Earlier reports have pointed to a new health-tracking spec for the Apple Watch 5's successor: blood oxygen tracking. A new tip may give this idea further weight. It also backs up other claims of sleep-tracking and even more advanced cardiovascular monitoring in the upcoming wearable.
https://www.notebookcheck.net/A-new-leak-lends-further-support-to-blood-oxygen-tracking-in-the-Apple-Watch-6.483815.0.html