Wear your health

The Apple Watch Series 4 is part of Apple’s strategy to give people a distinct reason to buy a wrist gadget that largely does things smartphones already do.

Apple Watch was first launched in April 2015.

What it can do

Take electrocardiograms, or EKGs, on the device (approved by the US Food and Drug Administration).

Watch for irregular heartbeats (the watch will use new sensors on the back and on the watch dial. A new app will indicate if each reading is normal or shows signs of atrial fibrillation.) Detect if the wearer has a fall. Tell the difference between and trip and a fall — and when the latter occurs, it will suggest calling 911. If it receives no response within a minute, the watch will automatically place an emergency call.

Only certain Apple Watch models support cellular calls. Those that don’t can still make emergency calls when near a paired iPhone or Wi-Fi service.

PRICE: $399 AND UP. Available in US September 21.

BATTERY LIFE: 18 hours