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A team of researchers at the �鶹��madou Graduate School of Biomedical Engineering (GSBmE) is trying to get on people’s nerves. They aren’t aiming to trigger maximum irritation – instead, they’re looking to find effective ways to trigger sensory neurons to send sound signals to the brain. 

Their research will contribute to the next generation of cochlear implant devices and could assist with other therapies to restore a person’s sensory functions.

, co-director of the Sir William Tyree Foundation Institute of Health Engineering (Tyree IHealthE) at �鶹��madou Sydney and a biomaterials expert, is leading one of the projects in this area, partly funded with a grant from implant manufacturer Cochlear Limited.

The team on Laura’s project is testing different materials and coatings to see if the tiny platinum electrodes used in the current cochlear implant could be made even smaller and more effective. But it will take time.

“There’s a big regulatory process that you have to go through to get a device approved, and to prove that it works and is safe,” Laura explains. “There’s a lot of experimental work and then there’s a lot of characterisation work and a lot of testing. It can take years.”

Neurological modelling  

To be approved, cochlear implants and similar ‘neuroprosthetics’ must successfully complete phases of animal testing and clinical trials. Before that, though, they undergo investigations designed to test their merit and validate their progression.

These initial rounds of research typically include the use of computer models or biological models, as Laura explains.

“Our researchers will often set up either computational models that can look at how a particular tissue works in three dimensions; or physical models, based on tissue samples that we use on the bench to actually test devices,” she says. 

Defining the possibilities with computational modelling 

is using computer modelling to map the effects of electrical stimulation on heart and nerve tissue. He has also used scans from patients to develop computer models that simulate how an electrical field moves through brain tissue. 

“We scan the heads of patients with MRI scans and build quite sophisticated computer models of their head… we can actually visualise the flow of current for that particular patient and see which parts of the brain are being affected,” he says. “That sort of research is helping us understand why some patients respond quite well to ECT and why others don’t.”

is another GSBmE researcher focussed on the development of neural stimulators. Like Socrates, he uses advanced computational modelling to inform his work on interventions that restore functions such as sight, and others that reduce feelings of pain.

“There are many unknowns in these fields, and the current state-of-the-art biological technology simply can’t record everything. That's why I'm using computational models – to predict information which is difficult to measure in biological experiments,” he explains. 

Tianruo has pioneered a computational model for the human retina which he believes to be the most accurate and clinically relevant model currently available. 

“In terms of designing a stimulation strategy [for the retina], there are just so many factors we need to consider. It would take years to test all those factors. Computational modelling helps us narrow things down – saving resources, saving money, saving time, saving lives.”

Exploring living complexities with biological modelling 

The tissue models being developed in Laura’s team by Dr Ulises Aregueta Robles for the cochlear implant project are unusually complex. 

“We currently have a project going where we’re making a three-dimensional cochlea on the bench,” she says. “We’ll be able to feed in the electrodes to see how changing the electrode mechanics might affect cells.”

Laura acknowledges the talent of the multidisciplinary teams working at GSBmE. Her own project draws on the expertise of biologists as well as chemical, materials and electrical engineers. 

“We’re very privileged to be in this situation where we have these fantastic people around us to work with us,” she says. “It is great because you do get to interact with not only a whole lot of different disciplines, but a whole lot of different people from around the world.”