One of the brilliant features of the Apple Watch 4 series that makes user field vibration is an ECG or heart rate rate. Just point your finger on Digital Crown on Apple Watch, the machine can display a heart rate wave on the chart to see it right away.
At this time, Apple turned off the ECG feature is not available. Apple has requested FDA approval to use it, but MacRumors has recently found Apple materials for internal use. Highlight Apple will soon release the ECG feature watchOS 5.1.2
The documentation describes the introduction of ECG applications to users who have a feature. It is not a medical device Therefore ECG measurements can not be used for medical diagnosis.
However, for those who buy Apple Watch Series 4 in Thailand, we will see whether the release of watchOS 5.1.2 is available in Thailand. License is required for each country.
Source – iClarfied