This smartphone app detects if users are having a stroke

A new app might soon be able to detect stroke symptoms in its users without the help of a physician. The app, called FAST.AI, is still in development and not available to the public, but preliminary research suggests that it can successfully detect facial asymmetry and arm weakness, two common signs of a stroke.

FAST.AI uses artificial intelligence to detect these using device footage and sensors. A study was conducted on its efficacy at four major metropolitan stroke centers in Bulgaria, on over 270 patients already identified by physicians to have suffered from strokes.

It found that the app could accurately detect facial asymmetry 97% of the time and arm weakness 72% of the time, according to the abstract of the paper being presented at the American Heart Association’s International Stroke Conference next week. The app has also been designed to detect slurred speech, but the accuracy of this feature was not tested in the study.

The name of the app comes from the acronym FAST, a common tool to help people remember warning signs of a stroke:

F stands for Face: Is any part of the face drooping?
A stands for Arm: Is one arm weak or numb?
S stands for Speech: Is the person slurring their words or speaking strangely?
T stands for Time: If the person is experiencing any of these services, time to call 911.

Stroke victims fare better if they’re treated within three hours of their stroke. In that time frame, they can receive drugs that can break up the clots causing parts of their brain to lose oxygen, which makes them more likely to recover fully afterwards, according to the CDC. An app like FAST.AI could potentially reduce the time between a patient having a stroke and receiving treatment, improving their outcome or even saving their life.