Well, we finally know what cardiac project Apple was talking with the FDA about two years ago. Apple Chief Operating Officer Jeff Williams announced today at Apple's special event in Cupertino that the company has received FDA clearance for both an atrial fibrillation-detecting algorithm and an ECG that will be built into the company's Series 4 Apple Watch, due to start shipping September 21. 

Williams announced several other new health features as well, most notably fall detection, which takes advantage of the device's new accelerometer and gyroscope.

"I’m also pleased to say we’ve received clearance from the FDA," Williams said at the event. "This is a De Novo clearance, so it’s the first of its kind. The irregular heart rhythm alert has also received FDA clearance. Both of these features will be available to US customers later this year and we’re working hard to bring them to customers around the world."

MobiHealthNews was half right when we predicted in February of this year that an algorithm for detecting atrial fibrillation could be the Apple's first FDA-cleared product. The company did receive clearance for such an algorithm, likely using data from the recently-concluded Apple Heart Study to submit the application.

"Apple Watch can now screen your heart rhythm in the background and it sends you a notification if it detects an irregular rhythm that appears to be atrial fibrillation," Williams said. "Now it won’t catch every instance of a-fib, but this is going to help a lot of people who didn’t realize they had an issue."

Williams also announced that the Watch will alert users to low heart rates in addition to high ones. But the far bigger news is the ECG, which is accomplished by adding electrodes to the digital crown and the back of the Watch.

"In addition to an optical heart sensor there is a new, Apple-designed electrical heart sensor that allows you to take an electrocardiogram, or ECG, to share with your doctor, a momentous achievement for a wearable device," designer Johnny Ives said in a prerecorded video played at the event. "Placing your finger on the digital crown creates a closed circuit with electrodes on the back, providing data that the ECG app uses to analyze your heart rhythm."

It takes about 30 seconds for a user to take an ECG, which is then stored in Apple's Health app. This means, via Apple Health Records, some users will also be able to send readings directly to their doctors.

"It’s amazing the same watch that you wear every day to make phone calls and respond to messages can now take an ECG," Williams said.

Fall detection

Apple's addition of fall detection is likely to be overshadowed by the ECG news, but it's also an impressive acheivement. 

"It’s interesting, identifying a fall may seem like a straightforward problem but it requires a tremendous amount of data and analysis," Williams said. "We collected data on thousands of people and captured data on real-world falls and we learned something. ... When you trip, your body will naturally pitch forward and your arms will go forward to brace yourself. However, if you slip, there’s a natural upward motion in the arms. These are motions Series 4 is ideally suited to recognize. With a new accelerator and gyroscope, the Watch analyzes wrist trajectory and impact acceleration to determine when a fall occurs. And from that it issues an alert."

When the Watch detects the fall, it will give the user an opportunity to call an emergency contact. But if it detects that the user is immobile for one minute after the fall, it will automatically reach out to authorities using Apple's emergency alert system. It also sends a message to emergency contacts in that situation.