Smartphones monitor blood clotting times

A method to test using your mobile phone how fast your blood clots has been developed by US scientists...

Millions of people take blood-thinning medication to prevent conditions like deep venous thrombosis (DVT), pulmonary embolism, heart attacks and strokes. As such, they require constant blood clot monitoring, usually necessitating a trip to the hospital and a delay while a sample is tested. Needless to say, this is inconvenient, inefficient and inherently higher risk. Now the University of Washington's Justin Chan has come up with a way to substitute your smartphone for the hospital haematology lab.

Chan's approach uses the vibration and camera features ubiquitous on smartphones. A plastic cup containing a drop (just 10 microlitres) of the patient's blood collected from a finger-prick is hung in front of the phone's camera. Also in the cup is a small copper particle.

By activating the phone's vibrate function, the attached cup and blood sample shake, causing the copper particle to move about in the blood sample. But when the blood clots, it becomes viscous and stops the copper particle from moving around.

The motion of the copper particle throughout the test is tracked by the smartphone camera. A specific algorithm created by the researchers can be used to analyse the motions of the copper particle and determine the blood clotting time. They show that this method gives highly accurate blood clotting time compared with conventional tests done in clinics.

A quick and inexpensive blood clot test using smartphones allows patients flexibility, convenience, and reassurance. Even in rural or developing areas, the prevalence of smartphones continues to grow. This means that patients who have limited access to clinics or hospitals will still be able to measure their blood clotting.

The next step before sharing this technology with all smartphone users is further testing with real patients to ensure it is easy to use for everyone.