New technology helps save lives during surgery Friday, 16 September 2016

Putting a patient under anaesthetic during an operation can be a fine balance between giving them enough so they don’t feel any pain, but not too much in case they suffer adverse effects.

This balance can be difficult to achieve, but new technology by Cortical Dynamics can help monitor patients while they’re under anaesthetic to make it easier to get this balance right.

The Brain Anaesthesia Response (BAR) monitor was developed by David Liley at Swinburne University.

Liley realised the existing processes for measuring anaesthesia were not optimal in terms of providing a solution for keeping people properly anaesthetised, so he worked on developing an alternative methodology to describe brain wave activity using mathematical equations.

“His approach was to analyse each individual’s EEG through the mathematical process that he developed, as opposed to the existing technologies that use essentially an average of features from thousands of people,” said David Breeze, executive director at Coritcal Dynamics.

While researchers have previously come up with alternative devices, Breeze said the data still used mathematical interpretations based on averages.

But the BAR monitor works by analysing an individual’s activity in the brain and interpreting that activity to effectively monitor a patient’s anaesthetics.

“When you’re anaesthetised, you have a hypnotic product that puts you to sleep and you have another product, which is the analgesic, to stop you feeling pain,” Breeze said. “Many operations also use muscle relaxants as part of a balanced anaesthesia.”

But if excessive or insufficient anaesthetics are used, the effects can be disastrous – people can wake up during surgery or suffer adverse effects later as a result of the anesthesia, such as needing a long time to recover or being physically ill.

Developments to help manage anaesthesia during surgery have included the introduction of intravenous anesthesia. But this can mean it can be hard to tell whether the patient is optimally anaesthetised, according to Breeze.

“The way in which operations have changed as a result of differences in the way in which anesthesia is introduced has meant that there is an increased demand for the sort of machine or the technology that Cortical has designed,” he said.

TGA approval

Liley spent a number of years working on the analysis methods used in the device and now has 22 patents in five patent families around the world.

“It took a quite a period of time for the research work to be done, and it also took three years for the technology just to be assessed and passed by the TGA here in Australia,” Breeze said.

As part of the Therapeutic Goods Administration (TGA) assessment, the authority compared the BAR monitor with existing technologies that carry out similar tasks.

“The sort of difficulties that we had was in fact in illustrating to the TGA that our technology worked in a way that was similar or better than the other existing monitoring devices,” Breeze said.

“[For example] within the TGA, they don’t have any expertise in this particular area of technology, so it took a long time and a lot of work to be able to demonstrate the efficacy of the BAR monitor.”

The team did this by having an independent expert look at all of the data it had collected over time and provided a report to illustrate that TGA requirements had been met.

The company also worked with Professor Michel Struys from Ghent University in Europe to take recorded brain activity data the professor had and worked with Professor Struys to demonstrate the effectiveness of the device.

Clinical trials

A clinical trial has been carried out at St. Vincent’s Hospital in Melbourne, where the BAR monitor was placed in an operating theater to collect data from 25 patients.

This allowed the company to compare the data it collected from the EEG on the patient’s forehead with the data that was simultaneously collected and put into another machine that is currently for sale in the marketplace.

The device picked up on some surprising data.

“In the collection of data from one of the patients, one of the drips that was supplying a drug that was part of the anesthesia … got dislodged,” Breeze said.

“When we went back and looked at that patient’s data, our device showed that the patient was not optimally anesthetised, whereas the other equipment appeared to demonstrate that the patient was anesthetised.”

Now that the BAR monitor has passed the TGA, it has approval for sale and distribution in Europe, with Cortical Dynamics signing an initial agreement with an Australian company and negotiating a further agreement for distribution in Europe. The company is also a semi-finalist in the Australian Technology Competition.

In the continually evolving world of medicine, Breeze said there is growing demand for products like the BAR monitor both in Australia and overseas.

“You come back to this basic role of anesthesia and the means of anesthesia have changed significantly,” he said. “So people are looking for a solution, a monitoring device that assists the anesthetist to keep the patient optimally anesthetised.”

[Photo credit: wellcome images via VisualHunt / CC BY-NC-ND]