Tim Cook has been spotted wearing the top-secret Apple diabetes device

Apple CEO Tim Cook has been spotted by staff at the Palo Alto campus wearing a prototype blood glucose monitor.

Just over a month ago we reported that Apple was reportedly working on devi ce that could help with the management of diabetes, but all we had to go on was reports of a secret team and a patent application.

Now it seems that the Apple CEO is being a fair amount more overt about the project. Sources confirmed to CNBC that: “Cook was wearing a prototype glucose-tracker on the Apple Watch”. The word ‘on’ is significant in that sentence.

Cook has previously been open about wearing a glucose monitoring device, but it hasn’t been clear whether this was an Apple device, or the device of another manufacturer.

In conversations with a group of students at Glasgow University, Cook very openly said: "I've been wearing a continuous glucose monitor for a few weeks, I just took it off before coming on this trip."

Fitness or health?

A keen fitness fanatic, Cook has apparently been using the device to monitor how his diet has been affecting his blood sugar. This ties in with another thing he said to the students: "There is lots of hope out there that if someone has constant knowledge of what they're eating, they can instantly know what causes the response... and that they can adjust well before they become diabetic."

The wording of this is very interesting if you know a bit about the legal situation that the Apple Watch will face if it becomes a device for diabetics.

If the Apple Watch becomes a medical device, it has to pass US Food and Drug Administration (FDA) approval before hitting the market; Cook has previously said he would want to avoid this as it would hinder production schedules.

By being a device for ‘healthy’ people to measure their blood glucose, the Apple Watch could avoid these checks, although how this would affect diabetics wanting to use this device is unclear.

One of the possible ways that Apple could make this a device for diabetics but keep the Apple Watch out of the FDA approval cycle would be to make it an independent device that works with the Watch.

As we've previously reported, Apple has filed a patent to make a modular strap for the Watch that could have this function (below), so hearing that the device was 'on' Cook's Watch instantly made us think of that.

Whatever it is, it’s very exciting to hear that it’s a real device now, and we hope it won’t be too long before we see a version on the market. Possibly the Apple Watch 3?