Brainwave breakthrough aids recovery

Recovery times from anaesthesia could be significantly reduced thanks to new research from Swinburne University of Technology and Perth-based biomedical company, Cortical Dynamics Ltd. 

In a paper published today in the medical journal Anesthesiology, Swinburne’s Professor David Liley outlines a new approach to analysing brainwaves during anaesthesia, which would allow doctors to separately monitor a patient’s level of consciousness and analgesic state.  

Presently doctors can use a range of electroencephalogram (EEG)-based monitors to determine if patients are adequately anaesthetised during surgery. However, according to Liley, this approach can be problematic. 

“EEG-based monitors have, over time, been very useful in operating theatres. However their downfall is that they use arbitrary, rule-of-thumb determinations to analyse brain signals and translate them into something that tells us about consciousness.   

“They are also unable to interpret the effect that analgesic agents – that is pain killers – have on brain activity,” he said.    

The advantage of Liley’s world-first approach is that it will allow doctors to monitor a person’s consciousness and analgesic state independently of one another.

 

In his latest study, Liley analysed brainwave data provided by his clinical collaborators in Europe. The data was from 45 patients who had been anaesthetised with propofol in the presence of varying levels of the synthetic opioid remifentanil.  

“Using a physiologically motivated signal analysis method we were able to detect the effects that the opioid had on the brain’s electrical activity, independent to the effects of the propofol. This will enable us to come up with a method that will allow doctors to monitor hypnotic and analgesic states independently of one another,” Liley said.

This approach could lead to numerous benefits for surgery patients. “Being able to optimise the delivery of anaesthesia will not only reduce the incidence of intra-operative awareness, it will also improve the patient’s recovery time and allow them to mobilise more quickly after an operation,” Liley said.  

“From a hospital’s perspective it’s also likely to save a considerable amount of money in terms of drug costs.”  

Liley and his team have already developed a prototype for a machine, the Brain Anaesthesia Response (BAR) Monitor, that applies the researchers’ physiologically motivated signal analysis method to electroencephalogram (EEG) data. 

The BAR Monitor is currently being commercialised through Cortical Dynamics Ltd, a BPH Corporate Ltd (ASX code: BPH) run company that was formed in 2004 based on Swinburne’s ongoing research into brain activity. 

Cortical Dynamics is working towards listing on the Australian Securities Exchange (ASX) later this year.

 

According to Liley the technology also has the potential for other diagnostic applications. It could improve the understanding of mental illnesses, stroke, psychosis and Alzheimer’s disease.

MEDIA NOTE: The Anesthesiology article and an editorial that accompanies the paper, written by Jamie Sleigh from the Department of Anaesthesia at Waikato Clinical School, are available upon request.

 

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