Researchers at the University of Washington have recently developed a blood clotting test that uses one drop of blood and a smartphone. The test uses the vibration and camera from the phone, as well as a plastic attachment. The plastic attachment has a small cup that is placed beneath the camera. It contains a copper particle and chemical that will start the clotting process with the addition of the blood.

During the test, the vibration of the smartphone will shake the cup, and the particle movement is monitored by the camera. Once the clot forms, the movement slows and eventually stops. The device will then calculate the prothrombin time (PT) and the international normalised ratio (INR) by gathering two timestamps. The first timestamp is recorded when the patient adds blood to the cup, and the second is recorded when the particle movement stops.

A test development like this has great potential to help a multitude of patients. This is a test that can be done quickly, with a device that most people already have and without the supervision of a healthcare professional. This test is accessible and easy to use. A device like this could be useful to those who have known clotting issues, patients who want to check their own INR and patients who may not have easy access to a healthcare facility. The test could also help ease hospital strain by preventing unnecessary visits, as patients can use it themselves before seeking additional help.

So far, this device has been tested on the plasma of 140 anonymous patients from the University of Washington Medical Center, 79 patients with known blood clotting issues, as well as the whole blood of 80 anonymous patients from other medical facilities. The next step is to test the device in at-home settings, as well as areas or countries that have limited resources.