Diverse innovation approaches tackle brain-computer interface challenges
Controlling devices directly with the mind is not the future: it is here and it is exciting. That is the message from speakers at the University of Melbourne’s ‘Innovation in Brain-Computer Interfaces’ event, which explored cutting-edge technologies that read and process signals from the brain and relay those instructions to devices.
The event, part of the Melbourne School of Engineering’s MedTech Research Platform online events program chaired by Professor David Grayden, Clifford Chair of Neural Engineering, brought together seven experts from around the world to present their work in the area of brain-computer interfaces, and to discuss the opportunities and challenges facing this research sector.
Watch a graphic recording of the session
Andi Partovi, PhD student at the University of Melbourne, explains that brain-computer interfaces enable two-way communications between the brain and external devices, such as computers, spellers or robotic arms.
“Such a direct link between the brain and eternal devices will allow people to give commands to those devices by just thinking about it, effectively mind-controlling the devices,” Partovi says.
There are three key challenges in achieving this. The first is reading the signals from the brain. Dr Farhad Goodarzy, Electrical Engineer and Research Fellow at the University of Melbourne, explains that this can be done either invasively or non-invasively.
Non-invasive methods are preferred as they do not involve surgery. These include an electroencephalography (EEG) cap placed on the scalp and brain imaging techniques that examine oxygen levels or metabolic activity in the brain as indicators of activity.
But there are disadvantages with this approach. “We have the best signal quality when we are close to the source of the activity,” Dr Goodarzy says. “Also, brain activity is very regional, and neurons are very interconnected and densely located.”
Dr Rikky Muller, Assistant Professor at the University of California, Berkeley, has been working on both wearable and implantable devices for recording brain signals.
The aim is to make devices as tiny and low-power as possible so can we implant them with extremely minimal invasive procedures
The implantable devices are based on electrodes that are currently used to administer deep brain stimulation to treat neurological conditions, such as epilepsy and Parkinson’s disease, but they are much smaller and, most importantly, wireless. This means there is less chance of infection and could enable wireless charging, which avoids the need for bulky batteries. “The aim is to make devices as tiny and low-power as possible so can we implant them with extremely minimal invasive procedures,” Dr Muller says.
Dr Muller and colleagues are also investigating whether brain activity can be recorded non-invasively via the ear canal, using a wireless earbud. The signals in the ear canal might be weaker, but it would be a less obtrusive method of recording than an EEG cap.
At the University of Melbourne, biomedical engineer Associate Professor Nicholas Opie and colleagues are deploying a brain-computer interface device into the brain via the blood vessels, instead of implanting it through the skull. The device, called the Stentrode, is inserted through a major blood vessel in the neck, then deployed into the brain and anchored in the motor cortex. The advantage of this approach is that, while it is in the blood vessel, the device remains effectively invisible to the brain, so it is less likely to be rejected.
Once the Stentrode is in place, whether inside or outside the skull, the second challenge is to process the signals and translate them into something that can instruct the device in question.
At g.tec medical engineering, founder and CEO Dr Christoph Guger and colleagues have been working on brain-computer interface technologies to help stroke patients recover movement, even decades after their injury. As the patient sees a computer avatar move a hand, they imagine themselves making that movement, and the brain interface picks up those signals and translates them into electrodes that stimulate the relevant muscles in the arm. “This is pairing cognitive processes again with motor behaviour,” Dr Guger says.
Brain-computer interfaces are two-way, and at the University of Technology Sydney, Associate Professor Tara Hamilton has been working to improve the communication back to the brain, for example, via devices such as the cochlear implant. One of her areas of research is how to improve the music experience of cochlear implant wearers by trying different stimulation strategies for the auditory nerve that the implant interacts with.
“At the moment, music is something that isn’t well translated with the current strategies,” Dr Hamilton says. “We’re working with a cochlear implant recipient, as well as some music theorists, to think about what are features of music that we might be able to convey a lot better to cochlear implant users.”
She is working on models to better understand how neurons behave, such as those in the auditory nerve. Her work also looks at implants to monitor and improve nerves damaged in spinal cord injury, and new devices to process data based on brain-inspired technologies.
“It’s a really exciting time to be in this area,” Dr Hamilton says. “There’s actually too much to do and too many rabbit holes to dive down.”
Watch the full session recording now.
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