The US Food and Drug Administration approved an Apple Watch accessory as a medical device for the first time yesterday.
The device, called a KardiaBand, inserts into a slot on an Apple Watch and combines its own software and the watch's to constantly monitor heart rate and physical activity.
The KardiaBand's artificial intelligence tracks how fast it is normal for the wearer's heart to beat at their various levels of activity in order to create a personalized profile of the wearer's normal heart activity.
When that a person's heart rate is abnormal for their activity level, it prompts the user to take an EKG, a far more accurate measure for identifying arrhythmias.
The FDA approved Apple Watch's first medical device accessory, the KardiaBand, to take EKGs of wearer's heart rates and detect a common arrhythmia
The KardiaBand EKG device can be purchased for $199, and works with a $99 annual subscription to software from KardiaBand's maker, AlivCor.
The Apple Watch, Fitbit and Jawbone UP products all measure heart rates, but studies have shown that their metrics are fairly inaccurate.
In January of last year, Fitbit was even sued based on its tracker's flaws.
The FDA, in an effort to keep up with emerging wearable technologies, created a fast track specific to the prolific sector.
Apple, Samsung and Fitbit were among the nine companies accepted to participate in the pilot program.
But Apple avoided the time, money and effort of the FDA-approval process. KardiaBand's add-on technology gives users the option to convert an Apple Watch into a more accurate heart rate monitor.
KardiaBand monitors heart rate through an electrocardiogram (EKG), the same diagnostic technology used by cardiologists and emergency rooms.
EKGs pick up on tiny electrical pulses associated with the heartbeat to measure its pace and rhythm.