Apple unveiled its new Apple Watch Series 4 with improved health features at an event where the Cupertino-based company officially introduced its 2018 line-up of iPhones — the premium iPhone XS, iPhone XS Max and iPhone XR at an event in California late on Wednesday. The device brings a design overhaul to the Apple Watch as the iPhone-maker is now using a new dual-core 64-bit chipset, custom designed to improve performance. Apart from heartbeat data, the devices would now also track heart rhythm and notify users. The new series has been approved by FDA for ECG recording as well but this feature would be limited to only US-based users initially.