Swedish researchers have developed a portable helmet that uses microwaves to quickly determine whether a person has had a stroke.

How well a patient recovers from a stroke is linked to how quickly the stroke is diagnosed and treatment is started. During the acute stage of a stroke around two million brain cells die every minute due to lack of oxygen. The faster the oxygen supply can be restored, the more brain (and therefore brain function) can be restored. The financial cost of strokes is enormous: estimated to be around 64 billion in Europe in 2010 alone. However, the human cost is even more devastating, with five million people dying each year and five million left permanently disabled.

http://www.wired.co.uk/news/archive/2014-06/17/strokefinder