Hartley Charlton, MacRumors:

Rockley Photonics, an Apple supplier, has today unveiled an advanced digital sensor system that is likely to come to the Apple Watch to enable a wide range of new health tracking features.

And:

The company today revealed a full-stack, “clinic-on-the-wrist” digital health sensor system, enabling wearable devices to monitor multiple biomarkers, including core body temperature, blood pressure, body hydration, alcohol, lactate, and glucose trends, and more.

The technology uses a miniaturized chip solution with optical sensors that provide continuous, non-invasive monitoring of various biomarkers, in an attempt to overcome many of the challenges associated with wearable health monitoring and avoid the need for invasive sensors that must perforate the skin.

Apple is Rockley Photonics’ biggest customer. Not too much of a stretch to imagine these new sensors making their way into a future Apple Watch.