Smartphone app can vibrate a drop of blood to evaluate its clotting efficiency

A blood clot arises as a result of any injury to the body tissues. Blood clots, on the other hand, can trigger severe complications like strokes or MI in heart related dysfunction. Anticoagulants such as aspirin or warfarin are often administered for life as prophylaxis. These medications reduce clot formation by extending the bleeding period.

In certain cases, adverse drug effects may occur, necessitating hospitalization as well. As a result, the patients require periodic testing. Coagulation studies, which require laboratory procedures, are evaluated using tests such as the PT/INR. Despite the fact that home-based PT/INR testing is available, it is extremely expensive for underdeveloped nations.

Researchers at the University of Washington have created a novel, low-cost ($0.03) system-based test that requires only a drop of blood and a smartphone vibration motor and camera. The device consists of a lightweight, compact (70×27.5×60.9mm) 3D-printed plastic attachment, a disposable plastic cup, and a tiny copper particle. Furthermore, the researchers’ automated analysis technique replaces the manual observation or interpretation of clotting data.

[Source to video: ]

The researchers developed a low-cost device that functions similarly to at-home blood glucose meters for diabetics: a person can test a drop of blood by pricking their finger. The scientists included a little copper particle because its motion was much easier to track. The phone captures two time stamps to determine PT and INR: the first when the user adds the blood and the second when the particle stops moving.

The approach was tested on three distinct types of blood samples by the researchers. As a proof of concept, the researchers began with plasma, a transparent component of blood that is easier to assess. At the University of Washington Medical Center, the researchers examined plasma from 140 anonymous individuals. The researchers also tested plasma from 79 individuals who had known blood-clotting problems. The test produced findings that were comparable to commercially available assays for both of these diseases.

This invention is still in its prototype stage. The code (  has been made public and the researchers are looking at commercialization and more testing. For example, all of these tests are now being performed in the laboratory. The next step is to engage with patients to put this technology through its paces at home. The researchers are especially interested in how the system performs in limited-resources sites.


  1. Chan, J., Michaelsen, K., Estergreen, J.K. et al. Micro-mechanical blood clot testing using smartphones. Nat Commun 13, 831 (2022).

Leave a Comment