Zepp Health has announced a new function for its popular Amazfit wearables at its 2021 Next Beat Future of Health conference, which it calls "Blood Pressure Measurement on the Wrist". It is based on an algorithm that estimates this metric using a given wearable's optical sensors.
https://www.notebookcheck.net/Zepp-Health-plans-to-upgrade-its-Amazfit-smartwatches-with-support-for-blood-pressure-monitoring.551485.0.html