The ultimate device will offer rapid health checks and results for scientific research.
The droplet is placed on a portable device built around a disc like a mini-DVD. The disc is set spinning to separate the sample into plasma and serum for a whole range of simultaneous tests.
On the ground, there are already numerous applications - the automated laboratory unit covers illnesses such as heart disease, prostate cancer, diabetes and liver disease.
Radisens Chief Executive Officer Jerry O'Brien realised "you don't need gravity for this to work - spinning it in space should work just as well."
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"Our subsequent approach has been to leverage our commercial developments for use in space as well. Potentially the technology could be ready for use in orbit within this decade," said O'Brien.
The first phase of the partnership with ESA assessed its suitability for space, with this new phase intending to design practical prototypes for use on the station and other future manned space missions.
"Being able to perform rapid analysis of astronauts' blood samples and monitor their physiological parameters aboard the Station, without having to transport the samples down to labs on the ground, would prove extremely useful," said ESA's Francois Gaubert.