal quality. And the system could provide a comfortable portable, function-rich, reconfigurable and low power-consumption way for the EEG related applications such as clinical diseases diagnosis and brain-computer interface (BCI).