Start-up stories: York Instruments

Brain waves

Gary Green has spent his career working at the interface between physics, neuroscience and medicine. He speaks to Margaret Harris about starting a company, York Instruments, t o c ommerciali z e a new b r a i n imaging technology t s t r u m e n

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How did you get into this f ie ld? I did my PhD in neuroscience at the Univers i t y o f O x f o r d , UK , ha v i n g f i r s t d o n e an und e rgraduate degree in bioscience. But when my supervisor offered me the PhD position, he said, “Okay, you’ve done a degree in stamp collecting; now you have to do proper science” – a reference to Ernest Rutherford’s famous comment that all science is either physics or stamp collecting. He had me attend all the undergraduate lectures and problem classes in physics as part of my PhD work in neuroscience. After qualifying in medicine, I worked in medical schools for three decades before I was invited to come to the University of York to set up a brainimaging centre.

Why did you decide to star t a company? The idea began when the company that made our magnetoencephalography (MEG) machine in the research centre at York went bankrupt, caught out by the collapse of Lehman Brothers in 2008. We had to learn how to maintain it ourselves, and that meant replacing all the electronics because the chips in it were 25 years old – we couldn’t get replacements. That brought us to the attention of a group of Americans who were interested in mild traumatic brain injuries (MTBI), the kind people get from car accid e n t s o r p l a y i n g c o n t a c t s p o r t s s u c h a s r u g b y

Neuroscience spin-off Gar y Gr een commercialized a speciali s t magnetoencephalogr aphy machine.

and American football. They heard that we were building our own MEG electronics, so they approached us and said, “Would you like to join us in forming a company?”

This was in 2014, and I initially refused because I enjoy running the York Neuroimaging Centre and I am still very active in research. But then I thought, “Well, maybe I s h o u l d t r y s ome t h i n g e l s e i n t h e l a s t p a r t o f my career.” Like most academics, I’d done a lifetime of publishing papers and getting grants, but normally, you publish your work and you hope someone else will pick it up and use it. You don’t usually get t he oppor tuni t y to tur n i t into something that will help someone.

What are the advantages of MEG over other brain-imaging techniques? Magnetic resonance imaging (MRI) is great for imaging the brain’s structure, but when people use it to study brain function, they do it indirectly, by looking at changes in the magnetic properties of blood. As soon as an area of the brain becomes active, you get an increase in the flow of oxygenated blood to that area, and when the oxygenation of the haemoglobin in your blood changes, so do its magnetic properties, which affects the MRI signal. But it’s a slow process, one that happens over a period of seconds, and the connection with brain activity is very indirect. I t ’s a proxy measurement.

One alternative is to stick electrodes on someone’s head and measure the electrical potentials – an electroencephalogram, or EEG. The problem is that when current flows in the brain and creates those differences in electrical potentials, it also flows in layers of tissue over the brain that are not very good at conducting electricity. Although you can sample that electrical activity thousands of times a second, the picture you get is spatially blurred, and it ’s a l s o n o t g o o d a t i mag i n g p r o c e s s e s t ha t a r e

Physics World  Careers 2020

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