Award-winning researcher will test stroke-detection devices
- 11 August, 2011 08:08
With a US$100,000 cash award from Microsoft, the University of Sydney's Alistair McEwan will set up trials of electronic devices that can diagnose heart attacks and strokes early.
McEwan, who works as a lecturer of computer engineering at the university's School of Electrical and Information Engineering, was selected as one of eight recipients of this year's Microsoft Research Faculty Fellowships, the company announced in July. The fellowships go to those who are "advancing computing research in novel directions," according to Microsoft.
In McEwan's case, this new direction is his approach to using bioelectronics for solving health issues. He uses the so-called bio-impedance measurement for emergency diagnosis of strokes and heart attacks. His focus is the electrode-skin interface of devices detecting those illnesses.
With bio-impedance measurement, an electromagnetic signal is introduced into the body and the resulting signal is recorded. This is different from an ECG (electrocardiogram), which passively monitors the electric field originating from a patient's body. "It's a bit like using our own light source to illuminate the scene rather than trying to take a photograph without a flash," said McEwan.
While he believes this method could be an improvement on ECG, there has been a big problem: Movement blurs the electric signals. McEwan tries to solve the problem by measuring multiple points on each electrode. In this way, "we can produce a better estimate of contact impedance of each electrode and how they are changing with movement," he said. Solving this movement problem would also assist in monitoring methods such as ECG or EEG (electroencephalogram) where movement artifacts are a problem, too. Blurred signals make it difficult to detect strokes or heart attacks.
For the diagnosis of strokes McEwan wants to use EEG and an array of bio-impedance measurements, in a technique called Electrical Impedance Tomography (EIT). Paramedics could use this method of neuroimaging in an ambulance to monitor for stroke or head injuries, McEwan said. "The device could be as compact as an iPod so [it] could be carried by high-risk patients or incorporated in a Holter monitor, a common wearable ECG monitor," he added.
With the funding from Microsoft, McEwan is now going to put the devices into preclinical trials. Using test setups made from materials such as gelatin to model the human body, he analyzes if the devices are sensitive enough to measure relevant information. His team will also perform measurements on volunteers.
Without the money made available by the Microsoft Research Faculty Fellowship, McEwan would have had to look for other sources to support his trials. "We would have continued to seek university, government and charity funding. There are also a number of Ph.D. students who contribute, but we would have taken longer without the Microsoft funding," he said.
Apart from the money, researchers awarded with a Microsoft Fellowship are able to use further resources from the software company. McEwan said he plans to use Microsoft's cloud computing service as computational power was the second big problem hampering bio-impedance measurement. One of the difficulties in his research was "solving a million-element model of the interior of the body with only a few hundred measurements from electrodes on the surface," McEwan said. He also wants to talk to Microsoft researchers about advanced algorithms for this problem.
McEwan received his Bachelor of Engineering, Bachelor of Commerce and Master of Philosophy degrees in economics and in electrical engineering from the University of Sydney, and his Doctor of Philosophy from England's Oxford University.