Skip to main content

Brain Anaesthesia Response (BAR) Monitoring System

BAR SystemThe core product the Brain Anaesthesia Response (BAR) monitor improves on currently used electroencephalogram (EEG) technologies by incorporating the latest advances in our understanding of  how the brain’s rhythmic electrical activity, the electroencephalogram (EEG), is produced.

The approach used is fundamentally different from all other devices currently available in the market in that its underlying algorithm produces EEG indexes which are directly related to the physiological state of the patient’s brain.

Other systems on the market produce EEG measures based on physiologically arbitrary statistical methods that utilise the trial-and-error identification of anaesthetic induced EEG regularities in patients undergoing a variety of operative procedures.

The BAR system provides much greater sensitivity to anaesthetic drug effect enabling the monitoring of a wider range of anaesthetic agents, some of which are not properly detected by the competing technologies.

The BAR monitors’ proprietary technology incorporates specific physiological insights regarding how the EEG is generated and how it is affected by anaesthetics and sedative drugs.  The BAR methodology differentiates changes in brain function using two uniquely defined measures referred to as the Cortical State (CS) measure and the Cortical Input (CI) measure.

An analysis of a comprehensive data set obtained from European Collaborators using the BAR methodology unambiguously indicated that the effects of remifentanil (a powerful synthetic opioid) and propofol (a widely used intravenous general anaesthetic agent) on brain electrical activity can be differentiated.  The ability of the BAR monitoring approach to detect the effects of remifentinal is particularly significant.  Remifentinal, an ultra-short acting opiod is used to provide intraoperative pain relief and thus detecting its effect on EEG measures of higher brain function indicates the potential for the BAR methodology to separately monitor hypnotic and analgesic state. At present there is no known EEG based depth of anaesthesia monitoring approach that is able to achieve this. Objectively monitoring hypnotic and analgesic state will lead to improved anaesthetic and surgical outcomes, by reducing recovery times and minimising drug costs. The detailed results of this analysis were published in the prestigious journal Anesthesiology[1].



[1] Anesthesiology, 2010,13(2):292-304