Apple Inc on Tuesday introduced a new Apple Watch Series 6 that monitors blood oxygen and starts at $399, kicking off a fall product lineup for a holiday shopping season that will be unlike any other due to Covid-19.

Apple is also introducing a low-cost Apple Watch SE starting at $279 that does not monitor blood oxygen saturation.

Apple was expected to update several products including iPads and headphones at an event on Tuesday broadcast from its Cupertino, California, headquarters. Its biggest seller - the iPhone - is expected to be announced next month after executives have said its launch will be delayed by several weeks because of pandemic-related disruptions.

Apple shares have soared this year even as the virus has crippled economies around the world, thanks in large part to booming sales of work-from-home items.

Apple shares were up 2% on Tuesday after climbing more than 50% for the year, well ahead of the 23% gain for the Nasdaq. Even though Apple stock has fallen from a record high earlier this month, it remains near its $2 trillion stock market valuation.

How the new products sell during the holiday shopping season in many markets will largely define how well Apple performs for its entire fiscal year, which started this month.

Apple said the Series 6 watch's new ability to monitor blood oxygen using infrared light should be used for fitness and wellness purposes. Doctors in India and other countries have used pulse oximeters to remotely check on Covid-19 patients and ensure their oxygen saturation level does not fall too low.

A level between 95% and 97% is considered normal by the American Lung Association https://www.lung.org/media/press-releases/pulse-oximeter-covid-19. Patients below 95% should call their doctor and those under 90% should go to the emergency room, health experts advise.

Low oxygen levels are usually not the sole indicator of having Covid-19, the association said.
The previous version of the Apple Watch can already take measurements similar to electrocardiogram.

Apple's Heart Study found that the watch could accurately detect atrial fibrillation, the most common type of irregular heartbeat, according to a study that explored the role of wearable devices in identifying potential heart problems. Atrial fibrillation increases the risk of stroke more than fivefold, according to the American Heart Association.

Apple rival Fitbit Inc introduced a way to measure changes in blood oxygen earlier this year.