One of the biggest new features in Apple Watch Series 4 is the ability to generate an ECG (electrocardiogram). An ECG is used to record the heart’s electrical activity to look for abnormal heart rhythm. The rhythm can be used to check for signs of Atrial Fibrillation (also known as AFib), a heart condition which should be treated by a doctor. Typically, such tests are done a clinic or hospital, but with Series 4, Apple has brought this test right to user’s wrists, which should help with early diagnosis of health issues.
ECG in Apple Watch
With Apple Watch Series 4, the company has built in electrodes in the Digital Crown and the back crystal. To generate an ECG, users have to open the ECG app and put their finger on the Digital Crown for 30 seconds. Touching the crown completes the circuit, and allows the Watch to send electrical impulses. The Watch reads and records these impulses to generate the ECG, which can be used to classify whether the user’s has an irregular rhythm (AFib) or a sinus rhythm, which means a normal rhythm.
The readings, and any relevant details, are stored in the Health app and can be exported as a PDF to share with a doctor. Since Apple Watch Series 4 has received an FDA approval, doctors can use the ECG for diagnosis.
Apart from ECG, Series 4 watches have also gained two new types of heart rate readings. It can detect unusually low or high heart rate rhythms and alert users to check with a doctor. This Irregular rhythm notification feature will also be available later this year.
Before you run out to buy a Series 4 watch just for this features, there are a few caveats. ECG app and Irregular rhythm notification will be released later this year for Series 4 users. The ECG app has only received approval in the US so users in rest of the world will have to wait longer, before their respective government health advisories clear the watch to be used for medical test results.
While the rest of the industry is still trying to catch up to Apple Watch’s features, it has moved to a whole new level. ECG and irregular rhythm notification are life saving features. For this alone, the watch will be extremely valuable for most users. For what started as a wearable that could track steps, basic heart rate and show tidbits of information on a small screen, Apple Watch has turned into a health guardian. Don’t be surprised when Apple adds blood glucose level detection in future watches, to help users with diabetes.
Read more in our coverage of other new Apple Watch Series 4 features.