We developed a new system by which the necessary EEG data can be automatically played back in a short time. This system consists of the 12-channel electroencephalograph (NIHON KODEN), the data recorder (TEAC R-280) and the function code generator (TEAC FC-2000) which is the instrument of automatic search for EEG record on the magnetic tapes.
When the EEG is recorded, one track out of 14 channels of magnetic tape is recorded with function code. Function code is located both at the beginning and at the end of the each EEG record : the former is called start frame, and the latter stop frame. On playing back an EEG record on the magnetic tape, the function code generator searches for start frame of necessary EEG record, and then the data recorder stops at its start frame. Thus, we can play back the necessary part of the record.
Duration of each recording unit is one minute, and the number of units from one patient is limitless.