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BAR Monitoring System

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.

Cortical's BAR Monitor receives CE Mark

Cortical Dynamics Ltd (“Cortical”) is pleased to announce it has received formal notification from the Therapeutic Goods Administration (“TGA”) that a decision has been made to issue MRA EC certificates (“CE Mark”) to Cortical under the Mutual Recognition Agreement (MRA) with the European Union therefore allowing the  CE mark to be applied to the BAR monitor.

Clinical Trails


St Vincent's Hospital, Melbourne, Australia

The BAR Monitor was used on patients undergoing elective first-time coronary artery bypass graft surgery. Patients received propofol for anaesthesia induction and were randomised to receive a low or moderate dose of the analgesic fentanyl. In this trial, the BAR monitor demonstrated the potential to monitor the level of hypnosis following anaesthesia induction with propofol via the CCS index and to facilitate the titration of fentanyl as a component of balanced anaesthesia via the CI index.


Ghent University Hospital,Belgium

Remifentanil, an ultra-short acting synthetic opioid, is an important intraoperative analgesic agent.  Being able to reliably detect its physiological effect is an important step towards monitoring the analgesic state of a patient.  This study involved the reanalysis of electroencephalographic (EEG) data recorded during propofol-remifentanil anaesthesia and showed that the BAR methodology, unlike existing EEG monitoring approaches, was capable of differentiating the effects of the anaesthetic agent propofol from the analgesic agent remifentanil.

Nitrous Oxide

Royal Melbourne Hospital, Australia

Nitrous oxide, while not potent enough to be a sole anaesthetic agent, is often co-administered with more powerful volatile agents such that the inspired concentrations of such agents can be reduced.  However the effects of nitrous oxide are poorly detected by existing electroencephalography (EEG) based methods.  This study demonstrated the BAR methodology to be more sensitive in detecting the effects of nitrous oxide than the leading existing EEG based method.

Remifentanil + noxious stimulus

Groningen University Medical Centre, Netherlands

This trial involves the application of the BAR methodology, and other EEG based methods, to detecting the effects of a painful intraoperative stimulus in the presence of varying levels of remifentanil, an important analgesic agent used routinely during surgery.  Results from this trial are due soon.


Swinburne University of Technology, Australia

Alprazolam, a member of the benzodiazepine class of sedative agents, at low doses typically produces characteristic changes in the resting electroencephalogram (EEG).  This study, involving a cohort of healthy participants, aimed to show that not only could the BAR monitor detect such changes. Results from the trial are due soon.