Smartphone System Can Assess Blood Clotting From Single Drop

MONDAY, Feb. 14, 2022 (HealthDay News) -- A micro-mechanical clot detection system using the vibration motor and camera on smartphones correlates strongly with laboratory and point-of-care prothrombin time (PT)/international normalized ratio (INR) testing for plasma and whole blood, according to a study published online Feb. 11 in Nature Communications.

Justin Chan, from the Paul G. Allen School of Computer Science and Engineering at the University of Washington in Seattle, and colleagues report on a proof-of-concept PT/INR testing system that makes use of the vibration motor and camera on smartphones to track micro-mechanical movements of a copper particle. Using 140 anonymized plasma samples, PT/INR computed by the smartphone system was compared with laboratory values.

The researchers found that the inter-class correlation coefficients were 0.963 and 0.966, which was within the accuracy range for commercial point-of-care testing coagulometers. Performance was similar on 80 anonymized samples of whole blood using a single drop of blood (10 µl). The smartphone system demonstrated a correlation of 0.974 for both PT/INR when tested with 79 blood samples with coagulopathic conditions.

"Almost every smartphone from the past decade has a vibration motor and a camera. This means that almost everyone who has a phone can use this. All you need is a simple plastic attachment, no additional electronics of any kind," a coauthor said in a statement. "This is the best of all worlds -- it's basically the holy grail of PT/INR testing. It makes it frugal and accessible to millions of people, even where resources are very limited."

Several authors are listed as inventors on the provisional patent application in the process of being submitted by the University of Washington.

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