Back in February this year, we saw a patent filed with the US Patent and Trademark Office (USPTO) titled “Terahertz Spectroscopy and Imaging In Dynamic Environments With Performance Enhancements using Ambient Sensors”. This patent application indicated that Apple might be working on blood sugar readings and as a result, could bring the glucose level monitoring on Apple Watches in the future. Now, the patent has got some credibility as UK health tech firm Rockley Photonics recently confirmed that Apple has been its largest customer for the past two years. The firm’s focus has been mainly on tracking blood glucose levels.

As reported by The Telegraph and Forbes, Rockley Photonics confirmed Apple as its biggest customer in a recent SEC filing. This means that the iPhone maker is doing more than just filing patents for this tech and could actually bring this to its iDevices, which most likely will be the Apple Watch. The Cupertino tech giant already has a heart-rate monitor and SpO2 monitor in its watches.

Besides tracking blood glucose levels, Rockley’s focus is also on tracking blood pressure, and even alcohol levels. This also adds to the speculation that these two features could also come to Apple Watch devices in future. Nothing can be said for sure right now though.

Nonetheless, measuring blood pressure could also lead to tracking of stress and monitor alcohol intake. However, the feasibility and keeping the price in check will also be big factors for the firm. And considering that Apple last year bifurcated its Watch family largely in two series – Watch 6 and Watch SE, we could see a premium one with all these features soon and with basic ones as a part of the SE lineup.