Here's another thing you may soon be able to do on your Apple Watch: Check your blood sugar. Sources tell CNBC that Apple has a secret team working to develop sensors that could continuously track blood sugar levels. If successful, it would be a breakthrough for people with diabetes, who could glance at their wrists to check glucose levels instead of pricking a finger several times a day. Apple isn't alone. Other companies have been racing, and so far failing, to come up with similar technology. The winner stands to gain a chunk of a global marketplace in blood-sugar monitoring worth more than $12 billion, per Reuters. In the US alone, there are 29 million people with diabetes. Before his death, Steve Jobs envisioned that wearable sensors could be tapped to tackle other health-related issues, such as monitoring vital signs like oxygen levels.
The project got a boost in 2010 when Apple bought a company called Cor and hired Bob Messerschmidt, then the enterprising CEO of Cor, who emailed him cold about using sensors for health. Since then, Apple has acquired experts in the field from various biomed companies in a quest to develop technology that could cost the Palo Alto giant up to $1 billion. Apple's team of about 30 people is working on an optical sensor that shines a light through the skin to measure glucose levels. It's not as easy as it sounds. The reason so many other previous efforts have failed is that as far as sensors go, measuring blood sugar is particularly hard, especially if you want to do so without piercing the skin. One expert in the field tells CNBC it's "the most difficult technical challenge I have encountered in my career." (Whole-body vibration could help those with diabetes.)