Multifrequency REG: Fundamental Background, Informational Meaning and Ways of Data Analysis and Automation

A long historical experience of monofrequency rheoencephalography (REG) showed its limited capabilities. The new approach ispresented - multifrequency REG that is REG record ing simultaneously at three frequencies - 16, 100 and 200 kHz. The d ifferent brain impedances received were analysed on the base of equivalent electrical circuits of brain tissue. First, this enables to calculate intra-extracellu lar electrical co mponent for evaluation of brain tissue hydration state by means of an original co mputational method. Second, dynamic cooperative analysis of mu lti -REG and transcranial Doppler pulsations provides the indices of intracranial CSF mobility (CSFm) and cranial co mpliance (CCe). Th ird, spectral analysis of processes recorded provides valuable information of regulatory processes involved. The application of this new approach to investigation of intracranial circu lation in healthy persons of different aging groupos and in neurosurgical patients showed its promising effectiv ity.