아날로그 뇌파기를 응용한 간단한 디지털 뇌파 시스템

Abstract

Purpose : The rapid development and wide popularity of Digital EEG(DEEG) is due to its convenience, accuracy and applicability for quantitative analysis. These advantages of DEEG make one hesitate to use analog EEG(AEEG). To assess the advantage of DEEG system utilizing AEEG(DAEEG) over conventional AEEG and the clinical applicability, a DAEEG system was developed and applied to animal model. Methods : Sprague-Dawley rat as status epilepticus model were used for collecting the EEG data. After four epidural electrodes were inserted and connected to 8-channel analog EEG(Nihon-kohden, japan), continous EEG monitoring via computer screen was done from two rats simultaneously. EEG signals through analog amplifier and filters were digitized at digital signal processor and stored in Window-based pentium personal computer. Digital data were sampled at a rate of 200 Hz and 12 bit of resolution. Acquisition software was able to carry out 'real-time view, sensitivity control and event marking' during continuous EEG monitoring. Digital data were stored on hard disk and backed-up on CD-ROM for off-line review. Review system consisted of off-line review, saving and printing out interesting segment ad annotation function. Results : This DAEEG system could utilize most major functions of DEEG sufficiently while making a use of an AEEG. It was easy to monitor continuously compared to conventional AEEG and to control sensitivity during ictal period. Marking the event such as a clinical seizure or during injection was less favorable than AEEG due to slowed processing speed of digital processor and central processing unit. Reviewing EEG data was convenient, but paging speed was slow. Storage and mangement of data was handy and economical. Conclusion : Relatively simple digital EEG system utilizing AEEG can be set-up at a laboratory level. It may be possible to make an application for clinical purposes.