It’s a race; if a stroke patient with cerebral thrombosis isn’t treated within a few hours,
lack of oxygen kills the brain tissues. The patient either dies or is left permanently disabled. On the other hand, if the blood clot is cleared quickly the patient could make a full recovery. Unfortunately, few receive treatment in time and our ageing populations only accelerate the problem, suffering and cost. Professor Mikael Persson and his team have found a way to slow down the world’s number two killer.
Haemorrhage or clot? A lethal decision
Approximately 75% of stroke patients suffer from a clot. Most of them could return to a good life with the swift application of an anticoagulant (a blood thinning treatment). The remaining 25% suffer a stroke due to a haemorrhage or bleeding. Of course, treating these people with an anticoagulant could be fatal, so correct diagnosis is critical.
The current method involves a computer tomography scan. This is effective. But if it takes more than four hours to get to the hospital and go through the procedures, the brain tissue will already be dead – and the treatment useless. If the diagnosis and perhaps even initial treatment could be carried out in the ambulance, millions of lives might be saved or improved.
Time for a brainwave
Around 2004, Mikael Persson and his team were studying the effects of mobile phone radiation on the brain. The medical effects are still being debated, but it became clear that the brain has a significant effect on radiation. Differences in tissue structure and electrical properties affect microwaves – which gave Mikael the idea of using microwaves to scan the brain. Five years later the company, Medfield Diagnostics, sold its first product – Stroke Finder R10 – to Sahlgrenska Hospital, a clinical partner in the project.
An X-ray helmet
Stroke Finder comprises three parts – a helmet-like device that sits on the patient’s head, a microwave and a computer. Inside the helmet are antennas which both transmit and receive microwaves to diagnose the brain. The helmet is connected to a microwave system controlled by the computer. The product is already more mobile than an X-ray machine, but needs to be even smaller to use in ambulances. So at Chalmers right now, several research groups are working across disciplines to shrink the equipment. Ideally to the size of a mobile phone.
Advanced signal processing
A major challenge is signal processing. Unlike X-rays, microwaves spread when they penetrate tissue. And the image field, and its dependence on brain tissue and any bleeding, is highly complex. Since Stroke Finder is based on 10 antennas, each transmitting and receiving microwaves at 400 different frequencies, the data involved is gigantic. From these data sets, the patient is diagnosed with the use of algorithms – also developed in interdisciplinary projects with scientists from several research groups.
One of a hundred
The task of Chalmers Innovation is to transform technology ideas into expansive companies. Since 1999 it has been instrumental in starting 100 businesses. Based at Sahlgrenska Science Park, Medfield Diagnostics is one of them. The company has received development funds from both public and private investors and venture capitalists.
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