iOS 14 code reveals Apple Watch blood oxygen monitoring feature

Apple is developing at least two new health features that will expand Apple Watch capabilities. Apple Watch will add blood oxygen monitoring for the first time, 9to5Mac found in iOS 14 code.

Diagram of the back of an Apple Watch Series 5
Diagram of the back of an Apple Watch Series 5

Zac Hall for 9to5Mac:

Blood oxygen levels between 95 and 100% are considered healthy; blood oxygen levels below 80% may lead to compromised heart and brain functionality. Risk of respiratory or cardiac arrest is common after continued low blood oxygen saturation.

To that end, Apple is developing a new health notification based on the vital measurement. When Apple Watch detects low blood oxygen saturation below a certain threshold, a notification will trigger alerting the user similar to current heart rate notifications.

It’s unclear at this point what hardware and software will be required for blood oxygen detection and notifications. It’s possible future Apple Watch Series 6 hardware will be required for the new health feature. It could also come to all or newer Apple Watch models with watchOS 7 in the fall. The original Apple Watch hardware is believed to be capable of measuring blood oxygen levels through the built-in heart rate monitor.

MacDailyNews Take: This will be a welcome addition to Apple Watch’s impressive and growing list of health capabilities and features. In addition, since Apple Watch Series 4 and 5 currently result in inconclusive ECG readings with heart rates between 100 and 120 beats per minute, the iOS 14 code also suggest that in a future update, in software and/or hardware, will remove that limitation with an upgraded version of Apple’s ECG app.


  1. Next on my list of desired medical apps will be on demand Blood Sugars. The new PulseOx will increase sales by a few million. Blood Sugars will generate sales in the tens of millions. Like most diabetics who are tired of sticking themselves in the finger.

    1. Ken, wouldn’t we all like the first transdermal sensor to be blood glucose? As far as I know, there apparently are many confounding factors in using perspiration glucose to make decisions about managing blood glucose. Current skin-mounted Bluetooth sensors have a tiny probe in the center of the inch-wide patch that penetrates the epidermis for better correlation with circulating glucose levels, which is pinged by the phone. Without skin penetration, the readings are currently unhelpful

      1. Actually the current continuous glucose monitors penetrate the skin and measure glucose in the fluid under the skin (not in your blood) which is slower to respond to the actual blood glucose levels in your veins.If the watch could measure actual blood glucose levels that would be a huge advance in diabetes control and much cheaper.

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