“Microwave helmet ‘can spot a stroke’,” reports BBC News.

There are two types of stroke. The majority of strokes are caused by a clot stopping blood flow to an area of the brain. This type of stroke can be treated with anti-clotting medications to break up or dissolve blood clots. However, this type of treatment is disastrous if the stoke turns out to have been caused by bleeding into the brain.

http://www.nhs.uk/news/2014/06June/Pages/can-a-microwave-helmet-really-detect-strokes.aspx