Design And Analysis Of DTMS-EEG Acquisition System

Psychiatric disorders have become a serious public health and social problem, while there is still few quantitative criteria to diagnose these diseases well. One of the effective approaches to detect and diagnose neurological disorders is to use Deep Transcranial Magnetic Stimulation (DTMS) as the input to arouse brain specificity, and the corresponding EEG signal as the output to reflect the states of the brain function. In this method, the core technology to diagnose neurological disorders is the EEG’s acquisition and analysis. This thesis has been proposed as a method to realize multichannel DTMS-EEG acquisition and wireless transmission.First, multichannel synchronous transmission system can be realized by controlling multichannel AD converters synchronously with the output of CPLD; Second, through 3-level amplification on hardware, active, passive and high order filtering processing, the EEG signal can be preprocessed properly before entering the AD converters; Then, through adding programmable gain amplifiers and analog switches, we can realize the special control of the EEG signal acquisition online under DTMS; Finally, the signal’s multichannel wireless transmission and transmission to PC for show and control can be realized by data compression through automatical bits selection.A method composed of Mutual Information method and Lempel-Ziv Complexity method (MILZC) is proposed to investigate the effects of acupuncture on the complexity of information exchanges between different brain regions based on EEGs. 8 subjects are manually acupunctured (MA) at’Zusanli’acupuncture point (ST-36) with different frequencies (i.e. 50, 100, 150 and 200 times/min), and the EEGs are recorded simultaneously. Three main findings are obtained: (a) MILZC values increase during the process of acupuncture; (b) MA with 100 and 150 times/min are more effective than that with 50 and 200 times/min; (c) contralateral hemisphere activation is more prominent than ipsilateral hemisphere’s. All these findings suggest that MILZC method can successfully characterize the variations of the complexity in brain information exchanges.The DTMS-EEG wireless transmission acquisition system in this paper contains a lot of advantages, such as multichannel synchronization, multichannel transmission and detecting the EEG online under DTMS. Therefore, it provides a new way to detect psychiatric disorders. Meanwhile, the MILZC-EEG analyzing method in the paper is suitable for studying psychiatric disorders based on the framework of the brain function network.