Abstract: A microprobe useful for assessing auditory function by enabling clinical and intraoperative measurements of blood flow, particularly cochlear blood flow and neural compound action potentials, particularly of the auditory nerve (cranial nerve VIII) is disclosed. In addition, a monitoring system containing this microprobe and a method of using the microprobe are described.

Abstract: The evoked potential processing system includes, in one embodiment, a spectral averaging method. Time based, digital pre-stimulus and post-stimulus electroencephalographic (EEG) signal streams are obtained and are converted into frequency spectrum signals. A differential spectrum is obtained. The differential spectrums from a plurality of sweeps are summed. The summed differential spectrum is then converted into a time based signal stream which contains the evoked potential (EP) signal therein. The EP signal can also be obtained utilizing a two-dimensional filter. Pre- and post-stimulus EEG signal streams for a sub-group of stimuli, wherein each stimulus in a group has the same intensity or frequency, are filtered by conventional averaging or spectral differential averaging. The time based, filtered, post-stimulus EEG signal streams are placed in an array and the array is then filtered by a two-dimensional Fast Fourier Transform (FFT) filter.