Apple Watch can track your heart rate for a medical study

Apple is trying out something entirely new starting Thursday: a medical study.

Apple Watch users are now able to enroll in a new study Apple is conducting with Stanford University School of Medicine, which uses the device’s heart-rate monitor to check for an irregular heart rate. While others have used Apple’s software and devices in medical studies, this is the first time that Apple has sponsored one itself. The move underscores Apple’s focus on using its products for health care.

“Working alongside the medical community, not only can we inform people of certain health conditions, we also hope to advance discoveries in heart science,” Apple chief operating officer Jeff Williams said in a statement.

Health and fitness have been a key focus for Apple, especially since launching the Apple Watch two years ago. Apple employs a small staff of medical professionals to develop its health products, and it is reportedly working on a diabetes glucose-monitoring device that won’t pierce the skin. It’s also worked with hospitals to include more of its tech in patients’ rooms.

This study takes all of that a step further: Now Apple itself will be running a study and submitting data to the Food and Drug Administration. The heart-rate researcher will look specifically at atrial fibrillation — or afib — which refers to an irregular heart rate and is a leading cause of stroke and other heart conditions. The condition kills about 130,000 people per year, according to estimates from the U.S. Centers for Disease Control and Prevention.

To join the study, Apple Watch owners must download the Apple Heart Study app. Participants must be over age 22. Once they have signed up, the Watch and Heart Study app will work to detect irregular heartbeats. If it notices something amiss, it will notify that person on the Watch and iPhone. From there, he or she may opt to see a doctor online, for a free consult on their health. Apple and Stanford are partnering with Boston firm American Well to provide those consults.

Study researchers will also then send an electrocardiogram patch to participants experiencing irregular heartbeats for a further reading.

Heart-rate monitoring features have been a core part of the Watch since it debuted as a heavily health- and fitness-focused product. More advanced tools to take your pulse were a major addition to Apple’s latest Watch software upgrade, and users can get alerts when they appear to have an elevated heart rate but aren’t active.

This move takes Apple into using that data to conduct research. The company declined to say whether it would take on further research in the future.

Apple has previously noted how its products can make it easier for researchers to find study participants, thanks to their broad reach. Traditionally, researchers have had to seek out study participants directly — through medical facilities, by email or with fliers. Then, they often must visit them in person to collect data. By enrolling using devices, Apple has said, it makes it easier for scientists to both find and monitor study participants.

At least 33 million units of the Watch have been sold, according to Asymco analyst Horace Dediu — Apple itself does not officially release sales figures, nor information on who is buying the Watch. But Apple researchers said they believe the Watch will provide a representative sample of the population for their study.

Apple declined to say how long the study will run.