The Cerebral Function Monitor (CFM) is a long term amplitude integrated EEG monitoring device (aEEG) specially fit for operation in intensive care environments. The device samples the EEG signal from two parietal electrodes situated on area P3, P4 on the 10/20 international EEG coding system. The EEG signal after going through initial preamplification is subjected to different filters that eventually filter the frequencies under 2 and over 20 Hz (muscle movements and electrical devices signal artifacts respectively), then rectify, smoothen and whiten the signal before compressing it to a semilogarithmic scale. The final output reflects the maximum and minimum amplitudes of the original electroencephalogram and is written out on heat sensible paper at a rate of 6 cm per hour. The CFM has been tested to date in a variety of situations at different age groups, from adults anesthetized and undergoing cardioplegia during open-heart surgery to preterm infants in an intensive care environment. The main usage of the CFM currently is for monitoring full-term newborns after birth asphyxia. The signal output from this group of patients underwent extensive investigations and brought the CFM from a status of an investigational tool to one of an accepted monitor in various neonatal intensive care units. Monitoring infants with the CFM after severe birth asphyxia is a quite accurate means for prognosis prediction and it can influence various treatment modalities. Another well established use of the CFM is monitoring for seizure activity, both clinical and silent with an added advantage of monitoring the treatment effect. In the various works cited above a good correlation was noted between the CFM output and the regular EEG signal, pointing out that the CFM is in fact a simplified one-channel EEG monitor. Thus, the main advantages of this device are its simplicity and ease of both application and interpreting on one hand and the possibility of continuous long-term monitoring with real time assessment of clinical events on the other.

Keywords: cerebral function monitoring, newborn infant, perinatal asphyxia, prognosis