Abstract
The authors have developed a fiber-optic, 4-channel EEG instrument for the reduction of electromagnetic interference, in which bioelectric signals were transmitted with being once converted to optical pulses through an electrical-to-optical transducer and were then inversed through an optical-to-electrical transducer immediately before entering the output instrument over a single fiber channel. It was confirmed in surgical patients under general anesthesia that EEG waveforms obtained with the fiber-optic EEG instrument were almost same with those recorded simultaneously with a conventional EEG instrument. EEG recording with the fiber-optic EEG instrument was not disrupted even during the use of electrocautery. Because electrical conductivity was interrupted with an optic fiber interposed between scalp electrodes and the EEG instrument, the fiber-optic EEG instrument seems to be useful for EEG recordings in a surgical center, where it is hard to exclude electromagnetic and electrostatic interferences.
