The electrically evoked brainstem potential was measured in guinea pigs with 260-channel surface microelectrode implanted on the cochlear nucleus. Even when surface bipolar stimulations with 200μm separation of two electrodes are employed, the unequivocal waves of electrically evoked auditory brainstem responses (EABRs), which increased in amplitude with increasing stimulation current, were constantly derived. Electrophysiological mapping using the 260-channel surface microelectrode indicated that more precise electrophysiological mapping may be possible based on the EABRpositive boundary.
The multi-channel surface microelectrode was expected to be usefully applied to the probe to determine the optimal location for the positioning of the ABI and stimulating electrode in ABI in clinical use.