The Apple Watch has become a serious medical monitor. It will now be able to detect falls, contact emergency responders, and diagnose irregularities in heart rhythm and blood pressure. Its ECG app has been granted a De Novo classification by the FDA.
ECG readings are taken from the wrist, using electrodes built into the Digital Crown and an electrical heart rate sensor in the back crystal. Users touch the Digital Crown and receive a heart rhythm classification in 30 seconds. It can classify if the heart is beating in a normal pattern or whether there are signs of Atrial Fibrillation . All recordings, their associated classifications and any noted symptoms are stored and can be shared with physicians.
The watch intermittently analyzes heart rhythms in the background and sends a notification if an irregular heart rhythm such as AFib is detected. It can also alert the user if the heart rate exceeds or falls below a specified threshold.
Fall detection is via a built in accelerometer and gyroscope, which measures forces, and an algorithm to identify hard falls. Wrist trajectory and impact acceleration are analyzed to detect falls. Users are then sent an alert, which can be dismissed or used to call emergency services. If immobility is sensed for 60 seconds, emergency services will automatically be called, and emergency contacts will be notified.