Apple's goal right now appears to be to eradicate screen borders. A year ago the iPhone X was launched with a virtually bezel-less display, the latest iPhone models have followed suit and the new Apple Watch achieves the same feat.

The screen of the Apple Watch Series 4 is 30% larger than its predecessor and has enough space to fit the date, weather information and six other pieces of information on the display in addition to the time as part of the colourful new "Infograph" watch face.

For users who think that's too much – and there are many of them – the display can be changed to simpler designs. And although the redesigned watch case with more rounded corners is now longer and wider, it still fits comfortably on the wrist.

Perhaps most impressive of all, the Watch has now become a fully-fledged fitness computer with a new electrical heart sensor and an air pressure sensor for measuring altitude.

The new accelerometer, in conjunction with the gyroscope, can also detect whether the wearer has fallen and can trigger an emergency call if necessary. By default this feature is switched off. Apple points out that the alarm can also be triggered by "violent movement".

The device also has improved heartbeat monitoring. Previously, the watch only sounded an alarm when it detected an unusually fast heart rhythm – now it's also triggered by a slow heart rate.

This feature is available to all Watch models except for the first generation (Series 0), which generally can't be upgraded to the new operating system, watchOS 5.

Apple has even shown that the watch can be used to create a simple electrocardiogram to detect cardiac arrhythmias early on. Some critics fear this will lead to a wave of false alarms, however.

"The Apple Watch should not be used as a substitute for a visit to the doctor," says Professor Thomas Deneke from the German Society of Cardiology. However, he says it could help doctors with their diagnosis by recording relevant heart rhythm data.

The watch's reworked crown also provides haptic and acoustic feedback. As you scroll through the menus, the crown clicks as if you were setting the date on a mechanical wristwatch. The so-called Taptic Engine makes the watch vibrate to indicate, for example, that a timer has expired.

The telephony function has also been improved. Voices sound clearer and louder and thanks to a new microphone it's hard to tell whether you're talking on the watch or an iPhone.

The Apple Watch Series 4 with an aluminium case costs US$399 (RM1,656). The built-in cellular option costs an extra US$100 (RM415). The stainless steel versions of the watch (all of which come with the cellular option) cost US$699 (RM2,901).

However, if you want to get into the Apple Watch ecosystem for less money you can always consider last year's model which is now selling for US$279 (RM1,158). – dpa